Next Article in Journal
The Use of Radio and Telemedicine by TMAS Centers in Provision of Medical Care to Seafarers: A Systematic Review
Previous Article in Journal
Accuracy of Computed Tomography Angiography for Diagnosing Extracranial Mural Lesions in Patients with Acute Internal Carotid Artery Occlusion: Correlation with Digital Subtraction Angiography
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Chlamydial and Gonococcal Genital Infections: A Narrative Review

OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, 4200-450 Porto, Portugal
CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
Molecular Diagnostics Laboratory, Unilabs Portugal, Centro Empresarial Lionesa Porto, Rua Lionesa, 4465-671 Leça do Balio, Portugal
Department of Gynecology-Obstetrics and Pediatrics, Faculdade de Medicina da Universidade do Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
Lower Genital Tract Unit, Centro Hospitalar de São João, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
Roche Sistemas de Diagnósticos, Estrada Nacional, 2720-413 Amadora, Portugal
Laboratório Nacional de Referência das Infeções Sexualmente Transmissíveis, Instituto Nacional de Saúde Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisboa, Portugal
Department of Community Medicine, Health Information and Decision (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, 4200-450 Porto, Portugal
Author to whom correspondence should be addressed.
J. Pers. Med. 2023, 13(7), 1170;
Submission received: 2 May 2023 / Revised: 18 July 2023 / Accepted: 19 July 2023 / Published: 21 July 2023


Sexually transmitted infections (STIs) constitute one of the leading causes of disease burden worldwide, leading to considerable morbidity, mortality, health expenditures, and stigma. Of note are the most common bacterial STIs, chlamydial and gonococcal infections, whose etiological agents are Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), respectively. Despite being usually asymptomatic, in some cases these infections can be associated with long-term severe complications, such as pelvic inflammatory disease, chronic pelvic pain, infertility, ectopic pregnancy, and increased risk of other STIs acquisition. As the symptoms, when present, are usually similar in both infections, and in most of the cases these infections co-occur, the dual-test strategy, searching for both pathogens, should be preferred. In line with this, herein we focus on the main aspects of CT and NG infections, the clinical symptoms as well as the appropriate state-of-the-art diagnostic tests and treatment. Cost-effective strategies for controlling CT and NG infections worldwide are addressed. The treatment for both infections is based on antibiotics. However, the continuing global rise in the incidence of these infections, concomitantly with the increased risk of antibiotics resistance, leads to difficulties in their control, particularly in the case of NG infections. We also discuss the potential mechanism of tumorigenesis related to CT infections. The molecular bases of CT and NG infections are addressed, as they should provide clues for control or eradication, through the development of new drugs and/or effective vaccines against these pathogens.

1. Introduction

Globally, sexually transmitted infections (STIs) are a public health concern that is still challenging, especially among adolescents and young adults [1,2,3]. Furthermore, according to the World Health Organization (WHO), during the pandemic of COVID-19, efforts were directed toward SARS-CoV-2 infections, leading to STIs being in oblivion, with a consequent increase in their incidence [4].
STIs are associated with high morbidity, especially in the psychological, sexual, and reproductive health domains in both women and men. Therefore, health professionals treating patients with STIs must consider that these diseases could affect the quality of life of the infected persons. Thus, they must consider the mental dimension, and treat the infections and the possible psychological consequences, as reported in previous studies [5,6]. Also, the impact on newborn infants of infected individuals due to vertical transmission cannot be neglected [7]. Women are significantly more affected than men, which, in part, is explained by anatomy, which makes women more exposed and susceptible to these infections [8].
Moreover, it is important to refer to the fact that STIs have high associated health expenditure [9,10,11]. Indeed, the best current approach to handling the problem is through well-organized screening and surveillance programs, to diagnose and treat the infected people in a timely and adequate way; consequently, this will allow for the control and breaking of the transmission chain [12]. Nevertheless, this is also costly, so the European Center for Disease Prevention and Control highlights that it is necessary to estimate STI prevalence and incidence better. Accordingly, each country must design and adopt prevention measures adapted to their reality [13,14,15,16]. In some regions, particularly Africa and Latin America, it remains challenging to control STIs. While not exclusively due to limited access to diagnostic instruments, this factor significantly contributes to the high incidence of these infections in those areas [1,8].
STIs are frequently asymptomatic; notwithstanding, they can cause a diversity of infirmities, including acute and chronic severe problems [13]. In particular, the most serious associated complications are reproductive organ ones, with symptoms reported by women and men that can comprise mainly genital, extragenital, or disseminated symptomatology [17]. Indeed, the majority of STI cases are asymptomatic, such as chlamydial and gonococcal infections, leading to infection persistence, increasing risk of transmission, and, importantly, in some cases possibly leading to the development of associated complications, which, in the worst-case scenario, could be irreversible and potentially fatal; these include infertility, ectopic pregnancy, scarring, chronic pain, neonatal death, congenital abnormalities, sexual dysfunction, and cancer, depending on the pathogen(s) that cause the infection(s) [17,18]. Although STIs can be caused by several types of pathogens (viruses, bacteria, and parasites), herein we will focus on the two most common bacterial ones: the Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections [19]. It is also important to highlight the fact that sometimes natural clearance of these infections could occur, and, despite being curable STIs, they could also frequently be associated with serious public health concerns, including NG antibiotic resistance [13]. Interestingly, while some authors defend the case that CT and NG co-infections occur randomly, it has been proved using mathematical models that the occurrence is indeed much higher than expected in a random model. However, the underlying mechanisms are still unknown [20,21,22].
According to the WHO, in 2020 there were 129 million new CT infections worldwide and 82 million new NG cases NG [23]. The Center for Disease Control and Prevention (CDC) estimates that in 2018 in the USA, 4 million new CT infections occurred, translating in an estimated medical cost of USD 691 million. Regarding NG infections, the CDC estimated that 1.6 million new cases occurred in the US, associated with a medical cost of around USD 270 million [11].
These infections are most frequent in females, peaking at 15–24 years [24]. Notwithstanding, Kaufman and others assert that there may be a shift in the age group of the incidence peak—specifically to the 25–30-years interval. However, it must be kept in mind that this particular study had external validity issues; therefore, further investigation is needed before these results can be assumed [25].
STIs are associated with 2.3 million deaths and 1.2 million cancer cases yearly. Accordingly, all countries must make an effort and adopt strategies to reduce their incidence, as highlighted in the WHO guide for the health sector Global health sector strategies on sexually transmitted infections for the period 2022–2030 [26].
Our review addresses the state of the art in CT and NG urogenital infections, to identify the knowledge gaps and understand the impact of the implemented infection control strategies that could be improved in the following years.

2. Pathogenesis of CT and NG Infections

CT and NG can infect different anatomical regions, namely, the urogenital, anorectal, and oropharyngeal tract [19]. Notwithstanding, the extensive studies on these infections have focused primarily on the urogenital tract, because it is the most common site of infection and transmission. Also, reproductive organ infections have more direct public health implications, such as pelvic inflammatory disease (PID), infertility, increased risk of human immunodeficiency virus (HIV) transmission, and other equally serious potential sequelae [22,27,28]. Nevertheless, it is crucial to remember that extragenital infections are also associated with increased risk of HIV transmission, and that in specific groups these extragenital infections are even more relevant and likely to occur, as we will discuss further [18,19].

2.1. Clinical Manifestation

It is well known that chlamydial and gonococcal infections are mostly asymptomatic, meaning that the diagnosis of the cases occurs mainly during screening [29,30]. If symptomatic, the presentation is usually non-specific, and a laboratory diagnosis is still warranted. The empirical clinical diagnostic procedure is insufficient, and must be guided by molecular methods, in detail by the Nucleic Acid Amplification Tests (NAATs), which mitigate the risk for false negative tests, detecting the exact bacterium and correctly guiding the treatment [31]. In detail, some of the main clinical outcomes of CT and NG genital infections, depending on the anatomical site and gender, are depicted in Figure 1.
Indeed, infertility is one of the most severe outcomes of these infections, and can affect both sexes (Figure 1). CT infection and associated infertilitywere recently revisited in detail in our previous work [12]. Interestingly, women’s capacity to become pregnant was studied in a clinical trial, in which investigators evaluated pregancy incidence and time to become pregant in CT-infected woman vs. non-infected woman, concluding that CT infection negatively impacts these parameters [32]. Moreover a causal relation between CT infection and ectopic pregnancy was established by Ahmad et al., using in vivo and in vitro models; this group also explained the associated mechanisms behind this [33]. Additionally, Pant et al. investigated the role of matrix metalloproteinase (MMP) expression in the fallopian tubes, which can also play a role in ectopic pregnancy [34].
Furthermore, regarding NG infections, in a recently published meta-analysis, the authors compared the number of NG-infected individuals among infertile populations. When comparing this number with the general population, they found that it was more than two-fold higher in the former, suggesting that this pathogen possibly plays a crucial role in infertility [35]. Finally, it is essential to highlight the fact that in pregnant women these infections are associated with obstetrical and neonatal complications, including conjunctivitis or pneumonia in neonates [36].

2.2. Potential Risk Factors for Tumorigenesis

It is well established that some pathogens, including viruses, parasites, and bacteria can trigger tumorigenesis [37]. In line with this, there are some reports concerning the potential role of CT in the induction of this oncogenic process, through some molecular mechanisms [12]. Indeed, the biological plausibility of this association arises from the fact that CT can induce chronic inflammation, cell proliferation through the MEK/ERK signaling pathway, apoptosis inhibition, cell proliferation, and DNA damage mediated by ROS production, and reduce the immune system response [38]. Previous studies reported a possible association with cervical and ovarian cancer. Thus, to further investigate these hypotheses, two different meta-analyses and a systematic review were conducted [38,39,40].
Interestingly, a systematic review with meta-analysis published in 2022 by Hosseininasab-nodoushan et al., corroborates the hypothesis that there is an association between CT infection and ovarian cancer risk (odds ratio [OR]: 1.344; 95% CI: 1.19–1.5). However, the authors acknowledged several limitations: the primary studies considered in the analysis were case–control studies which did not allow for the determination of causality, and there was considerable heterogeneity and possible publication biases [39]. Nevertheless, their results have a clinical significance that must be further investigated. In addition, previous reports have pointed to a potential role for PID in the subsequent development of ovarian cancer. Additional studies are needed to fill the gaps in this topic, specifically, to understand whether non-chlamydial or chlamydial-driven PID may be differential players in ovarian cancer risk [41,42].
Haiyan et al., performed a meta-analysis to clarify the potential association between CT infection and cervical cancer risk. In their study, they not only identified a statistically significant association between CT infection and cervical cancer, but also demonstrated that HPV co-infection with CT is associated with higher risk of cervical cancer [40]. Later, Karim et al. conducted a systematic review in which they summarized all the information on this topic. They concluded that CT can be a risk factor for cervical cancer development, highlighting the fact that this bacterium makes HPV infection more successful, and contributes to molecular processes triggering carcinogenesis. Finally, they also elucidated how CT and HPV infections share some risk factors; therefore, they assert that the individuals who tested positive for one of these pathogens could have higher probability of having the other [38].
Importantly, to the best our knowledge, there are no previous reports regarding the association between CT infection and other tumors. We could not find evidence regarding an association between NG infection and the risk of neoplasia in the literature.

2.3. Infection Molecular Pathways and Host Immune Response

Understanding the molecular mechanisms of the pathogens’ growth and proliferation is vital for targeting these pathways in infection control. Thus, herein we will explore the life cycle of NG and CT infections. Both bacteria invade the epithelial mucosa, which triggers an immune response by the host cells [43]. It must be noted that, although CT is an obligate intracellular pathogen, which means it depends on the host cell for its replication, NG is a facultative pathogen [44] (Figure 2).
Indeed, the worst consequences of a CT infection begin with chronic inflammation that is not resolved, triggering an excess recruitment of immune cells, especially neutrophils, concomitantly with an overproduction of growth factors, cytokines, and chemokines. This pro-inflammatory milieu and the pathogen persistence could cause severe tissue damage and wound healing delays. Moreover, new insights have been recently made regarding the underlying mechanism of CT pathogenesis, where it was found that the prolonged strong signaling which was mediated by the leukemia inhibitory factor (LIF)/LIF receptor (LIFR) and triggered by a CT infection is a key pathway involved in the more harmful sequelae, namely, infertility, ectopic pregnancy, and cancer [45].
NG cannot survive outside the human host. Its infection cycle, represented in Figure 3, usually initiates when it comes into contact with the bacterium adhesins expressed on the host’s mucosal epithelial cells’ surface.
In the first step, there is contact between the type IV pili of the bacterium with the CD46 and CR3 receptors of the cell, which enable ulterior interactions with other cell surface molecules. Also, other bacterium structures, such as colony opacity-associated proteins (OPA) and lipooligosaccharide (LOS), may link to the host cells’ asialoglycoprotein receptor (ASGP-R) and the carcinoembryonic antigen-related cell adhesion molecule family (CEACAM), enabling NG replication to emerge in the epithelium and allowing the subsequent transcytosis and invasion processes [46,47]. To the best of our knowledge, the invasion process depends on the infection site; that is, the bacterium–host-cell communication differs between the cervix and the urothelial tract, involving different molecules as key players, as reported by Green et al. [46].
Concomitantly, these molecular interactions trigger an inflammatory immune response, through the NF-κΒ molecular pathway activation and pro-inflammatory cytokine production. This pro-inflammatory gradient triggers the recruitment of immune cells to the infection site, including macrophages, leukocytes, and neutrophils [47]. These immune cells interact with the pathogens, and are responsible for their phagocytosis and elimination; however, NG has mechanisms of immune escape and suppression, specifically by causing the inhibition of dendritic cells, B cells, and T cells, as further detailed by McSheffrey and Gray-Owen [48,49].

3. Gold Standard Diagnostic Method

Chlamydial and gonococcal infections are diagnosed by detecting these bacteria in urogenital, rectal, oropharyngeal, or ocular secretions [50]. According to European and CDC guidelines, the detection of CT and NG should be performed using nucleic acid amplification tests (NAATs), which are based on the amplification of specific bacteria nucleic acid target sequences, mostly used due to their higher sensitivity [19,50,51,52]. Notwithstanding, it must be highlighted that this strategy is not 100% specific and sensitive, and the specimen origin influences the analysis power of the diagnostic test. In detail, European guidelines strongly recommend the use of first-void urine (up to 20 mL sampled >1 h after previous micturition) or cervicovaginal swabs (collected by a health-care worker or self-collected) for the diagnosis of urogenital infections in men and women, respectively.
Of note, the type of specimen chosen will also depend on the available NAATs selected, because they differ in the target nucleic acid sequence and in the amplification technique [51,52]. Herein, we will describe the main FDA-approved commercial kits available to test for both urogenital infections, or more, simultaneously, which is in line with our position regarding the best strategy for a comprehensive screening [53] (Table 1). For example, one of the most complete tests, due to the validation of its use with several specimen types, is Roche COBAS CT/NG test, which is performed through a real-time PCR technique, with dual targets (CT and NG) and internal control in order to check the sample adequacy and detect the presence of PCR inhibitors. In line with this, the VENUS Trial (Vaginal, Endocervical and Urine Screening Trial for CT/NG), in which this test was used, showed that higher sensitivity and specificity were achieved in vaginal swab and male urine samples. Nevertheless, with other samples, the performance was also excellent (sensitivity > 94%), highlighting the great advantage and superiority of the CT/NG molecular testing [54]. Thus, despite being the most reliable technique, it is important to keep in mind that NAATs are associated with some false negative results, and the smaller the sensitivity of the test chosen, the more missing infected individuals there will be [55]. Also, some CT variants were considered hard to detect using some NAATs, leading to false negatives. Thus, acting upon clinical suspicion, a different NAAT test, comprehending a different genomic target, should be used [56,57,58,59].
It is worth noting that it is still necessary and important to use the culture method in cases of resistance, specifically, to test the phenotype or genotype involved in antibiotic resistance mechanisms, also allowing the possible detection of new pathogen strains with mutations that cannot be detected in NAATs [66].
Lymphogranuloma venereum (LGV), according to the CDC guidelines, requires a more prolonged treatment. Thus, in order not to miss an LGV diagnosis, and to allow physicians to implement an adequate therapy, the routine use of laboratory tests that distinguish LGV strains should be mandatory, namely in anorectal CT+ samples. Additionally, regularly performing ompA-genotyping of CT strains would allow for the evaluation of the association between the ompA-genotype and the severity of the CT infection [67,68]. There are nowadays NAATs commercial tests directed at genomic targets that differentiate LGV strains from common D-K. These tests, together with the analysis of the ompA gene, should be able to detect new CT variants [69]. This is of utmost importance when LGV strains may induce more invasive infections involving the lymphatic system.
Regarding the test of cure, which is the repetition of the test after completion of the treatment, the strategy must be well designed to obtain the correct result, to make the clinical decision to try new therapy (in the case of a positive test), or to document pathogen eradication. Following the guidelines, health organizations generally recommend not testing earlier than approximately 4 weeks after the treatment completion, to avoid false positive results due to the detection of the genetic material of dead pathogens [16,23].
Notably, some studies have shown that when the diagnosis is focused only on reproductive tract specimens, there is a probability of a failing CT or NG diagnosis. Cost-effectiveness studies, for example, such as the one published by Eckman and colleagues, should be performed to understand to what point the extra-urogenital screening strategy would be useful and more appropriate than the urogenital tract screening, only in particular groups or in the general population [65,70,71,72]. In line with this, it could be necessary to adapt CT and NG screening strategies, collecting the appropriate biological samples, to some populations, particularly, men who have sex with men (MSM), who have a higher risk of extragenital infections, rather than urogenital ones [73].
Recently, there have been studies supporting the thesis that the screening strategies for CT and NG infections will only be effective if reformulated for adaption to the 21st century and the specific population being screened, considering the sexual behavior and gender identity of each individual. Accordingly, depending on the risk behavior, different anatomic sites may have to be screened [74,75]. Curiously, there is evidence suggesting that pooled testing for CT and NG detection (pooled rectal, pharyngeal, and urogenital samples), a strategy that tries to minimize the costs of multiple-site screening, is the most cost-effective way to diagnose all chlamydial and gonococcal infections [76]. In line with this, further studies should be pursued to corroborate this hypothesis to assist with the new directions in screening methods for these infections.

4. Challenges and Opportunities of the Current Therapeutic Weapons

Gonococcal and chlamydial infections are exclusively treated with antibiotics, despite some authors suggesting possible natural compounds as potential alternatives to be targeted in future studies [22,77,78]. Briefly, in the case of adolescents and adults, the most common subsets of CT and NG infected patients, CDC guidelines for CT treatment recommends doxycycline 100 mg orally, twice daily for 7 days. The alternative regimens are based on azithromycin 1 g orally, in a single dose, or levofloxacin 500 mg orally, once a day for 7 days [79,80]. In the case of NG infections, the CDC guidelines recommends following the regimen of a single 500 mg intramuscular dose of ceftriaxone. In addition, if the co-infection with CT was not discarded, the treatment should include 100 mg orally 2 times a day for 7 days [81]. Of note, the treatment of urogenital infections in pregnant women, neonates and children, as well as of extra-genital infections, is an exception that is beyond the scope of this paper [79,81].
Antibiotic resistance is a challenge that is a common barrier to overcome during the treatment of bacterial infections [82]. Interestingly, it must be highlighted that Chlamydia suis, a pathogen for pigs that can also affect humans through zoonotic transmission, is also treated preferentially with azithromycin, a tetracycline drug, but C. suis is the only species of Chlamydia (genus) for which there has been found a tetracycline-resistant stable phenotype [83,84,85]. This is an important topic to be pursued in future research in CT antibiotic resistance, as explained by Donati et al., as genetic recombination between both species can occur through horizontal gene transfer, putatively turning CT tetracycline resistant [86].
Considering CT and NG infections, the latter poses major concerns regarding this topic, as reported by the WHO [87]. In addition, through whole genome sequencing of NG, investigators concluded that the pathogen had been shaped by the molecules used to treat the infections, giving rise to two main genomic lineages: a multidrug-resistant and a multidrug-susceptible one [88]. Notably, the European Centre for Disease Prevention and Control (ECDC) has developed a program (European Gonococcal Antimicrobial Susceptibility Program) that monitors the drug susceptibilities of NG, namely to ceftriaxone, cefixime, azithromycin, ciprofloxacin, spectinomycin and gentamicin. There is an ongoing similar program in the United States: the Gonococcal Isolate Surveillance Project, funded by the CDC [89,90,91]. Indeed, the most frequent mechanisms of resistance of this pathogen are mediated by mutation in the penA gene, which encodes PBP2 transpeptidase (against the beta-lactam antibiotics) and mtrR and mtrCDE gene mutation, involved in multidrug efflux transport (leading to azithromycin resistance) [92].
NG susceptibility to some microenvironmental changes, such as temperature, oxygen, desiccation, and many fatty acids, can be a window of opportunity for treatment, which deserves further investigation [52]. Furthermore, because NG developed resistance to all approved drugs, future strategies may encompass a better and more expedient diagnosis of the infection to treat these case in an effective and timely way, re-test after treatment, and test sex partners. Moreover, some authors assert that alternative strategies may include, for example, performing a molecular prediction of resistance, developing new drugs, and repurposing old ones [93].
Current treatment options and opportunities for CT infections have been thoroughly discussed elsewhere [22]. In summary, CT antibiotic resistance, as in most bacterial infections, occurs due to an inappropriate use of the drugs. While some gene mutations give protection or resistance to specific drugs, frequently the treatment regimen chosen does not consider this, leading to infection persistence. Specifically, some authors have described how 23S rRNA gene mutations can be associated with azithromycin resistance [94]. No recent studies confirm the relevant 23S rRNA mutations to predict CT azithromycin resistance, meaning that CT azithromycin resistance is rare [85].
Notwithstanding, despite the absence of laboratory proof, it does not necessarily mean that there is no association. In detail, it is important to analyze Niekerk and colleagues’ study design and the limitations, such as the reduced sample size and the epidemiological characteristics of the participants (for example, convenience sampling causes selection bias), to better conclude if there is plausibility for this association. Regarding tetracycline resistance, reports defend its possible association with tet(M) gene mutations [95,96]. Others reported that gyrA, parC, and ygeD gene mutations can provide fluoroquinolone resistance [96]. In line with this, we could understand that there are some conflicting studies, reflecting a lack of fundamental studies to gather robust evidence to reach a conclusion regarding the plausibility of the association between clinically relevant gene mutations and antibiotic resistance.
Therefore, the treatment strategy must be improved, moving from a “one-size-fits-all” model to a more personalized treatment approach, according to each patient’s particular case; specifically, evaluating the presence of some bacterial mutations. Curiously, some authors have published an interesting work regarding an alternative potential treatment for bacterial STIs, such as CT and NG infections. It defends the potential role of bacteriophage therapy, a method especially efficient for gram-positive bacteria, which, unlike CT and NG (gram-negative bacteria), do not have cell membranes and a cell wall, making them an easy target for this strategy. However, despite additional research needed to prove the success of this strategy as a treatment option, there are efforts to try to overcome the challenges of this, using biological engineering techniques such as cell-penetrating peptides [97].
As for NG infections, the new window of opportunity for treating CT infections includes new drug development, specifically non-antibiotic therapy, or the drug repurposing strategy as an alternative, to “save time” [98]. Recently, some authors have published interesting findings suggesting the use of 4EpDN cyclic peptomer as a prophylactic CT treatment [99]. Also, Kazakova et al. investigated the role of C-ring oxygen and nitrogen erythrodiol derivativesin treating CT [100]. Others have targeted CT more specifically, using peptide-based inhibitors [100,101]. However, these studies need further research to conclude the promising role of such molecules and to decide if these results could be translated into clinical practice.
Investigators do their best to fight these infections. Nevertheless, despite these efforts, infection control is still hard to achieve. In line with that, maybe the critical strategy to solve these challenges would be to focus on the individuals who present some resistance to the infections. As demonstrated last year by Su et al., cGAS-STING signaling pathway played an important role in innate immunity for combating CT infections, in the female mice lower genital tract [102]. This interesting finding must be studied in humans.
In fact, vaccination would be the crowning achievement against both infections. However, such a strategy is still challenging, despite the vast efforts made during recent years and notwithstanding some ongoing trials that could bring new findings and progress [93].

5. Discussion of Future Directions in CT and NG Infection Control

As previously mentioned, CT and NG infections are a significant concern in developed countries because of the rising number of infected people and the consequent high costs for the economy and the patients [103]. Therefore, due to the urgency in these health problems’ control, some developed countries have implemented a screening program within the national health system to detect and treat these infections in a timely way, before irreversible injuries form [104,105,106]. Moreover, some governmental health institutions, such as the US CDC, have created guidelines regarding recommendations for the screening of several STIs, namely, CT and NG infections in distinct subsets: women, pregnant women, MSM, heterosexual men, transgender and gender-diverse persons, and people living with HIV [107]. Notwithstanding, despite the evidence and health institutions’ recommendations, these screening programs are not implemented in a generalized manner, due to the lack of funding and policy support, or the weakness of the health system [108]. Of note, another reason that could explain the non-implementation of these screening programs, as recently discussed by van Bergen and colleagues, is that it is not a linear decision, as it must consider the benefit-to-harm CT-screening ratio. They assert that even though it seems an excellent strategy for infection management, preventing new infection, and treating the infected person in a timely way, actually, it can have a “dark side”, the overuse of antibiotics that can trigger resistance [109]. This study highlights the fact that there is a critical lack of studies on CT screening and the infection itself. To effectively understand the “real world” benefits in the population, there is an urgent need for updated evidence regarding infection prevalence reduction, PID and infertility prevention, antibiotic resistance impact, and CT clearance. Fulfilling these knowledge gaps is crucial to understanding whether or not the paradigm shift from a “test-and-treat” strategy to one with new testing policies, must be considered. The authors suggest an updated Cochrane review and also updated CDC and WHO guidelines, which would be helpful in the assessment of more robust evidence and in establishing consensus recommendation strategies regarding the prevention of future CT infections [109].
The vaccine strategy would be the better way to deal with these infections, avoiding antibiotic resistance and giving immunity to all individuals, protecting them from future potential contact with the pathogens. However, CT and NG vaccines are unavailable, despite the enormous efforts made over the years [93]. It is relevant to mention that, recently it was proved that cross-protectivity was provided by the N. meningitidis serogroup B vaccine, MeNZB, for NG infections [110]. In addition, despite the low protectivity, the hope of effective vaccine development is increasing, due to the additional antigen mining new tools to boost this research process. Thus, the future of the vaccine strategy development would be more focused on in silico approaches, which, concomitantly with the proteomic advances, may allow the most rapid identification of new targets and the eventual development of a successful vaccine [111]. In addition, some authors assert that, while vaccines or new effective drugs are not available, it would be an excellent strategy to apply some personalized medicine in the treatment, to identify patient-specific drug susceptibility through the pathogen genotyping and phenotyping [112,113]. Therefore, while a vaccination strategy is still unavailable, this could be the key to the near-future treatment of these infections, to ultimately prescribe only the effective drugs for each infected individual, avoiding multiple drug resistance to all the available antibiotics [112].
Importantly, besides CT and NG infection control, which is also used for other STIs, primary prevention strategies should be given relevance. These types of strategies should play a more significant role, mainly at school, where educational programs should be implemented to talk to adolescents about these diseases and explain to them the preventive measures to consider, such as using condoms, to protect their health. It is important to remember that some circumstances can contribute to a higher risk of having CT or NG. In particular, individuals at higher risk of STIs, specifically HIV, can use pre-exposure prophylaxis (PrEP). The higher risk occurs because these individuals could wrongly think this is a magic bullet that allows sexually risky sexual behaviors because it eliminates the chance of HIV. In fact, it increases the risk of catching another STI, such as CT or NG, and if not mentioned and explained very carefully, they would participate in more risky sexual behavior [114].

6. Conclusions

Chlamydial and gonococcal infections are among the most common STIs around the world. The infection rates are the highest in individuals aged <25 years old. These infections are mostly asymptomatic, and can lead to long-term severe complications in both sexes, although the worse outcomes occur in women. As the symptoms of both infections are very similar, and the evidence shows that co-infection frequently occurs, we assert that the diagnosis technique must comprise CT and NG testing, in a dual-test strategy.
Moreover, when it comes to bacterial infections that must be treated with antibiotics, it is common for resistance and multi-resistance to these medications to arise and become additional barriers to treating CT and NG infections. In this regard, focusing on gonococcal infection is essential, due to its highest resistance rate reported by several authors.
Finally, to overcome these completely preventable health problems, all the governmental institutions must invest more in primary prevention, sharing information, and promoting STI literacy in society, and while they are doing this, also consider infection control through screening programs. In brief, it is essential to bear in mind that these health problems affect multiple layers of society, not only in the economic field but also in their social and family negative impacts. In recent years, it has been noteworthy that some countries have developed strategies to fight against CT and NG, establishing recommendation guidelines, monitoring antibiotic resistance, and making efforts in vaccine development. Nevertheless, there is still the need for more studies to fully understand the mechanisms behind this bacteria resistance and the mechanism of infection concerning infertility and, potentially, cancer development. With this study, we hope to contribute to finding the knowledge gaps regarding CT and NG infections, encouraging future investigations in this field. We have also discussed the future directions of the study of these infections, to highlight the most pertinent topics to pursue in other investigations.

Author Contributions

Conceptualization, N.V.; methodology, R.R. and N.V.; validation, N.V.; formal analysis, R.R., C.S. and N.V.; investigation, R.R., P.V.-B., M.J.B., C.C., C.S. and N.V.; resources, N.V.; data curation, R.R.; writing—original draft preparation, R.R.; writing—review and editing, P.V.-B., M.J.B., C.C., C.S. and N.V.; visualization P.V.-B., M.J.B., C.C., C.S. and N.V.; supervision, N.V.; project administration, N.V.; funding acquisition, N.V. All authors have read and agreed to the published version of the manuscript.


This work was financed by FEDER—Fundo Europeu de Desenvolimento Regional through the COMPETE 2020—Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia, in a framework of the projects in CINTESIS, R&D Unit (reference UIDB/4255/2020), and within the scope of the project “RISE—LA/P/0053/2020”. N.V. would also like to thank the support from FCT and FEDER (European Union), award number IF/00092/2014/CP1255/CT0004 and CHAIR in Onco-Innovation at FMUP.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.


R.R. thanks F.C.T. for her PhD grant (2022.11755.BDANA).

Conflicts of Interest

The authors declare no conflict of interest.


  1. Zheng, Y.; Yu, Q.; Lin, Y.; Zhou, Y.; Lan, L.; Yang, S.; Wu, J. Global burden and trends of sexually transmitted infections from 1990 to 2019: An observational trend study. Lancet Infect. Dis. 2022, 22, 541–551. [Google Scholar] [CrossRef]
  2. Agwu, A. Sexuality, Sexual Health, and Sexually Transmitted Infections in Adolescents and Young Adults. Top. Antivir. Med. 2020, 28, 459–462. [Google Scholar] [PubMed]
  3. Zhang, J.; Ma, B.; Han, X.; Ding, S.; Li, Y. Global, regional, and national burdens of HIV and other sexually transmitted infections in adolescents and young adults aged 10–24 years from 1990 to 2019: A trend analysis based on the Global Burden of Disease Study 2019. Lancet Child Adolesc. Health 2022, 6, 763–776. [Google Scholar] [CrossRef] [PubMed]
  4. WHO. STIs in 2022: Emerging and Re-Emerging Outbreaks. Available online: (accessed on 13 February 2023).
  5. Ciccarese, G.; Drago, F.; Copello, F.; Bodini, G.; Rebora, A.; Parodi, A. Study on the impact of sexually transmitted infections on Quality of Life, mood and sexual function. Ital. J. Dermatol. Venerol. 2021, 156, 686–691. [Google Scholar] [CrossRef]
  6. Ginieri-Coccossis, M.; Triantafillou, E.; Papanikolaou, N.; Baker, R.; Antoniou, C.; Skevington, S.M.; Christodoulou, G.N. Quality of life and depression in chronic sexually transmitted infections in UK and Greece: The use of WHOQOL-HIV/STI BREF. Psychiatriki 2018, 29, 209–219. [Google Scholar] [CrossRef] [Green Version]
  7. Farhoudi, B.; Shahmohamadi, E.; SeyedAlinaghi, S.; Rostam Afshar, Z.; Parmoon, Z.; Mirzapour, P.; Nadji, S.; Golsoorat Pahlaviani, F.; Tashakorian, M. Prevalence of sexually transmitted infections (STIs) and related factors among female prisoners in Tehran, Iran. Int. J. Prison. Health 2022. ahead-of-print. [Google Scholar] [CrossRef] [PubMed]
  8. Van Gerwen, O.T.; Muzny, C.A.; Marrazzo, J.M. Sexually transmitted infections and female reproductive health. Nat. Microbiol. 2022, 7, 1116–1126. [Google Scholar] [CrossRef] [PubMed]
  9. Chesson, H.W.; Blandford, J.M.; Gift, T.L.; Tao, G.; Irwin, K.L. The estimated direct medical cost of sexually transmitted diseases among American youth, 2000. Perspect. Sex. Reprod. Health 2004, 36, 11–19. [Google Scholar] [CrossRef]
  10. Schnitzler, L.; Evers, S.; Jackson, L.J.; Paulus, A.T.G.; Roberts, T.E. Are intersectoral costs considered in economic evaluations of interventions relating to sexually transmitted infections (STIs)? A systematic review. BMC Public Health 2022, 22, 2180. [Google Scholar] [CrossRef]
  11. CDC. Sexually Transmitted Infections Prevalence, Incidence, and Cost Estimates in the United States. Available online: (accessed on 13 February 2023).
  12. Rodrigues, R.; Sousa, C.; Vale, N. Chlamydia trachomatis as a Current Health Problem: Challenges and Opportunities. Diagnostics 2022, 12, 1795. [Google Scholar] [CrossRef]
  13. López de Munain, J. Epidemiología y control actual de las infecciones de transmisión sexual. Papel de las unidades de ITS. Enfermedades Infecc. y Microbiol. Clínica 2019, 37, 45–49. [Google Scholar] [CrossRef]
  14. Bloch, S.C.M.; Jackson, L.J.; Frew, E.; Ross, J.D.C. Assessing the costs and outcomes of control programmes for sexually transmitted infections: A systematic review of economic evaluations. Sex. Transm. Infect. 2021, 97, 334–344. [Google Scholar] [CrossRef] [PubMed]
  15. Chesson, H.W.; Spicknall, I.H.; Bingham, A.; Brisson, M.; Eppink, S.T.; Farnham, P.G.; Kreisel, K.M.; Kumar, S.; Laprise, J.F.; Peterman, T.A.; et al. The Estimated Direct Lifetime Medical Costs of Sexually Transmitted Infections Acquired in the United States in 2018. Sex. Transm. Dis. 2021, 48, 215–221. [Google Scholar] [CrossRef] [PubMed]
  16. European Center for Disease Prevention and Control. Available online: (accessed on 2 February 2023).
  17. Garcia, M.R.; Leslie, S.W.; Wray, A.A. Sexually Transmitted Infections; StatPearls Publishing LLC.: Treasure Island, FL, USA, 2022. [Google Scholar]
  18. Ye, Z.H.; Chen, S.; Liu, F.; Cui, S.T.; Liu, Z.Z.; Jiang, Y.J.; Hu, Q.H. Patterns of Sexually Transmitted Co-infections and Associated Factors Among Men Who Have Sex with Men: A Cross-Sectional Study in Shenyang, China. Front. Public Health 2022, 10, 842644. [Google Scholar] [CrossRef]
  19. Chan, P.A.; Robinette, A.; Montgomery, M.; Almonte, A.; Cu-Uvin, S.; Lonks, J.R.; Chapin, K.C.; Kojic, E.M.; Hardy, E.J. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature. Infect. Dis. Obs. Gynecol. 2016, 2016, 5758387. [Google Scholar]
  20. Althaus, C.L.; Turner, K.M.; Mercer, C.H.; Auguste, P.; Roberts, T.E.; Bell, G.; Herzog, S.A.; Cassell, J.A.; Edmunds, W.J.; White, P.J.; et al. Effectiveness and cost-effectiveness of traditional and new partner notification technologies for curable sexually transmitted infections: Observational study, systematic reviews and mathematical modelling. Health Technol. Assess. 2014, 18, 1–100. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  21. Leonard, C.A.; Schoborg, R.V.; Low, N.; Unemo, M.; Borel, N. Pathogenic Interplay Between Chlamydia trachomatis and Neisseria gonorrhoeae that Influences Management and Control Efforts—More Questions than Answers? Curr. Rep. 2019, 6, 182–191. [Google Scholar] [CrossRef] [Green Version]
  22. Rodrigues, R.; Marques, L.; Vieira-Baptista, P.; Sousa, C.; Vale, N. Therapeutic Options for Chlamydia trachomatis Infection: Present and Future. Antibiotics 2022, 11, 1634. [Google Scholar] [CrossRef] [PubMed]
  23. WHO. Sexually Transmitted Infections (STIs). Available online: (accessed on 12 February 2023).
  24. Mohseni, M.; Sung, S.; Takov, V. Chlamydia; StatPearls Publishing LLC.: Treasure Island, FL, USA, 2022. [Google Scholar]
  25. Kaufman, H.W.; Gift, T.L.; Kreisel, K.; Niles, J.K.; Alagia, D.P. Chlamydia and Gonorrhea: Shifting Age-Based Positivity Among Young Females, 2010–2017. Am. J. Prev. Med. 2020, 59, 697–703. [Google Scholar] [CrossRef] [PubMed]
  26. WHO. Global Health Sector Strategies on, Respectively, HIV, Viral Hepatitis and Sexually Transmitted Infections for the Period 2022–2030. Available online: (accessed on 11 February 2023).
  27. Foschi, C.; Zagarrigo, M.; Belletti, M.; Marangoni, A.; Re, M.C.; Gaspari, V. Genital and extra-genital Chlamydia trachomatis and Neisseria gonorrhoeae infections in young women attending a Sexually Transmitted Infections (STI) clinic. New Microbiol. 2020, 43, 115–120. [Google Scholar] [PubMed]
  28. Rajabpour, M.; Emamie, A.D.; Pourmand, M.R.; Goodarzi, N.N.; Asbagh, F.A.; Whiley, D.M. Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among women with genitourinary infection and pregnancy-related complications in Tehran: A cross-sectional study. Int. J. STD AIDS 2020, 31, 773–780. [Google Scholar] [CrossRef]
  29. Detels, R.; Green, A.M.; Klausner, J.D.; Katzenstein, D.; Gaydos, C.; Handsfield, H.; Pequegnat, W.; Mayer, K.; Hartwell, T.D.; Quinn, T.C. The incidence and correlates of symptomatic and asymptomatic Chlamydia trachomatis and Neisseria gonorrhoeae infections in selected populations in five countries. Sex. Transm. Dis. 2011, 38, 503–509. [Google Scholar] [CrossRef] [Green Version]
  30. Pillay, J.; Wingert, A.; MacGregor, T.; Gates, M.; Vandermeer, B.; Hartling, L. Screening for chlamydia and/or gonorrhea in primary health care: Systematic reviews on effectiveness and patient preferences. Syst. Rev. 2021, 10, 118. [Google Scholar] [CrossRef]
  31. Mehta, S.D.; Rothman, R.E.; Kelen, G.D.; Quinn, T.C.; Zenilman, J.M. Clinical Aspects of Diagnosis of Gonorrhea and Chlamydia Infection in an Acute Care Setting. Clin. Infect. Dis. 2001, 32, 655–659. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  32. Ahmad, S.F.; Brown, J.K.; Campbell, L.L.; Koscielniak, M.; Oliver, C.; Wheelhouse, N.; Entrican, G.; McFee, S.; Wills, G.S.; McClure, M.O.; et al. Pelvic Chlamydial Infection Predisposes to Ectopic Pregnancy by Upregulating Integrin β1 to Promote Embryo-tubal Attachment. eBioMedicine 2018, 29, 159–165. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  33. Pant, S.; Dimri, A.; Arora, R.; Siraj, F.; Raisuddin, S.; Rastogi, S. Differential expression of matrix metalloproteinases in the fallopian tube of women with Chlamydia trachomatis-associated tubal ectopic pregnancy. Microb. Pathog. 2022, 165, 105468. [Google Scholar] [CrossRef] [PubMed]
  34. Hoenderboom, B.M.; van Bergen, J.; Dukers-Muijrers, N.; Götz, H.M.; Hoebe, C.; de Vries, H.J.C.; van den Broek, I.V.F.; de Vries, F.; Land, J.A.; van der Sande, M.A.B.; et al. Pregnancies and Time to Pregnancy in Women with and without a Previous Chlamydia trachomatis Infection. Sex. Transm. Dis. 2020, 47, 739–747. [Google Scholar] [CrossRef] [PubMed]
  35. Chemaitelly, H.; Majed, A.; Abu-Hijleh, F.; Blondeel, K.; Matsaseng, T.C.; Kiarie, J.; Toskin, I.; Abu-Raddad, L.J. Global epidemiology of Neisseria gonorrhoeae in infertile populations: Systematic review, meta-analysis and metaregression. Sex. Transm. Infect. 2021, 97, 157–169. [Google Scholar] [CrossRef]
  36. Chan, P.A.; Janvier, M.; Alexander, N.E.; Kojic, E.M.; Chapin, K. Recommendations for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis, including extra-genital sites. Med. Health R. I. 2012, 95, 252–254. [Google Scholar] [PubMed]
  37. Howley, P.M. Gordon Wilson Lecture: Infectious Disease Causes of Cancer: Opportunities for Prevention and Treatment. Trans. Am. Clin. Clim. Climatol. Assoc. 2015, 126, 117–132. [Google Scholar]
  38. Karim, S.; Souho, T.; Benlemlih, M.; Bennani, B. Cervical Cancer Induction Enhancement Potential of Chlamydia Trachomatis: A Systematic Review. Curr. Microbiol. 2018, 75, 1667–1674. [Google Scholar] [CrossRef]
  39. Hosseininasab-Nodoushan, S.-A.; Ghazvini, K.; Jamialahmadi, T.; Keikha, M.; Sahebkar, A. Association of Chlamydia and Mycoplasma infections with susceptibility to ovarian cancer: A systematic review and meta-analysis. Semin. Cancer Biol. 2022, 86, 923–928. [Google Scholar] [CrossRef] [PubMed]
  40. Zhu, H.; Shen, Z.; Luo, H.; Zhang, W.; Zhu, X. Chlamydia Trachomatis Infection-Associated Risk of Cervical Cancer: A Meta-Analysis. Medicine 2016, 95, e3077. [Google Scholar] [CrossRef]
  41. Paavonen, J.; Turzanski Fortner, R.; Lehtinen, M.; Idahl, A. Chlamydia trachomatis, Pelvic Inflammatory Disease, and Epithelial Ovarian Cancer. J. Infect. Dis. 2021, 224 (Suppl. S2), S121–S127. [Google Scholar] [CrossRef] [PubMed]
  42. Trabert, B.; Waterboer, T.; Idahl, A.; Brenner, N.; Brinton, L.A.; Butt, J.; Coburn, S.B.; Hartge, P.; Hufnagel, K.; Inturrisi, F.; et al. Antibodies Against Chlamydia trachomatis and Ovarian Cancer Risk in Two Independent Populations. Gynecol. Oncol. 2018, 111, 129–136. [Google Scholar] [CrossRef] [Green Version]
  43. Darville, T. Pelvic Inflammatory Disease Due to Neisseria gonorrhoeae and Chlamydia trachomatis: Immune Evasion Mechanisms and Pathogenic Disease Pathways. J. Infect. Dis. 2021, 224, S39–S46. [Google Scholar] [CrossRef] [PubMed]
  44. Alibek, K.; Karatayeva, N.; Bekniyazov, I. The role of infectious agents in urogenital cancers. Infect. Agents Cancer 2012, 7, 35. [Google Scholar] [CrossRef] [Green Version]
  45. Wang, J.; Wang, K. New insights into Chlamydia pathogenesis: Role of leukemia inhibitory factor. Front. Cell. Infect. Microbiol. 2022, 12, 1029178. [Google Scholar] [CrossRef] [PubMed]
  46. Green, L.R.; Cole, J.; Parga, E.F.D.; Shaw, J.G. Neisseria gonorrhoeae physiology and pathogenesis. Adv. Microb. Physiol. 2022, 80, 35–83. [Google Scholar] [PubMed]
  47. Quillin, S.J.; Seifert, H.S. Neisseria gonorrhoeae host adaptation and pathogenesis. Nat. Rev. Genet. 2018, 16, 226–240. [Google Scholar] [CrossRef]
  48. McSheffrey, G.G.; Gray-Owen, S.D. Chapter 82—Neisseria gonorrhoeae. In Molecular Medical Microbiology, 2nd ed.; Tang, Y.-W., Sussman, M., Liu, D., Poxton, I., Schwartzman, J., Eds.; Academic Press: Boston, MA, USA, 2015; pp. 1471–1485. [Google Scholar]
  49. Walker, E.; van Niekerk, S.; Hanning, K.; Kelton, W.; Hicks, J. Mechanisms of host manipulation by Neisseria gonorrhoeae. Front. Microbiol. 2023, 14, 1119834. [Google Scholar] [CrossRef]
  50. Recommendations for the laboratory-based detection of Chlamydia trachomatis and Neisseria gonorrhoeae—2014. MMWR Recomm. Rep. 2014, 63, 1–19.
  51. Lanjouw, E.; Ouburg, S.; de Vries, H.; Stary, A.; Radcliffe, K.; Unemo, M. 2015 European guideline on the management of Chlamydia trachomatis infections. Int. J. STD AIDS 2016, 27, 333–348. [Google Scholar] [CrossRef]
  52. Unemo, M.; Ross, J.; Serwin, A.; Gomberg, M.; Cusini, M.; Jensen, J. 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults. Int. J. STD AIDS 2020. [Google Scholar] [CrossRef]
  53. Nucleic Acid Based Tests. Available online: (accessed on 28 April 2023).
  54. Roche Diagnostics Protocol. Available online: (accessed on 4 April 2023).
  55. Katz, S.S.; Danavall, D.C.; Morris, M.R.; Herrod, B.P.; Dale, S.E.; Nye, M.B.; Kersh, E.N.; Kirkcaldy, R.D.; Raphael, B.H. Chlamydia trachomatis Variants Escaping Detection in the Aptima Combo 2 Assay in the United States. Sex. Transm. Dis. 2022, 49, 448–452. [Google Scholar] [CrossRef]
  56. Velicko, I.; Kühlmann-Berenzon, S.; Blaxhult, A. Reasons for the sharp increase of genital chlamydia infections reported in the first months of 2007 in Sweden. Eurosurveillance 2007, 12, E5–E6. [Google Scholar] [CrossRef]
  57. Feodorova, V.; Sultanakhmedov, E.; Saltykov, Y.; Zaitsev, S.; Utz, S.; Corbel, M.; Gaydos, C.; Quinn, T.; Motin, V. First Detection of Chlamydia trachomatis ‘Swedish’ Variant (nvCT) in a Russian Couple with Infertility. Open Microbiol. J. 2018, 12, 343–352. [Google Scholar] [CrossRef] [PubMed]
  58. Escobedo-Guerra, M.R.; Katoku-Herrera, M.; Lopez-Hurtado, M.; Villagrana-Zesati, J.R.; de Haro-Cruz, M.d.J.; Guerra-Infante, F.M. Identification of a new variant of Chlamydia trachomatis in Mexico. Enfermedades Infecc. y Microbiol. Clínica 2019, 37, 93–99. [Google Scholar] [CrossRef] [PubMed]
  59. López-Hurtado, M.; Flores-Salazar, V.R.; Gutierréz-Trujillo, R.; Escobedo-Guerra, M.R.; Guerra-Infante, F.M. Utilidad del Cobas® Taqman® Ct Test, v2.0 para la detección de cepas de Chlamydia Trachomatis circulantes en México. Rev. Peru. de Investig. en Salud 2022, 6, 91–100. [Google Scholar] [CrossRef]
  60. Van Der Pol, B.; Torres-Chavolla, E.; Kodsi, S.; Cooper, C.K.; Davis, T.E.; Fife, K.H.; Taylor, S.N.; Augenbraun, M.H.; Gaydos, C.A. Clinical Performance of the BD CTGCTV2 Assay for the BD MAX System for Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis Infections. Sex. Transm. Dis. 2021, 48, 134–140. [Google Scholar] [CrossRef] [PubMed]
  61. FDA Datasheet. Available online: (accessed on 10 July 2023).
  62. Van Niekerk, J.M.; van der Veer, B.; Hoebe, C.; van de Bovenkamp, J.; van Herk, C.; van Loo, I.H.M.; van Alphen, L.B.; Wolffs, P.F.G. Despite Excellent Test Characteristics of the cobas 4800 CT/NG Assay, Detection of Oropharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae Remains Challenging. J. Clin. Microbiol. 2021, 59. [Google Scholar] [CrossRef] [PubMed]
  63. Bristow, C.C.; McGrath, M.R.; Cohen, A.C.; Anderson, L.J.; Gordon, K.K.; Klausner, J.D. Comparative Evaluation of 2 Nucleic Acid Amplification Tests for the Detection of Chlamydia trachomatis and Neisseria gonorrhoeae at Extragenital Sites. Sex. Transm. Dis. 2017, 44, 398–400. [Google Scholar] [CrossRef]
  64. Xu, Y.; Aboud, L.; Chow, E.P.F.; Mello, M.B.; Wi, T.; Baggaley, R.; Fairley, C.K.; Peeling, R.; Ong, J.J. The diagnostic accuracy of pooled testing from multiple individuals for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae: A systematic review. Int. J. Infect. Dis. 2022, 118, 183–193. [Google Scholar] [CrossRef]
  65. Adamson, P.C.; Klausner, J.D. Diagnostic Tests for Detecting Chlamydia trachomatis and Neisseria gonorrhoeae in Rectal and Pharyngeal Specimens. J. Clin. Microbiol. 2022, 60, e0021121. [Google Scholar] [CrossRef]
  66. Brendefur Corwin, L.M.; Campbell, P.; Jakobsen, K.; Müller, F.; Lai, X.; Unemo, M.; Leegaard, T.M.; Vildershøj Bjørnholt, J.; Olsen, A.O. Improvement in Neisseria gonorrhoeae culture rates by bedside inoculation and incubation at a clinic for sexually transmitted infections. Ann. Clin. Microbiol. Antimicrob. 2023, 22, 27. [Google Scholar] [CrossRef]
  67. Ciccarese, G.; Drago, F.; Rebora, A.; Parodi, A. Updates on lymphogranuloma venereum. J. Eur. Acad. Dermatol. Venereol. 2021, 35, 1606–1607. [Google Scholar] [CrossRef] [PubMed]
  68. Zhou, Y.; Cai, Y.-M.; Li, S.-L.; Cao, N.-X.; Zhu, X.-F.; Wang, F.; Han, Y.; Yin, Y.-P.; Chen, X.-S. Anatomical site prevalence and genotypes of Chlamydia trachomatis infections among men who have sex with men: A multi-site study in China. BMC Infect. Dis. 2019, 19, 1041. [Google Scholar] [CrossRef] [Green Version]
  69. Borges, V.; Isidro, J.; Correia, C.; Cordeiro, D.; Vieira, L.; Lodhia, Z.; Fernandes, C.; Rodrigues, A.M.; Azevedo, J.; Alves, J.; et al. Transcontinental Dissemination of the L2b/D-Da Recombinant Chlamydia trachomatis Lymphogranuloma venereum (LGV) Strain: Need Broad Multi-Country Molecular Surveillance. Clin. Infect. Dis. 2021, 73, e1004–e1007. [Google Scholar] [CrossRef] [PubMed]
  70. Dukers-Muijrers, N.H.; Schachter, J.; van Liere, G.A.; Wolffs, P.F.; Hoebe, C.J. What is needed to guide testing for anorectal and pharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae in women and men? Evidence and opinion. BMC Infect. Dis. 2015, 15, 533. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  71. Wilson, J.D.; Wallace, H.E.; Loftus-Keeling, M.; Ward, H.; Davies, B.; Vargas-Palacios, A.; Hulme, C.; Wilcox, M.H. Swab-yourself Trial with Economic Monitoring and Testing for Infections Collectively (SYSTEMATIC): Part 1. A Diagnostic Accuracy and Cost-effectiveness Study Comparing Clinician-taken vs Self-taken Rectal and Pharyngeal Samples for the Diagnosis of Gonorrhea and Chlamydia. Clin. Infect. Dis. 2021, 73, e3172–e3180. [Google Scholar] [PubMed]
  72. Eckman, M.H.; Reed, J.L.; Trent, M.; Goyal, M.K. Cost-effectiveness of Sexually Transmitted Infection Screening for Adolescents and Young Adults in the Pediatric Emergency Department. JAMA Pediatr. 2021, 175, 81–89. [Google Scholar] [CrossRef] [PubMed]
  73. Jansen, K.; Steffen, G.; Potthoff, A.; Schuppe, A.K.; Beer, D.; Jessen, H.; Scholten, S.; Spornraft-Ragaller, P.; Bremer, V.; Tiemann, C. STI in times of PrEP: High prevalence of chlamydia, gonorrhea, and mycoplasma at different anatomic sites in men who have sex with men in Germany. BMC Infect. Dis. 2020, 20, 110. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  74. Man, O.M.; Ramos, W.E.; Vavala, G.; Goldbeck, C.; Ocasio, M.A.; Fournier, J.; Romero-Espinoza, A.; Fernandez, M.I.; Swendeman, D.; Lee, S.J.; et al. Optimizing Screening for Anorectal, Pharyngeal, and Urogenital Chlamydia trachomatis and Neisseria gonorrhoeae Infections in At-Risk Adolescents and Young Adults in New Orleans, Louisiana and Los Angeles, California, United States. Clin. Infect. Dis. 2021, 73, e3201–e3209. [Google Scholar] [CrossRef] [PubMed]
  75. Ratnayake, A.; Campbell, M.B.; Jones, A.; Gomes, G.; Martin, D.H.; Kissinger, P.J. Anal and Oral Sex Behaviors Among Young Black Men Who Have Vaginal Sex: Evidence of the Need for Extragenital Testing for Chlamydia and Gonorrhea. Sex. Transm. Dis. 2022, 49, 826–830. [Google Scholar] [CrossRef] [PubMed]
  76. Wilson, J.D.; Wallace, H.E.; Loftus-Keeling, M.; Ward, H.; Davies, B.; Vargas-Palacios, A.; Hulme, C.; Wilcox, M.H. Swab-Yourself Trial with Economic Monitoring and Testing for Infections Collectively (SYSTEMATIC): Part 2. A Diagnostic Accuracy and Cost-effectiveness Study Comparing Rectal, Pharyngeal, and Urogenital Samples Analyzed Individually, Versus as a Pooled Specimen, for the Diagnosis of Gonorrhea and Chlamydia. Clin. Infect. Dis. 2021, 73, e3183–e3193. [Google Scholar] [PubMed]
  77. Mulaudzi, R.B.; Ndhlala, A.R.; Van Staden, J. Ethnopharmacological evaluation of a traditional herbal remedy used to treat gonorrhoea in Limpopo province, South Africa. S. Afr. J. Bot. 2015, 97, 117–122. [Google Scholar] [CrossRef]
  78. Gutiérrez, D.L.; Sánchez Mora, R.M. Tratamientos alternativos de medicina tradicional para Chlamydia trachomatis, agente causal de una infección asintomática. Nova 2018, 16, 65–74. [Google Scholar] [CrossRef]
  79. CDC Guidelines CT Treatment. Available online: (accessed on 5 April 2023).
  80. Francisco-Natanauan, P.; Leatherman-Arkus, N.; Pantell, R.H. Chlamydia and Gonorrhea Prevalence and Treatment in Detained Youths: Strategies for Improvement. J. Adolesc. Health 2021, 68, 65–70. [Google Scholar] [CrossRef]
  81. CDC Guidelines NG Treatment. Available online: (accessed on 5 April 2023).
  82. Huemer, M.; Mairpady Shambat, S.; Brugger, S.D.; Zinkernagel, A.S. Antibiotic resistance and persistence—Implications for human health and treatment perspectives. EMBO Rep. 2020, 21, e51034. [Google Scholar] [CrossRef]
  83. De Puysseleyr, K.; De Puysseleyr, L.; Dhondt, H.; Geens, T.; Braeckman, L.; Morré, S.A.; Cox, E.; Vanrompay, D. Evaluation of the presence and zoonotic transmission of Chlamydia suis in a pig slaughterhouse. BMC Infect. Dis. 2014, 14, 560. [Google Scholar] [CrossRef] [Green Version]
  84. De Puysseleyr, L.; De Puysseleyr, K.; Braeckman, L.; Morré, S.A.; Cox, E.; Vanrompay, D. Assessment of Chlamydia suis Infection in Pig Farmers. Transbound. Emerg. Dis. 2017, 64, 826–833. [Google Scholar] [CrossRef] [PubMed]
  85. van Niekerk, J.M.; van Loo, I.H.M.; Lucchesi, M.; Morré, S.A.; Hoebe, C.; Dukers-Muijrers, N.; Wolffs, P.F.G. Direct assessment of possible mutations in the 23S rRNA gene encoding macrolide resistance in Chlamydia trachomatis. PLoS ONE 2022, 17, e0265229. [Google Scholar] [CrossRef]
  86. Donati, M.; Balboni, A.; Laroucau, K.; Aaziz, R.; Vorimore, F.; Borel, N.; Morandi, F.; Vecchio Nepita, E.; Di Francesco, A. Tetracycline Susceptibility in Chlamydia suis Pig Isolates. PLoS ONE 2016, 11, e0149914. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  87. Multi-Drug Resistant Gonorrhoea. Available online: (accessed on 5 April 2023).
  88. Sánchez-Busó, L.; Golparian, D.; Corander, J.; Grad, Y.H.; Ohnishi, M.; Flemming, R.; Parkhill, J.; Bentley, S.D.; Unemo, M.; Harris, S.R. The impact of antimicrobials on gonococcal evolution. Nat. Microbiol. 2019, 4, 1941–1950. [Google Scholar] [CrossRef]
  89. Cole, M.J.; Quaye, N.; Jacobsson, S.; Day, M.; Fagan, E.; Ison, C.; Pitt, R.; Seaton, S.; Woodford, N.; Stary, A.; et al. Ten years of external quality assessment (EQA) of Neisseria gonorrhoeae antimicrobial susceptibility testing in Europe elucidate high reliability of data. BMC Infect. Dis. 2019, 19, 281. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  90. Cole, M.J.; Quinten, C.; Jacobsson, S.; Day, M.; Amato-Gauci, A.J.; Woodford, N.; Spiteri, G.; Unemo, M.; Stary, A.; Haller, M.; et al. The European gonococcal antimicrobial surveillance programme (Euro-GASP) appropriately reflects the antimicrobial resistance situation for Neisseria gonorrhoeae in the European Union/European Economic Area. BMC Infect. Dis. 2019, 19, 1040. [Google Scholar] [CrossRef] [PubMed]
  91. Kirkcaldy, R.D.; Harvey, A.; Papp, J.R.; Del Rio, C.; Soge, O.O.; Holmes, K.K.; Hook, E.W., 3rd; Kubin, G.; Riedel, S.; Zenilman, J.; et al. Neisseria gonorrhoeae Antimicrobial Susceptibility Surveillance—The Gonococcal Isolate Surveillance Project, 27 Sites, United States, 2014. MMWR Surveill. Summ. 2016, 65, 1–19. [Google Scholar] [CrossRef] [Green Version]
  92. Mlynarczyk-Bonikowska, B.; Kowalewski, C.; Krolak-Ulinska, A.; Marusza, W. Molecular Mechanisms of Drug Resistance and Epidemiology of Multidrug-Resistant Variants of Neisseria gonorrhoeae. Int. J. Mol. Sci. 2022, 23, 10499. [Google Scholar] [CrossRef] [PubMed]
  93. Lin, E.Y.; Adamson, P.C.; Klausner, J.D. Epidemiology, Treatments, and Vaccine Development for Antimicrobial-Resistant Neisseria gonorrhoeae: Current Strategies and Future Directions. Drugs 2021, 81, 1153–1169. [Google Scholar] [CrossRef]
  94. Mestrovic, T.; Ljubin-Sternak, S. Molecular mechanisms of Chlamydia trachomatis resistance to antimicrobial drugs. Front. Biosci. 2018, 23, 656–670. [Google Scholar] [CrossRef] [Green Version]
  95. Scurtu, L.G.; Jinga, V.; Simionescu, O. Fascinating Molecular and Immune Escape Mechanisms in the Treatment of STIs (Syphilis Gonorrhea, Chlamydia, and Herpes Simplex). Int. J. Mol. Sci. 2022, 23, 3550. [Google Scholar] [CrossRef]
  96. Benamri, I.; Azzouzi, M.; Sanak, K.; Moussa, A.; Radouani, F. An overview of genes and mutations associated with Chlamydiae species’ resistance to antibiotics. Ann. Clin. Microbiol. Antimicrob. 2021, 20, 59. [Google Scholar] [CrossRef]
  97. Cater, K.; Międzybrodzki, R.; Morozova, V.; Letkiewicz, S.; Łusiak-Szelachowska, M.; Rękas, J.; Weber-Dąbrowska, B.; Górski, A. Potential for Phages in the Treatment of Bacterial Sexually Transmitted Infections. Antibiotics 2021, 10, 1030. [Google Scholar] [CrossRef] [PubMed]
  98. Itoh, R.; Kurihara, Y.; Yoshimura, M.; Hiromatsu, K. Bortezomib Eliminates Persistent Chlamydia trachomatis Infection through Rapid and Specific Host Cell Apoptosis. Int. J. Mol. Sci. 2022, 23, 7434. [Google Scholar] [CrossRef]
  99. Lam, H.N.; Lau, T.; Lentz, A.; Sherry, J.; Cabrera-Cortez, A.; Hug, K.; Lalljie, A.; Engel, J.; Lokey, R.S.; Auerbuch, V. Developing Cyclic Peptomers as Broad-Spectrum Type III Secretion System Inhibitors in Gram-Negative Bacteria. Antimicrob. Agents Chemother. 2021, 65, e01690-20. [Google Scholar] [CrossRef]
  100. Kazakova, O.; Rubanik, L.; Lobov, A.; Poleshchuk, N.; Baikova, I.; Kapustina, Y.; Petrova, A.; Korzun, T.; Lopatina, T.; Fedorova, A.; et al. Synthesis of erythrodiol C-ring derivatives and their activity against Chlamydia trachomatis. Steroids 2021, 175, 108912. [Google Scholar] [CrossRef]
  101. Hwang, J.; Strange, N.; Phillips, M.J.; Krause, A.L.; Heywood, A.; Gamble, A.B.; Huston, W.M.; Tyndall, J.D. Optimization of peptide-based inhibitors targeting the HtrA serine protease in Chlamydia: Design, synthesis and biological evaluation of pyridone-based and N-Capping group-modified analogues. Eur. J. Med. Chem. 2021, 224, 113692. [Google Scholar] [CrossRef] [PubMed]
  102. Su, X.; Xu, H.; French, M.; Zhao, Y.; Tang, L.; Li, X.D.; Chen, J.; Zhong, G. Evidence for cGAS-STING Signaling in the Female Genital Tract Resistance to Chlamydia trachomatis Infection. Infect. Immun. 2022, 90, e0067021. [Google Scholar] [CrossRef]
  103. Hunter, P.; Dalby, J.; Marks, J.; Swain, G.R.; Schrager, S. Screening and prevention of sexually transmitted infections. Prim. Care 2014, 41, 215–237. [Google Scholar] [CrossRef] [PubMed]
  104. Moore, A.; Traversy, G.; Reynolds, D.L.; Riva, J.J.; Thériault, G.; Wilson, B.J.; Subnath, M.; Thombs, B.D. Recommendation on screening for chlamydia and gonorrhea in primary care for individuals not known to be at high risk. Cmaj 2021, 193, E549–E559. [Google Scholar] [CrossRef] [PubMed]
  105. Sheringham, J.; Baraitser, P.; Simms, I.; Hart, G.; Raine, R. Chlamydia screening in England: A qualitative study of the narrative behind the policy. BMC Public Health 2012, 12, 317. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  106. Low, N.; Hocking, J.S.; van Bergen, J. The changing landscape of chlamydia control strategies. Lancet 2021, 398, 1386–1388. [Google Scholar] [CrossRef] [PubMed]
  107. CDC Screening Recommendations. Available online: (accessed on 6 April 2023).
  108. Ma, W.; Chen, Z.; Niu, S. Advances and challenges in sexually transmitted infections prevention among men who have sex with men in Asia. Curr. Opin. Infect. Dis. 2023, 36, 26–34. [Google Scholar] [CrossRef] [PubMed]
  109. Van Bergen, J.E.A.M.; Hoenderboom, B.M.; David, S.; Deug, F.; Heijne, J.C.M.; van Aar, F.; Hoebe, C.J.P.A.; Bos, H.; Dukers-Muijrers, N.H.T.M.; Götz, H.M.; et al. Where to go to in chlamydia control? From infection control towards infectious disease control. Sex. Transm. Infect. 2021, 97, 501. [Google Scholar] [CrossRef] [PubMed]
  110. Humbert, M.V.; Christodoulides, M. Immunization with recombinant truncated Neisseria meningitidis-Macrophage Infectivity Potentiator (rT-Nm-MIP) protein induces murine antibodies that are cross-reactive and bactericidal for Neisseria gonorrhoeae. Vaccine 2018, 36, 3926–3936. [Google Scholar] [CrossRef] [PubMed]
  111. Jefferson, A.; Smith, A.; Fasinu, P.S.; Thompson, D.K. Sexually Transmitted Neisseria gonorrhoeae Infections-Update on Drug Treatment and Vaccine Development. Medicines 2021, 8, 11. [Google Scholar] [CrossRef]
  112. Buono, S.A.; Watson, T.D.; Borenstein, L.A.; Klausner, J.D.; Pandori, M.W.; Godwin, H.A. Stemming the tide of drug-resistant Neisseria gonorrhoeae: The need for an individualized approach to treatment. J. Antimicrob. Chemother. 2014, 70, 374–381. [Google Scholar] [CrossRef]
  113. Donà, V.; Low, N.; Golparian, D.; Unemo, M. Recent advances in the development and use of molecular tests to predict antimicrobial resistance in Neisseria gonorrhoeae. Expert. Rev. Mol. Diagn. 2017, 17, 845–859. [Google Scholar] [CrossRef] [PubMed]
  114. Ssemata, A.S.; Muhumuza, R.; Stranix-Chibanda, L.; Nematadzira, T.; Ahmed, N.; Hornschuh, S.; Dietrich, J.J.; Tshabalala, G.; Atujuna, M.; Ndekezi, D.; et al. The potential effect of pre-exposure prophylaxis (PrEP) roll-out on sexual-risk behaviour among adolescents and young people in East and southern Africa. Afr. J. AIDS Res. 2022, 21, 1–7. [Google Scholar] [CrossRef] [PubMed]
Figure 1. Common clinical conditions associated with chlamydial and gonococcal genital infections according to gender. PID—pelvic inflammatory disease; STI—sexually transmitted infection.
Figure 1. Common clinical conditions associated with chlamydial and gonococcal genital infections according to gender. PID—pelvic inflammatory disease; STI—sexually transmitted infection.
Jpm 13 01170 g001
Figure 2. Chlamydia trachomatis cell cycle of infection. This pathogen alternates between two distinct forms. The infectious form, named the elementary body (EB), when in contact with a host cell, can reach the cell cytoplasm by adhesion and internalization into a vacuole. Herein, EBs are converted into the alternative non-infectious form, the reticulate body (RB). These can go through the replication process, using the host’s resources, and using the cell’s energy and nutrients; when they reach a critical volume, the RBs transform into the previous form, the EBs. Finally, there are two possible mechanisms for the extracellular EB release, (1) lysis of the host cell or (2) extrusion. This cycle occurs repeatedly in the adjacent cells [12]. Figure created using BioRender.
Figure 2. Chlamydia trachomatis cell cycle of infection. This pathogen alternates between two distinct forms. The infectious form, named the elementary body (EB), when in contact with a host cell, can reach the cell cytoplasm by adhesion and internalization into a vacuole. Herein, EBs are converted into the alternative non-infectious form, the reticulate body (RB). These can go through the replication process, using the host’s resources, and using the cell’s energy and nutrients; when they reach a critical volume, the RBs transform into the previous form, the EBs. Finally, there are two possible mechanisms for the extracellular EB release, (1) lysis of the host cell or (2) extrusion. This cycle occurs repeatedly in the adjacent cells [12]. Figure created using BioRender.
Jpm 13 01170 g002
Figure 3. Neisseria gonorrhoeae (NG) infection. Briefly, NG infection starts with the host cell interaction, establishing contact through some host cell receptors (CD46 and CR3) and type IV pili communication. After cell adhesion, this bacterium starts its replication and invasion processes, via transcytosis. Concomitantly, NG releases some cellular fragments, such as peptidoglycans and lipo-oligosaccharides (LOS), which, in contact with some cell surface molecules, namely, asialoglycoprotein receptor (ASGP-R) and carcinoembryonic antigen-related cell adhesion molecule family (CEACAM), can activate some signaling pathways (such as NF-kB pathway), triggering processes such as pro-inflammatory cytokine and chemokine production (including IL-1, IL-6, IL-8). In addition, this pro-inflammatory gradient of molecules drives the immune cell recruitment to the local, mainly dendritic, cells, macrophages, and neutrophils. Although these immune cells’ role is to trigger pathogen destruction, mostly through phagocytosis by neutrophils, up to the infection clearance, NG can frequently survive, and the infection can persist. Figure created using BioRender.
Figure 3. Neisseria gonorrhoeae (NG) infection. Briefly, NG infection starts with the host cell interaction, establishing contact through some host cell receptors (CD46 and CR3) and type IV pili communication. After cell adhesion, this bacterium starts its replication and invasion processes, via transcytosis. Concomitantly, NG releases some cellular fragments, such as peptidoglycans and lipo-oligosaccharides (LOS), which, in contact with some cell surface molecules, namely, asialoglycoprotein receptor (ASGP-R) and carcinoembryonic antigen-related cell adhesion molecule family (CEACAM), can activate some signaling pathways (such as NF-kB pathway), triggering processes such as pro-inflammatory cytokine and chemokine production (including IL-1, IL-6, IL-8). In addition, this pro-inflammatory gradient of molecules drives the immune cell recruitment to the local, mainly dendritic, cells, macrophages, and neutrophils. Although these immune cells’ role is to trigger pathogen destruction, mostly through phagocytosis by neutrophils, up to the infection clearance, NG can frequently survive, and the infection can persist. Figure created using BioRender.
Jpm 13 01170 g003
Table 1. Main FDA-approved CT/NG tests. Mgen—Mycoplasma genitalium; T. vaginalisTrichomonas vaginalis; CLIA—clinical laboratory improvements amendment.
Table 1. Main FDA-approved CT/NG tests. Mgen—Mycoplasma genitalium; T. vaginalisTrichomonas vaginalis; CLIA—clinical laboratory improvements amendment.
NAATsSource TypeControlMethodTargetLimitations
(Becton Dickinson and Company; Franklin Lakes, NJ, USA)
Vaginal, endocervical or gynecological swab; urine.Sample processing controlPCRCT/NG and Trichomonas vaginalisOnly allow genital infection diagnosis; co-infections could affect test performance [60].
Alinity m STI Assay
(Abbott Molecular, Inc.; Des Plaines, IL, USA)
Vaginal, endocervical, or gynecological specimens; urine.Independent internal and cellular controls.RT-PCRCT/NG, T. vaginalis and MgenFalse negative test could occur for Mgen, when the sample is an endocervical swab [61].
Abbott RealTime CT/NG
(Abbott Molecular Inc.; Des Plaines, IL, USA)
vaginal, or urethral swab; urine.
Internal controlPCRCT/NGIf asymptomatic, endocervical and male urethral swab specimens should not be used [61].
(Roche Molecular Systems, Inc.; Rotkreuz, Switzerland)
Urine, pharyngeal, rectal, cervical, and urogenital samples.Internal controlPCRCT/NGRelatively low oropharyngeal loads of NG could not be detected [62].
APTIMA Combo 2 Assay
(Hologic Gen-Probe, Inc.; Marlborough, MA, USA)
Urine, vaginal, pharyngeal, rectal, and endocervical samples.Positive and negative controlTranscription-Mediated AmplificationCT/NGStill requires a laboratory-based platform [63].
BDProbeTec ET CT and NG Amplified DNA Assays
(Becton Dickinson Microbiology Systems; Franklin Lakes, NJ, USA)
Endocervical and urethral swabs; urine.Amplification controlStrand Displacement AmplificationCT/NGLower sensitivity in urine samples.
GEN-PROBE PACE 2C System for Chlamydia trachomatis and Neisseria gonorrhoeae
(Gen-Probe, Inc.; Marlborough, MA, USA)
Endocervical specimens.Two positive controlsNucleic acid hybridization techniqueCT/NGTest limited to endocervical specimens.
Hybrid Capture II CT/GC Test
(QIAGEN N.V.; Hilden, Germany)
Cervical specimens.Internal controlNucleic acid hybridization techniqueCT/NGTest with lower sensitivity [64].
Xpert CT/NG
(Cepheid; Sunnyvale, CA, USA)
Urine, pharyngeal, rectal, vaginal and endocervical samples.Sample processing control, sample adequacy control and probe check control.PCRCT/NGIt is not currently a CLIA-waived test (it must be performed in specific laboratories used to moderate- or high-complexity testing) [65].
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Rodrigues, R.; Vieira-Baptista, P.; Catalão, C.; Borrego, M.J.; Sousa, C.; Vale, N. Chlamydial and Gonococcal Genital Infections: A Narrative Review. J. Pers. Med. 2023, 13, 1170.

AMA Style

Rodrigues R, Vieira-Baptista P, Catalão C, Borrego MJ, Sousa C, Vale N. Chlamydial and Gonococcal Genital Infections: A Narrative Review. Journal of Personalized Medicine. 2023; 13(7):1170.

Chicago/Turabian Style

Rodrigues, Rafaela, Pedro Vieira-Baptista, Carlos Catalão, Maria José Borrego, Carlos Sousa, and Nuno Vale. 2023. "Chlamydial and Gonococcal Genital Infections: A Narrative Review" Journal of Personalized Medicine 13, no. 7: 1170.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop