Zoonotic Dis., Volume 3, Issue 4 (December 2023) – 6 articles

Migratory and local birds may disperse ticks and their associated pathogens. The aim of this study was to provide information regarding ticks infesting birds in Asturias, a region that accounts for most of the Lyme disease hospitalizations in Spain. From September 2021 to April 2023, trained and experienced bird-banders collected ticks from birds in two estuary and four forest locations. A total of 1698 birds (52 species, 38 genera, and 26 families) were captured. A total of 51 ticks (28 larvae, 20 nymphs, and 3 females) were collected from 43 birds, belonging to three species: Ixodes ricinus (31), Ixodes frontalis (18), and Haemaphysalis concinna (1). The average prevalence of tick infestation was 2.5% and the average tick burden was 1.2 ticks per infested host. The bird species Turdus merula, Parus major, Luscinia svecica, and Anthus pratensis were among the most infested. Anaplasma phagocytophilum was detected in one I. ricinus nymph collected from Phylloscopus collybita. We have not detected Borrelia burgdorferi s.l., Rickettsia spp., Coxiella burnetii, or piroplasmids in any of the 51 analyzed ticks. These results suggest low infestation rate in migratory/estuary birds and a higher rate in forest/sedentary ones. Despite this, the detection of pathogens, although with low prevalence, can pose a risk to public health. Full article

The microbiological contamination of wild boar meat depends on the hygiene practices that hunters apply during its preparation, from the point of collection to its refrigeration. This study assesses Portuguese hunters’ knowledge of hygiene practices when handling wild boar carcasses that can jeopardise meat safety. A general structured survey entitled “Private consumption of game meat and good hygiene practices” was distributed to Portuguese hunters. Of the 206 respondents, 95% use wild boar meat for private consumption without prior inspection or initial examination by a veterinarian. This study also revealed that the vast majority of respondents have several risky practices that can compromise the safety of wild boar meat consumed (evisceration, handling, refrigeration, and transport). It is also evident that there is a lack of knowledge related to recognising lesions compatible with zoonotic infections in the hunted animals. These inappropriate knowledge and practices can pose a risk to hunters (occupational zoonotic health) and consumers (foodborne diseases). To reduce this risk, hunters need to be trained and informed about proper game meat handling practices. Full article

Toxoplasma gondii is a ubiquitous protozoan parasite of public health concern, with severe health consequences among immunocompromised individuals and pregnant mothers. Pigs are intermediate hosts of this zoonotic parasite and consumption of undercooked pork is a risk factor for T. gondii infection. We investigated the seroprevalence and risk factors for T. gondii in pigs in Kenya. A cross-sectional study was conducted at a non-integrated abattoir in Kiambu, Kenya, where 446 blood samples were collected from slaughtered pigs between 5 January and 5 March 2021. For each pig sampled, additional data were collected on the county of origin, farm size, sex and live weight. Serum was harvested from each pig blood sample, and these were subjected to indirect enzyme-linked immunosorbent assay tests to detect the presence of immunoglobin G (IgG) for T. gondii infection. The overall seroprevalence for T. gondii was 34.53% (95% C.I. 30.16–39.17). Risk factors for T. gondii seropositivity in pigs included farm size (p < 0.001) and the live weight of pigs (p = 0.044). The high seroprevalence of T. gondii indicates that consumers of raw and undercooked pork may be at a high risk of infection. It is therefore recommended that strategies for the mitigation of risk of exposure in populations should prioritize public health education for pig farmers, pork handlers and consumers on risk reduction measures along the pork value chains. Full article

Human cases of fatal encephalitis caused by Borna disease virus 1 (BoDV-1) have been increasingly reported. We envisaged the present systematic review in order to provide a comprehensive summary of clinical features associated with BoDV-1 encephalitis. Systematic research of four databases (PubMed, EMBASE, MedRxiv, BioRxiv) was performed during July 2023, and corresponding clinical and epidemiological data were collected and analyzed. A total of 37 BoDV-1 encephalitis cases from 15 different study cases and two countries (Germany, No. 35; France, No. 2) were detected, and their features were summarized (case fatality ratio, 91.9%). Age distribution followed a “U-shaped” distribution, with a first peak in individuals younger than 14 years (18.9%) and the second one in subjects older than 50 years (43.2%). Environmental risk factors were irregularly reported, but 17 out of 37 cases either lived in rural areas or reported repeated outdoor activities (45.9%). Interaction with pets and livestock was reported in eight cases (21.6%), stressing the zoonotic potential of BoDV-1 infections. Moreover, 16.2% of cases were reported among recipients of solid organ transplantations (five kidneys; one liver). Overall survival in children/adolescents vs. adults (≥18 years) was not significantly different (Hazard Ratio 0.878; 95% Confidence Interval from 0.366 to 2.105). Magnetic Resonance Imaging identified the involvement of basal ganglia, mostly of the caudate nucleus (42.4%) and thalamus (33.3%). Cerebrospinal fluid was often characterized by pleocytosis (78.4%). On the other hand, no distinctive clinical features were identified: initial symptoms were specific and included headache, fever, and confusion. In conclusion, BoDV-1 infection can result in fatal encephalitis, whose actual burden still remains unascertained. As the epidemiology of BoDV-1 is similarly elusive, encephalitis cases of unclear cause should be routinely tested for bornaviruses. Full article

Tuberculosis (TB) results from infection with members of the Mycobacterium tuberculosis complex (MTBC) and represents a major global public health concern. We here sought to assess the perceptions of human and animal TB and the prevalence of circulating MTBCs lineages and associated risk factors through a cross-sectional survey of 335 individuals presenting with symptoms of pulmonary or extrapulmonary TB in the Manyara region of Tanzania. After the enrollment of participants, a questionnaire survey was conducted, samples were collected for bacterial culture, and real-time multiplex PCR was performed to differentiate amongst primary animal and human MTBC lineages. The results show poor TB awareness: 31.6% of the participants were not aware of human TB; 82.4% were unaware of animal TB and 95.2% lacked awareness of zoonotic TB (zTB) transmission. A total of 18 recovered specimens (5%; 95% CI: 3–8%) were positive by culture, all of which were typed as M. tuberculosis sensu stricto using a lineage-specific PCR assay. While no single risk factor was significantly associated with MTBC culture positivity, the survey revealed considerable self-reported high-risk practices for contracting zTB. Together, the results show that Manyara residents have poor knowledge of diseases caused by MTBCs and high evidence of risky practices for contracting zTB. Full article

Frequent animal–human interactions in sub-Saharan Africa (SSA) pose an increased risk for the transmission of zoonotic diseases. While there are sporadic reports of zoonotic diseases outbreaks in SSA, a synthetic overview is necessary to better understand how the sub-region is impacted by these pathologies. We conducted a systematic review of zoonotic diseases studies conducted in SSA between 2000 and 2022. Quantitative reports including case reports/series from countries spanning West, Central, East, and Southern SSA and that provided empirical data on the occurrence of zoonotic diseases in humans with documented evidence of animal origin were eligible for inclusion. The 55 eligible articles provided 82 reports of zoonotic diseases for a total of 28,934 human cases (pooled attack rate: 54.4 per 1000) and 1182 deaths (pooled fatality rate: 345.4 per 1000). Only 31 (37.8%) of the studies were conducted during ongoing outbreaks. We identified the zoonotic diseases in SSA with the highest attack rates (rickettsiosis, toxoplasmosis, Q-fever) and CFR (Marburg, Ebola, leptospirosis), which should be prioritized for surveillance and response preparedness. Addressing the threat of zoonotic diseases in SSA requires the strengthening of health systems and implementation of a one health approach. Importantly, research should be encouraged during ongoing epidemics to fortify immediate response strategies and work toward preventing future outbreaks. Full article