Bushmeat Hunting and Zoonotic Transmission of Simian T-Lymphotropic Virus 1 in Tropical West and Central Africa.

Simian T-lymphotropic virus 1 (STLV-1) enters human populations through contact with nonhuman primate (NHP) bushmeat. We tested whether differences in the extent of contact with STLV-1-infected NHP bushmeat foster regional differences in prevalence of human T-lymphotropic virus 1 (HTLV-1). Using serological and PCR assays, we screened humans and NHPs at two Sub-Saharan African sites where subsistence hunting was expected to be less (Taï region, Côte d'Ivoire [CIV]) or more (Bandundu region, Democratic Republic of the Congo [DRC]) developed. Only 0.7% of human participants were infected with HTLV-1 in CIV (n = 574), and 1.3% of humans were infected in DRC (n = 302). Two of the Ivorian human virus sequences were closely related to simian counterparts, indicating ongoing zoonotic transmission. Multivariate analysis of human demographic parameters and behavior confirmed that participants from CIV were less often exposed to NHPs than participants from DRC through direct contact, e.g., butchering. At the same time, numbers of STLV-1-infected NHPs were higher in CIV (39%; n = 111) than in DRC (23%; n = 39). We conclude that similar ultimate risks of zoonotic STLV-1 transmission-defined as the product of prevalence in local NHP and human rates of contact to fresh NHP carcasses-contribute to the observed comparable rates of HTLV-1 infection in humans in CIV and DRC. We found that young adult men and mature women are most likely exposed to NHPs at both sites. In view of the continued difficulties in controlling zoonotic disease outbreaks, the identification of such groups at high risk of NHP exposure may guide future prevention efforts.IMPORTANCE Multiple studies report a high risk for zoonotic transmission of blood-borne pathogens like retroviruses through contact with NHPs, and this risk seems to be particularly high in tropical Africa. Here, we reveal high levels of exposure to NHP bushmeat in two regions of Western and Central tropical Africa. We provide evidence for continued zoonotic origin of HTLV-1 in humans at CIV, and we found that young men and mature women represent risk groups for zoonotic transmission of pathogens from NHPs. Identifying such risk groups can contribute to mitigation of not only zoonotic STLV-1 transmission but also transmission of any blood-borne pathogen onto humans in Sub-Saharan Africa.

Low occurrence of Salmonella spp. in wild birds from a Swiss rehabilitation centre.

BACKGROUND: Salmonella are bacteria of the family Enterobacteriaceae with a wide host range. Infection in birds causes subclinical disease to mass mortality events. Wild birds may act as healthy carriers posing a hazard to livestock and humans. The present study investigated the occurrence of Salmonella in wild birds admitted to a rehabilitation centre in order to assess the exposure of the staff to this zoonotic pathogen. METHODS: Faecal swabs of 552 avian patients (68 species) were collected over the course of 12 months. Each sample was propagated in enrichment broth and subsequently incubated on a RAPID'Salmonella plate. Salmonella isolates were serotyped, and antimicrobial susceptibility testing was performed. RESULTS: Six Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) and 1 S. Schleissheim were detected; all were pansusceptible to the antibiotics tested. CONCLUSION: Despite the low positive rate in the tested population, the authors recommend applying protective equipment and hygiene measures when handling wild birds.

Antimicrobial resistant and extended-spectrum ß-lactamase producing Escherichia coli in common wild bird species in Switzerland.

A total of 294 fecal swabs from 294 wild birds in Switzerland were cultivated for antimicrobial resistant (AMR) Escherichia coli. Samples were also subcultivated to detect E. coli with extended-spectrum ß-lactamases (ESBL), carbapenemases, and plasmid-mediated aminoglycoside or colistin resistance, respectively. Samples from 17 (5.8%) of the birds contained 19 AMR E. coli, whereof 26.3% were multidrug resistant. Five (1.7%) ESBL-producing E. coli were detected. The isolates harbored blaCTX-M-1 (two isolated from carrion crows and from one great spotted woodpecker, respectively), blaCTX-M-15 (originating from a grey heron), blaCTX-M-55 (from a carrion crow), and blaCTX-M-65 (from a common blackbird). Phylogenetic analysis assigned three isolates to commensal phylogroups A and B1, one to extraintestinal pathogenic group B2, and one to phylogroup F. Multilocus sequence typing identified sequence types (STs) that have been found previously in ESBL E. coli in wild birds (ST58, ST205, ST540). One isolate harboring blaCTX-M-55 was assigned to the recently emerged fluoroquinolone-resistant, extraintestinal pathogenic E. coli clone ST1193. Wild birds have the potential to disperse AMR, including clinically important resistance genes, from anthropogenic-influenced habitats to diverse areas, including vulnerable natural environments such as surface waters or mountain regions.

Resource-Effective Serosurveillance for the Detection of West Nile Virus in Switzerland Using Abattoir Samples of Free-Range Laying Hens.

West Nile virus (WNV) is an important zoonotic pathogen maintained in a natural transmission cycle between mosquitoes and birds as reservoir hosts. In dead-end hosts, such as humans, infection may result in fatal neurologic disease translating into disease and death-related suffering and increased health care costs. In humans, WNV may also be transmitted through blood transfusions and organ transplants. WNV is not present in Switzerland yet, but competent vector species (especially Culex pipiens and Aedes japonicus) are prevalent and an introduction of the virus, likely through wild birds, is expected at any time. Therefore, it is important for Switzerland to be prepared and establish a surveillance system for WNV to initiate increased prevention activities, such as the screening of blood and organ donations and public education activities in case virus circulation is detected. The long-term goal of these surveillance measures would be a reduced infection rate in humans resulting in less suffering and reduced health care costs. To provide the basis for a pragmatic and resource-effective WNV surveillance program, this study used aliquots of serum samples of free-range laying hens taken at the abattoir and collected in the frame of the ongoing Swiss Avian Influenza and Newcastle Disease monitoring program for a 2-year period. All 961 aliquots were analyzed using a commercial competitive WNV enzyme-linked immunosorbent assay (ELISA). The study allowed to set up sampling and laboratory routines as a basis for future WNV surveillance activities. At this stage there is no evidence for circulation of WNV in Switzerland.

The Degree of One Health Implementation in the West Nile Virus Integrated Surveillance in Northern Italy, 2016.

West Nile virus (WNV) is endemic in the Po valley area, Northern Italy, and within the legal framework of the national plan for the surveillance of human vector-borne diseases, WNV surveillance has over time been implemented. The surveillance plans are based on the transdisciplinary and trans-sectorial collaboration between regional institutions involved in public, animal, and environmental health. This integrated surveillance targets mosquitoes, wild birds, humans, and horses and aims at early detecting the viral circulation and reducing the risk of infection in the human populations. The objective of our study was to assess the degree of One Health (OH) implementation (OH-ness) of the WNV surveillance system in three North Italian regions (Emilia-Romagna, Lombardy, Piedmont) in 2016, following the evaluation protocol developed by the Network for Evaluation of One Health (NEOH). In detail, we (i) described the OH initiative (drivers, outcomes) and its system (boundaries, aim, dimensions, actors, stakeholders) and (ii) scored different aspects of this initiative (i.e., OH-thinking, -planning, -sharing, -learning, transdisciplinarity and leadership), with values from 0 (=no OH approach) to 1 (=perfect OH approach). We obtained a mean score for each aspect evaluated. We reached high scores for OH thinking (0.90) and OH planning (0.89). Lower scores were attributed to OH sharing (0.83), transdisciplinarity and leadership (0.77), and OH learning (0.67), highlighting some critical issues related to communication and learning gaps. The strengths and weaknesses detected by the described quantitative evaluation will be investigated in detail by a qualitative evaluation (process evaluation), aiming to provide a basis for the development of shared recommendations to refine the initiative and conduct it in a more OH-oriented perspective.