Zoonoses and Public Health最新文献

Coronaviruses (CoV) are RNA viruses associated with enteric and respiratory diseases and known for their emergence potential in humans and other mammals. CoVs originate from zoonotic transmission, in which bats are natural reservoirs. Previous studies suggest that CoV diversity is positively correlated with bat diversity, whereas anthropogenic influence can increase prevalence in bat hosts. The present study investigates the presence of CoVs in bats in the Amazon-Cerrado transition region in the state of Mato Grosso, Brazil. In total, 57 individuals were captured, belonging to 17 species in 7 subfamilies and 4 families. Among the captured bats in the region, the most abundant species were Carollia perspicillata (24.6%; 14/57), C. brevicauda (17.5%; 10/57), and Phyllostomus hastatus (10.5%; 6/57). Bat sampling richness evidenced a diversity pattern consistent with fragmented forests. A total of 16 faecal samples were collected and tested for CoV infection, with 2 positive samples sequenced (12.5%; 95% CI 3.49-36.02). Phylogenetic analyses characterised the CoVs found as divergent sequences within distinct branches of American Alphacoronavirus lineages previously reported. The RdRp phylogenetic tree exhibited biome-associated structuring as well as multiple bat host species within the clades, indicating a wide distribution within hosts and biomes. Nevertheless, further studies are necessary to ascertain the relationship between CoV spatial dynamics and the role of the Brazilian Amazon-Cerrado transition zone, where deforestation increases human-bat contact and access its spillover potential risk.

Introduction: Tick observation data collected through citizen science is increasingly utilised to map tick-borne infection risk areas indirectly, that is, based on the rate of tick encounters or occurrence of ticks. However, direct associations between tick observations and Lyme borreliosis (LB) cases have received little attention. In the current study, associations between weekly tick observations and LB cases were studied on a nationwide scale in Finland, in order to determine if tick observations precede cases in a predictable manner, and whether tick observations could be used to predict peaks in cases.

Methods and results: Nationwide weekly electronic citizen science tick observation data from a tick surveillance website (www.punkkilive.fi/en) and Lyme borreliosis data from the Finnish Institute for Health and Welfare from 2021 to 2023 were utilised in the current study. Negative binomial models were fitted to assess whether tick observations explain variation in LB cases beyond simple seasonality, and to determine if weekly disease cases can be predicted based on tick observation data originating from either humans, pets (dogs & cats) or all sources. Disease cases followed observations with a three to four week lag. Tick observation data were observed to explain variation in LB cases beyond simple seasonality. Models only utilising observations from humans to predict disease cases had the best performance. Finally, differences in the phenology of the two human-biting tick species present in Finland were observed to influence temporal patterns of observations and LB cases on smaller spatial scales.

Conclusions: This study revealed that LB cases can be predicted utilising citizen science tick observation data. Consequently, crowdsourced tick observation data can be used to predict when peaks in disease cases are to be expected, allowing for specifically targeted awareness campaigns. This, in turn, may lead to symptoms being detected and recognised earlier, allowing for more rapid treatment and fewer sequelae. Guidance on setting up similar models is provided. Actors with access to such data are encouraged to set up similar early warning systems. This increased utility of the data can be leveraged to justify setting up tick observation services, as well as to motivate citizens to participate.

Background: Human activities play a significant role in the emergence of infectious diseases. We aimed to test whether artificial irrigation affects the occurrence of a zoonotic bacteria sensitive to desiccation, pathogenic Leptospira species (pathoLep), in micromammals inhabiting Mediterranean ecosystems.

Methods: A total of 361 individuals, including 217 Algerian mice (Mus spretus), 79 wood mice (Apodemus sylvaticus), and 65 greater white-toothed shrews (Crocidura russula), were captured during the four seasons of 2022 in six sites along a riparian forest close to a large city in north-eastern Spain and the surrounding agricultural fields, which are irrigated by flooding. A piece of kidney from each individual was analysed by means of two real-time PCR protocols targeting the lipL32 gene, which is exclusively found in pathoLep. Generalised Linear Models were used to study the factors that may be related to the presence of pathoLep.

Results: DNA of pathoLep was detected in 28% of the individuals, a relatively high occurrence compared to similar studies. The best model for the general micromammal population included four significant factors: season, age, species, and habitat. Prevalence was significantly lower during the dry seasons; in juveniles than in adult individuals; in the wood mouse than in the Algerian mouse and the shrew; and in natural than in agricultural habitats. Prevalence was consistently higher in agricultural habitats during all the seasons, reaching over 55% prevalence in these areas during spring. For the core species, the Algerian mouse, the best model included two factors (seasons and habitat), in the same sense as the general population model.

Conclusions: This study shows that pathoLep are widespread among micromammals in the Middle Ebro Valley and that their occurrence is shaped by intrinsic and extrinsic factors. We identified a human activity (artificial irrigation) as an important driver favouring leptospiral survival in rural environments.

Introduction: The emergence of methicillin-resistant Staphylococcus species (MRS) poses a growing threat to both human and veterinary health.

Methods: We performed a comparative genomic characterisation of 49 methicillin-resistant Staphylococcus isolates collected from humans, dogs, and cats in a veterinary hospital from Central Chile.

Results: Whole-genome sequencing revealed S. aureus, S. pseudintermedius, and S. epidermidis as the most prevalent species, with distinct patterns of antimicrobial resistance and virulence. Average Nucleotide Identity (ANI) and phylogenetic analyses highlighted species-specific clustering but also revealed divergent lineages among Staphylococcus aureus and Staphylococcus epidermidis isolates. Resistance to β-lactams was widespread, with the blaZ and mecA genes predominating, while macrolide and aminoglycoside resistance genes were variably distributed. S. aureus exhibited the highest virulence gene content, whereas S. pseudintermedius isolates carried superantigen-encoding enterotoxin genes, suggesting potential zoonotic risk. MLST and SCCmec typing confirmed the circulation of community-associated MRS lineages, notably SCCmec type IV.

Conclusions: This study provides a first comprehensive characterisation of methicillin-resistant Staphylococcus spp. isolates from human and animal hosts at a veterinary hospital in Santiago, Chile. These findings underscore the need for continuous surveillance under the One Health approach to monitor the potential transmission of high-risk clones and resistance determinants between humans and companion animals.

Introduction: Leptospirosis is a major but under-reported zoonotic disease, and epidemiological data from South Sudan remain limited. This study estimated the true prevalence of Leptospira spp. exposure and identified associated risk factors among slaughterhouse workers and slaughtered cattle in Western Bahr El Ghazal.

Methods: A cross-sectional study was conducted in major slaughterhouses. Serum samples from workers and cattle were tested using the microscopic agglutination test (MAT). Bayesian hierarchical models were used to adjust for diagnostic test imperfections and to estimate true prevalence. Structured questionnaires captured occupational and animal-level risk factors for analysis within the Bayesian framework.

Results: The estimated true prevalence was 10% in slaughterhouse workers and 85% in slaughtered cattle, indicating a high zoonotic exposure risk. Among workers, flaying, inconsistent use of protective equipment, and handling higher numbers of carcasses per day were significantly associated with seropositivity. In slaughtered cattle, exposure varied by breed, age, and sex. The model further indicated a 78% probability that a randomly selected slaughterhouse was affected and a 65% probability that infection levels among workers remained below 5%.

Conclusions: This study provides the first Bayesian-based estimates of leptospiral exposure in slaughterhouse settings in Western Bahr El Ghazal. The findings underscore the need to improve occupational safety, strengthen surveillance, and apply One Health approaches to reduce zoonotic transmission. Despite limitations, including lack of environmental data, the Bayesian framework proved effective for generating robust prevalence estimates in a resource-limited setting. Expanded geographic coverage and incorporation of environmental assessments are recommended to inform targeted leptospirosis control strategies.

Introduction: Influenza A viruses (IAVs) are responsible for respiratory infections in a wide range of species, including birds, swine and humans. The role of wild boar (Sus scrofa) in IAV epidemiology remains underexplored. Here, we present a longitudinal serologic and virologic surveillance study of wild boars in Spain from 2015 to 2023.

Methods: A total of 1643 nasal exudates and 2932 serum samples were analysed using quantitative RT-PCR, ELISA and haemagglutination inhibition (HI) assays to detect IAV positive samples and IAV targeted antibodies to characterise circulating viral subtypes. In addition, in the context of highly pathogenic avian influenza H5N1 outbreaks, we explored the potential transmission of avian IAV to wild boar.

Results: In summary, 6% of the serum samples tested positive and one IAV H3N1 was isolated. The seroprevalence remained stable from 2015 to 2018, undetected in 2019 and increased significantly from 2020 to 2023. The most frequently detected subtype was Eurasian avian-like H1 (clade 1C) while pandemic H1 (clade 1A) and human-like H1 (clade 1B) were less common. Human seasonal-like H3 strains from the 2000s (2000s-like H3) emerged in 2017 and have become more seroprevalent in recent years. A subset of wild boar sera from areas overlapping with H5N1 HPAI outbreaks in poultry and wild birds tested positive for recombinant H5 by ELISA, although H5N1 HI assays were negative.

Conclusions: The monitoring of IAV in wild boar population allowed the identification of the temporal and spatial trends and shifts in the prevalence and characterisation of the infecting IAV strains. Our data suggest potential spillover events from human or other sources and support the inclusion of integrated monitoring of the wild suids as IAV reassortment-prone hosts in influenza surveillance programs.

Background: Rabies, a fatal zoonotic encephalitis, is rarely reported in elephants.

Objectives: To present the first confirmed case of rabies in a captive Asian elephant in Bihar, India, using both ante-mortem and post-mortem diagnostics and discuss its implications for wildlife conservation and public health.

Methods: An 8-year-old female elephant exhibited acute neurologic signs including aggression, muscle spasms, anorexia and recumbency. Corneal smears and saliva samples were tested ante-mortem using the fluorescent antibody test (FAT) and a rapid diagnostic kit. Following the animal's death on Day 6, a post-mortem necropsy was performed, and direct fluorescent antibody (DFA) testing on brain tissues confirmed the diagnosis.

Results: Rabies antigen was detected in corneal smears (FAT) and confirmed in cerebellum and brainstem tissues (DFA). No bite history was evident. The elephant died on Day 6 post-onset. All personnel classified as exposed under WHO criteria through contact with infectious secretions or involvement in high-risk clinical or necropsy procedures received immediate post-exposure prophylaxis.

Introduction: Livestock markets are critical hubs within animal trade networks that influence pathogen dissemination at the regional and national scale. Indeed, a 2016 Salmonella serovar Heidelberg outbreak, initially linked to surplus dairy calves at livestock markets, sickened 63 people across 17 states. The objectives of this repeated cross-sectional study were to (i) assess the prevalence and relatedness of Salmonella serovars of public health relevance in Ohio and Wisconsin livestock markets; and (ii) determine if S. Heidelberg was circulating in Midwestern livestock markets.

Methods: Twenty-four livestock markets (14 from WI and 10 from OH) were enrolled in the study from April to November 2019. Market environments were sampled twice 3 months apart. State inspectors used boot swabs to sample the loading docks, main livestock thruway, and two pens used to hold surplus calves at each market. Swabs were shipped overnight to the Wisconsin Veterinary Diagnostic Laboratory for sample culture and serotyping. Whole genome sequencing was conducted at the Ohio Department of Agriculture.

Results: Sample-level Salmonella prevalence was 99.1% (111/112) in WI markets and 94.9% (75/79) in OH markets with all negative OH samples collected from the same market. Salmonella ser. Heidelberg was not recovered from any market; however, other serovars of public health relevance were identified including Newport, Agona and Typhimurium. Sequencing data revealed closely related strains across markets. For instance, a group of closely related Salmonella ser. Panama isolates was recovered from three WI markets, and the isolates clustered closely with isolates from retail meat, other livestock species, and human diagnostic labs.

Conclusion: These results suggest livestock markets play an important and under-researched role in the dissemination of pathogens between livestock populations.