Ecohealth最新文献

Anthropogenic pollution may disrupt wildlife immune function and increase susceptibility to, and ability to withstand, infection. Of particular concern is avian influenza virus (AIV), which in its low-pathogenic form is endemic in many wild bird populations, notably waterfowl and shorebirds, and in its high-pathogenic form poses a threat to wildlife, livestock and people. Many pollutants have immunomodulative properties, yet little is known about how these pollutants affect AIV infection risk specifically. We examined concentrations of known immunomodulatory compounds, per- and polyfluoroalkyl substances (PFASs), and assessed their influence on AIV infection in three reservoir species, red-necked stint (Calidris ruficollis, n = 121), pacific black duck (Anas superciliosa, n = 57) and grey teal (Anas gracilis, n = 62). Using data on viral prevalence (cloacal/oropharyngeal swabs) and seroprevalence (AIV anti-nucleoprotein antibodies), we found no significant effect of PFASs pollution (total PFASs < 0.01-470 ng/g in red-necked stint, < 0.01-600 ng/g in pacific black duck and 0.3-200 ng/g in grey teal) on infection status in our three species. This may be due to relatively low pollutant concentrations, but we cannot rule out possible population culling through a synergy of pollution and infection stressors. We therefore recommend further studies on infection incidence in more polluted populations or species.

Sand flies are a group of insects (Diptera, Psychodidae, Phlebotominae) in which some species may transmit agents of leishmaniasis. This study aimed to analyze the sand fly fauna in urban parks in Rio Branco, capital of Acre state, addressing its diversity, infection by Leishmania, and food sources in sand fly females. The sand flies were collected with CDC-type automatic light traps installed in three urban parks in Rio Branco: Captain Ciríaco, Horto Florestal and Chico Mendes. For comparison analysis of species richness and diversity between the parks, we analyzed rarefaction and prediction curves. For detection of Leishmania spp., molecular tests were performed by polymerase chain reaction (PCR) using ITS1 as a marker, followed by genetic sequencing. Identification of the blood meal source in engorged females was performed by PCR using a fragment of the cytochrome b gene (cyt b), followed by sequencing and phylogenetic analysis. A total of 2,672 specimens were collected, distributed in 14 genera and 35 species. Of these, Nyssomyia antunesi and Evandromyia walkeri predominated, and important proven and suspected vectors were also found. Horto Florestal was the park with the greatest diversity, richness, and evenness of species, while the Captain Ciríaco presented the lowest diversity and richness. A female of Ny. antunesi was PCR-positive for Leishmania guyanensis. Human blood was the most frequent food source detected, mainly in Ev. walkeri and Ny. antunesi. This research showed that the studied parks of Rio Branco can act as foci for the maintenance of Leishmania, and people who frequent these urban areas may be in risk for contracting leishmaniasis.

The fungal pathogen Batrachochytrium salamandrivorans (Bsal) is one of two species (the other, B. dendrobatidis/Bd) that cause amphibian chytridiomycosis, an emerging infectious disease that has been indicated in the declines of hundreds of amphibian species worldwide. While Bd has been near globally distributed for decades, Bsal is a more recently emerged pathogen, having been identified just over a decade ago with current impacts localized to salamandrids in parts of Europe. However, because there is concern that Bsal will cause widespread declines if introduced to naïve regions-such as the Americas where the greatest diversity of salamandrids exist-it is imperative that widespread monitoring strategies be implemented to mitigate the spread of Bsal. As standard molecular diagnostic approaches-such as qPCR-tend to be expensive, time-consuming, or require specialized instrumentation and training, we have developed a simplified, rapid, CRISPR-based approach for Bsal-DNA detection. Here, we demonstrate this approach-termed FINDeM (Field-deployable, Isothermal, Nucleotide-based Detection Method)-and show that it can detect clinically relevant concentrations of Bsal DNA in under an hour using only inexpensive supplies and body-heat inducible reactions. Further, we highlight drawbacks and limitations associated with FINDeM-such as decreased DNA extraction yields and detection sensitivity when compared to more traditional approaches-and provide suggestions for additional development and future application of this method.

Habitat degradation induced by human activities can exacerbate the spread of wildlife disease and could hinder the recovery of imperiled species. The endangered green turtle Chelonia mydas is impacted worldwide by fibropapillomatosis (FP), a neoplastic infectious disease likely triggered by the Scutavirus chelonidalpha5 with coastal anthropogenic stressors acting as cofactors in disease development. Here, we studied fibropapillomatosis dynamics and its demographic consequences using an 11-year capture-mark-recapture dataset in Anse du Bourg d'Arlet/Chaudière (ABAC) and Grande Anse d'Arlet (GA), two juvenile green turtle foraging grounds in Martinique, French West Indies. Afflicted turtles had similar mortality and permanent emigration rates to the non-afflicted ones. Fibropapillomatosis was commonly observed in large individuals and disease recovery may take several years. Consequently, permanent emigration before full recovery from the disease is suspected and might affect the developmental migration success. Additionally, the results revealed that the FP had higher prevalence and severity, and progressed two times faster in ABAC than in GA despite the proximity (< 2 km) and the similarity of the two foraging grounds. The reasons for these differences remain unidentified. Locally, further studies should be focused on the determination of the external and internal cofactors related to the observed FP dynamics. Finally, the investigations should be extended at a global regional scale to determine potential deleterious effect of the FP on the adult life-stage. These perspectives improves upon our overall understanding on the interplay between wildlife diseases, hosts and environmental factors.

Land-use change and increased human-livestock-wildlife interactions have generated numerous possibilities for viral spillover, demanding enhanced surveillance in biodiverse regions. We investigated adenovirus diversity in small mammals, an understudied host taxon, from a forest-plantation mosaic in the Western Ghats biodiversity hotspot. We observed high prevalence (up to 39.39%) and identified five lineages of adenoviruses with unique mutations in the dominant small mammal species, Rattus satarae. These lineages significantly differed from other known murine adenoviruses (p-distance > 25%), indicating the likelihood of novel adenoviruses in this endemic small mammal and suggesting potential for unexplored DNA virus diversity in the region.

Our aim was to investigate respiratory viruses circulating in animals from the urban Atlantic Forest, which is located in the most densely populated area near Rio de Janeiro in Brazil. This study focused on the detection of Influenza A viruses and diverse coronaviruses, including SARS-CoV-2, in domestic and wild animals, including bats, nonhuman primates, rodents, and marsupials. From August 2020 to September 2022, biological samples were collected from a total of 72 pets, 66 primates, 20 rodents, 36 marsupials, and 390 bats. Samples were tested using RT-PCR for Influenza A and coronaviruses, and positive samples were sequenced. When blood samples were available, they were tested for SARS-CoV-2 antibodies. All terrestrial animals were negative for evidence of infection with SARS-CoV-2 and Influenza A viruses. However, samples from 17 phyllostomid bats, including Great fruit-eating bat (Artibeus lituratus), Silky short-tailed bat (Carollia brevicauda), Seba's short-tailed bat (Carollia perspicillata), Common big-eared bat (Micronycteris microtis), Greater spear-nosed bat (Phyllostomus hastatus), White-lined broad-nosed bat (Platyrrhinus lineatus), Little yellow-shouldered bat (Sturnira lilium), Greater round-eared bat (Tonatia bidens), and Common vampire bat (Desmodus rotundus), were positive for bat coronaviruses classified as Alphacoronavirus. Our study adds new information on the occurrence of coronaviruses in bats and contributes to a long-term program of Influenza surveillance. Developing active surveillance for viruses in wildlife species, as implemented in this study, is crucial for understanding zoonotic risks and preventing future global pandemics.

The black rat Rattus rattus is an exotic and synanthropic rodent prominent in Brazil and with high adaptation to urban areas. The species have an omnivorous diet feed on human food resources, potentially becoming infected and spreading infectious agents that cause zoonoses such as leptospirosis, leishmaniosis, Chagas disease, and toxoplasmosis, which are significant public health concerns in the country. We analyzed the epidemiologic profile of R. rattus infected with these agents using molecular diagnostics in the Olivença district, known for its tourism potential, in Ilhéus, Bahia, Brazil. Of 140 animals, the prevalence rates were 30.0% (42) for Leptospira spp., 3.57% (5) for Leishmania spp., and 0.71% (1) for both Trypanosoma cruzi and Toxoplasma gondii. One animal was co-infected with Leptospira interrogans and T. gondii and another with Leptospira spp. and L. (L.) infantum. The high prevalence of Leptospira spp.-infected animals suggests rodents may be a significant infection source for local hosts, as L. interrogans is most common in rodents and humans. Rodents likely become infected through ingestion or contact with contaminated water bodies or food, particularly for Leptospira spp. and T. gondii. It is worth noting that the studied area has beach, high foot traffic, and popular tourist restaurants, which implies the presence of food waste and litter in the environment. This study found synanthropic rodents infected with significant zoonotic agents, indicating their presence in the environment. These agents may not impact the rodent population but can cause serious diseases in humans and other domestic and wild animal species.

Chytridiomycosis is a wildlife disease that has caused significant declines in amphibian populations and species extinctions worldwide. Asia, where the causal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamndrivorans (Bsal) originated, has not witnessed mass die-offs. It is hypothesized that Asian amphibians may have evolved immunity to clinical Batrachochytrium infection, but this has not been explored in depth due to limited knowledge of endemic lineages and infection patterns. We investigated Bd's genetic diversity and infection patterns in south China's Guangxi region using the internal transcribed spacer (ITS) marker and nested PCR. Across the 17 forest sites studied (N = 1088 individuals; 1012 adults and 76 tadpoles), the overall prevalence of Bd infection was 4.74% in adult individuals and 5.26% in tadpoles. We found seven new haplotypes, four of which were closely related to the BdASIA-1 lineage from South Korea. The most prevalent haplotype (genetically similar to BdASIA-3) was found in 11 out of 15 infected species, including a salamander with non-lethal skin lesions. A generalized linear model of our environmental data indicates that Bd infection is correlated with mean temperature of the warmest quarter and elevation, with higher infection prevalence associated with lower temperature and relatively higher elevation in southern China. Our findings suggest significant undiscovered genetic diversity of Asian Bd lineages in this region. Longer-term studies are required to further investigate Bd diversity, prevalence, seasonality, and impact on native species and populations in Southern China and across the region of origin in Asia.

One Health is an integrative approach aiming to achieve optimal health outcomes by recognizing the interconnection between humans, animals, and the environment. This study explores the understanding, perspectives, hurdles, and implications of intersectoral collaboration within Pakistan's human health system, focusing on One Health principles. A qualitative phenomenological approach was employed, involving 17 key informant interviews with purposively selected stakeholders from public health, agriculture, veterinary medicine, agriculture and environmental science. Thematic analysis was conducted to generate themes. There are varying levels of understanding and awareness of One Health principles, with some showing strong comprehension; while, others showed significant knowledge gaps. Barriers such as institutional silos, fragmented policies, and limited resources were identified for operationalizing the intersectoral collaboration requisite for One Health. Successful collaborative initiatives demonstrated the potential of One Health in achieving significant health outcomes. Meaningful engagement of stakeholders and capacity building emerged as critical needs, with recommendations for continuous in-service training centered on One Health principles. Unified policies, strengthened institutional support, and continuous capacity building will enhance One Health agenda. Overarching governance and decentralized decision-making processes can promote consistency and cooperation across sectors for advancing One Health initiatives and effectively addressing complex human health challenges in Pakistan.