Molecular survey of Zika virus in the animal-human interface in traditional farming.

Backyard animal husbandry is common in rural communities in developing countries and, given the conditions in which it occurs, it can increase the risk of disease transmission, such as arboviruses. To determine the presence of the Zika virus (ZIKV) and abundance of its arthropod vectors we evaluated the socioeconomic implications involved in its transmission in two highly vulnerable Mayan communities in the state of Yucatan that practice backyard farming. An analytical cross-sectional study was carried out throughout 2016 to understand socioeconomic variables and seasonal patterns in mosquito populations. We selected 20 households from each community. Social exclusion indicators were analyzed, human and domestic animals were sampled, and mosquitoes were collected and identified. Four out of eight indicators of social exclusion were higher than the reported national averages. We captured 5,825 mosquitoes from 16 species being Culex quinquefasciatus and Aedes aegypti the most abundant. The presence of chickens and human overcrowding in dwellings were the most significant factors (P = 0.026) associated with the presence of Ae. aegypti. Septic tanks (odds ratio = 6.64) and chickens (odds ratio = 27.41) in backyards were the main risk factors associated with the presence of immature states of Ae. aegypti in both communities. Molecular analysis to detect ZIKV was performed in blood samples from 416 humans, 1,068 backyard animals and 381 mosquito pools. Eighteen humans and 10 pig pools tested positive for ZIKV. Forty-three mosquito pools tested positive for flavivirus. Ten of the 43 pools of positive mosquitoes were sequenced, corresponding 3/10 to ZIKV and 1/10 to Dengue virus type 2. The findings obtained indicate the continuous circulation of Flavivirus (including ZIKV) in backyard environments in vulnerable communities, highlighting the importance of studying their transmission and maintenance in these systems, due that backyard animal husbandry is a common practice in these vulnerable communities with limited access to health services.

Spatial distribution patterns of tick community structure in sympatric jaguars (Panthera onca) and pumas (Puma concolor) from three ecoregions in Mexico.

We examined tick communities on wild felid hosts in three ecoregions of Mexico. We collected 186 ticks of 7 species from 10 pumas (Puma concolor) and 9 jaguars (Panthera onca). Tick community composition varied across the ecoregions, and across host species within each region. Overall, Ixodes affinis, Amblyomma ovale, and Amblyomma tenellum were the most abundant species; however, only the latter two ticks were distributed across all three ecoregions, while I. affinis, along with Ixodes spinipalpis, Amblyomma inornatum, and Amblyomma parvum were restricted to more limited geographical regions. Ixodes affinis occurred strictly in southern tropical rainforest ecoregions and was significantly more abundant in Selva Lacandona compared with the Yucatán Peninsula. Amblyomma ovale was significantly more common in the tropical dry forest in the Pacific coastal ecoregion. Amblyomma tenellum abundance tended to be higher on jaguars, while I. affinis abundance was higher on pumas. Regional distribution patterns of some tick species (e.g., I. affinis and I. spinipalpis) may be determined by off-host environmental conditions rather than host factors. In contrast, at the local scale, occurrence and abundance of some tick species (e.g., A. tenellum, A. ovale and Rhipicephalus microplus) might be driven by ecological-host factors, such as habitat use or predator-prey relationships.

A database of common vampire bat reports.

The common vampire bat (Desmodus rotundus) is a sanguivorous (i.e., blood-eating) bat species distributed in the Americas from northern Mexico southwards to central Chile and Argentina. Desmodus rotundus is one of only three mammal species known to feed exclusively on blood, mainly from domestic mammals, although large wildlife and occasionally humans can also serve as a food source. Blood feeding makes D. rotundus an effective transmissor of pathogens to its prey. Consequently, this species is a common target of culling efforts by various individuals and organizations. Nevertheless, little is known about the historical distribution of D. rotundus. Detailed occurrence data are critical for the accurate assessment of past and current distributions of D. rotundus as part of ecological, biogeographical, and epidemiological research. This article presents a dataset of D. rotundus historical occurrence reports, including >39,000 locality reports across the Americas to facilitate the development of spatiotemporal studies of the species. Data are available at https://doi.org/10.6084/m9.figshare.15025296 .

Beyond words: From jaguar population trends to conservation and public policy in Mexico.

The jaguar (Panthera onca) is one of the most threatened carnivores in the Americas. Despite a long history of research on this charismatic species, to date there have been few systematic efforts to assess its population size and status in most countries across its distribution range. We present here the results of the two National Jaguar Surveys for Mexico, the first national censuses in any country within the species distribution. We estimated jaguar densities from field data collected at 13 localities in 2008-2010 (2010 hereafter) and 11 localities in 2016-2018 (2018 hereafter). We used the 2010 census results as the basis to develop a National Jaguar Conservation Strategy that identified critical issues for jaguar conservation in Mexico. We worked with the Mexican government to implement the conservation strategy and then evaluated its effectivity. To compare the 2010 and 2018 results, we estimated the amount of jaguar-suitable habitat in the entire country based on an ecological niche model for both periods. Suitable jaguar habitat covered ~267,063 km2 (13.9% of the country's territory) in 2010 and ~ 288,890 km2 (~14.8% of the country's territory) in 2018. Using the most conservative density values for each priority region, we estimated jaguar densities for both the high and low suitable habitats. The total jaguar population was estimated in ~4,000 individuals for 2010 census and ~4,800 for the 2018 census. The Yucatan Peninsula was the region with the largest population, around 2000 jaguars, in both censuses. Our promising results indicate that the actions we proposed in the National Jaguar Conservation Strategy, some of which have been implemented working together with the Federal Government, other NGO's, and land owners, are improving jaguar conservation in Mexico. The continuation of surveys and monitoring programs of the jaguar populations in Mexico will provide accurate information to design and implement effective, science-based conservation measures to try to ensure that robust jaguar populations remain a permanent fixture of Mexico's natural heritage.

Molecular identification and phylogenetic characterization of influenza A virus at a wildlife-livestock interface in Mexico.

Influenza A virus (IAV) outbreaks constitute a constant threat to public health and pose a remarkable impact on socio-economic systems worldwide. Interactions between wild and domestic birds, humans and swine can lead to spillover events. Backyard livestock systems in proximity to wetlands represent high-risk areas for viral spread. However, some gaps remain in our knowledge of IAV transmission at the wildlife-livestock interface in Mexico. Hence, the study aimed at molecular identification and phylogenetic characterization of IAV in the wild duck-backyard livestock interface at a wetland of Mexico. A total of 875 animals were tested by real-time RT-PCR (qRT-PCR). We detected IAV in 3.68% of the wild ducks sampled during the winter season 2016-2017. Nonetheless, the samples obtained from backyard poultry and swine tested negative. The highest IAV frequency (11.10%) was found in the Mexican duck (Anas diazi). Subtypes H1N1, H3N2 and H5N2 were detected. Phylogenetic analyses revealed that IAV detected in wild birds from the Lerma wetlands was mostly related to swine and poultry IAV strains previously isolated in the United States and Mexico. Except, the UIFMVZ377/H5N2 related to North American waterbirds. In conclusion, the co-circulation of three IAV subtypes in wild ducks close to backyard farms in Mexico, as well as the local identification of influenza viruses genetically related to Mexican and North American IAV strains, highlights the importance of the Lerma marshes for influenza surveillance given the close interaction among wild birds, poultry, pigs and humans.

Gastrointestinal helminths of waterfowl (Anatidae: Anatinae) in the Lerma marshes of central Mexico: Some pathological aspects.

Gastrointestinal helminths of migratory waterfowl can cause several lesions that may affect the health and even the survival of their hosts. As part of an ongoing project that aims to inventory the helminth species that infect this group of birds, as well as the histopathologic lesion they cause, a total of 200 digestive tracts of nine species of anatid birds (Spatula discors, S. cyanoptera, S. clypeata, Mareca strepera, M. americana, Anas crecca, A. acuta, A. platyrhynchos diazi, and Oxyura jamaicensis) were collected in the Atarasquillo marsh of Lerma, in the State of Mexico. The present work had a twofold goal: to determine the taxonomic identity of the helminth species present in waterfowl as well as their infection levels and to describe the lesions caused by gastrointestinal parasites in migratory and resident anatids in Atarasquillo marsh, State of Mexico. The specimens were examined using routine helminthological and histopathological techniques. A total of 23 helminths were identified: six trematodes (Zygocotyle lunata, Notocotylus triserialis, Notocotylus seineti, Psilochasmus oxyurus, Australapatemon burti and Cotylurus magniacetabulus), four cestodes (Cloacotaenia megalops, Fimbriaria fasciolaris, Gatrotaenia cygni and Diorchis sp.), eleven nematodes (Echinuria uncinata, Tetrameres sp., Tetrameres fissispina, Hystrichis sp., Streptocara sp., Amidostomum sp., Epomidiostomum uncinatum, Capillaria sp., Capillaria contorta, Ascaridia sp. and Heterakis sp.) and two acanthocephalans (Pseudocorynosoma constrictum and Filicollis sp.). At the proventriculus level, Echinuria uncinata caused the most severe lesions; in the gizzard, Amidostomum sp. and E. uncinatum produced hemorrhages and necrosis. Finally, the main lesions found in the intestine (necrosis, heterophilic granulomas and the formation of lumps on the serosa) were caused by the implantation of the acanthocephalans' proboscis. Eleven species of gastrointestinal helminths found are new records for the Lerma marshes, as well as the first record in Mexico of the nematode Capillaria contorta and the acanthocephalan Filicollis sp.

Phylogenetic characterization of a reassortant H5N2 influenza A virus from a resident Mexican duck (Anas diazi).

Congregation of different migratory and resident bird species on aquatic ecosystems during winter migration increases contact rates and enhances influenza A virus (IAV) transmission. However, scarce research has been focused on the resident bird's contribution to the viral ecology at a local scale. The Mexican duck (Anas diazi) is an endemic endangered anatid from Mexico. This resident species shares aquatic habitats with migratory birds in the wetlands of Central Mexico. Therefore, here we describe the phylogenetic analysis of an IAV (A/Mexican duck/EstadodeMexico; Lerma/UIFMVZ377/2016(H5N2)) isolated in this species, during spatiotemporal concurrence with migratory anatids in the winter season. All eight gene sequences were obtained by nextgeneration sequencing. Maximum Likelihood trees were constructed using MEGA-X, with General Time Reversible + Invariant (GTR+I), Subtree Pruning and Regrafting (SPR) heuristic method, and 1000 bootstrap replicates. Similarities with six different IAV subtypes were observed through a BLAST search: H6N5, H7N7, H5N2, H4N6, H9N2, and H11N9, detected in wild ducks during 2015 in the Pacific, Central and Mississippi flyways stop sites across the United States of America and Canada. The molecular identification of this reassortant H5N2 IAV highlights the importance of resident species as a reservoir host and its potential participation in the maintenance and transmission of IAV in wetlands surrounded by rural areas.

Detection and Molecular Identification of Sarcocystis rileyi (Apicomplexa: Sarcocystidae) From a Northern Shoveler (Anas clypeata) in Mexico.

We detected macroscopic Sarcocystis cysts in a Northern Shoveler ( Anas clypeata ) in the Lerma Marshes, State of Mexico, Mexico in February 2014. The 5.0×2.0-mm macrocysts in the breast muscle of the duck were ovoid and yellow. Using an optical microscope, we saw parasitic forms of a Sarcocystis sp. among muscular fibers; the cysts measured 3.5×1.1 mm. The external wall had a smooth surface and the internal wall had a spongy texture. We identified the macrocysts as Sarcocystis rileyi according to sequences of the 18S rRNA gene, 28S rRNA gene, and ITS-1 region. Sarcocystosis should be considered in similar assessments in wild waterfowl in Mexico. Awareness of S. rileyi among anatids in the Lerma Marshes will contribute to more-effective conservation and management actions.