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Zoonotic emergence requires spillover from animals to humans, hence animal-human interactions. A lot has been emphasized on human intrusion into wild habitats (e.g., deforestation, hunting) and the development of agricultural and farming activities. However, the highly human-modified urban and peri-urban socio-ecosystems are also of great concern due to huge amounts of pet, domesticated and wild animals (e.g., birds, rodents and bats) that live in very close contact to very dense human populations. This adds to the existence of wet wildlife markets, urban parks and wastelands, zoos and even labs, where spillover from wildlife to humans may also occur. Furthermore, cities are transport hubs that form hotspots of import/export of living resources including animals, thus potentially promoting rapid and wide-scale spread of reservoir and vectors, hence pathogens, as well as pathogen admixture through viral recombination or bacterial plasmid exchanges. Finally, cities are deeply modified environments where living organisms, including reservoirs, vectors and pathogens, undergo strong selective pressures, thus opening the gate to evolutionary novelties, hence potential new infectious threats. As such, we believe urban socio-ecosystems should be paid more attention in terms of drivers of zoonotic emergence in humans needing adapted surveillance and mitigation. Accordingly, we propose and discuss several avenues of research and examples of actions that could be tested or generalized (e.g., focus on hotspots of emergence risks like informal settlements, wet markets or transport hubs; development of participative surveillance programs; shift towards inter-sectoral academic courses; massive investment into education and community information) in order to operationalize effective zoonotic surveillance. We advocate that this would allow ones to add emergence-preventive and early warning to usual outbreaks response strategies, thus significantly improving our collective ability to prevent zoonotic emergence and subsequent pandemics.

Trypanosoma lewisi belongs to the so-called atypical trypanosomes that occasionally affect humans. It shares the same hosts and flea vector of other medically relevant pathogenic agents as Yersinia pestis, the agent of plague. Increasing knowledge on the population structure (reproductive mode, population size, dispersal) of this parasite thus represents a challenging but important issue. The use of polymorphic genetic markers, together with suitable population genetics tools, is a convenient way to achieve such objectives. To date, the population biology of T. lewisi is poorly known and, to our knowledge, no population genetics studies have ever been conducted. Here, we present the development of nine microsatellite markers of this species. We investigated their polymorphism in different countries from Africa and South-East Asia from DNAs extracted from the spleen of their rodent reservoirs (essentially rat species). Several amplification problems arose, especially with South-East Asian individuals. This led to retain only those individuals with complete genotypes (most of them originating from West Africa, notably Cotonou, Benin) to ensure an optimal estimate of heterozygosity. Our results pointed towards a mainly (at least 95-99%) clonal mode of propagation, a strong subdivision at the smallest scale available (i.e., urban neighborhoods, i.e. 0.250 km²), and a generation time most probably shorter than 4 months. In future studies, more extensive sampling at smaller geographic scales (i.e., households), within a one- or two-months window and with improved amplification conditions, should lead to a more precise picture of the fine population structure of this parasite.

Simple Summary: The ultrastructural study of spermatozoa in parasites such as the Digenea provides data that, like classical morphological features, biological data, and genetic characterization, can help achieve a better understanding of phylogenetic relationships at different taxonomic levels. In this context, the present study provides the first ultrastructural data of spermatozoa in a digenean species of the genus Artyfechinostomum. These results increase the database of ultrastructural spermatological characteristics within the group of Echinostomatoidea. The comparison of these features with the existing data allows us to establish a coherent model of the sperm cell for species belonging to this superfamily. The study of sperm characteristics has proven useful for elucidating interrelationships in several groups of Platyhelminthes, such as digeneans. Thus, in the present work, the ultrastructural organization of the mature spermatozoon of the digenean Artyfechinostomum malayanum (Echinostomatidae), a parasite of Rattus norvegicus (Rodentia: Muridae) from Dong Thap Province, Vietnam, was investigated for the first time using transmission electron microscopy. The male gamete of A. malayanum exhibits two axonemes of different lengths, showing the 9 + '1' pattern of the Trepaxonemata, a nucleus, two mitochondria, two lateral expansions, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies, and granules of glycogen. Thus, the mature spermatozoon follows a Type V sperm model proposed for digeneans. We also highlight some noteworthy characteristics in Echinostomatidae with possible phylogenetic implications, such as two lateral expansions in the anterior region of the spermatozoon and two mitochondria. [ABSTRACT FROM AUTHOR]

Simple Summary: Heterakis spumosa Schneider, 1886 is a parasite commonly found in rodents, primarily associated with the black rat Rattus rattus and the brown rat R. norvegicus, two global invasive rodent species, and the house mouse Mus musculus. This parasite originated probably from Asia, and has been reported in various rodent species, but molecular information from its putative native region is still lacking. Our sampling efforts across Southeast Asia allowed us to collect and analyze this species from two localities in Lao PDR and five localities in Thailand. Additionally, specimens from Europe were included in the analysis. All specimens were analyzed using mtCOI gene and nuclear ribosomal ITS1. Our findings revealed the presence of two distinct clades of H. spumosa, with no discernible association with hosts and geographical localities. Heterakis spumosa, a parasitic worm infecting rodents, is globally prevalent in black rats, brown rats, and house mice. It is hypothesized to originate from Asia due to its widespread presence in Southeast Asia in various Murinae. Previous molecular studies focused on European, African, and Japanese specimens, but none included samples from the putative native range. Rodents were collected between 2008 and 2015 across various localities in Southeast Asia and Europe, identified by morphology or genetic barcoding. Viscera were examined or preserved for later inspection. DNA was extracted from H. spumosa. PCR amplification targeting the mtCOI gene and ITS1 region was conducted in this study using newly designed primers (based on Heterakis reference sequences). PCR amplicons were subsequently sequenced and analyzed. In this study, the phylogenetic analysis using ITS1 sequences revealed that Heterakis samples from Thai and Laotian rodents belong to the species H. spumosa, exhibiting low genetic variation compared to samples from other regions. Genetic distance calculations using mtCOI sequences confirmed the marked distinction of H. spumosa from other Heterakis species. Our phylogenetic analyses using partial mtCOI and ITS1 sequences have significantly enhanced our comprehension of the genetic diversity and evolutionary history of the nematode H. spumosa. [ABSTRACT FROM AUTHOR]

The use of pesticides in agriculture has raised concerns due to their potential impact on human, animal and ecosystem health. Within a collaborative research framework, a study was co-constructed between researchers and local stakeholders in rural communities of Nan province (Thailand) to assess pesticide exposure levels. A total of 1,023 human serum samples were collected from volunteer participants. The level of exposure to organophosphate compounds showed that 12 (1.1%) and 134 (13%) individuals had hazardous or risky conditions, respectively. Generalized linear modeling revealed that age (older participants), chemical usage (spraying pesticide), habitat landscape characteristics (i.e., villages surrounded by orchard, forest, teak, rubber and rain-fed rice) and soil erosion appeared significant factors to explain the level of exposure. In addition, domestic animals (dogs and cattle) and wildlife (rodents and fishes) living in the vicinity were also assessed for their level of exposure. Applying the One Health principle helps understand pesticide exposure in people, domestic animals and wildlife by linking environmental characteristics at the local scale and thereby developing appropriate policies and regulations to be implemented. [ABSTRACT FROM AUTHOR]

Simple Summary: The chigger mite Neoschoengastia gallinarum (Hatori, 1920) is a parasite that feeds on the skin tissue of birds across multiple countries in Southeast and East Asia. In domestic chickens, heavy infestations with this mite can lead to skin irritation and damage to the carcass, reducing economic value. In this study, we collected N. gallinarum samples from wild birds of conservation concern and domestic chickens in Peninsular Malaysia and Thailand. Sequence analyses of three genes from the mites were compared across four Malaysian populations, one Thai population, and previously published sequences from southeastern China. A variety of methods were applied to classify these sequences and determine the extent of interbreeding between populations. These methods agreed in identifying three clusters of sequences by country of origin, although there was partial overlap between Thailand and China. The populations from Malaysia and Thailand appear to be reproductively isolated from one another and may represent distinct species with almost identical morphological features, except for leg length. Further studies are required to determine if these genetic dissimilarities are accompanied by distinct ecological, behavioural, or pathological differences in N. gallinarum in different regions of Asia. Neoschoengastia gallinarum is widely distributed in Asia, preferentially parasitising birds, and heavy infestations have clinical impacts on domestic fowl. In common with other trombiculid mites, the genetic diversity and potential variation in host preferences or pathology induced by N. gallinarum are poorly understood. This study aimed to unravel the geographical variation and population structure of N. gallinarum collected from galliform birds in Peninsular Malaysia and Thailand by inference from concatenated mitochondrial-encoded cytochrome c oxidase subunit I (COI), and nuclear-encoded internal transcribed spacer 2 (ITS2) and 18S ribosomal DNA gene sequences, including a comparison with previously published data from southeastern China. Our multi-locus sequence analysis revealed three monophyletic clades comprising (A) specimens from Peninsular Malaysia, (B) the samples from Thailand together with a minority of Chinese sequences, and (C) the majority of sequences from China. Similarly, most species delimitation approaches divided the specimens into three operational taxonomic units. Analysis of molecular variance revealed 96.41% genetic divergence between Malaysian and Thai populations, further supported by the absence of gene flow (Nm = 0.01). In conclusion, despite the two countries sharing a land border, populations of N. gallinarum from Peninsular Malaysia and Thailand appear to be genetically segregated and may represent distinct cryptic species. [ABSTRACT FROM AUTHOR]

The article discusses the increase in emerging and reemerging infectious diseases caused by viruses of animal origin, particularly RNA viruses. These viruses can cause serious illness and have high mortality rates in humans. The persistence of viruses in animal reservoirs and their pathogenicity in humans are not fully understood, but outbreaks are often influenced by human activities that disrupt ecosystems and increase contact between infected animals and humans. The article emphasizes the importance of interdisciplinary approaches, such as the "One Health" concept, in preventing new viral emergences. It also highlights the need for good surveillance of viruses in animals, techniques for identifying and diagnosing viruses, and ecological and anthropological approaches to assess the risk and consequences of epidemics. The article concludes that a global "One Health" approach is essential in the face of increasing emerging infectious diseases. [Extracted from the article]