Predicting current and future distributions of Malagasy bats: Implications for management of coronavirus spillover.

Global environmental change is known to be an important factor for the emergence of infectious diseases. Habitat modification of wild animal hosts favor pathogen spillover, particularly in degraded tropical ecosystems. We predicted the distribution of seven of eight bat families on Madagascar in response to climate change and urbanization, based on ecological niche modeling.

Role of individual and population heterogeneity in shaping dynamics of multi-pathogen shedding in an island endemic bat.

Understanding processes driving pathogen transmission in bats is critical to prevent spillovers and emergence events. Although substantial research has addressed this topic, few studies have directly examined shedding dynamics (as opposed to serological studies) and co-infection patterns using fine-scale spatio-temporal datasets. Here, based on the monitoring of 5,714 Reunion free-tailed bats (Mormopterus francoismoutoui) in 17 roosts over 24 months, we studied the co-shedding dynamics of paramyxoviruses (PMV) and Leptospira bacteria (LEPTO) in urine, and herpesviruses (HSV) in saliva.

Limited or No Serologic Evidence for Reunion Harrier (Circus maillardi) Exposure to Avian Influenza Virus, West Nile Virus, and Infectious Bronchitis Virus.

Using molecular testing and serology, we investigated Reunion Harrier (Circus maillardi) exposure to avian influenza virus, West Nile virus, and infectious bronchitis virus. We detected influenza virus antibodies in 2 of 73 birds and hypothesized that infection might occur by consumption of poultry.

High astrovirus diversity in an endemic bat species suggests multiple spillovers from synanthropic rodents and birds.

Beyond the role of bats as natural host reservoirs of infectious agents, the impact of viral spillover from other animal species to bats has been neglected. Given the limited virus-host specificity of astroviruses (AstVs) and their propensity for cross-species transmission, we hypothesized that AstVs could be transmitted within animal communities (rodents, birds, and bats) and that native endemic bats may be exposed to viruses hosted by other species. We investigated the presence of AstV RNA in 3,796 biological samples collected in Reunion Island from ( = 3421), an endemic free-tailed bat species, and also from small terrestrial mammals and birds: ( = 146), ( = 74), ( = 36), ( = 99), and ( = 20).

Astroviruses in terrestrial Malagasy mammals.

Small terrestrial mammals are major hosts of infectious agents responsible for zoonotic diseases. Astroviruses (AstVs)-the cause of non-bacterial gastroenteritis mainly affecting young children-have been detected in a wide array of mammalian and avian host species. However, understanding the factors that influence AstV infection within and across hosts is limited.

Tracking seabird migration in the tropical Indian Ocean reveals basin-scale conservation need.

Understanding marine predator distributions is an essential component of arresting their catastrophic declines. In temperate, polar, and upwelling seas, predictable oceanographic features can aggregate migratory predators, which benefit from site-based protection. In more oligotrophic tropical waters, however, it is unclear whether environmental conditions create similar multi-species hotspots.

Migratory patterns of two major influenza virus host species on tropical islands.

Animal migration is a major driver of infectious agent dispersal. Duck and seabird migrations, for instance, play a key role in the spatial transmission dynamics and gene flow of avian influenza viruses (AIV), worldwide. On tropical islands, brown and lesser noddies ( and ) may be important AIV hosts, but the lack of knowledge on their migratory behaviour limits our understanding of virus circulation in island networks.

A population in perpetual motion: Highly dynamic roosting behavior of a tropical island endemic bat.

Although island endemic bats are a source of considerable conservation concerns, their biology remains poorly known. Here, we studied the phenology and roosting behavior of a tropical island endemic species: the Reunion free-tailed bat (). This widespread and abundant species occupies various natural and anthropogenic environments such as caves and buildings.

Synchronicity of viral shedding in molossid bat maternity colonies.

Infection dynamics in vertebrates are driven by biological and ecological processes. For bats, population structure and reproductive cycles have major effects on RNA virus transmission. On Reunion Island, previous studies have shown that parturition of pregnant females and aggregation of juvenile Reunion free-tailed bats () are associated with major increase in the prevalence of bats shedding RNA viruses.

Bombali Ebolavirus in Mops condylurus Bats (Molossidae), Mozambique.

We detected Bombali ebolavirus RNA in 3 free-tailed bats (Mops condylurus, Molossidae) in Mozambique. Sequencing of the large protein gene revealed 98% identity with viruses previously detected in Sierra Leone, Kenya, and Guinea. Our findings further support the suspected role of Mops condylurus bats in maintaining Bombali ebolavirus.

Interaction between Old World fruit bats and humans: From large scale ecosystem services to zoonotic diseases.

The Old World tropical and subtropical frugivorous bat genus Rousettus (Pteropodidae) contains species with broad distributions, as well as those occurring in restricted geographical areas, particularly islands. Herein we review the role of Rousettus as a keystone species from a global "One Health" approach and related to ecosystem functioning, zoonotic disease and public health. Rousettus are efficient at dispersing seeds and pollinating flowers; their role in forest regeneration is related to their ability to fly considerable distances during nightly foraging bouts and their relatively small body size, which allows them to access fruits in forested areas with closed vegetation.

Spread of SARS-CoV-2 Variants on Réunion Island, France, 2021.

In January 2021, after detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, genomic surveillance was established on Réunion Island to track the introduction and spread of SARS-CoV-2 lineages and variants of concern. This system identified 22 SARS-CoV-2 lineages, 71% of which were attributed to the Beta variant.

Seasonality of coronavirus shedding in tropical bats.

Anticipating cross-species transmission of zoonotic diseases requires an understanding of pathogen infection dynamics within natural reservoir hosts. Although bats might be a source of coronaviruses (CoVs) for humans, the drivers of infection dynamics in bat populations have received limited attention. We conducted a fine-scale 2-year longitudinal study of CoV infection dynamics in the largest colony of Reunion free-tailed bats (), a tropical insectivorous species.

Investigation of astrovirus, coronavirus and paramyxovirus co-infections in bats in the western Indian Ocean.

Co-infections have a key role in virus transmission in wild reservoir hosts. We investigated the simultaneous presence of astroviruses, coronaviruses, and paramyxoviruses in bats from Madagascar, Mayotte, Mozambique, and Reunion Island. A total of 871 samples from 28 bat species representing 8 families were tested by polymerase chain reactions (PCRs) targeting the RNA-dependent RNA-polymerase genes.

Astrovirus in Reunion Free-Tailed Bat ().

Astroviruses (AstVs) are RNA viruses infecting a large diversity of avian and mammalian species, including bats, livestock, and humans. We investigated AstV infection in a free-tailed bat species, , endemic to Reunion Island. A total of 380 guano samples were collected in a maternity colony during 38 different sampling sessions, from 21 June 2016 to 4 September 2018.

Analysis of partial sequences of the RNA-dependent RNA polymerase gene as a tool for genus and subgenus classification of coronaviruses.

The recent reclassification of the , and the introduction of multiple new taxonomic categories including both subfamilies and subgenera for coronaviruses (family subfamily ), represents a major shift in how official classifications are used to designate specific viral lineages. While the newly defined subgenera provide much-needed standardization for commonly cited viruses of public health importance, no method has been proposed for the assignment of subgenus based on partial sequence data, or for sequences that are divergent from the designated holotype reference genomes. Here, we describe the genetic variation of a 387 nt region of the coronavirus RNA-dependent RNA polymerase (RdRp), which is one of the most used partial sequence loci for both detection and classification of coronaviruses in molecular epidemiology.

Impact of Annual Bacterial Epizootics on Albatross Population on a Remote Island.

The reduced species richness typical of oceanic islands provides an interesting environmental setup to examine in natura the epidemiological dynamics of infectious agents with potential implications for public health and/or conservation. On Amsterdam Island (Indian Ocean), recurrent die-offs of Indian yellow-nosed albatross (Thalassarche carteri) nestlings have been attributed to avian cholera, caused by the bacterium Pasteurella multocida. In order to help implementing efficient measures for the control of this disease, it is critical to better understand the local epidemiology of P.

Bat coronavirus phylogeography in the Western Indian Ocean.

Bats provide key ecosystem services such as crop pest regulation, pollination, seed dispersal, and soil fertilization. Bats are also major hosts for biological agents responsible for zoonoses, such as coronaviruses (CoVs). The islands of the Western Indian Ocean are identified as a major biodiversity hotspot, with more than 50 bat species.

Phylogeography and Antigenic Diversity of Low-Pathogenic Avian Influenza H13 and H16 Viruses.

Low-pathogenic avian influenza viruses (LPAIVs) are genetically highly variable and have diversified into multiple evolutionary lineages that are primarily associated with wild-bird reservoirs. Antigenic variation has been described for mammalian influenza viruses and for highly pathogenic avian influenza viruses that circulate in poultry, but much less is known about antigenic variation of LPAIVs. In this study, we focused on H13 and H16 LPAIVs that circulate globally in gulls.

Parasites of seabirds: A survey of effects and ecological implications.

Parasites are ubiquitous in the environment, and can cause negative effects in their host species. Importantly, seabirds can be long-lived and cross multiple continents within a single annual cycle, thus their exposure to parasites may be greater than other taxa. With changing climatic conditions expected to influence parasite distribution and abundance, understanding current level of infection, transmission pathways and population-level impacts are integral aspects for predicting ecosystem changes, and how climate change will affect seabird species.

Bat Astrovirus in Mozambique.

Astroviruses (AstVs) are responsible for infection of a large diversity of mammalian and avian species, including bats, aquatic birds, livestock and humans. We investigated AstVs circulation in bats in Mozambique and Mayotte, a small island in the Comoros Archipelago located between east Africa and Madagascar. Biological material was collected from 338 bats and tested for the presence of the AstV RNA-dependent RNA-polymerase gene with a pan-AstV semi-nested polymerase chain reaction assay.