Biology subjects

Daszak, P.

Publications and source records attributed to Daszak, P..

8 recordsLinked to original sources

bioRxiv2024

A global-scale dataset of bat viral detection suggests that pregnancy reduces viral shedding

Understanding viral infection dynamics in wildlife hosts can help forecast zoonotic pathogen spillover and human disease risk. Bats are particularly important reservoirs of zoonotic viruses, including some of major public health concern such as Nipah virus, Hendra virus, and SARS-related coronaviruses. Previous work has suggested that metapopulation dynamics, seasonal reproductive patterns, and other bat life history characteristics might explain temporal variation in spillover of bat-associated viruses into people. Here, we analyze viral dynamics in free-ranging bat hosts, leveraging a multi-year, global-scale viral detection dataset that spans eight viral families and 96 bat species from 14 countries. We fit hierarchical Bayesian models that explicitly control for important sources of variation, including geographic region, specimen type, and testing protocols, while estimating the influence of reproductive status on viral detection in female bats. Our models revealed that late pregnancy had a negative effect on viral shedding across multiple data subsets, while lactation had a weaker influence that was inconsistent across data subsets. These results are unusual for mammalian hosts, but given recent findings that bats may have high individual viral loads and population-level prevalence due to dampening of antiviral immunity, we propose that it would be evolutionarily advantageous for pregnancy to either not further reduce immunity or actually increase the immune response, reducing viral load, shedding, and risk of fetal infection. This novel hypothesis would be valuable to test given its potential to help monitor, predict, and manage viral spillover risk from bats.

ecology↗

bioRxiv2022

Identification and genetic characterization of MERS-related coronavirus isolated from Nathusius' pipistrelle (Pipistrellus nathusii) near Zvenigorod (Moscow region, Russia)

The majority of emerging infectious diseases are caused by pathogens with zoonotic origin, and most of these emerged from wildlife reservoirs. Bats are diverse, and widely distributed globally, and are the known or hypothesized reservoir of a series of emerging zoonotic viruses. Analyses of bat viromes have been used to identify novel viruses with potential to cause human infection. We characterized the fecal virome of 26 samples collected from six bat species captured during 2015 in Moscow Region. Of these 13/26 (50%) samples were found to be coronavirus positive. We sequenced and assembled the complete genome of a novel MERS-related Betacoronavirus from Pipistrellus nathusii, named MOW-BatCoV strain 15-22. Of P. nathusii 3/6 samples were found to carriers of MOW-BatCoVs. The genome organization of MOW-BatCoV/15-22 was identical to other known MERS-related coronaviruses. Phylogenetic analysis of whole genomes suggests that MOW-BatCoV/15-22 falls into a distinct subclade closely related to human and camel MERS-CoV, and MERS-related CoVs from the bat species Hypsugo savii and Pipistrellus kuhlii (from Italy) and Neoromicia capensis (from South Africa). Unexpectedly, phylogenetic analysis of the novel MOW-BatCoV 15-22 spike genes showed the closest similarity to a bat CoV Neoromicia/5038 and CoVs from Erinaceus europaeus (the European hedgehog), thus MOW-BatCoV could arise as result of recombination between ancestral viruses of bats and hedgehogs. Computer molecular docking analysis of MOW-BatCoV 15-22 Spike glycoprotein binding to DPP4 receptors of different mammal species predicted highest binding interaction with DPP4 of the bat M. brandtii (docking score -320.15) and the European hedgehog, E. europaeus (docking score -294.51). Hedgehogs are widely kept as pets, and are commonly found in areas of human habitation. Our finding of a novel bat-CoV likely able to infect hedgehogs suggests the potential for hedgehogs to act as intermediate hosts for bat-CoVs between bats and humans.

genomics↗

bioRxiv2021

Nipah virus detection at bat roosts following spillover events in Bangladesh, 2012-2019

Knowledge of the dynamics and genetic diversity of Nipah virus circulating in bats and at the human-animal interface is limited by current sampling efforts, which produce few detections of viral RNA. We report on a series of investigations at bat roosts identified near human Nipah cases in Bangladesh between 2012 and 2019. Pooled bat urine samples were collected from 23 roosts; seven roosts (30%) had at least one sample with Nipah RNA detected from the first visit. In subsequent visits to these seven roosts, RNA was detected in bat urine up to 52 days after the presumed exposure of the human case, although the probability of detection declined rapidly with time. These results suggest that rapidly deployed investigations of Nipah virus shedding from bat roosts near human cases could increase the success of viral sequencing compared to background surveillance and enhance our understanding of Nipah virus ecology and evolution.

ecology↗

bioRxiv2021

Taxonomic classification methods reveal a new subgenus in the paramyxovirus subfamily Orthoparamyxovirinae

As part of a broad One Health surveillance effort to detect novel viruses in wildlife and people, we report several paramyxoviruses sequenced primarily from bats during 2013 and 2014 in Brazil and Malaysia, including seven from which we recovered full-length genomes. Of these, six represent the first full-length paramyxovirus genomes sequenced from the Americas, including two sequences which are the first full-length bat morbillivirus genomes published to date. Our findings add to the vast number of viral sequences in public repositories that have been increasing considerably in recent years due to the rising accessibility of metagenomics. Taxonomic classification of these sequences in the absence of phenotypic data has been a significant challenge, particularly in the paramyxovirus subfamily Orthoparamyxovirinae, where the rate of discovery of novel sequences has been substantial. Using pairwise amino acid sequence classification (PASC), we describe a novel genus within this subfamily tentatively named Jeishaanvirus, which we propose should include as subgenera Jeilongvirus, Shaanvirus, and a novel South American subgenus Cadivirus. We also highlight inconsistencies in the classification of Tupaia virus and Mojiang virus using the same demarcation criteria and show that members of the proposed subgenus Shaanvirus are paraphyletic. Importantly, this study underscores the critical importance of sequence length in PASC analysis as well as the importance of biological characteristics such as genome organization in the taxonomic classification of viral sequences.

microbiology↗

bioRxiv2021

Zoonotic potential of a novel bat morbillivirus

Morbilliviruses are amongst the most contagious viral pathogens that infect mammals. Metagenomic surveys have identified numerous morbillivirus sequences in bats, but no full-length authentic morbillivirus has been isolated or characterized from bats. Here we detail the discovery of full-length Myotis Bat Morbillivirus (MBaMV) from a bat surveillance program in Brazil. After determining that MBaMV utilizes bat CD150 but not human CD150 as an entry receptor, we generated an infectious clone of MBaMV using reverse genetics. MBaMV exhibited features consistent with other morbilliviruses, including pleomorphic virions, P-editing and the rule-of-six. MBaMV replicated well in human epithelial cell lines in a nectin-4 dependent manner. Surprisingly, MBaMV was able to infect human macrophages in a CD150-independent manner. However, MBaMV was restricted by cross-neutralizing human sera and did not evade the human innate immune system, indicating that while zoonotic spillover into humans may be possible, MBaMV replication in humans would likely be restricted.

microbiology↗

bioRxiv2020

No evidence of coronaviruses or other potentially zoonotic viruses in Sunda pangolins (Manis javanica) entering the wildlife trade via Malaysia.

The legal and illegal trade in wildlife for food, medicine and other products is a globally significant threat to biodiversity that is also responsible for the emergence of pathogens that threaten human and livestock health and our global economy. Trade in wildlife likely played a role in the origin of COVID-19, and viruses closely related to SARS-CoV-2 have been identified in bats and pangolins, both traded widely. To investigate the possible role of pangolins as a source of potential zoonoses, we collected throat and rectal swabs from 334 Sunda pangolins (Manis javanica) confiscated in Peninsular Malaysia and Sabah between August 2009 and March 2019. Total nucleic acid was extracted for viral molecular screening using conventional PCR protocols used to routinely identify known and novel viruses in extensive prior sampling (>50,000 mammals). No sample yielded a positive PCR result for any of the targeted viral families - Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae and Paramyxoviridae. In light of recent reports of coronaviruses including a SARS-CoV-2 related virus in Sunda pangolins in China, the lack of any coronavirus detection in our upstream market chain samples suggests that these detections in downstream animals more plausibly reflect exposure to infected humans, wildlife or other animals within the wildlife trade network. While confirmatory serologic studies are needed, it is likely that Sunda pangolins are incidental hosts of coronaviruses. Our findings further support the importance of ending the trade in wildlife globally.

molecular biology↗

bioRxiv2020

Origin and cross-species transmission of bat coronaviruses in China

Bats are presumed reservoirs of diverse coronaviruses (CoVs) including progenitors of Severe Acute Respiratory Syndrome (SARS)-CoV and SARS-CoV-2, the causative agent of COVID-19. However, the evolution and diversification of these coronaviruses remains poorly understood. We used a Bayesian statistical framework and sequence data from all known bat-CoVs (including 630 novel CoV sequences) to study their macroevolution, cross-species transmission, and dispersal in China. We find that host-switching was more frequent and across more distantly related host taxa in alpha-than beta-CoVs, and more highly constrained by phylogenetic distance for beta-CoVs. We show that inter-family and -genus switching is most common in Rhinolophidae and the genus Rhinolophus. Our analyses identify the host taxa and geographic regions that define hotspots of CoV evolutionary diversity in China that could help target bat-CoV discovery for proactive zoonotic disease surveillance. Finally, we present a phylogenetic analysis suggesting a likely origin for SARS-CoV-2 in Rhinolophus spp. bats.

evolutionary biology↗

bioRxiv2019

United States wildlife and wildlife product imports from 2000-2014

The global wildlife trade network is a massive system that has been shown to threaten biodiversity conservation, introduce non-native species and pathogens, and cause chronic animal welfare concerns. Despite its scale and impact, comprehensive characterization of the global wildlife trade is hampered by data that are limited in their temporal or taxonomic scope and detail. To help fill this gap, we present data on 15 years of the importation of wildlife and their derived products into the United States (2000-2014), originally collected by the United States Fish and Wildlife Service. We curated and cleaned the data and added taxonomic information to improve data usability. These data include > 2 million wildlife or wildlife product shipments, representing > 60 biological classes and > 3.2 billion live organisms. These data will be broadly useful to both scientists and policymakers seeking to better understand the volume, sources, biological composition, and potential risks of the global wildlife trade.

ecology↗