Bats host the most virulent—but not the most dangerous—zoonotic viruses (original) (raw)

Bats and zoonotic viruses: can we confidently link bats with emerging deadly viruses?

An increasingly asked question is ‘can we confidently link bats with emerging viruses?’. No, or not yet, is the qualified answer based on the evidence available. Although more than 200 viruses – some of them deadly zoonotic viruses – have been isolated from or otherwise detected in bats, the supposed connections between bats, bat viruses and human diseases have been raised more on speculation than on evidence supporting their direct or indirect roles in the epidemiology of diseases (except for rabies). However, we are convinced that the evidence points in that direction and that at some point it will be proved that bats are competent hosts for at least a few zoonotic viruses. In this review, we cover aspects of bat biology, ecology and evolution that might be relevant in medical investigations and we provide a historical synthesis of some disease outbreaks causally linked to bats. We provide evolutionary-based hypotheses to tentatively explain the viral transmission route through mammalian intermediate hosts and to explain the geographic concentration of most outbreaks, but both are no more than speculations that still require formal assessment.

Bats: carriers of zoonotic viral and emerging infectious diseases

Journal of Experimental Biology and Agricultural Sciences, 2016

Bats are reported as reservoir host for several viruses, which cause significant illness in human and animals. Some of the bat transmitted zoonotic viral diseases such as Ebola, Hendra, Nipah and rabies may cause severe human casualties. They also harbor several other viruses such as MERS and SARS corona viruses, which may cause disease in human through direct spillover to human or through an intermediate host or vectors. Being reservoir hosts bats do not get affected by these viruses. This probably may happen due to the specificity of bat immune system, which reacts differently with viral pathogens in comparison to their other mammalian counterparts. Although bats are important reservoir hosts for several zoonotic viruses, very little information is available regarding host/virus relationships as only few experimental studies have been done on bat colonies, lack of expertise for study of bat immunology and antiviral responses and difficulty in conducting field work. However, with t...

Global Trends of Emerging Infectious Diseases and the Impacts on Biodiversity: Spillover, Diversity and the Role of Bats in Evolutionary Relationships as Zoonotic Virus Reservoirs

South Asian Journal of Research in Microbiology

Introduction: It is possible that the evolution of man is associated with manifestations of microscopic beings that have accompanied him since ancient times. Emerging infectious diseases have been warning for decades that habitat fragmentation and degradation, antropization effects, animal trafficking increase the risk of diseases spreading from wildlife to human populations. Aims: The purpose of this study was to review the current events about the pandemics that occurred on the planet and the current situation of bat involvement, their high degree of ecological plasticity that these beings present with the emergence and spread of viruses. Methodology: Review the current knowledge about viral diversity, host condition and possible mammalian reservoirs in the face of pandemics and the close relationship of bats with humans and other possibly incriminated species. Given the epidemics of the last century, it is possible to observe that the increased interaction between humans and wild...

Viral networks and detection of potential zoonotic viruses in bats and rodents: A worldwide analysis

Zoonoses and Public Health

Bats and rodents are recognized to host a great diversity of viruses and several important viral zoonoses, but how this viral diversity is structured and how viruses are connected, shared and distributed among host networks is not well understood. To address this gap in knowledge, we compared the associative capacity of the host-virus networks in rodents and bats with the identification of those viruses with zoonotic potential. A virus database, detected by molecular methods, was constructed in the two taxonomic groups. We compiled 5,484 records: 825 in rodents and 4,659 in bats. We identified a total of 173 and 166 viruses, of which 53 and 40 are zoonotic viruses, in rodents and bats, respectively. Based on a network theory, a non-directed bipartite host-virus network was built for each group. Subsequently, the networks were collapsed to represent the connections among hosts and viruses. We identified both discrete and connected communities. We observed a greater degree of connectivity in bat viruses and more discrete communities in rodents. The Coronaviridae recorded in bats have the highest values of degree, betweenness and closeness centralities. In rodents, higher degree positions were distributed homogeneously between viruses and hosts. At least in our database, a higher proportion of rodent viruses were zoonotic. Rodents should thus not be underestimated as important reservoirs of zoonotic disease. We found that viruses were more frequently shared among bats than in rodents. Network theory can reveal some macroecological patterns and identify risks that were previously unrecognized. For example, we found that parvovirus in megabats and Gbagroube virus in rodents may represent a zoonotic risk due to the proximity to humans and other zoonotic viruses. We propose that epidemiological surveillance programmes should consider the connectivity of network actors as a measure of the risks of dispersion and transmission.

Bats and Coronaviruses

Viruses, 2019

Bats are speculated to be reservoirs of several emerging viruses including coronaviruses (CoVs) that cause serious disease in humans and agricultural animals. These include CoVs that cause severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), porcine epidemic diarrhea (PED) and severe acute diarrhea syndrome (SADS). Bats that are naturally infected or experimentally infected do not demonstrate clinical signs of disease. These observations have allowed researchers to speculate that bats are the likely reservoirs or ancestral hosts for several CoVs. In this review, we follow the CoV outbreaks that are speculated to have originated in bats. We review studies that have allowed researchers to identify unique adaptation in bats that may allow them to harbor CoVs without severe disease. We speculate about future studies that are critical to identify how bats can harbor multiple strains of CoVs and factors that enable these viruses to “jump” from bats to other m...