African fruit bats are the natural hosts of Marburg and Ebola viruses, both of which are filoviruses. These RNA viruses are zoonotic - they can cross the species barrier and infect people, and they are also known and feared for their pathogenicity. Now researchers have isolated another filovirus called Lloviu virus (LLOV). The research has shown that LLOV can infect people. This study, which was reported in Nature Communications, has highlighted the importance of preparing for future pandemics.
There is debate about whether bats or rodents tend to harbor viruses that can infect humans, or whether they are unexceptional and don't harbor anymore zoonotic viruses than other species. But in the case of LLOV, genetic material that indicates the presence of the virus has been revealed in bats in Spain and Hungary.
While human LLOV infections have not yet been reported, our population continues to grow around the world, and our settlements have extended, sometimes deeply into the natural habitats of many animals. Our connections to the many animals used in agriculture also remain close. We don't have a robust repository of antiviral medications, and public health officials have warned about the potential for viral disease to spread. Other microbes with pathogenic potential like bacteria and fungi also remain threats.
Now that we know that LLOV can infect and replicate in human cells, we know that it will be important to watch for the virus. The researchers have stressed that additional research should be performed so we can learn more about how LLOV could spread, and what antibodies might be useful against it. The study has also shown that even though Ebola is a filovirus, antibodies against Ebolavirus are ineffective against LLOV, so Ebola vaccines would probably not be useful for protecting people from LLOV.
This study is "a smoking gun. It's vital that we know both more about the distribution of this virus and that research is done in this area to assess the risks and to ensure we are prepared for potential epidemics and pandemics," noted Dr. Simon Scott of the Medway School of Pharmacy.
Importantly, we know now we have a knowledge gap when it comes LLOV, and potentially other viruses as well. Researchers are aiming to address that problem; a consortium based in Europe now wants to know more about whether LLOV poses a threat to people. They also want to know more about other viruses that animals (including bats) in Europe may be hosting, and whether those viruses, such as coronaviruses, could be transmitted to people.