Viral sequences related to known human coronavirus outbreaks have been identified in horsehoe bats. Picture: 123RF/NICOLAS FERNANDEZ
Bats are prone to act as a reservoir for viruses. Chinese populations of the horseshoe bat genus have already been found to host viruses similar to the new coronavirus. This suggests that it’s important to watch out for related viruses in this genus of bats elsewhere, including African countries. The horseshoe bat genus is found around the world and there are 40 species in Africa. But so far no viruses related to the cause of Covid-19 disease have been reported from African bat species.Global surveillance for coronavirus diversity in bats has expanded rapidly in the past two decades because of a previous novel coronavirus disease outbreak, severe acute respiratory syndrome , in China in 2002. This virus resulted in significant illness and death among human populations.
These viruses in bats weren’t directly linked to the human outbreak. But it did indicate that spillover of these viruses circulating in bat populations was possible when opportunities for contact occurred. No new cases of SARS have been reported since 2004 but the continued presence of various SARS-related strains in horseshoe bat populations makes re-emergence possible.
Coronavirus surveillance studies in bats in other African countries have been mostly one-off studies and haven’t included all the species or considered seasonal shedding of viruses. Highly diverse and novel coronavirus sequences were reported in cases where surveillance studies were performed. This contributed to the hypothesis that bats were the original evolutionary source.
Most countries in Africa do not have active programmes in place to watch for corona-and other bat-borne viruses in bats and to understand their epidemiology and ecology. We do know that bat coronaviruses are excreted in faecal material, which makes it easier to transmit them through bat populations and creates opportunities for exposure to other species.No outbreaks of coronaviruses with a link to bats have been reported in Africa. But we still need to be vigilant.
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