Evidence for spillover of henipaviruses, from bats into human populations in Africa, is reported online in Nature Communications this week. However, it is unknown whether these infections are asymptomatic or can cause any type of disease in humans.
Henipaviruses (HNVs) such as Nipah and Hendra viruses infect several species of fruit bats in southern Asia, Australia and Africa. Although harmless to bats, Asian and Australian HNVs can cause acute encephalitis and respiratory illness in domestic animals and in humans, often with lethal consequences. Ongoing deforestation of vast areas in Africa is leading to more frequent contacts between bats and humans. However, human infections with African HNVs have so far not been reported.
Benhur Lee and colleagues analysed blood samples obtained from 44 fruit bats and 487 people from southern Cameroon. They find that 48% of the bat samples and around 1% of the human samples tested positive for antibodies that react specifically against HNV components, which indicates present or past infection. The positive human samples were derived almost exclusively from people living in areas undergoing deforestation and who reported butchering bats for bushmeat.
Further surveillance is required to determine the extent of the spillover of African HNVs into human populations, and to find out whether these infections can actually lead to disease.