A type of fruit bat may harbour a virus that causes haemorrhagic fever in humans, according to research by a team of French, Gabonese and US scientists.
The research, published in PLoS ONE last month (22 August), is based on fieldwork in Gabon and the Democratic Republic of Congo between 2005 and 2006. Researchers set traps to capture the animal hosts of Ebola and Marburg, closely-related viruses that trigger uncontrollable bleeding.
Marburg virus infection is rare but highly contagious. There is no available treatment and the virus kills 85 per cent of those infected. Despite being identified four decades ago, its animal host has never been confirmed.
The researchers caught over 1100 bats, representing ten different species.
Lead researcher Eric Leroy, of Gabon's Franceville International Medical Research Center, said that based on analysis of antibodies against the virus and the detection of virus genetic material, the Egyptian fruit bat is the only natural reservoir of the virus.
A press release from one of the research partners, France's Institute of Research for Development, noted that children who had collected fruit from trees housing bats were the first victims of a 2004 outbreak in Angola.
And there was an outbreak in 1998–2000 in gold miners in the Democratic Republic of Congo who shared their mine with bats.
The release said the results should help define the regions most at risk from Marburg virus, noting that "West Africa constitutes an important area of migration" for the Egyptian fruit bat.
But South African researcher Bob Swanepoel, from the National Institute of Communicable Diseases, urged caution, saying "There is strong evidence that bats are involved but it is premature to say it is fruit bats [that are the human reservoir]."
Swanepoel noted that the Democratic Republic of Congo outbreak appeared to be seasonal. "Insect bats may harbour the virus and give it to fruit bats, and the seasonality may be due to bat breeding cycles, parasites or changes in insect diet," he says.
Swanepoel added that the most urgent need is how to identify live Marburg virus — as opposed to only genetic fragments and antibodies — in the animal host.
Référence : PLoS ONE 2 e764 (2007) doi 10.1371/journal.pone.0000764