Investigators have now detected Marburg virus in West Africa for the first time, a December 21, 2018, statement from the US Centers for Disease Control and Prevention (CDC) reports. The deadly virus was isolated from fruit bats in Sierra Leone.
Transmission of Marburg virus predominantly occurs via close contact, as well as via infected blood and other body fluids. It can also occur by infected semen.
The Egyptian fruit bat or Egyptian rousette (Rousettus aegyptiacus) is the natural reservoir host of Marburg virus. The bats shed the virus in their saliva, urine, and feces while feeding on fruit. And people become exposed to the virus when they eat fruit that has been contaminated by infected bats, or if they are bitten by infected bats while capturing them to eat.
Because fruit bats infected with Marburg virus do not show obvious signs of illness, and because of their ability to fly across great distances, these bats play an important role in transmitting the infection.
According to the CDC, 5 Egyptian rousette fruit bats in Sierra Leone tested positive for active infection with Marburg virus. This discovery came during the course of 2 studies that began in 2016 after the large Ebola outbreak in West Africa.
Both studies set out aiming to identify the reservoir of Ebola virus. One is led by the CDC and Njala University in Freetown, Sierra Leone. The other is led by the University of California, Davis, and the University of Makeni in Sierra Leone, and is funded by the United States Agency for International Development.
The CDC statement indicates that testing of 4 of the Marburg virus-positive bats identified genetically diverse strains, suggesting that the virus has been in Sierra Leone bat colonies for many years. In addition, 2 of these 4 strains are genetically similar to the one linked with the largest and deadliest Marburg outbreak that occurred in Angola in 2005. And this marks the first report of these Angolan strains in bats, CDC says.
At the time of the CDC statement, there had been no reported cases of human Marburg virus in Sierra Leone. Nevertheless, the presence of the virus in fruit bats in the area now poses a public health threat to the people there.
“This discovery is an excellent example of how our work can identify a threat and help us warn people of the risk before they get sick,” Jonathan S. Towner, PhD, who led the CDC team in one of the projects, concluded in the statement.