Up to now, Ebola, the dangerous virus that cyclically appears in several areas of Africa and claims a high number of victims, had five known strains, three of which – Bundibugyo, Sudan and Zaire – are associated with infections in humans (in particular, the Zaire strain is responsible for the epidemic that devastated West Africa between 2013 and 2016, and the ongoing outbreak in the Democratic Republic of the Congo). In recent months a sixth strain, called Bombali, was isolated in the saliva and feces of bats (natural reservoirs of many of these viruses) in Sierra Leone. Now, however, the same virus has been identified in a different kind of bat from Angola, and captured (for scientific purposes) in Kenya, almost 6000 kilometers from Sierra Leone, in an area where, up to now, no animal that carried an Ebola virus had ever been found.
In an article in the scientific journal Emerging Infectious Diseases, published by the Centers for Disease Control and Prevention of the United States, a team of researchers from the Universities of Helsinki and Nairobi reported that a high concentration of the virus was discovered in the tissue of bats found in Kenya, proof of a highly-active virus. These animals, however, produce massive amounts of specific antibodies, which enable them to not succumb to the virus and to live with it without encountering any problems (by doing so, however, the bats act as reservoirs for Ebola).
According to the researchers, the Bombali strain does not appear to be capable of infecting humans, as confirmed by the tests carried out on febrile patients in the hospitals in the area where the virus was isolated. However, the risk of it jumping from one species to another (the feared “spill-over infection”, as experts call it) is ever present, and this is why the situation is being monitored very carefully , with attempts being made to keep the “geography” of the virus under control without harming the bats at the same time, as they play a vital role in the fight against dangerous insects like the aedes aegypti mosquito, which carries many diseases, like yellow fever, dengue and others.
It is important to examine the highest number of bats possible and to study the viruses that these animals carry – say the researchers – in order to be aware of any changes that may be harmful to humans as soon as possible. The more information that is collected, the greater the possibilities are to create vaccines and medicines that are effective against the hemorrhagic fevers triggered by Ebola.
But how did the virus reach Kenya, seeing that bats are not able to fly 6000 kilometers? The Ebola virus, add the experts, has probably existed for much longer than was thought up until now (the identification of the virus dates back to only a few decades ago) and has a much wider transmission range than expected in the animal world.
Journalist since 1983, has been dealing with scientific divulgation for years, especially in the fields of medicine and biology. Creator of Sportello Cancro, the site created by corriere.it on oncology, in collaboration with the Umberto Veronesi Foundation. He collaborated with the pages of the Science of Corriere della Sera for several years. He is currently President of the Lugano Science Foundation.