There is no longer human contact with bats at a cave linked to the Marburg virus disease outbreak in Rwanda, according to the Minister of State for Health, Dr. Yvan Butera.
Butera made the observation on October 31 during a media briefing about Mpox and Marburg outbreaks in Africa, which was hosted by Africa CDC, on October 31.
He pointed out that measures to contain Marburg virus disease outbreak were ongoing in Rwanda, indicating that surveillance remains strong, including close monitoring of the outbreak site linked to fruit bats believed to be the source of the outbreak.
According to information from the Ministry of Health, researchers sequenced the virus genomes and found that all sequences share a single zoonotic origin, meaning the virus jumped from animal to human just once – and had not passed through multiple hosts.
On October 25, the World Health Organization (WHO) stated that the index case (first identified case) was a male between 20 and 30 years old with a history of exposure to bats in a cave, based on available updates from the outbreak investigation.
Butera said that they were able to trace back that the index case was exposed to a mining cave considered a host of the fruit bats in question were found.
"In terms of surveillance, we put a clear-cut demarcation where these bats reside, there's no longer contact with humans,” he said as he responded to a journalist’s question on the virus surveillance, with a focus on the implicated cave.
At a press conference about Mpox and Marburg outbreaks in Africa held on October 24, the Minister of Health, Dr. Sabin Nsanzimana, said that they identified the mining cave where fruit bats linked to the Marburg virus disease outbreak in Rwanda have been living. Mining activities there were stopped to prevent human contact with such animals, he said.
ALSO READ: Exact origin of Marburg virus identified
Apart from demarcating the cave in question, Butera said that there has been a comprehensive mapping of all the potential sites that might have similar fruit bats under a One Health perspective, working with other agencies that work in this field.
"We have been able to map all the sites and put in place preventive and secure measures where you don't have human to bat interaction to prevent future events,” he said, adding that they will continue working to understand the period of shedding of this particular fruit bats.
According to WHO, Marburg virus disease is a highly virulent disease that causes haemorrhagic fever and is clinically similar to Ebola virus disease.
Marburg and Ebola viruses are both members of the Filoviridae family (filovirus). People are infected with Marburg virus when they come into close contact with Rousettus bats, a type of fruit bat that can carry the Marburg virus and are often found in mines or caves.
Data from the Ministry of Health show that Rwanda had recorded 66 cases of Marburg virus as of October 31, which include 49 recoveries, and 15 deaths – implying a fertility rate of almost 23 per cent.
On October 31, the US-based Sabin Vaccine Institute announced the shipment of approximately 1,000 additional doses of its investigational vaccine, in a continued collaboration with Rwanda to address the current Marburg virus outbreak. The doses, it stated, to be administered under the updated protocol sponsored by Rwanda Biomedical Center, target approximately 1,000 at-risk individuals, including mine workers, who are expected to receive the single-dose vaccine.
Marburg virus disease is associated with a high case fertility rate, around 50 per cent on average, shows information from WHO. As noted, case fatality rates have varied from 24 per cent to 88 per cent in past outbreaks.