Uganda Battling Deadly Marburg Outbreak

Although the Ebola virus outbreaks that have plagued countries in Africa may be our most recent hemorrhagic fever memory, a cousin within the filovirus family is starting to cause concern in Uganda. Marburg Hemorrhagic Fever, a rare, but serious virus, is a zoonotic disease in which outbreaks are frequently triggered by interaction with the African fruit bat, Rousettus aegyptiacus. Primates can also become infected with Marburg, but, the Rousettus bat is the reservoir for the virus and it can easily transmit the disease by way of its significant geographical distribution.

Marburg first found itself on our infectious diseases radar in 1967 because of a series of simultaneous outbreaks in laboratories in Marburg and Frankfurt Germany, as well as Belgrade, Serbia. Over 30 individuals became ill in these laboratory incidents. An epidemiological investigation found that the first few cases were a result of exposure to imported African green monkeys or their tissue during laboratory research. The virus is typically transmitted from animals to humans, and then spread between humans through direct contact with droplets of body fluids or contact with contaminated equipment, etc. Hospitals and immediate caregivers in the infected individual’s home can be sources of transmission.

The viral infection has an incubation period of 5 to 10 days and symptoms are usually fever, chills, headache, and myalgia. These can progress to a maculopapular rash, vomiting, diarrhea, and eventually shock and multi-organ failure. The case fatality rate for Marburg is 23% to 90%, and this can be seen throughout the history of outbreaks.

Marburg is deadly and poses challenges and increased risk to health care workers, which makes the recent outbreak in Uganda that much more concerning. The latest World Health Organization (WHO) information reports 6 cases (2 confirmed, 1 probable, and 3 suspected cases, which includes 2 healthcare workers). The first diagnosed case was a woman who had nursed her brother, a male in his 30s, during his illness with an unknown source. Her brother did not respond to treatment and died. Based on his symptoms and early reports, he is considered the probable index case, but his sister was the first laboratory-confirmed case. Their other brother is now a confirmed case. He was exposed to the virus during transportation of his sister to the hospital. He refused medical care and his whereabouts were unknown for a period of time.

The latest reports have indicated that the man has since died, bringing the death toll to 3 for this outbreak. The spread of the infection within this family (2 brothers and 1 sister) highlights the risk for close contacts and those caring for infected individuals. The current case fatality rate for this outbreak is 50%

Contact tracing for this outbreak has been significant and includes upwards of 200 people. Currently, the biggest concerns are the high volume of contacts and that the most recent deceased patient had previously traveled across the border to western Kenya to visit 2 traditional healers. This could push the outbreak into the neighboring country. Public health officials in Kenya have been notified and are maintaining surveillance for potential cases.

Given the high fatality rate of Marburg and its ease of transmission through body fluids, control and prevention measures are vital. WHO reports that it will continue to provide up-to-date case counts and information; however, the current efforts to perform contact tracing are complicated by the rural areas and reported resistance by some community members.

Contagion^® will continue to track this outbreak on the Contagion® Outbreak Monitor and through written coverage.