Marburg virus disease outbreak in Rwanda

As of 24 October 2024, a total of 64 Marburg virus disease cases, including 15 deaths (case fatality ratio (CFR) 23.4%), have been reported in Rwanda. Among the initial 62 confirmed cases with available data, 70% were males, and 48% were aged between 30 to 39 years.

The highest number of new confirmed cases were reported in the first two epidemiological weeks of the outbreak with 26 cases reported in epidemiological week 39 (23 to 29 September 2024) and 23 cases in week 40 (30 September to 6 October).

This was followed by a sharp decline in weeks 41 and 42, with 12 and one case reported respectively. Contact tracing is ongoing, with 1146 contacts under follow-up as of 20 October 2024. Based on available updates from the outbreak investigation, the index case was a male between 20 and 30 years old with a history of exposure to bats in a cave.

Marburg virus disease (MVD) is a severe disease with a fatality ratio of up to 88%. This rate can be lower with good and early patient care.

MVD was initially detected in 1967 after two simultaneous outbreaks in Marburg and Frankfurt in Germany, and in Belgrade, Serbia. The outbreak was associated with laboratory work using African green monkeys (Cercopithecus aethiops) imported from Uganda. Subsequently, outbreaks and sporadic cases have been reported in Angola, the Democratic Republic of the Congo, Equatorial Guinea, Ghana, Guinea, Kenya, Rwanda, South Africa (in a person with recent travel history to Zimbabwe), Tanzania and Uganda.

The incubation period (interval from infection to onset of symptoms) varies from 2 to 21 days.

MVD begins abruptly, with high fever, severe headache and severe malaise. Muscle aches and pains are a common feature. Severe watery diarrhoea, abdominal pain and cramping, nausea and vomiting can begin on the third day. Non-itchy rash have been reported in patients between 2 and 7 days after onset of symptoms.

From day 5 of the disease, patients may develop haemorrhagic manifestations, including fresh blood in vomitus and faeces, bleeding from the nose, gums and vagina. Bleeding at venepuncture sites (where intravenous access is obtained to give fluids or obtain blood samples) can also be observed. Involvement of the central nervous system can result in confusion, irritability and aggression. Orchitis (inflammation of one or both testicles) has been reported occasionally in the late phase of disease.