Marburg outbreak in Uganda: Five cases reported
The Ugandan Ministry of Health declared an outbreak of Marburg Virus Disease (MVD) last week and WHO delivered an update on the outbreak yesterday.
As of 24 October, five cases have been reported – one confirmed case, one probable case with an epidemiological link to the confirmed case, and three suspected cases including two health workers.
Marburg virus Image/CDC
Chronologically, the first case-patient (probable case) reported was a male in his 30s, who worked as a game hunter and lived near a cave with a heavy presence of bats. On 20 September, he was admitted to a local health centre with high fever, vomiting and diarrhoea, and did not respond to antimalarial treatment. As his condition deteriorated, he was transferred to the referral hospital in the neighbouring district, where he died the same day. No samples were collected. He was given a traditional burial, which was attended by an estimated 200 people.
The sister (confirmed case) of the first case-patient nursed him and participated in the burial rituals. She became ill and was admitted to the same health centre on 5 October 2017 with fever and bleeding manifestations. She was subsequently transferred to the same referral hospital, where she died. She was given a traditional burial. Posthumous samples were collected and sent to the Uganda Virus Research Institute (UVRI). On 17 October, Marburg virus infection was confirmed at UVRI by RT-PCR and it was immediately notified to the Ministry of Health.
The third case-patient (suspected case) is the brother of the first two cases. He assisted in the transport of his sister to the hospital, and subsequently became symptomatic. He refused to be admitted to hospital, and returned to the community. His whereabouts are currently not known though there is an ongoing effort to find him.
Two health workers who were in contact with the confirmed case have developed symptoms consistent with Marburg virus disease and are under investigation (suspected cases). Laboratory results to rule out Marburg virus disease are pending.
Contact tracing and follow-up activities have been initiated. As of 23 October, 155 contacts including 66 who had contact with the first case and 89 who had contact with the second case-patient have been listed in the two affected districts, including 44 health care workers. The number of family and community contacts is still being investigated.
Uganda has previous experience in managing recurring viral haemorrhagic fever outbreaks including Marburg virus disease. Cases have historically been reported among miners and travellers who visited caves inhabited by bat colonies in Uganda. Marburg virus disease outbreaks have been documented during:
- 2007 – 4 cases, including 2 deaths in Ibanda District, Western Uganda;
- 2008 – 2 unrelated cases in travellers returning to the Netherlands and USA, respectively after visiting caves in Western Uganda;
- 2012 – 15 cases, including 4 deaths in Ibanda and Kabale districts, Western Uganda; and
- 2014 – 1 case in healthcare professional from Mpigi District, Central Uganda.
Related: Marburg virus in Uganda: Should we be concerned?
Marburg hemorrhagic fever is a rare, severe type of hemorrhagic fever which affects both humans and non-human primates. Caused by a genetically unique zoonotic (that is, animal-borne) RNA virus of the filovirus family, its recognition led to the creation of this virus family. The five species of Ebola virus are the only other known members of the filovirus family.
Recent scientific studies implicate the African fruit bat (Rousettus aegyptiacus) as the reservoir host of the Marburg virus. The African fruit bat is a sighted, cave-dwelling bat which is widely distributed across Africa. Fruit bats infected with Marburg virus do not to show obvious signs of illness. Primates, including humans, can become infected with Marburg virus, which can progress to serious disease with high mortality.
Just how the animal host first transmits Marburg virus to humans is unknown.
Related: The World’s Deadliest Viruses
After an incubation period of 5-10 days, the onset of the disease is sudden and is marked by fever, chills, headache, and myalgia. Around the fifth day after the onset of symptoms, a maculopapular rash, most prominent on the trunk (chest, back, stomach), may occur. Nausea, vomiting, chest pain, a sore throat, abdominal pain, and diarrhea then may appear. Symptoms become increasingly severe and may include jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, and multi-organ dysfunction. The case-fatality rate for Marburg hemorrhagic fever outbreaks is between 23-88%.
Confirmed cases of Marburg HF have been reported in Uganda, Zimbabwe, the Democratic Republic of the Congo, Kenya, and Angola. Cases of Marburg HF have occurred outside Africa, though infrequently.
