Marburg Virus Outbreak: Tanzania Announces Spread of Deadly Disease

Tanzania has announced its first-ever cases of Marburg virus disease, a deadly infection that has a fatality rate of around 50 percent.

The World Health Organization (WHO) said in a statement that Tanzania's National Public Health Laboratory has confirmed that eight people so have contracted the virus, of which five have died. In addition, 161 people who have been in contact with these patients have been identified and are being monitored. The patients were tested for the virus after they developed such symptoms as fever, vomiting, bleeding and renal failure.

Since February, there has also been an ongoing outbreak in Equatorial Guinea, which has had nine confirmed cases and 20 suspected cases of the virus, according to the WHO.

Marburg virus is a hemorrhagic fever virus, classified as a Risk Group 4 pathogen by the WHO along with smallpox, Nipah virus and Ebola. Marburg is in the same viral family as Ebola, the Filoviridae family.

"The disease caused by Marburg and Ebola are virtually indistinguishable," Thomas Geisbert, a professor of microbiology and immunology at the University of Texas Medical Branch in Galveston, told Newsweek.

The virus first came to the attention of the international medical community in 1967 after two simultaneous outbreaks in Belgrade, Serbia, and Germany's Frankfurt and Marburg, which the virus was named after. These outbreaks were thought to have resulted from medical work using African green monkeys that had been imported from Uganda, although the exact route of transmission is unknown. Fruit bats are a natural host of the virus and can transmit the disease via their feces.

Since its first outbreak, the virus has had outbreaks in Uganda, Kenya, the Democratic Republic of Congo and Angola. The most recent outbreaks were in Guinea in 2021 and Ghana in 2022. The most deaths occurred in Angola, between 2004 and 2005, when 227 people died out of 252 cases.

Death rates have varied between 24 and 88 percent in past outbreaks, the WHO says, depending on the strain of the virus and how the cases were managed, but the average was around 50 percent.

Between humans, the virus is transmitted via the contact of broken skin or mucous membranes with infected body fluids, including urine, saliva, sweat, feces, vomit, breast milk, amniotic fluid and semen, according to the U.S. Centers for Disease Control and Prevention.

Even if a man has recovered from the virus, his semen can still spread the disease if he has unprotected sex, as the virus has been found to persist inside the testicles. Additionally, the virus can be spread via objects contaminated with the body fluids of an infected person, such as clothes, bedding and needles.

"First responders and family members with an infected member are most at risk," Demetrius Matassov, director of viral vaccine development at Auro Vaccines, told Newsweek. "[Marburg virus disease] doesn't spread like COVID. However, if improper biosafety practices occur, then the risk of infection increases."

Clinically, the Marburg virus is rather similar to Ebola, its close relative.

Symptoms begin after an incubation period of between two and 21 days and become increasingly severe five days after the first ones occur.

"Symptoms occur abruptly and include fever, headache and myalgia," Geisbert said. "This progresses to symptoms that can include nausea, vomiting, chest and abdominal pain, sore throat and diarrhea. Macular rashes can also occur.

"Symptoms in severe cases include jaundice, liver failure, shock, hemorrhage and multi-organ dysfunction. So similar to DIC [disseminated intravascular coagulation] in septic shock," he said.

Because of Marburg's similarity to Ebola, Lassa fever and other infectious diseases including malaria, typhoid fever or dengue fever, it can be hard to identify, especially if a small number of cases are involved. Often, health care professionals are infected by patients.

There are no specific treatments for the virus. Health care providers are only able to help the patient rehydrate with oral or intravenous fluids and treat specific symptoms.

"There is currently no vaccine for Marburg virus disease licensed for human use," Geisbert said. "There are several vaccines that have shown strong potential in preclinical, nonhuman primate models that are being advanced for human use.

"These include a Sabin chimpanzee adenovirus-based Marburg vaccine and the IAVI VSV-based Marburg vaccine, which are probably the lead candidates," he continued. "A particular advantage of the IAVI VSV-based Marburg vaccine is that it has shown protection in nonhuman primates even if given shortly after virus exposure, like the rabies vaccine.

"This VSV-based vaccine employs the same technology of the licensed Merck ERVEBO vaccine that was successfully used to combat the 2013-16 Ebola outbreak in West Africa," Geisbert said.

The Tanzanian outbreak is expected to not spread to other countries, but a concerted effort must be made to minimize the virus's transmission.

"If identification and subsequent isolation of infected people are done properly, then the spread of the MARV virus would be limited," Matassov said. "However, being that the outbreaks occur in rural areas and medical facilities are limited, any outbreak of MARV should be taken seriously to minimize its spread."

In a statement, Ahmed Ogwell Ouma, acting director of the Africa Centers for Disease Control and Prevention, said, "These emerging and reemerging infectious diseases are a sign that the health security of the continent needs to be strengthened to cope with the disease threats.

"We urge members of the public to continue sharing information in a timely manner with the authorities to enable a most effective response," Ouma said.

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