Mysterious Outbreak of Deadly Marburg Virus Spreads in Tanzania, Equatorial Guinea

A child suffering from malaria lies on a bed at the hospital of Nyarugusu, in north west o

The World Health Organization (W.H.O.) said on Thursday that eight new cases of the deadly Marburg disease have been reported in Equatorial Guinea, bringing the total of confirmed and probable cases to 20 since the mysterious outbreak began in February. Tanzania surprisingly reported five deaths this week in that country’s first known Marburg infections.

Marburg is a hemorrhagic fever similar to Ebola. (Like every major disease except Covid-19, the name of the Marburg virus is derived from the geographic location of its first verified outbreak, in this case the city of Marburg, Germany in 1967.) Tanzanian health officials originally believed they were dealing with Ebola, based on the symptoms, until further testing revealed the patients were infected with Marburg. 

Two key differences between Marburg and Ebola are that Ebola is considered more contagious and spreads to humans from more animal species, and there are effective vaccines against Ebola, while no such treatment exists for Marburg to date. 

The U.S. Centers for Disease Control (CDC) recommends hospital therapies such as “balancing the patient’s fluids and electrolytes, maintaining oxygen status and blood pressure, replacing lost blood and clotting factors, and treatment for any complicating infections,” but notes there have been no human trials of experimental vaccines so far. 

Marburg is also considerably more lethal than Ebola, which is itself considered one of the more life-threatening diseases. According to W.H.O., Marburg has a fatality rate of up to 88 percent, while the rate for Ebola is about 50 percent. 

The two diseases share many symptoms, including high fevers, severe headaches, nausea, and Ebola’s notorious uncontrolled internal bleeding – a symptom that has grown less common in recent strains of Ebola, but is frequently observed in Marburg victims. 

Outbreaks of the Marburg virus are watched very carefully for both of these reasons, especially when the origin of the outbreak is difficult to ascertain, because a more contagious strain of the virus would be deeply troubling to health officials.

Ummy Mwalimu /

Tanzanian Health Minister Ummy Mwalimu said on Tuesday the outbreak occurred in the northwestern region of Kagera, which lies along the borders of Uganda, Rwanda, and Burundi. Uganda recently suffered from an outbreak of a rare, virus-resistant Ebola that was officially declared over in January after 142 confirmed infections and 56 fatalities. 

Mwalimu said the government has been able to contain the disease in Kagera through intensive efforts, including contact tracing and distributing leaflets with protective advice. She said four of the five Marburg fatalities were members of the same family, while the fifth was a health care worker.

“This is not the first time Marburg has occurred in Africa. It has happened several times in our neighboring country, Uganda, and they have typically managed to contain it through strong community involvement,” said W.H.O. Tanzania representative Zabulon Yoti.

According to W.H.O. contact tracing, 161 people in Tanzania are considered to be at risk of Marburg infection, mostly living near two villages in Kagera. The virus can incubate for up to 21 days before infected people experience symptoms.

Equatorial Guinea reported eight new Marburg cases on Thursday, spread between three different provinces over 90 miles apart. W.H.O. considered this a troubling indication that the disease is spreading more widely through Equatorial Guinea than Tanzania.

Two of the new cases were reported from Kie-Ntem province, which runs along the border of Cameroon. Cameroon restricted border crossings in February after Equatorial Guinea declared an outbreak, but two suspected Marburg cases were still found in Cameroon, a pair of 16-year-olds who were not known to have traveled to Equatorial Guinea. 

Four cases have been confirmed in Bata, a seaport and the second-largest city in Equatorial Guinea. The U.S. Centers for Disease Control has established a laboratory in Bata to help track and contain the outbreak.

Equatorial Guinea’s health ministry reported eight fatal cases of an unknown hemorrhagic fever in early February. Five days later, one of the victims tested positive for Marburg. As with Tanzania, Equatorial Guinea has never previously confirmed a Marburg outbreak. Of the nine confirmed and 20 probable cases observed in the outbreak so far, 20 of the patients have died.


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