Rwanda is in the midst of an outbreak of Marburg virus disease, a hemorrhagic fever with a high fatality rate that has killed 11 people there this year.
The disease has been found in multiple African countries over the last several decades but never before in Rwanda, in east-central Africa. It was first detected in the country in late September, and since then, 36 cases have been reported, according to the health ministry of Rwanda.
This week, the authorities in Germany closed part of Hamburg’s central train station after a medical student and his companion reported feeling ill. The medical student had had contact with an infected patient while in Rwanda. Both people in Germany tested negative for Marburg, the authorities announced this week, emphasizing that there was no risk to the public.
Here’s what we know about the disease.
What is Marburg virus disease?
Marburg was first detected in 1967, when outbreaks of hemorrhagic fever occurred simultaneously in laboratories in the German cities of Marburg and Frankfurt and in Belgrade, in what is now Serbia. The cases were linked to African green monkeys that had been imported from Uganda. Other cases were later found in Angola, the Democratic Republic of Congo, Ghana, Kenya, South Africa and Uganda, according to the World Health Organization.
The Marburg virus is the pathogen that causes the disease in humans.
The disease is clinically similar to Ebola in its spread, symptoms and progression, although it is caused by a different virus, according to the W.H.O.
Even though Marburg has not spread widely, it has been deadly, with case fatality rates ranging from 24 to 88 percent, depending on which strain people contract and on the management of cases, according to the W.H.O. Ebola’s case fatality rates are nearly the same.
There are no vaccines or antiviral treatments for the disease, medical experts said, but hydrating patients and treating their symptoms can improve their chances of survival.
What are the symptoms of Marburg virus disease?
Marburg can cause severe viral hemorrhagic fever, which interferes with the blood’s ability to clot. The incubation period ranges from two to 21 days, and symptoms begin abruptly with high fever, severe headache and severe malaise, according to the W.H.O.
“Mortality is very high,” said Dr. John Amuasi, who leads the global health and infectious disease research group at the Kumasi Center for Collaborative Research in Tropical Medicine in Kumasi, Ghana. “And there’s no asymptomatic Marburg.”
Patients can confirm whether they have Marburg through antibody, antigen and polymerase chain reaction tests, health organizations said.
What is happening in Rwanda?
Health officials in Rwanda declared an outbreak on Sept. 27. According to the latest government update, 36 cases have been confirmed by health officials, which first detected the disease among patients in health facilities, and 11 people have died.
The source of the virus is still unclear, and infected patients have been isolated to prevent the spread of the disease. Cases have already been detected in several districts in the country, according to the C.D.C.
The country’s health minister has announced plans for clinical trials and experimental vaccines and treatments in the coming weeks.
“This is part of our efforts to help people recover quickly by utilizing vaccines and medicines specifically developed to fight this outbreak, currently in the final phase of research,” the minister, Sabin Nsanzimana, told Reuters.
While cases have been reported outside Kigali, Rwanda’s capital, the W.H.O. warned that the presence of Marburg in the capital heightened the risk that the disease could spread to other countries, because of the international airport there.
The two people who were tested for the disease in Hamburg, in Northern Germany, included a 26-year-old medical student who was in contact with a patient as part of his studies but was adequately protected, according to the German authorities.
He and his companion received polymerase chain reaction, or P.C.R., tests that came back negative. Health authorities said the companion had mild symptoms of another disease. The medical student was to be isolated for 21 days, the incubation period for Marburg virus disease, as a precaution, they said.
How does the outbreak compare with previous ones?
The outbreak in Rwanda is in its early stages, though at 36 cases it already appears to be significant.
In 2023, the W.H.O. reported 17 confirmed and 23 probable cases in Equatorial Guinea, with 12 of the confirmed cases and all probable cases reported as deaths. Six deaths were reported in Tanzania in 2023, with nine confirmed cases, according to the W.H.O. In 2022, Ghana’s health authorities declared an outbreak after three people were infected with Marburg and two of them died, according to the W.H.O. The three were from the same household, and one victim was an infant.
In 2021, there was one case in Guinea, which resulted in death, and three of four people who had the disease in Uganda in 2017 also died, according to the C.D.C.
More than 200 people died in an outbreak in Angola from 2004 to 2005 and more than 100 died of the disease in the Democratic Republic of Congo from 1998 to 2000, according to the C.D.C. Other outbreaks of Marburg have not involved as many cases.
The risk is low in the United States.
As of Thursday, the U.S. Centers for Disease Control and Prevention was advising travelers to Rwanda to “practice enhanced precautions,” or what is known as Level 2 in the travel notices it issues for international destinations. (Level 3 advises people to reconsider nonessential travel, and Level 4 recommends avoiding all travel).
Enhanced precautions include avoiding nonurgent medical care in the outbreak areas, the C.D.C. explains, and not making contact with bodily fluids. People should also avoid areas where there might be bats, such as caves, and stay away from traditional healers, the agency says.
The C.D.C. said on Thursday that the risk to the general population in the United States remained low. “To date, no cases of Marburg virus disease related to this outbreak have been reported in the United States,” the C.D.C. said in a statement.
The agency was monitoring the situation in Rwanda, where it has had an office since 2002, and it was sending experts to assist with the investigation and response to the outbreak, its statement said.
