The Marburg virus is the newest health scare on the global stage, with health officials in the U.S. and other countries warning doctors to look out for the deadly disease that is circulating in two African countries.
The World Health Organization said the virus infected at least 16 people in Equatorial Guinea, a tiny country on the Atlantic coast, as of mid-April. Eleven of those patients have died.
Tanzania, on the opposite coast, is dealing with its own outbreak of at least eight cases since late March.
The U.S. and the wider world haven’t reported cases, but the situation has the potential to be “very disruptive,” said Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security.
“In Equatorial Guinea, for instance, multiple provinces are involved and there are likely undocumented chains of transmission,” he said.
The virus that causes Marburg disease is an RNA (ribonucleic acid) virus in the filovirus family. The six species of Ebola virus are the only other known members of the filovirus family, according to the U.S. Centers for Disease Control and Prevention.
“Unlike Ebola, however, there is not a vaccine and no treatments,” Dr. Adalja said.
The National Institute of Allergy and Infectious Diseases said in January that a human study of an investigational vaccine for Marburg showed a robust antibody response, though further trials are needed before shots can be deployed in active outbreaks.
The CDC describes Marburg disease as a rare but severe hemorrhagic fever that can affect humans and nonhuman primates. The agency has documented 15 outbreaks of varying size since 1967, with a number of countries in sub-Saharan Africa as the source. Certain bats in those countries are the natural reservoir species for the virus.
Marburg is transmitted among people through blood or bodily fluids and can spread via broken skin or through the eyes, nose and mouth.
Case-fatality rates, meaning the share of confirmed cases that end in death, have varied widely — from 23% to 90% — in past outbreaks, due in part to factors like the ability to catch cases early and stabilize patients in hospitals.
The CDC said it doesn’t think the twin outbreaks are related to each other but rather the result of independent spillover events from animals. The agency has scientists on the ground to assist with the response in both nations.
“The teams are assisting with case investigation, contact tracing and laboratory training. Along with local and global partners, CDC is also assessing border risk for Marburg crossing into neighboring countries,” the agency said in a statement.
The CDC this month warned U.S. doctors to be on the lookout for symptoms of the disease, particularly if patients have a travel history within the affected African countries. The notice tells physicians to coordinate testing with local authorities or seek guidance from a CDC hotline.
The failure to connect the dots between travel and symptoms was an issue for one Dallas-area hospital during the West African Ebola outbreak of 2014-16.
Doctors sent home a man who had traveled from Liberia in 2014 and had a high fever, only to readmit him and find he had Ebola. The patient later died, and the broader outbreak in West Africa killed 11,000 people.
There are no direct flights from Equatorial Guinea or Tanzania to the U.S., and the risk to the American population is considered low.
Still, World Health Organization Director-General Tedros Adhanom Ghebreyesus wants all countries to be vigilant, saying the outlook in Equatorial Guinea remains murky.