Casualty. Italian pediatrician Maria Bonino (center), who worked in Uige province, has died, presumably from infection with the Marburg virus.

Marburg Outbreak Puzzles Scientists

As many as 117 people have died in Angola during what could become the largest recorded outbreak of the Marburg virus, a rare cousin of the Ebola virus that also causes hemorrhagic fever, the World Health Organization (WHO) announced today. Also today, a Canadian team with a mobile lab was scheduled to arrive in the country, hoping to help staunch the epidemic and learn more about the mysterious disease.

Marburg--which can cause fever, pains, diarrhea, coughing, nausea, and hemorrhaging--was first discovered in 1967, when a shipment of monkeys from Uganda caused simultaneous outbreaks in the German towns of Marburg and Frankfurt and in Belgrade, then the capital of Yugoslavia, sickening 31 and killing seven. Three mini-outbreaks are known to have occurred in Africa in the 1970s and 1980s, involving six people. The largest outbreak so far occurred in the Democratic Republic of the Congo between 1998 and 2000, with 149 known cases and 123 deaths. There are no cures or vaccines against the disease.

To experts, the current outbreak's location and its manifestation are unusual. Because Marburg had been found only in Eastern and Central Africa, "you'd think this had to be Ebola," says Thomas Geisbert of the U.S. Army Medical Research Institute of Infectious Diseases in Ft. Detrick, Maryland. According to WHO, about 75% of the victims so far have been children under the age of 5, which is also strange for a hemorrhagic fever virus, says Thomas Ksiazek of the U.S. Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, the lab that first identified Marburg almost 2 weeks ago in samples shipped from Angola. Initial sequencing, however, does not suggest it's an unusual strain, Ksiazek adds.

Although a few cases have been identified in the Angolan capital Luanda, the current outbreak is concentrated in the northern province of Uige, according to WHO, which has a team on the ground to help local authorities. Logistical hurdles in a poor, war-ravaged country such as Angola can be a challenge, but stopping the outbreak shouldn't be "particularly problematic," Ksiazek says. Marburg is not highly contagious (infection requires close contact), and tracing and strictly isolating patients usually brings the virus under control.

To help with diagnosis, virologist Heinz Feldmann and lab technician Allen Grolla of Canada's National Microbiology Laboratory left for Angola this weekend, carrying with them a mobile lab to test samples locally. While stamping out the disease comes first, the team hopes to do some research as well, says Feldmann's colleague Steven Jones--for instance, by trying to find out which immune response protects some people from the disease.

Related sites
WHO update about the situation in Angola
CDC page about Marburg hemorrhagic fever