Medical experts are having some success countering an outbreak of a deadly Ebola-like virus in Angola, but it has yet to be brought fully under control, the U.N. health agency said Friday.

The rare Marburg virus (search) has killed 174 people out of a total 200 cases, said Dr. Mike Ryan, director of alert and response operations for the World Health Organization.

"The situation right now in Angola is not under control yet," Ryan told reporters in Geneva. "This is still a crisis, and a health crisis on a national level."

WHO believes it is having an impact on the virus in the northern province of Uige, where it first appeared in October, Ryan said.

Several deaths attributed to the virus recently have been reported in four other provinces, but all the victims had been in Uige. Two cases have been confirmed in Angola's capital, Luanda, but there has been no transmission of the virus there.

"We do believe we're having an impact on the epidemic in Uige," Ryan said.

Like Ebola, which also has hit Africa, Marburg is a hemorrhagic fever. It spreads through contact with bodily fluids and can kill rapidly. There is no vaccine.

All contact with people infected with Marburg and with their bodily fluids should be avoided, said Dr. Pierre Formenty, a WHO expert on hemorrhagic fevers. People should also avoid touching the bodies of those who have died from Marburg.

WHO, the U.S. Centers for Disease Control and Prevention and Doctors Without Borders have deployed teams in Uige to combat the virus.

The worst previously recorded outbreak of the virus killed 123 people in neighboring Congo between 1998 and 2000, the last known outbreak of Marburg.