With only two patients left in an isolation ward Tuesday, doctors are hopeful an outbreak of the deadly Ebola virus in Congo may soon be contained. But because people can carry Ebola for up to three weeks before getting sick, experts say it's too soon to consider the outbreak over. "We are close to controlling the Ebola outbreak," Dr. Michel Van Herp, an epidemiologist with Medecins Sans Frontieres, said Monday. "But we remain vigilant because the virus is still circulating."

Van Herp recently spent three weeks helping track the virus in Kampungu, the outbreak's epicenter.

To date, health authorities have confirmed 24 cases and six deaths of Ebola. More cases are expected to be announced by Congo's Ministry of Health on Tuesday.

Officials at the World Health Organization first became aware of the outbreak in August. Since then, dozens of international epidemiologists and other public health experts have flown to Congo to help contain the virus.

Experts are encouraged with their education efforts about the disease.

They say the word is getting out about the importance of seeking medical help if people develop symptoms including a fever, muscle aches, intense weakness or a sore throat.

One woman recently walked into the isolation ward by herself after becoming symptomatic, said Dr. Dominique Legros, a medical epidemiologist from WHO.

"She didn't want to infect anyone else who might have had to carry her," he said from Congo. "We think that's a very good sign that the population understands how serious this is."

About 200 people are still being watched closely by health authorities. Every day, health teams visit about 20 villages within a radius of about 20 miles around Kampungu.

Fighting Ebola has been complicated by the presence of other diseases like shigella, typhoid, and malaria. All of those diseases have symptoms similar to Ebola in the early stages.

"Ebola is never a nice disease, and having other things to handle has made the outbreak more difficult," said Rosa Crestani, a nurse with Medecins Sans Frontieres who has been working in Kampungu. She spoke by phone from Congo.

The Zaire subtype of Ebola that has been detected in the Congo can kill up to 90 percent of people infected. The virus attacks the body's internal organs, and can cause bleeding from the ears, eyes and elsewhere.

Ebola is transmitted by close contact with infected animals or humans. Experts are not sure how the current outbreak began, but think that it may have started when villagers in the area ate an infected animal. It was then probably spread at several funerals, where people typically touch the body during the burial ceremony.

Written By MARIA CHENG