KAMPALA, Uganda (AP) _ Health workers are monitoring the health of more than 4,000 people who had contact with Ebola victims in northern Uganda, where an outbreak of the highly contagious disease has killed 160 people, an official said Monday.

``One patient alone can infect more than 20 people. We consider all those who attended the burials of Ebola victims and those who looked after them in hospital as Ebola contacts,'' said Dr. Paul Onek, head of health services in Gulu.

``We do not call them suspects but contacts. We have identified them in villages around Gulu and we are monitoring their health condition,'' he added.

The outbreak was confirmed Oct. 14 in Gulu district, 225 miles north of Kampala, and later spread to two other districts northwest and southwest of the capital.

The Ebola virus can take up to two weeks to incubate. Once the first flu-like symptoms develop, the patient can transmit the virus through contact with bodily fluids, such as mucus, saliva and blood.

In later stages, the victim begins bleeding internally, vomiting blood and producing bloody diarrhea and eventually bleeding from all orifices. At this point, and for a short time after death, the patient is most contagious.

There is no known cure, but victims aggressively treated with fluids to fight dehydration stand better chances of survival.