Ebola: a timeline

Ebola hemorrhagic fever is a serious disease that often kills humans and primates such as monkeys, gorillas and chimpanzees. It has surfaced periodically since it was first identified in 1976.

The disease is spread through infection with the Ebola virus, which is named after a river in the Democratic Republic of Congo (formerly Zaire) where it was first identified.

The virus has five known subtypes: Ebola-Zaire, Ebola-Sudan, Ebola-Ivory Coast and Ebola-Bundibugyo and Ebola-Reston. All strains but Ebola-Reston have infected humans.

Ebola hemorrhagic fever begins with flu-like symptoms, followed by bloody diarrhea and vomiting. Within days, some victims start bleeding through their nose, mouth and eyes. The most severe strains of Ebola kill up to 90 per cent of those infected.

The virus is spread through direct contact with the blood or secretions of an infected person. So far, there is no cure.

1976: The Ebola virus is first identified in Sudan and Zaïre (now the Democratic Republic of the Congo). Ebola-Zaire infects 318 people and kills 280 in Zaire. In Sudan, Ebola-Sudan infects 284 people, killing 151.

That same year, in Britain, one person is contaminated with Ebola-Sudan through an accidental needle prick at a laboratory, but survives.

1979: Ebola-Sudan infects 34 people in Sudan, killing 22. This outbreak occurs in the same area as the 1976 outbreak.

1989: Ebola-Reston found in laboratory monkeys in Reston, Va. The strain appears elsewhere in the U.S. in 1990 and 1996, and in Siena, Italy in 1992. All the monkeys are traced to one facility in the Philippines but the source of the strain is not identified.

1993: Members of the Japanese cult Aum Shinrikyo reportedly sent medical personnel to Zaire to acquire a sample of Ebola to be used as a weapon of terror.

1994: Ebola-Zaire infects 52 people in Gabon, killing. The outbreak occurs in gold-mining camps deep in the rain forest, and is at first thought to be yellow fever.

1994: A scientist contracts Ivory-Coast Ebola after conducting an autopsy on a wild chimpanzee in the Tai Forest. The scientist flies from Ivory Coast to Switzerland to receive treatment, and survives.

1995: Ebola-Zaire epidemic strikes the Democratic Republic of Congo. The virus infects 315 people, killing 250. The outbreak is traced to a patient who worked in a forest.

1996: Combined, two Ebola-Zaire outbreaks infect 97 people in Gabon, killing 66 of them. The first outbreak starts in January when hunters eat a dead chimpanzee found in the forest.

That same year, a medical professional treats patients infected with Ebola-Zaire virus, then travels to South Africa where he is hospitalized. He survives, but a nurse who looked after him becomes infected and dies.

2000: Ebola-Sudan is reported in northern Uganda. It infects 425 people and kills 224. It is the first reported emergence of the Sudan strain since 1979.

2001: Ebola-Zaire breaks out in Gabon and the Republic of Congo. Of the 122 people infected, 96 die.

2002: Ebola-Zaire infects 143 people in the Republic of Congo, killing 128. The country suffers another outbreak the following year. Thirty-five people are infected and all but six of them die.

2004: Ebola-Sudan infects 17 people and kills seven of them (41 percent) in southern Sudan.

2007: Ebola-Zaire breaks out in the Democratic Republic of Congo. Of the 264 people infected with the virus, 187 die from it.

2007: Ebola-Bundibugyo emerges in western Uganda. Of the 149 people infected with the virus, 37 die from it.

November 2008: Ebola-Reston surfaces in the Philippines when the virus infects pigs for the first time. No human infections are reported.

March 12, 2009: A German scientist accidentally pricks her finger with a needle used to inject Ebola into lab mice. She is administered an experimental vaccine. Having survived the three-week incubation period, she is declared healthy and safe on April 2. It remains unclear whether the vaccine prevented the woman from falling ill or whether she was never infected with the virus. Researchers are investigating.