In August 1976, an outbreak of Ebola virus disease occurred in Zaire. The first recorded case was from Yambuku, a small village in Mongala District, northeast of the capital city of Kinshasa. The virus responsible for the initial outbreak, named after the relatively nearby Ebola River, was first thought to be Marburg virus but was later identified as a new type of virus related to the genus Marburgvirus. A total of 318 cases and 280 deaths resulted from this outbreak, which, along with an outbreak in Sudan that had begun a few weeks previously, were the first outbreaks of Ebola ever recorded.
Epidemiology
Mabalo Lokela, the headmaster of a local school in Yambuku, was the first case of the 1976 outbreak in Zaire. Lokela had toured with a Yambuku mission in August 1976 near the Central African Republic border and along the Ebola River. Lokela was initially diagnosed with malaria at the Yambuku Mission Hospital and given quinine. However, Lokela returned to the mission hospital on 1 September with a high fever. Rest was recommended, and he returned home to his village of Yalikonde, about one kilometer from the mission complex. By 5 September, Lokela was in a critical condition with profuse bleeding from all orifices, vomiting, acute diarrhea, chest pains, headache, fever and in an agitated and confused state. Lokela died shortly afterwards on 8 September. On 28 August, a second man presented symptoms, claiming he was from the nearby village of Yandongi. He left the hospital on 30 August, as no clear cause could be identified from his symptoms, and was not seen again. On the same day, Yombe Ngongo, a patient at the hospital receiving treatment for anemia, checked out of the hospital and returned to her village. She soon fell seriously ill, and was tended to by her younger sister Euza. Yombe Ngongo died on 7 September, and her sister Euza followed on 9 September. Soon after Lokela's visit, a number of other cases were presented at the Yambuku Mission Hospital. A report from the World Health Organization noted that "almost all subsequent infections had either received injections at the hospital or had had close contact with another case." Shortly after family members prepared his body for burial, in accordance with local customs, 21 of Lokela's friends and relatives fell seriously ill and 18 later died. The mission hospital's reuse of unsterilized needles also contributed to the spread of infection. Yambuku Mission Hospital was a remote Catholic hospital and had no doctors and no laboratory facilities to aid in diagnosis. Treatment was conducted by four Belgian nuns, a priest, one female nurse from Zaire, and seven male Zaireians. Urgent pleas for assistance were sent out on 12 September. On 15 September, the first doctor to arrive, Mgoi Mushola, prepared a report in which he noted that none of the many treatments provided met with success; this was the first formal description of Ebola virus disease. Peter Piot, a microbiologist and physician who investigated the ensuing epidemic, concluded that it was inadvertently caused by the Sisters of Yambuku Mission Hospital, who had given unnecessary vitamin injections to pregnant women in their prenatal clinic without sterilizing the needles and syringes. In all, 318 cases of Ebola were identified in Zaire, and 280 resulted in death. An additional 284 cases and 151 deaths occurred in nearby South Sudan in an unrelated outbreak. Yambuku Mission Hospital was closed after 11 of its 17 staff members died. Belgian nuns serving the community were also infected, and two of them died, along with Mayinga N'Seka, a Zairean nurse, after the group was transported to Kinshasa. With assistance from the WHO, the outbreak was eventually contained by quarantining local villagers in their communities, sterilizing medical equipment, and providing protective clothing to medical personnel. The small Congolese Air Force provided helicopters to allow the outbreak team to visit 550 villages in the area.
History
The table below summarises the eleven outbreaks that have occurred in the DRC since 1976:
