quality:corruption, structural:reformatting, information:classification
Zaire

On 26 August 1976, the second outbreak of EVD began in Yambuku, a small rural village in Mongala District in northern Zaire (now known as the Democratic Republic of the Congo). This outbreak was caused by EBOV, formerly designated Zaire ebolavirus, a different member of the genus Ebolavirus than in the first Sudan outbreak. The first person infected with the disease was the village school's headmaster Mabalo Lokela, who began displaying symptoms on 26 August 1976. Lokela had returned from a trip to Northern Zaire near the border of the Central African Republic, after visiting the Ebola River between 12 and 22 August. He was originally believed to have malaria and was given quinine. However, his symptoms continued to worsen, and he was admitted to Yambuku Mission Hospital on 5 September. Lokela died on 8 September 14 days after he began displaying symptoms.

Soon after Lokela's death, others who had been in contact with him also died, and people in Yambuku began to panic. The country's Minister of Health and Zaire President Mobutu Sese Seko declared the entire region, including Yambuku and the country's capital, Kinshasa, a quarantine zone. No-one was permitted to enter or leave the area, and roads, waterways, and airfields were placed under martial law. Schools, businesses and social organisations were closed. The initial response was led by Congolese doctors, including Jean-Jacques Muyembe-Tamfum, one of the discoverers of Ebola. Muyembe took a blood sample from a Belgian nun; this sample would eventually be used by Peter Piot to identify the previously unknown Ebola virus. Muyembe was also the first scientist to come into direct contact with the disease and survive. Researchers from the Centers for Disease Control and Prevention (CDC), including Piot, co-discoverer of Ebola, later arrived to assess the effects of the outbreak, observing that "the whole region was in panic."

Piot concluded that Belgian nuns had inadvertently started the epidemic by giving unnecessary vitamin injections to pregnant women without sterilizing the syringes and needles. The outbreak lasted 26 days and the quarantine lasted two weeks. Researchers speculated that the disease disappeared due to the precautions taken by locals, the quarantine of the area, and discontinuing of the injections.

During this outbreak, Ngoy Mushola recorded the first clinical description of EVD in Yambuku, where he wrote the following in his daily log: "The illness is characterised with a high temperature of about 39 °C (102 °F), haematemesis, diarrhoea with blood, retrosternal abdominal pain, prostration with 'heavy' articulations, and rapid evolution death after a mean of three days."

The virus responsible for the initial outbreak, first thought to be the Marburg virus, was later identified as a new type of virus related to the genus Marburgvirus. Virus strain samples isolated from both outbreaks were named "Ebola virus" after the Ebola River, near the first-identified viral outbreak site in Zaire. Reports conflict about who initially coined the name: either Karl Johnson of the American CDC team or Belgian researchers. Subsequently, a number of other cases were reported, almost all centred on the Yambuku mission hospital or close contacts of another case. In all, 318 cases and 280 deaths (an 88% fatality rate) occurred in Zaire. Although the two outbreaks were at first believed connected, scientists later realised that they were caused by two distinct ebolaviruses, SUDV and EBOV.