The Zaire virus, formerly named Zaire Ebola Virus, has the highest case-fatality rate, up to 90% in some epidemics, with an average case fatality rate of approximately 83% over 27 years. There have been more outbreaks of Zaire ebolavirus than any other species. The first outbreak took place on 26 August 1976 in Yambuku. Mabalo Lokela, a 44-year-old schoolteacher, became the first recorded case. The symptoms resembled malaria, and subsequent patients received quinine. The initial transmission was believed to be due to reuse of the needle for Lokela's injection without sterilization. Subsequent transmission was also due to lack of barrier nursing and the traditional burial preparation method, which involves washing and gastrointestinal tract cleansing.