Kalenga OI, et al - Authors provided the early epidemiological information arising from the ongoing investigation of this outbreak of Ebola virus disease in Équateur Province in the northwest of the country. Findings suggested similar epidemiological features of the ongoing Ebola virus outbreak in the Democratic Republic of the Congo to previous Ebola virus disease outbreaks. The outbreak should be sufficiently controlled by the early detection, rapid patient isolation, contact tracing, and the ongoing vaccination programme. If the epidemiological situation does not change, the forecast of the number of cases does not exceed the current capacity to respond. Although preliminary, the information presented has been essential in guiding the ongoing investigation and response to this outbreak.

Methods

• Experts classified cases as suspected, probable, or confirmed using national case definitions of the Democratic Republic of the Congo Ministère de la Santé Publique.
• They gauged all cases to obtain demographic characteristics, determine possible exposures, describe signs and symptoms, and identify contacts to be followed up for 21 days.
• The reproduction number and projected number of cases for the 4-week period from May 25, to June 21, 2018 was also evaluated.

Results

• Findings suggested that as of May 30, 2018, 50 cases (37 confirmed, 13 probable) of Zaire ebolavirus were reported in the Democratic Republic of the Congo.
• Results repoated 21 (42%) in Bikoro, 25 (50%) in Iboko, and four (8%) in Wangata health zones.
• As per data, Wangata is part of Mbandaka, the urban capital of Équateur Province, which is connected to major national and international transport routes.
• Researchers noted that 25 deaths from Ebola virus disease had been reported by May 30, 2018, with a case fatality ratio of 56% (95% CI 39–72) after adjustment for censoring.
• They found that this case fatality ratio is consistent with estimates for the 2014–16 west African Ebola virus disease epidemic (p=0·427).
• Fourty years (range 8–80) was the median age of people with confirmed or probable infection and 30 (60%) were male.
• In people with confirmed or probable Ebola virus disease, the most commonly reported signs and symptoms were fever (40 [95%] of 42 cases), intense general fatigue (37 [90%] of 41 cases), and loss of appetite (37 [90%] of 41 cases).
• The frequently reported symptoms were gastrointestinal symptoms, and 14 (33%) of 43 people reported haemorrhagic signs.
• Over time, the time from illness onset and hospitalisation to sample testing decreased.
• A total of 1458 contacts had been identified by May 30, 2018, of which 746 (51%) remained under active follow-up.
• Data suggested that 1·03 (95% credible interval 0·83–1·37) was the estimated reproduction number and the cumulative case incidence for the outbreak by June 21, 2018, is projected to be 78 confirmed cases (37–281), assuming heterogeneous transmissibility.