DRC's deadliest Ebola outbreak likely began months before May declaration

The Democratic Republic of Congo’s most lethal Ebola outbreak, officially declared in May, is now believed to have started several months earlier, according to recent epidemiological analysis. Genetic sequencing of virus samples and a review of patient records suggest that the first undetected cases occurred in late 2022, predating the May 2023 announcement by up to three months. The outbreak, which ultimately claimed more than 2,200 lives and infected over 3,000 people, surpassed the 2014‑2016 West African epidemic in mortality rate, prompting an unprecedented international response that included vaccination campaigns, contact‑tracing teams, and the deployment of World Health Organization experts.

The revised timeline underscores gaps in surveillance and reporting mechanisms within remote regions of the country, where limited healthcare infrastructure can delay detection of emerging pathogens. Health officials say the earlier onset may explain the rapid spread observed in the initial weeks after the outbreak’s formal recognition. Authorities are now reviewing protocols to improve early warning systems and to ensure faster mobilization of resources in future crises, aiming to reduce the window between virus emergence and public health intervention.