The latest Ebola figures from the Democratic Republic of Congo appear to offer some hope after the number of cases was dramatically scaled back.
At one point, authorities reported more than 1,000 suspected cases and nearly 250 suspected deaths. They now report around 380 confirmed cases in DR Congo, including 60 deaths, plus 15 confirmed cases and one death in neighboring Uganda.
The decline reflects better data, as laboratories ruled out many patients who had fever but were suffering from other conditions such as malaria. The WHO Director General, Dr. Tedros Adhanom Ghebreyesus, said the outbreak had a "big head start" but response teams are now "catching up."
Contact tracing remains a major concern. Only about 45% of people in direct contact with an Ebola patient are currently being followed up, partly because the epicenter is in a conflict-hit area. The WHO says at least 90% of contacts must be traced to bring an outbreak under control.
Mistrust among some communities is another challenge. An Ebola burial team was reportedly attacked this week in South Kivu province, forcing responders to abandon a coffin and raising fears of further transmission. Traditional burial practices involve high-risk contact with bodily fluids, which spread the virus.
The outbreak is concentrated in three provinces of eastern DR Congo, an area roughly the size of the United Kingdom, much of it rural and difficult to reach. It is also unfolding in one of the most volatile regions in Africa, with many armed groups operating.
This outbreak is caused by the Bundibugyo species of Ebola, which has only occurred twice before. Because it is much rarer, there is no vaccine or proven treatment.
The WHO assesses the risk as very high within DR Congo, high in the region, but low globally. On Friday, the US CDC said its models show that without strong intervention, the outbreak could become as large as the 2014-16 West Africa outbreak.
The US announced an additional $38 million for Ebola response, bringing total direct funding to more than $200 million.