Congo's Ebola contact tracing is missing most new cases, Africa CDC chief says

Set the government's count of more than 8,500 recorded cases ^[9] against more than 4,000 deaths ^[1] and you get a crude ratio of about 47 deaths per 100 cases ^[24]. Both inputs are lower bounds. The ratio also lumps finished cases in with cases whose outcome is still unknown, so it is a rough guide. Kaseya described the people missing from both counts. "There are so many other people who are becoming sick, who are not tested, treated, or listed," he said ^[4].

Contact tracing exists to find exposed people before they fall ill. Kaseya called it the biggest challenge to date ^[11]. The traced figure leaves about 77% of expected contacts unaccounted for ^[26]. But "expected" is an estimate of how many people each patient exposed, so part of that gap comes from a model. The share of new cases that were never on a contact list is counted directly ^[2], and it points the same way. The tracing is happening in a region with heavy population movement from trade, conflict displacement and mining, and with deep mistrust of the government and misinformation about the virus ^[22].

Bundibugyo has no approved vaccine or treatment ^[8]. Containment rests on tracing, isolation and burials, the tasks Kaseya wants villages and local leaders to take on ^[13]. Burials are where the record is thinnest. Some residents still have "a hard time believing the disease exists," said Michel Ngimba of the National Institute of Biomedical Research in Butembo ^[19]. He described families reluctant to report a death, or to let a sample be collected from a relative who had Ebola symptoms when they died ^[20]. Other families "want to arrange the funeral quickly," Ngimba said, and because Ebola bodies are highly contagious, a quick funeral can start a new chain of transmission ^[23]. "The situation has become more difficult to monitor (and) surveillance has to deal with situations that are highly fluid and sometimes difficult to document," he said ^[21].

Those reporting gaps flow straight into the North Kivu figures. The province's share of new confirmed cases has risen 16 percentage points since the end of August ^[25]. The virus has reached 17 of its 34 health zones, and in nine of them more than half of patients with confirmed infections have died, according to Health Ministry data ^[16]. The WHO has said shortages of health workers and supplies at treatment centres there are contributing to more deaths ^[14]. The thing these figures do not tell you is how much of the province's 58% fatality rate ^[15] comes from gaps in care and how much from who gets tested. Refused post-mortem samples would push a measured rate down ^[20]. Testing that misses milder cases would push it up.

Stephanie Hoffmann, who coordinates MSF's Ebola treatment centre in Butembo, called the response "chaotic" ^[6]. "There is a lack of coordination and organization, but there's certainly a lack of actors present here," she told the AP ^[7]. In parts of North Kivu, patients have turned to regular health facilities, according to MSF ^[17]. "Local healthcare workers are the ones feeling this the most because they have to make the decision between sending their community members home to potentially die by themselves or putting themselves at risk to help treat them in their health center," Hoffmann said ^[18].

Kaseya made any end date conditional on changing the method. "I'm unable to tell you when we can stop this outbreak unless we implement the village-centered approach," he said ^[12].