A Mystery Disease Has Killed Dozens So Far in Northwestern Congo

Something is killing people in the Democratic Republic of Congo, and no one knows what it is. World Health Organization officials have reported two clusters of a mystery illness in the area that has sickened hundreds and killed dozens in the past few weeks alone.

WHO officials in the African Region released the latest update on the situation last Thursday. So far, there have been 431 cases and 53 deaths attributed to an unknown illness in northwestern DRC dating back to January. Initial tests have ruled out established suspects like Ebola and Marburg, and it’s still unclear whether there’s a single culprit to blame.

DRC officials reported the newest cases in mid-February. The largest and latest outbreak is occurring in Bomate Village, with at least 419 people sickened and 45 dead as of February 15. Several weeks earlier, a cluster of illness was also reported in Boloko Village. At least 12 cases and eight deaths were documented in Boloko and the nearby village of Danda.

Though the two outbreaks are in the same region (the Équateur Province), it’s not certain yet whether they are truly connected. People in both outbreaks have experienced similar symptoms, which include fever, vomiting, diarrhea, fatigue, abdominal pain, and headache. Some people have also experienced hemorrhaging (potentially life-threatening blood loss), but tests for Ebola and Marburg virus—well-known causes of hemorrhagic fever—have come up negative in both outbreaks.

Whatever the cause, it’s rapidly striking victims down. In nearly half of the deaths, people have succumbed to their illness within 48 hours, and the overall mortality rate is currently around 10%. The limited medical resources and general isolation of these villages is also hampering efforts to treat cases and identify the cause.

“The situation in Équateur Province presents significant public health risk, with two clusters of an unknown disease causing high morbidity and mortality,” WHO officials wrote in their report. “The remote geography and limited healthcare infrastructure exacerbate response challenges, with overwhelmed health facilities struggling to manage cases.”

Unknown clusters of illness occasionally happen in the world, and usually, they’re eventually identified as something established. Last December, for instance, an outbreak of a mystery deadly illness in a different part of the DRC was ultimately attributed to a severe form of malaria (likely aided by high rates of malnutrition in the area). Rarely, however, these clusters do lead to the discovery of a new disease-causing germ.

Currently, WHO officials say that the most likely possibilities for these latest outbreaks are malaria, food or water poisoning, typhoid fever, meningitis, or some other type of viral hemorrhagic fever. Perhaps significantly, the first cases in the earlier cluster were found in young children who had recently eaten a bat carcass just before becoming sick. Bats are known to carry many viruses and bacteria that can sicken humans, and they’re considered a major risk for the spread of novel diseases that could spill over into humans.

WHO officials and extra medical supplies have been sent to the region to aid local doctors, and further genetic testing of patients’ samples is now underway.