Two more deaths have been reported in an unexplained illness cluster in Liberia, raising the total to 11, and though tests have ruled out Ebola, authorities are eyeing foodborne or waterborne illnesses as the possible cause.
In an Apr 29 update, Liberia's Ministry of Health (MOH) said 20 illnesses have been reported, up from 17 a few days ago. The case-fatality rate is 55%.
The outbreak began on Apr 23 and is linked to attendance at a funeral of a religious leader in Greenville in Sinoe County. Symptoms include diarrhea, vomiting, and mental confusion. The first case outside of Sinoe is in a person from Montserrado County who had links to the funeral.
Five people are still hospitalized in stable condition, and health officials are monitoring 52 close contacts. Public health workers have been involved in active case finding, and no new cases have been reported since Apr 28.
Twelve patients Ebola-negative
In a similar update from the World Health Organization (WHO) Regional Office for Africa, officials said nearly all of the affected people participated in at least one aspect of the funeral, including burial, "repass" (thought to be a meal following the funeral), and "wake keeping."
The WHO said though dreaded Ebola has been ruled out, there is still an urgent need to establish what sparked the illness cluster. It said the dramatic evolution over a short time, combined with sudden deaths and case clustering, points to a common exposure to a pathogenic agent.
"The likelihood of foods, drinks, or water poisoning is high, and the ongoing toxicology testing will be very critical to provide some answers," officials said in the report, adding that the risk of spread is easing with the sharp decline in the number of cases and deaths.
According to the MOH, analysis of three urine specimens found no common pattern and is inconclusive. Lab tests to rule out cholera and shigellosis are ongoing. Eleven specimens have been shipped to the US Centers for Disease Control and Prevention (CDC) for testing. Efforts are under way to send samples to a WHO-affiliated lab in South Africa and a Doctors Without Borders lab in France.
Water sampling in Sinoe County was negative for coliforms, and food samples have been collected and preserved at the national reference laboratory for testing.
Seventeen specimens from 12 patients have tested negative for Ebola.
Liberia's MOH has asked the WHO and CDC to expedite toxicology testing outside the country, and the WHO is supporting the deployment of a pathologist to do an autopsy on a body that is preserved. Except for a corpse in Monrovia, all bodies were safely handled by a burial team in Sinoe County.
See also:
Apr 29 Liberia MOH situation report
Apr 28 WHO African regional office weekly bulletin on outbreaks and other emergencies