Surveillance is being strengthened through line-listing of cases, contact identification and follow-up, active case search and collection of food and drink samples for toxicology testing.
An 11-year-old child was admitted to hospital on 23 April with diarrhoea, vomiting and mental confusion after attending the funeral of a religious leader the day before. The child died within one hour of admission.
Meningitis reported but food source not ruled out
In Montserrado County, 42 individuals who were at the burial in Greenville on 22 April are being closely monitored.
As of 9 May, 31 cases including 13 deaths were reported in Sinoe County.
The Ministry of Health of Liberia (MOH) sent blood, urine, and plasma samples to the US Centers for Disease Control and Prevention (CDC) for testing of infectious diseases and environmental toxins.
Four of the deceased patients tested positive for meningitis C (Neisseria menigitidis) but the investigation is ongoing to determine if the bacteria is responsible for other illnesses.
A total of 26 cases including 10 deaths were reported from Sinoe County - all in people who had attended the funeral.
The other two cases, both fatal, were from the capital Monrovia in Montserrado County.
The first case had attended the funeral and presented with fever, headache and vomiting on 27 April. He died at a hospital in Monrovia. Two days later, his partner who did not attend the funeral also became ill and passed away the same day.
WHO said 21 specimens have tested negative for Ebola virus disease (EVD) and Lassa fever.
The Sinoe County Health Team is coordinating the response with the WHO, UNICEF, CDC, Africa Field Epidemiology Network (AFENET) and other partners. The Rapid Response Team (RRT) and the Incident Management System are also involved.
Preliminary results from water testing from sources serving the affected areas have ruled out bacterial contamination. Heavy metal and chemical testing is ongoing.
WHO said at this stage the overall risk of spread of the event is low.
“The event is clustered among the participants of the funeral. In addition, there is a sharp decrease in the number of cases and deaths reported since 25 April. These findings are indicative of a point source of exposure.
“The possibility of a food/ drink/ water contamination event is being actively investigated and the toxicology laboratory test will help to elaborate this hypothesis. A case-control study to identify possible exposures linked to illness is being conducted.”
The agency recommended close follow up of cases and people who attended the funeral as well as reinforcement of hygiene and food safety measures in the affected areas.
Meanwhile, WHO has created an office for Humanitarian and Health Emergencies Preparedness in Istanbul.
Dr Zsuzsanna Jakab, WHO regional director for Europe and Professor Recep Akdağ, minister of Health of Turkey signed an agreement for the office.
Dr Jakab also presented the “Action plan for the prevention and control of non-communicable diseases in the WHO European Region” to the Turkey-WHO Strategic Partnership Forum, visited a refugee health centre and met with officials from the Ministry of Health to discuss health priorities.
The office will contribute to WHO’s capacity to assist countries in preventing, preparing for and managing risk of all-hazard humanitarian and health emergencies at regional and global levels.