WHO's Medical Detectives Work With Health Authorities to Solve a Mystery

The Ebola preparedness team visits the traditional healer whose family lost several members to the Lassa fever outbreak in and around Tanguiéta, Benin. Photo courtesy of WHO/M. Ndoutabe

On a hot afternoon in November 2014, Benin’s minister of health, Dr. Dorothée Kinde Gazard and World Health Organization (WHO) country representative Dr. Youssouf Gamatié visited the Hôpital de Saint Jean de Dieu in Tanguiéta, in the country’s northwest. They were in a somber frame of mind. Four employees of the hospital had died from a severe febrile illness, some with signs of a viral hemorrhagic fever, over a period of two weeks – an event that for public health experts sounds the alarm for an outbreak of a dangerous infectious disease. Given the current Ebola virus disease outbreak in West Africa, one thing immediately came to mind – Benin could become the fourth.

Blood samples from the people who died at the hospital had been sent to a specialized laboratory in Lagos, Nigeria. The minister and Gamatié were greatly relieved when the lab reported that the samples were negative for Ebola virus. However, an unanswered question remained: what disease had killed a two-week-old baby, a hospital interpreter specialized in local languages and health workers including a highly respected pediatrician?

A group of infectious disease experts led by WHO and including staff from the Centers for Disease Control and Prevention, Canada Public Health Institute, Centre PASTEUR of Lyon in France, and other partner organizations had coincidentally just arrived in Benin. The team had been deployed as part of WHO’s Ebola virus disease Preparedness Strengthening initiative to help 14 priority countries in the African region prepare for a possible Ebola outbreak.

“The signs and symptoms of the illness that hit people in Tanguiéta suggested a hemorrhagic fever,” says Dr. Catherine Smallwood, a technical officer working in WHO’s Ebola preparedness team. “Benin had never identified a case of Lassa fever – but this was the disease that came most prominently to mind once Ebola was ruled out because Lassa fever cases had been reported from neighbouring Nigeria during 2014.”
  
Lassa fever is an acute viral hemorrhagic illness, and is present in several West African countries in Benin’s vicinity. It is transmitted to humans through contact with food or household items contaminated with the urine and feces of a local rat, which carries the virus. It can also spread through person-to-person contact, including in hospitals or laboratories lacking proper infection prevention and control measures. In severe cases, Lassa fever is fatal in up to 15 percent of patients.

The international team advised Benin’s health ministry to have the blood samples tested for Lassa virus and began working with national experts who had already been identified as Benin’s national core team for response to Ebola alerts.

Two members of the Ebola Preparedness Strengthening Team set out for Tanguiéta just as the minister and Gamatié were on their way back to Cotonou, Benin’s economic capital. Their vehicles crossed paths as the head of the Lagos laboratory called to say that two samples from the hospital had tested positive for Lassa fever.

The international team and the health ministry joined forces to initiate an Ebola-type response to the Lassa fever outbreak in Tanguiéta. They worked with hospital staff to build an isolation center, taught them how to use personal protective equipment and began monitoring more than 200 people who had come in contact with Lassa fever patients.

By now it was clear how the Lassa outbreak had begun. A woman living in a village near Tanguiéta had died from Lassa fever two days after giving birth to a baby girl. The baby fell sick when she was two weeks old and was taken to the Hôpital de Saint Jean de Dieu, where she was treated by the hospital’s paediatrician. The illness spread from there.

Team members visited the baby’s household, which was headed by a well-known traditional healer. Two of his three wives had just died of Lassa fever. “He believed that a curse was being put on him and his family,” Smallwood says. “When the district medical officer explained to him the cause was a disease and that taking certain measures would prevent its spread, he was relieved.”

The healer agreed to help prevent the disease from spreading – he lit cinders around his house, a traditional way of telling people to stay away. In addition, the district medical officer, who had strong ties to the community, led efforts to make local people aware of the presence of Lassa fever, and what to do if someone in their family fell ill. 

“The WHO-led mission to Benin highlighted the importance of preparedness and coordination at all levels -- for a rapid, systematic and effective response,” says Gamatié. “The measures the team introduced brought the Lassa fever outbreak quickly under control, and they would have been just as effective for an Ebola outbreak.” Overall there were 16 Lassa fever cases and nine deaths, and since late November no new cases have emerged.

While the experts in Tanguiéta led the response to the Lassa fever outbreak, the other members of the WHO-led team stayed in Cotonou, completing the mission they had been sent to accomplish. They assessed Benin’s ability to safely detect, investigate and report potential Ebola cases; and trained health personnel through field visits, table-top exercises and simulation of Ebola care in a hospital environment.

Source: WHO