Liberia’s and Guinea’s last known Ebola patients in a latest flare-up of the disease that hit both countries have now been discharged. All remaining contacts of confirmed cases that were placed under a 3-week period of medical monitoring have been cleared.
Liberia’s Ministry of Health, WHO and partners involved in the response held a ceremony at the Ebola treatment facility in Monrovia to celebrate the recovery and discharge of a 2-year-old boy, the final patient in the flare-up in Liberia. His 5-year-old brother recovered a week earlier. On 29 April, the country also began a 42-day period of increased surveillance – amounting to two 21-day incubation cycles of the virus.
Guinea’s final Ebola patient, a 70-year-old man, tested negative for the virus a second time on 19 April and returned to his village in the southern prefecture of Macenta to a warm welcome. Guinea began its 42-day countdown on that day, and will be able to declare the flare-up over on 31 May if there are no additional cases.
An inter-agency cross-border response
This latest re-emergence of Ebola came to light on 16 March when Guinean national health authorities and WHO were alerted to suspect deaths and infections in the southern prefecture of Nzérékoré. A rapid case investigation confirmed the new cluster of Ebola cases.
In all, 8 people in Guinea’s Nzérékoré and Macenta prefectures died from Ebola and 2 survived during the flare-up. Most of the cases were from the same extended family. More than 1,000 people who may have had contact with the confirmed cases were identified, and following intensive community sensitization and outreach, the majority of the contacts were placed under medical observation for 21 days. To help contain the spread, 1500 contacts and contacts of theirs were vaccinated with an experimental Ebola vaccine. Providing the vaccine is part of an ongoing drug trial, the outcome of which will inform its possible licensing for future use.
The effort to control the outbreak in Guinea was not without resistance. Some high-risk contacts went missing, including a woman whose husband was among the Ebola fatalities. Epidemiological investigation teams later discovered that she travelled with her 3 children to Liberia to stay with relatives. She came down with Ebola symptoms there, and died on 31 March, spreading the flare-up of Ebola to that country. Two of her three boys also became infected, but both survived. They are the 2-year-old boy and his 5-year old brother who were released from the care centre last week.
Similarly to Guinea, Liberian health authorities and partners worked to quickly trace, isolate and monitor the health of identified contacts of the 3 confirmed cases, over 100 in all, and step up infection prevention and control measures in health facilities and the impacted community.
Cross-border cooperation was also stepped up. The Ministries of Health in Guinea and Liberia, with WHO and the US Centers for Disease Control, organized additional information sharing, surveillance and overall coordination with partners in Nzérékoré.
Origins of transmission
Genetic sequencing from blood samples of the confirmed cases indicate the source of the virus is from a single and known transmission chain – suggesting exposure to infected body fluids from a survivor – rather than a re-introduction of Ebola virus from the wild.
WHO continuously stresses that flare-ups of Ebola like this one are likely to occur for some time, although with decreasing frequency, due to virus persistence in some survivors. It has been documented that Ebola virus can live in tissues and fluids of survivors, for well over a year.
WHO is working with the Ebola-affected countries to improve disease surveillance for Ebola and other infectious diseases, and strengthen health services to include improved clinical care, screening and counselling for survivors.