The World Health Organization reports a suspected case of yellow fever (YF), a 67-year-old male farmer resident of Kono District, Eastern Province, Sierra Leone, tested positive for YF by plaque reduction
neutralization test (PRNT) at Institut Pasteur in Dakar on 19 October 2022.
The onset of symptoms was on 25 May 2022 with fever. Investigation carried out from 5 to 6 November 2022 showed that he is unvaccinated against YF and that other signs and symptoms included history of severe generalized body pain, muscle cramps, and jaundice.
No additional suspected cases were found during active case finding in the surrounding health facilities and in the community. The patient fully recovered after treatment in the health facility and has since resumed his normal farming activities. According to WHO and UNICEF estimates (WUENIC), YF vaccination coverage was 85% in Sierra Leone in 2021.
Yellow fever is an acute viral hemorrhagic fever that is spread through the bites of infected mosquitoes.
Symptoms of yellow fever (fever, chills, headache, backache, and muscle aches) develop 3-6 days after infection. About 12% of people infected with yellow fever virus will develop severe illness that can lead to liver disease, bleeding, shock, organ failure, yellowing skin (jaundice), and sometimes death. Among those who develop severe disease, 30-60% die.