On Thursday, the World Health Organization (WHO) reported that nine countries in the WHO African Region (Cameroon, Chad, Central African Republic (CAR), Côte d’Ivoire, the Democratic Republic of Congo (DRC), Ghana, Niger, Nigeria, and Republic of Congo) this year reported human laboratory confirmed cases of yellow fever (YF) in areas that are at high risk for the disease and have a history of YF transmission and outbreaks.
Since the beginning of 2021 and as of 20 December, there have been 300 probable and 88 laboratory confirmed cases of YF. Among the probable cases there have been 66 deaths reported from six countries (Ghana = 42; Cameroon = 8; Chad = 8; Nigeria = 4; Congo = 2; DRC = 2), the overall case fatality ratio (CFR) among the probable cases is 22%, with a very wide variation among countries e.g Ghana (40%) and Cameroon (21%).
Several issues are concerning the WHO notes: Some are classified as having a fragile, conflict-affected or vulnerable (FCV) setting; cases have been confirmed in inaccessible health districts with weak YF surveillance, preparedness, and response systems, and significant population displacements into neighbouring countries and the overall YF vaccination coverage in these regions is not sufficient to provide herd immunity and prevent outbreaks.
The national coverage in the countries of concern were all under 80% with the exception of Ghana (88%): Congo (69%), Cote D’Ivoire (69%), Niger (67%), Cameroon (57%), DRC (56%), Nigeria (54%), CAR (41%), and Chad (35%).
Yellow fever is an acute viral hemorrhagic fever that spreads through the bites of infected mosquitoes.
Symptoms of yellow fever (fever, chills, headache, backache, and muscle aches) develop 3-6 days after infection. About 15% 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.
There are no medications to treat or cure yellow fever. Yellow fever vaccine is the best protection against this disease.