Yellow Fever Outbreaks Cause 11% Case Fatality Rate

Since the ancient Yellow Fever virus was identified in Africa centuries ago, the continent has reported extensive, deadly outbreaks.

In 2023, this unfortunate trend continued.

The World Health Organization (WHO) today published Disease Outbreak News confirming that the African Region continues to confront Yellow Fever outbreaks.

Since the beginning of 2023, and as of late February 2024, a total of 13 countries in the WHO African Region have documented probable and confirmed cases of yellow Fever.

As of March 20, 2024, the WHO's preliminary data indicates a case fatality rate of 11%.

While the overall risk at the African regional level was re-assessed as moderate and the global risk remains low, active surveillance is required due to the potential for onward transmission through international travel and the presence of the competent vector in neighboring regions.

Yellow Fever is an epidemic-prone mosquito-borne vaccine-preventable disease transmitted to humans by infected mosquitoes, notably Aedes sp. and Haemagogus species.

The urban proliferation of Aedes spp. These mosquitoes bite during the day and can significantly amplify transmission risks, particularly in densely populated areas, leading to swift yellow fever outbreaks.

The WHO-led global Eliminate Yellow Fever Epidemics (EYE) secretariat coordinated preventive and reactive efforts during 2023. Approximately 62 million people have been vaccinated in Africa through vaccination campaigns. 

The WHO, the European Medicines Agency, and the Pan American Health Organization say a single yellow fever vaccination can grant life-long protection and promote sustained immunity for about 90% of people vaccinated.

The U.S. CDC says Yellow Fever vaccination is generally not recommended in areas with low potential for virus exposure.

However, vaccination might be considered for a small subset of travelers to these areas who are at increased risk for exposure to the virus because of prolonged travel or heavy exposure to infected mosquitoes.

The CDC says that any traveler's vaccination must consider the traveler's risk of being infected with the virus, country entry requirements, and individual risk factors for serious vaccine-associated adverse events.

"The yellow fever vaccine is a safe and highly effective way to prevent infection from what can be a deadly illness," Jeri Beales, MSN, RN, informed Precision Vaccinations. Beasles provides travelers with health information and vaccinations at Destination Health Travel Clinic near Boston, MA.

"This mosquito illness can spread rapidly between people, especially in urban areas where the mosquito has adapted to live, which is why some countries in Africa require proof of vaccination to enter."

"Children as young as nine months can be protected, and after vaccination, you may experience mild arm soreness, pain at the injection site, and sometimes a low-grade fever."

As of March 20, 2024, the YF-VAX® vaccine is licensed in the U.S. and available at certified travel vaccine clinics and pharmacies.

And the Stamaril® vaccine is available internationally in about 40 countries.