Since December 5, 2015, a Yellow fever outbreak in Angola has claimed 125 lives, with 664 suspected cases [1, 2]. The municipality of Viana in Luanda Province is the hot spot of this outbreak, with 173 suspected cases and 29 deaths. The last yellow fever outbreak in Angola occurred in 1986, but poor sanitation, low vaccination coverage and high population density in urban areas may have contributed to and exacerbated the scale of this outbreak [1, 3, 4].
Yellow fever is a mosquito-borne disease caused by yellow fever virus, part of the genus flavivirus . The main vector of the disease is the Aedes aegypti mosquito, which is also responsible for transmission of Zika virus, dengue and chikungunya . There are 44 countries that are considered to be endemic, including 31 countries in Africa and 13 countries in Latin America. There are an estimated 44,000 deaths and 130,000 cases of yellow fever occur annually .
Early symptoms of yellow fever include fever, muscle pain, chills, decreased appetite, nausea, and vomiting . In severe cases of yellow fever, patients develop high fever, hemorrhage, jaundice, and renal failure . Approximately 50% of severe yellow fever cases die within 10 to 14 days . There remains no specific treatment for yellow fever virus and treatment given is often palliative . However, there exist effective vaccines against yellow fever. A single dose of yellow fever vaccine provides life-long protection and is considered the most important and effective preventive method [2, 4]. According to the World Health Organization, the vaccination coverage of population at risk in affected regions must be at least 60 to 80% to effectively prevent outbreaks .
Authorities in Angola have launched programs in response to the current outbreak. In addition to raising public awareness and improving vector control, a massive vaccination campaign was initiated in early February . The current primary task is to immunize nearly 1.7 million people across Viana . The vaccination campaign will expand to cover other areas in the future . This outbreak may be an opportunity to boost immunization coverage of the population at risk to prevent future outbreaks in the region.