The yellow fever outbreak started on December 5, 2015, in the Viana municipality in Luanda province. By March 21, the outbreak had spread to 16 of the country’s 18 provinces, according to the Angola Health ministry.
The WHO said on Thursday that there are now 450 laboratory confirmed cases of yellow fever out of 1,132 suspected cases nationally, and the numbers are expected to rise.The outbreak is described by WHO as the first one in three decades.
Luanda remains the epicenter of the current yellow fever outbreak, with 818 suspected cases and 281 confirmed, and health officials have been able to track the spread of the virus. In early February, an immunization campaign was started in Luanda and has been implemented in six municipalities out of a targeted 12. Half of severely infected patients usually die within 10 to 14 days, reports ABC News.
WHO adds that while 5.7 million people have been vaccinated for yellow fever, as part of a campaign to vaccinate 12 million people in several African countries, there is a global shortage of the vaccine.
Yellow fever is a mosquito-borne virus
Yellow fever is spread through the bite of the Aedes aegypti mosquito, the same one that spreads the Zika virus, but other Aedes mosquitoes such as the tiger mosquito (Aedes albopictus) can also be vectors for the disease.
The virus that causes yellow fever is a flavivirus. According to the latest statistics, there are an estimated 84,000–170,000 cases and up to 60 000 deaths annually. Yellow fever occurs in 34 Sub-Saharan African countries and 13 Latin American countries. About 90 percent of the cases every year come from Sub-Saharan Africa.
The concerns over a cross-border and international spread of the disease are important. If someone with yellow fever enters another region or country, and that country has a mosquito species able to transmit the virus, and specific climatic conditions plus the animal reservoir needed to maintain it, then the virus could spread. In other words, if a person with the virus is bitten by the right mosquito, the mosquito could end up being a vector for the disease.
