The number of yellow fever cases in Angola have risen slightly in the past week as health officials continue in their attempt to get the outbreak, that started last December, under control.

Aedes aegypti/CDC
Aedes aegypti/CDC

The World Health Organization (WHO) is reminding all travelers to the country that they are required to receive the yellow fever vaccination and to have a valid certificate of vaccination to prove that they are protected from the disease and to prevent its further spread.

Since the outbreak in Angola began in December 2015, 1 975 suspected cases of yellow fever (618 laboratory confirmed) and 258 deaths have been reported, the majority of them in the capital, Luanda, and in 2 other provinces. Amid concerns that the virus will spread to other urban areas and to neighboring countries, a large-scale vaccination campaign was launched in February 2016 and has so far reached almost 7 million people.

“Cases of yellow fever linked to this outbreak have been detected in other countries of Africa and Asia. We are particularly concerned that large urban areas are at risk and we strongly urge all travelers to Angola to ensure they are vaccinated against yellow fever and carry a valid certificate,” said Dr Margaret Chan, WHO Director-General.

Under the International Health Regulations (IHR), all travelers to Angola are required to be vaccinated against yellow fever. The IHR are a legally binding framework to stop the spread of infectious diseases and other health threats. IHR require that any travelers to Angola who have medical grounds for not being vaccinated against yellow fever, must have those grounds certified by the appropriate authorities.

Yellow fever, which is spread by infected mosquitoes, particularly the Aedes mosquito, is an acute viral hemorrhagic disease for which there is currently no specific treatment. A small proportion of patients who contract the virus develop severe symptoms and approximately half of those die within 10 to 14 days. A single dose vaccination, however, provides protection for life and is both safe and affordable. It is effective 10 days after the date of immunization.