Angola is grappling with a yellow fever outbreak, which has infected more than 450 people and killed 178 – the first epidemic of the disease to hit the country in 30 years.

The outbreak, which was first reported in the capital city Luanda in December 2015, has since spread to 6 of the country’s 18 provinces.

“Such outbreaks usually occur in tropical rainforests,” explains Dr Sergio Yactayo, expert on epidemic diseases at WHO. “With the majority of cases reported in the capital city Luanda, the situation is more dangerous and difficult to contain because the disease can spread easily from one person to another. We are already seeing cases spread to a number of provinces outside Luanda.”

Yellow fever virus is transmitted by infected mosquitoes, the most common species being Aedes aegypti – the same mosquito that spreads the Zika virus. Symptoms include fever, headache, muscle pain, nausea, vomiting, and fatigue. A small percentage of infected people experience a second more severe phase of illness which includes high fever, jaundice and internal bleeding. At least half of severely affected patients who don’t receive treatment die within 10 to 14 days.

Angola is one of 34 countries in Africa where yellow fever occurs, and vaccination against the disease is recommended.

Vaccination a powerful weapon but in short supply

WHO has taken urgent action to contain this outbreak, working with the Angolan Ministry of Health and partners to vaccinate people in the affected provinces. As of 24 March 2016, WHO and partners have vaccinated 5.7 million people in Luanda against yellow fever using vaccines from the International Coordination Group emergency stockpile.

WHO has established an incident management system and deployed around 65 experts in epidemiology, vector control, community engagement and other areas to support the vaccination campaign.

WHO’s recently established Contingency Fund for Emergencies released US$ 500 000 to enable a rapid response to this outbreak in Angola and WHO’s African Public Health Emergency Fund has provided US$ 289 383. WHO has also supported the development of an emergency response plan to provide an additional US$ 3 million funds from the UN Office for the Coordination of Humanitarian Affairs to cover 50% of the costs of the vaccines for the province of Luanda.

Vaccine storage

“The vaccination campaign has so far been effective. We are seeing case numbers dropping considerably, especially in Luanda. However, we have to keep going and vaccinate all the people in Luanda and the affected provinces to end this outbreak. This is an enormous job which is exhausting supplies of vaccines,” says Dr Yactayo.

Whilst concerted efforts are being made to stop the outbreak, there is a global vaccine shortage, with the emergency stockpile completely depleted. An additional 1.5 million doses are needed to vaccinate the population at risk in Luanda province alone.

With the spread of the outbreak to other provinces in Angola and increasing numbers of imported cases reported by countries in Africa, WHO requests prioritizing vaccination of people at highest risk. WHO is in discussion with manufacturers and partners to divert shipments of vaccines for national routine immunization programmes until the emergency stockpile is replenished.

Partners working with WHO and the Ministry of Health include UNICEF, CDC/Atlanta, CORE Group, Médicins Sans Frontières, Medicos del Mundo, the National Red Cross of Angola and local community based organizations.

Yellow fever reports in other countries

Cases of yellow fever have been exported during this outbreak by travellers to countries including China, Democratic Republic of Congo (DRC) and Kenya. Namibia and Zambia are on high alert for imported cases.

Source: WHO