Despite detecting several cases of yellow fever in Angola and the Democratic Republic of Congo (DRC), the World Health Organization (WHO) announced on May 19 that the situation does not constitute a public health emergency.

While intensified measures are needed in order to control the spread of the disease, Professor Oyewale Tomori, head of the WHO's yellow fever emergency committee, explained that they do not see a need to declare an international health emergency.

Since the discovery of the yellow fever outbreak in December 2015, as many as 2,400 people have been stricken by the disease, and about 300 of those infected have already died. It is now considered to be the worst outbreak of the disease to ever hit Angola in 30 years.

The first cases of the current yellow fever outbreak were detected in Luanda. However, the disease soon spread to 14 of the country's 18 provinces.

In the DRC, doctors have detected 50 cases of yellow fever infection. Many of these cases are associated with Angola's disease outbreak. Uganda has also reported cases of local disease transmission, resulting in almost 60 cases.

Health officials have expressed concern over the epidemic possibly spreading to other countries where many people have yet to receive vaccinations, such as in Zambia and Namibia.

What Is Yellow Fever?

According to the Centers for Disease Control and Prevention (CDC), yellow fever is an infectious disease caused by a virus found in tropical and subtropical areas in Africa and South America.

The disease is spread through the bite of two types of mosquitoes, one of which is the Aedes aegypti that has also been associated with the transfer of dengue and Zika virus.

People infected by the yellow fever virus typically show symptoms within three to six days after being bitten by a carrier mosquito. Symptoms include nausea, loss of appetite, vomiting, muscle pain and fever, and last between three and four days.

Yellow fever can sometimes be confused with other illnesses such as malaria or dengue fever.

So far, there is no known cure for yellow fever. Infected individuals are asked to keep themselves well hydrated and are provided with supportive care such as monitoring and pain management.

About 15 percent of people who contract yellow fever progress into the second phase of the disease. These individuals can develop jaundice and show bleeding from the mouth, nose, eyes and stomach. They may also experience bloody feces and vomit.

Those who enter the second phase of yellow fever can die within 10 to 14 days following their illness.

The WHO said a large number of people in affected areas have already received vaccination against the disease. However, as of March, the group's stockpile of yellow fever vaccines has been exhausted.

Dr. Bruce Aylward, the WHO's executive director of outbreaks and health emergencies, said they expect to have 7 million new doses of fever vaccines by the end of May, which should be enough to provide vaccination for residents in affected areas.

People who are planning to travel to nations where yellow fever is present are advised to have themselves vaccinated before entering the country. They will be required to show proof that they have already received vaccination once they arrive.

Photo: U.S. Department of Agriculture | Flickr