Yellow fever is not a new disease. Nigeria had several episodes of yellow fever outbreak in the 19th century but between the years 1986 – 2017, the country was declared free of this disease until September 2017 when Nigeria experienced a new outbreak.

What is yellow fever?

Yellow fever is a deadly viral illness caused by yellow fever virus. It is a hemorrhagic disease. This means a major symptom and cause of death of this illness is bleeding.

Yellow fever is transmitted by the bite of an infected aedes aegypti mosquito. Yellow fever causes jaundice in infected person, bringing about the name ‘yellow’. Other symptoms include fever, headache, vomiting etc. 

An infected person who visited an area where people are not immunized against yellow fever can spread the disease to them especially if there is a high density of aedes aegypti mosquito around that area. In this regards, ensuring major population of each community get vaccinated against the disease is the key to preventing the outbreak.

What is the likely cause of the recent yellow fever outbreak?

Yellow fever was eradicated because of the high level of vaccination in communities. This brought about herd immunity. This implies that the majority vaccinated will prevent transmission by breaking the chain of transmission. Those not vaccinated thereby benefits from those vaccinated.

A community were the major population is not vaccinated is at risk of having an outbreak of this disease as introduction of this virus to the community by an infected person will spread rapidly to the unvaccinated individuals leading to an outbreak.

How is yellow fever transmitted?

Yellow fever is caused by yellow fever virus. This is carried by a specie of mosquito called aedes aegypti. When an infected mosquito bites an individual, it transmits the virus to the individual. Please note that yellow fever can infects both monkeys and human. If this mosquito bites an infected monkey, this mosquito can infect any individual it bites.

Research so far has shown that yellow fever is not spread from person to person. Rather, it is spread to human through bite by an infected aedes aegypti mosquito.

What are the symptoms of yellow fever?

When yellow fever virus enters the body of human, it incubates for 3 – 6days after which it begins to show symptoms. In some people, it could be asymptomatic.

People who develop symptoms initially present with non-specific symptoms like fever, vomiting and headache. They may later develop internal bleeding and damage to organs like kidney and liver.

How can yellow fever be prevented?

Vaccination is the key to preventing yellow fever infection and outbreak. When the majority of people in a community is vaccinated, it serves as protection for others not vaccinated thereby breaking the chain of transmission of the virus.