Yellow fever is common in Africa, South and Central America but surprisingly not in Asia. Why it is not found in Asia is inexplicable though racial resistance is suspected. Epidemic outbreaks have occurred from time to time in the past in Sudan, Ethiopia, Senegal, Ghana, Nigeria and the Gambia. For Nigerians who travel to Central and South America, the disease is found in Honduras, parts of Brazil, Colombia, Venezuela, Bolivia, Peru and Ecuador.
Yellow fever is a notifiable disease and certain countries still insist on yellow vaccination for travelers from countries where the disease is common before entry.
Yellow fever affects man and monkeys and can spread from monkeys to man.
A full recovery from an infection confers lifelong immunity.
1. Yellow fever is an infectious disease
Yellow fever is an infectious disease of sudden onset which is characterized by fever, yellowness of the eyes, bleeding from the nose/mouth/anus, body pains, headache etc. It could be confused with Hepatitis (infection of the liver), malaria, dengue fever and even Ebola fever. Differentiation is by laboratory tests.
2. Yellow fever is caused by a virus
It is caused by a virus which is carried by a specific type of mosquito from man to man or from monkey to man.
3. It is spread by a mosquito
Yellow fever is spread by a mosquito which carries the virus from an infected person or monkey to another person.
4. Symptoms include of the eyes/dark urine.
The symptoms of yellow fever include sudden onset of fever, yellowness of the eyes, dark urine, bloody stool, bleeding from the nose/mouth, body pains etc. Consult a doctor if you or your family member has the symptoms above for thorough examination and laboratory investigations.
5. The disease can affect any age.
The disease affects both children and adults, there is no age advantage. However, farmers are more at risk of the jungle type of yellow fever; the type that affects man and monkeys.
6. Fatality rate is about 15 percent
Most infections are mild but possible complications of yellow fever include delirium, coma and death
7. It is vaccine preventable
Prevention on personal basis is by vaccination. A vaccination against yellow fever gives protection for about 10 years effective after 10 days of the vaccination.
Use of mosquito net is also helpful as the virus is present in the blood of the infected person in the first few days of being ill and so can be picked up by the mosquito; in fact the sick person is nursed within a mosquito-netted environment.