Yellow fever

Yellow fever is a mosquito-borne viral illness commonly seen in tropical and subtropical areas of South America and Africa. The "yellow" in the name refers to jaundice, which is one of the key symptoms of yellow fever seen in certain patients. Many people do not experience symptoms, but the most common symptoms that occur are fever, muscle pain with prominent backache, headache, loss of appetite, and nausea or vomiting. The virus transmission is primarily via Aedes and Haemagogus mosquitos. It has an incubation period of 3-6 days, which means it takes around 3 to 6 days for the symptoms to appear post infection.  

Yellow fever is difficult to diagnose, especially during the early stages. More severe cases can be confused with severe malaria, leptospirosis, viral hepatitis, and other hemorrhagic fevers.Tests that help in the diagnosis of yellow fever are polymerase chain reaction (PCR) testing of blood. Sometimes, urine testing can also help detect the virus in the early stages of the disease.

The yellow fever vaccine is recommended if a person is traveling to an area where yellow fever is found and a country that requires to have a certificate of vaccination against yellow fever.  The vaccine provides immunity only after 10 days of vaccination. It confers lifelong immunity to people residing in yellow fever endemic countries.