Yellow fever is a dangerous infectious disease that is transmitted by the bite of a mosquito. It occurs in the sub-tropical and tropical regions of Africa and South America. In 85% of cases the disease is relatively mild and lasts 3-15 days. However, in 15% of cases yellow fever enters a second phase that is fatal approximately 20% of the time. The symptoms during the first stage include; fever, headache, chills, back ache, nausea and/or vomiting. In the second stage fever reoccurs and may be accompanied by jaundice (liver damage), abdominal pain, bleeding of the eyes and mouth and bloody vomit. Let’s take a look at what causes this dangerous illness.
What causes yellow fever?
We already know that yellow fever is transmitted by the bite of a mosquito. The most common culprit is the yellow fever mosquito, but other species can also carry the disease. Yellow fever is actually caused by a virus, called the yellow fever virus, that infects the mosquito when it bites an infected person. This virus then replicates inside the mosquito and spreads to the salivary glands, which is then passed onto the next person, or animal, that it bites.
There is no cure for yellow fever and the treatment for the disease is supporting the patient with pain relief and rehydrating where necessary. However, a vaccine is available to prevent people from contracting the disease. It is effective 10 days after injection and offers about 10 years of immunity. Anyone who has been infected by, and subsequently recovered from, the yellow fever virus retains immunity to the virus for life.