CAUSES Yellow Fever is caused by the Yellow Fever virus. The virus is in the flavivirus group. There are two distinct types, called topotypes. When an infected mosquito bites an animal, the animal gets infected with Yellow Fever. The person's skin turns a shade of yellow, because the disease affects the liver. There is an excessive amount of bile in the blood. The illness can lead to Hepatitis and hemorrhagic fever. Yellow Fever has been around for 400 years, and it mainly happens during the rainy season in Africa.

SPREAD Yellow Fever is a disease transmitted to humans through the bites of infected mosquitoes. It can lead to Hepatitis A or B and hemorrhagic fever. Humans and monkeys are the principal animals that are affected by Yellow Fever. The virus is carried through animals, from one to another. (horizontal transmission) by a biting mosquito, the vector. The mosquito, Aedes Aegypti Mosquito, can also pass the virus to her offspring via infected eggs. There are two types of Yellow Fever: Jungle Yellow Fever and Urban Yellow Fever. Jungle Yellow fever occurs when a mosquito bites a monkey, carries germs from the monkey, and spreads it to a human. Urban Yellow Fever is the most common type. It is spread when one mosquito bites a human, and then comes in contact with another human. The mosquito carries germs from one person to another, causing the other person to catch the disease. People get Yellow Fever from the bite of an infected female mosquito. The  mosquito is called Aedes Aegypti Mosquito. She bites humans (male mosquitoes don't bite) and takes germs and viruses from one person she has bitten and spreads it to the other person. The other person gets Yellow Fever. The reason why the Aedes Aegypti Mosquito bites people is that she needs blood for her eggs.

PREVENTION To prevent getting Yellow Fever, you can get the vaccine before traveling to countries that Yellow Fever occurs in. Every person over 9 months is eligible to get the vaccine for Yellow Fever. The disease only occurs in parts of South America and Africa. Travelers should take extra precautions, because Yellow Fever can be deadly. Symptoms start 3-6 days after the mosquito bites.

TREATMENT There is no specific treatment for this disease. People infected with Yellow Fever should avoid coming in contact of any mosquitoes, and stay in bed. "Dehydration and fever can be treated with oral rehydration salts", says World Health Organization, a web site informing people about diseases.