Yellow fever Because of this sylvatic cycle, yellow fever cannot be eradicated except by eradicating the mosquitoes that serve as vectors. In Africa, a third infectious cycle known as "savannah cycle" or intermediate cycle, occurs between the jungle and urban cycles. Different mosquitoes of the genus "Aedes" are involved. In recent years, this has been the most common form of transmission of yellow fever in Africa. Concern exists about yellow fever spreading to southeast Asia, where its vector "A. aegypti" already occurs. After transmission from a mosquito, the viruses replicate in the lymph nodes and infect dendritic cells in particular. From there,
Yellow fever ribavirin is an effective early treatment of many pathological features of the disease. Ribavirin treatment during the first five days after virus infection improved survival rates, reduced tissue damage in the liver and spleen, prevented hepatocellular steatosis, and normalised levels of alanine aminotransferase, a liver damage marker. The mechanism of action of ribavirin in reducing liver pathology in yellow fever virus infection may be similar to its activity in treatment of hepatitis C, a related virus. Because ribavirin had failed to improve survival in a virulent rhesus model of yellow fever infection, it had been previously discounted as a possible