Yellow fever Brazil. In March 2018, Brazil shifted its policy and announced it planned to vaccinate all 77.5 million currently-unvaccinated citizens by April 2019. Some countries in Asia are theoretically in danger of yellow fever epidemics (mosquitoes with the capability to transmit yellow fever and susceptible monkeys are present), although the disease does not yet occur there. To prevent introduction of the virus, some countries demand previous vaccination of foreign visitors if they have passed through yellow fever areas. Vaccination has to be proved by the production of a vaccination certificate which is valid 10 days after the vaccination and lasts for
Colorado tick fever Colorado tick fever Colorado tick fever (CTF) (also called mountain tick fever, American tick fever, and American mountain tick fever) is a viral infection (Coltivirus) transmitted from the bite of an infected Rocky Mountain wood tick ("Dermacentor andersoni"). It should not be confused with the bacterial tick-borne infection, Rocky Mountain spotted fever. The type species of the genus "Coltivirus", Colorado tick fever virus (CTFV) infects haemopoietic cells, particularly erythrocytes, which explains how the virus is transmitted by ticks and also accounts for the incidence of transmission by blood transfusion. The disease develops from March to September, with the highest infections