Yellow fever is caused by a virus that is spread by the Aedes aegypti mosquito. These mosquitoes thrive in and near human habitations where they breed in even the cleanest water. . Humans and monkeys are most commonly infected with the yellow fever virus. Mosquitoes transmit the virus back and forth between monkeys, humans or both. When a mosquito bites a human or a monkey infected with yellow fever, the virus enters the mosquito's bloodstream and circulates before settling in the salivary glands. When the infected mosquito bites another monkey or human, the virus then enters the host's bloodstream, where it may cause illness.
No antiviral medications have proved helpful in treating yellow fever. As a result, treatment consists primarily of supportive care in a hospital. This includes providing fluids and oxygen, maintaining adequate blood pressure, replacing blood loss, providing dialysis for kidney failure, and treating any other infections that develop.
Malariariskexiststhroughouttheyearinthewholecountryataltitudesbelow2000m,withoverall40–50%ofcasesduetoP.falciparum and the remainder due to P.vivax. There is no transmission in parts of the states of Himachal Pradesh, Jammu and Kashmir, and Sikkim. Risk of falciparum malaria is relatively higher in the north-eastern states, in the Andaman and NicobarIslands,Chhattisgarh,Gujarat,Jharkhand,Karnataka(withtheexception ofthecityofBangalore) MadhyaPradesh, Maharasthra (with the exception of the cities of Mumbai,Nagpur,Nasik and Pune),Orissa and WestBengal (with the exception of the city of Kolkata).
Spatial estimates of transmission intensity can be combined with vaccination coverage levels to evaluate the impact of past or proposed vaccination campaigns, thereby helping to allocate resources efficiently for yellow fever control. This method has been used by the Global Alliance for Vaccines and Immunization (GAVI Alliance) to estimate the potential impact of future vaccination campaigns.