Mosquito-borne diseases

Find out more about chikungunya virus disease, including basic facts, infographics, and information on surveillance, and prevention and control.

Dengue is a mosquito-borne viral disease widely spread in tropical and subtropical regions. It is transmitted by Aedes mosquitoes. Most of the clinical cases present a febrile illness, severe forms include hemorrhagic fevers and shock with fatalities.

The Japanese encephalitis virus is present in Asia, from Japan to India and Pakistan, and outbreaks are erratic and spatially and temporally limited phenomena, occurring quite unpredictably, even if all conditions appear to be present in a definite place. It is a leading cause of viral encephalitis in Asia, with 30-50,000 cases reported annually. Most human infections are asymptomatic. On average, one person in 200 infected develops a severe neuroinvasive illness. The case fatality rate in patients with severe disease is 20- 30% 

Malaria is caused by Plasmodium parasites. During the 20th century, malaria was eradicated from many temperate areas, including the whole of the EU, and is now limited to tropical countries. Due to the large number of imported cases in Europe, malaria is mainly a travel medicine issue.

Rift Valley fever is an acute viral febrile haemorrhagic disease that affects primarily ruminants in Africa and in the Arabian Peninsula: cattle, buffalo, sheep, goats and camels. Humans may become infected by mosquito bites and through direct or indirect contact with the blood or organs of infected animals.

Sindbis virus is widely and continuously found in insects, such as Culex mosquitoes, in Eurasia, Africa, and Oceania. However, clinical infection in humans has almost exclusively been reported in northern Europe where it is endemic and where large outbreaks occur intermittently.

West Nile virus (WNV) infection is a mosquito-borne zoonosis. The virus is transmitted among birds via the bite of infected mosquitoes and incidentally humans and other mammals may become infected.

Yellow fever (YF) cause a wide spectrum of symptoms, from mild to fatal. In severe cases there may be spontaneous haemorrhage. Mortality of these clinical cases can be as high as 80%, on a par with Ebola, Marburg and other haemorrhagic viral infections.

Zika virus disease is a mosquito-borne disease caused by Zika virus. Most infections are either asymptomatic or cause a mild illness. However, there is now a strong consensus in the scientific community about the link between Zika infection and congenital malformations, as well as developing Guillain–Barré (GBS) syndrome.