5 Monivong Boulevard, P.O Box. 983, Phnom Penh, Cambodia [email protected]

Arboviruses (ARthropod-BOrne VIRUS) are a group of about 600 viruses that are transmitted to vertebrates by blood-sucking insects (like mosquitoes) and ticks.

The most known arboviruses responsible for human diseases are Dengue viruses (there are 4 viruses namely 1, 2, 3, 4), Chikungunya, Zika, Japanese encephalitis, West Nile, yellow fever, Rift Valley fever, all transmitted by mosquitoes, and Congo-Crimean Hemorrhagic Fever virus transmitted by ticks.

Dengue, Chikungunya, Zika and Japanese encephalitis have been recorded in Cambodia.

Dengue viruses are responsible for outbreaks every year, with 5 000 to 40 000 severe (hospitalized) cases (between 10 and 200 deaths) depending on years, according to Ministry of health. The mosquito vectors are Aedes aegypti and Aedes albopictus, present in all inhabited areas, including main cities. Larvae of these species develop in small water containers likes pots, jars, tires, cans, tree holes,..There is no drug against Dengue virus. Several companies have developed a vaccine, already marketed, or in evaluation phase. The most efficient way for avoiding dengue is protection against mosquitoes.

Chikungunya virus circulated in 2011 and 2012 in Cambodia and has been isolated in neighbouring countries in recent years.

Zika virus has been detected in 2007, 2008, 2009, 2010 and 2015 In Cambodia, and in 2016 in Thailand, Vietnam and Laos. This virus is currently responsible for major outbreaks in the world with severe cases of microcephaly in babies when mothers got Zika infection during pregnancy.

Both Chikungunya and Zika viruses are also transmitted by Aedes aegypti and Aedes albopictus. There is no drug and no vaccine against these viruses.

Japanese encephalitis virus is transmitted by Culex mosquitoes, mainly to birds and pigs, but Humans can be contaminated via an infected mosquito bite. There is an efficient vaccine available in Cambodia, against this disease.