Disease Transmission


Aedes aegypti mosquitoClick here for what you need to know about the Zika virus and how to prevent it.

Aside from the irritation and annoyance that mosquitoes inflict on humans and livestock alike, the threat of disease pathogen transmission is always present. Malaria, Dengue, Yellow Fever, and Encephalitis (West Nile virus, St. Louis, Eastern Equine) are just a few representatives of a long list of diseases for which mosquitoes serve as vectors. Citizens of the U.S. are fortunate to live in an area of the world where the standard of living is high and public health agencies are active with control and prevention programs. However, in other parts of the world where this is not the case, mosquito-borne diseases like malaria account for over 2 million deaths a year.

Part of our ongoing operation is disease surveillance for 3 of the encephalitis viruses transmitted by mosquitoes: West Nile Virus (WN), St Louis Encephalitis (SLE) and Eastern Equine Encephalitis (EEE). Primary focus is the collection of mosquitoes via various trapping techniques, keying in on those species considered as most likely to transmit these viruses. The mosquitoes are sorted by species, placed in pools of up to 100 specimens in a vial and shipped to the LSU Vet School for virus isolation.

Dead birds are no longer collected as part of our disease surveillance program. The State of Louisiana no longer tests dead birds because West Nile Virus is already known to be endemic to Louisiana. Dead birds also do not provide information on when or where the bird was infected. Keep in mind that finding a dead bird around the home does not mean that WNV was the cause of death. Bird deaths are caused by a lot of different things with WNV being just one of them.

Here are links to the various diseases transmitted by mosquitoes. Not all of them are found here, but all are important considering the speed of travel in today’s society.

Arboviral encephalitis: Inflammation of the brain (encephalitis) caused by infection with an arbovirus, a virus transmitted by a mosquito, tick or another arthropod. Infection of vertebrates, including humans, occurs when an infected arthropod feasts upon them for a blood meal. 

Arbovirus Transmission Cycle