Why Mosquitoes Are A Serious Threat

Mosquito Borne-Diseasediseased child

Mosquitoes can cause sickness and death through the diseases they can carry. The information provided below describes which mosquito-borne (carried) diseases threaten us here in Louisiana both currently and potentially. Apart from the ability to carry diseases, mosquitoes also cause major nuisance problems for rural homeowners and can ruin recreational activities such as hunting and outdoor sports. In extreme situations, high levels of flood-water mosquito species can pose a life-threatening situation for livestock and wild animals as well.

Economic Impact

The economic impact of the problems that mosquitoes cause is staggering for such a tiny little insect. In Africa alone where mosquito control efforts are severely lacking businesses note that work absences related to mosquito-borne diseases cost them $12 billion a year in lost productivity. Back here at home, excluding the cost of mosquito control efforts by governmental agencies, the cost of WNV related health care is estimated to be over 56 million dollars per year in the U.S. alone.

Mosquito-Borne Disease Quick Facts

  • According to the World Health Organization, mosquitoes infect between 330-600 million people a year with Malaria and Dengue, just two of the life-threatening diseases that mosquitoes can carry.
  • According to the World Health Organization, over 400,000 deaths occurred from malaria in 2019. The Centers for Disease Control reports that 22,000 people die from Dengue related deaths every year. 
  • According to the Centers for Disease Control in the United States alone since 2001 over 50,000 confirmed cases of West Nile Virus infections in humans have occurred. Of those cases, over 2,300 have resulted in death. 
  • Over 1 million pets in the U.S. alone are estimated to be infected with heartworms. The infection rate for dogs over 2 years old is thought to be over 80% in South Louisiana.
  • Mosquitoes kill more people (over 700,000 per year) than any other animal on the planet by far. The closest in fact would be snakes, they kill around 50,000 people per year. 

For More Information

To obtain more information about mosquitoes and the diseases they can carry check out these informative links.


Top Mosquito-Borne Disease Threats in The U.S.

  1. Eastern Equine Encephalitis
  2. St. Louis Encephalitis
  3. West Nile Virus
  4. Zika Virus
  5. Heartworm

Eastern Equine Encephalitishorse

  • Abbreviation: Eastern Equine Encephalitis (EEE)
  • Fatality Rate: 30%
  • Primary Mosquito Vector: Culiseta Melanura in birds / Culex Quinquefasciatus in man
  • Potential Mosquito Vectors: Cs. Inornata, Aedes Albopictus, Aedes Sollicitans, Aedes Vexans, Aedes Infirmatus, Aedes Atlanticus, and Coquillettidia Perturbans 
  • Threat Status: Intermittent

Deadliest Mosquito-Borne Disease in The U.S.

Eastern Equine Encephalitis much like West Nile Virus and St. Louis Encephalitis is a viral infection maintained in the wild by a bird to mosquito to bird cycle. Horses are involved with humans as dead-end hosts meaning they cannot transmit the disease between themselves. Of the many mosquito-borne diseases, EEE is the deadliest mosquito-borne disease to occur in the United States with a 30% fatality rate for those infected. Half of those who survive the infection are stricken with various degrees of mental disability and paralysis. People younger than 15 and those older than 50 are the most prone to infection although EEE can affect persons of any age.

1947 Outbreak

A major outbreak of EEE struck Louisiana in 1947 when the virus caused disease in over 15,000 horses and 15 human cases resulting in 7 people dead. Since that outbreak understanding of the transmission cycle in the wild and the creation of a vaccine for horses has resulted in much fewer infections for horses and humans. Although incidents of disease in humans have been low in recent times EEE still remains a deadly mosquito-borne disease for both horses and man.