Certain areas of the world present more of a threat of mosquito-borne illness than others. But despite our best efforts to eradicate them, serious and even life-threatening illnesses can still be spread by mosquitos here in America. Malaria, one well-known mosquito-borne disease known to be common in South Asia and Africa, can also be found here in America.

What is Malaria?

Malaria is a disease caused by a parasite in the genus Plasmodium. When this parasite infects a human host, it replicates and induces high fevers, shaking chills, and flu-like symptoms. Treatment for malaria is necessary, for without treatment, the affected individual may develop severe complications or even die.

How Do Mosquitos Spread Malaria?

Mosquitos spread malaria by biting humans. When an anopheles mosquito bites a person who has been infected with malaria, the bite transfers the parasite from the human’s bloodstream to the mosquito, infecting it. When an infected mosquito bites another human, it can transfer the parasite to their bloodstream, where the parasite may replicate and cause malaria. By so doing, a single mosquito can spread malaria to multiple humans over the course of its lifespan.

Where are Mosquitos that Spread Malaria Found in the U.S.?

Malaria is spread by the female anopheles mosquito, commonly called the “malaria mosquito” or “marsh mosquito”. Anopheles mosquitos in the U.S. have been reported in over 30 states and can be found in the West and in the Eastern U.S. They usually live near marshes, swamps, natural bodies of water, or even swimming pools, because stagnant water is the perfect breeding ground for mosquitos.

A History of Malaria in America

Malaria was once a major public health problem in America, especially with the vast swamps that used to dominate the American South. In the 1940s, the National Malaria Eradication Program was established to eliminate malaria in the continental U.S. This program applied DDT spray to houses, drained swamps, removed mosquito breeding sites, and even sprayed insecticides from aircraft vehicles to gradually and completely eliminate transmission of malaria in our country.

But while the continental U.S. was declared free of malaria as a public health problem in 1949, malaria in America is by no means eradicated. Over the past 50 years, mosquito-borne malaria has occurred in more than 150 locally acquired cases and over 60 limited outbreaks in the United States. Additionally, more than 2,000 people in America are diagnosed with malaria each year. Most of these are in travelers and immigrants who have recently visited countries where malaria is more common, such as South Asia and sub-Saharan Africa. If a female anopheles mosquito were to bite one of these affected individuals, she could then spread malaria to other Americans.

The mosquitos that can carry malaria are found all across America, and future malaria outbreaks could occur due to increasing global travel and climate changes. It is important that we take steps to prevent mosquito bites and control the mosquito population in the U.S.