Mosquito-Borne Diseases

They have been called the most dangerous animal in the world. Mosquitoes are not only a nuisance, they can carry diseases that are a serious health threat to people and pets. With just one bite, mosquitoes can transmit West Nile virus and other viruses that cause encephalitis. They can also transmit heartworm disease to dogs and cats.

Click below to learn more about these mosquito-borne diseases.

Dengue Fever

Dengue Fever

Dengue Fever is primarily a disease of the tropics that is transmitted by the Aedes Aegypti mosquito. Aedes Aegypti is a day-biting mosquito that prefers to feed on humans. It is also transmitted by the Aedes Albopictus (the Asian Tiger Mosquito). Those infected with dengue can suffer from a spectrum of illnesses ranging from a viral flu to severe and fatal hemorrhagic fever (DHF). DHF causes severe internal bleeding, shock, and circulatory collapse, and is usually fatal to children.

The Dengue Fever is passed back and forth between mosquitoes and humans, and causes an extraordinarily painful ailment that exists in four known strains or serotypes. Dengue is especially dangerous to children, who generally have one infection, but if bitten again can get a more serious infection that can lead to DHF.

Until recently, Dengue Fever was relatively unknown in the Western Hemisphere. Dengue is increasingly becoming a plague of global proportions and may soon eclipse Malaria as the most significant mosquito-borne viral disease affecting humans.

EEE

Encephalitis – in various forms such as St. Louis, Western Equine, LaCrosse, Eastern Equine, and West Nile Virus – is endemic to the United States and increasing in incidence. Eastern Equine Encephalitis (EEE) has a 30% - 60% mortality rate once contracted. Severe damage to the central nervous system occurs in those that survive the illness.

EEE is maintained in nature through a cycle between the Culiseta Melanura mosquito and birds that live in freshwater swamps. Although Culiseta Melanura do not bite humans, some will "cross bite“ – bite an infected bird and then bite a human or animal (horse, emu, and other exotic birds) – thereby spreading the disease. These mosquitoes are also known as bridge vectors, a species that transmits a disease from one host to another. These bridge vectors may take a meal from a bird and later take another meal from a mammal.

Symptoms usually occur within 2-10 days after being bitten by an infected mosquito. These symptoms include high fever, stiff neck, headache, confusion, and lethargy. Encephalitis, swelling of the brain, is the most dangerous symptom.

Malaria

Malaria is caused by a parasite that is transmitted from person to person by the bite of an Anopheles mosquito. Anopheles bite during the nighttime and are present in almost all countries in the tropics and subtropics.

Symptoms of Malaria include fever, chills, headache, muscleache, and malaise. In its early stages it can resemble the onset of the flu. These symptoms can develop 6-8 days after being bitten by an infected mosquito or as late as several months after the traveler has left the area.

Malaria can sometimes be prevented by the use of anti-malarial drugs and protection against mosquito bites. Some estimates place 40% of the world's population at risk for malaria. It is estimated that worldwide, Malaria claims over one million lives annually.

Yellow Fever

Yellow Fever is a disease caused by the bite of the Aedes Aegypti mosquito. Common in parts of Africa and South America, the symptoms of include fever, chills, headache, backache, nausea, and vomiting. Jaundice can also occur. More serious cases may affect the blood, liver, and kidneys. The disease can be fatal and is spread when an infected mosquito bites a person with Yellow Fever, and then transmits it by biting another person.

There is no specific treatment for yellow fever, other than to relieve the symptoms. Once a person has had yellow fever, they are immune to further infection. The best way to prevent the disease is through vaccination and mosquito control.

West Nile

West Nile Virus symptoms include fever, headache, nausea, vomiting, and rash, which are mild symptoms to severe symptoms that include neck stiffness, stupor, disorientation, tremor, coma, vision loss, and paralysis. These severe symptoms may dissipate in a few weeks or could remain permanently. The onset of symptoms usually begins three to 14 days after a mosquito bite.

80% of the people who are infected with West Nile will show no symptoms at all, while only 20% will show mild to serious symptoms. People who are mostly likely to show symptoms if bitten by an infected mosquito are infants, elderly and people with auto-immune deficiencies.