Public Health Importance Mosquitoes are known to transmit several important disease-causing organisms to man and animals. Encephalitis, dengue, filariasis, yellow fever, and malaria have affected man in mosquito infested areas throughout history. Encephalitis and occasional cases of malaria remain as important mosquito-borne diseases in Texas. Heartworm in dog is also a common mosquito-borne disease in the humid eastern area and coastal plains of Texas. Encephalitis is a viral inflammation of the brain and is caused by mosquitoes infected with the causal virus feeding on man, horses and mules.
Birds serve as important natural hosts for the virus in the disease cycle.
Public health officials often survey migrating bird populations to determine the incidence of virus and the potential for transmission to man and animal by feeding mosquitoes. Three virus strains, Eastern and Western equine encephalitis and St. Louis encephalitis, are known to occur in Texas. Symptoms in humans include high fever, convulsions, delirium and other characteristic central nervous system dysfunctions. Medical assistance should be obtained quickly if symptoms occur. Heartworm Mosquito control is important for pet owners because they transmit heartworm in the dog.