Mosquito Borne Illnesses

For those who have seen recent news reports, the thought of mosquito borne diseases can be scary. Typically, in East Tennessee, we see a significant number of mosquito related illnesses in late summer, mainly in late July, August and September. These illnesses have a wide range of severity, from mild upper respiratory symptoms to severe central nervous system infections. The most common mosquito borne illness in our area is Enterovirus infection. Enterovirus infection typically will cause some fever, body aches, sore throat, and in worse cases where the central nervous system is involved, will cause headaches and upset stomach. Routine Enterovirus infections typically run their course in 3-5 days and do not require antibiotics, since they are viruses and not susceptible to antibiotics. Some of the worst of these cases will require brief hospitalizations for patients with severe headache who need pain control, or those who are vomiting and unable to remain hydrated. These illnesses are uniformly short lived and patients make a complete recovery.

The less common but more serious mosquito borne infections come from a family of viruses called the LaCrosse family. These viruses are transmitted by a mosquito bite, exactly the same way enteroviruses are, but they tend to infect the spinal fluid and brain more frequently than enteroviruses. LaCrosse infections are typically more severe than Enterovirus infections and commonly lead to high fever, vomiting, seizures and other symptoms of meningitis. Unfortunately, like all viruses, these infections do not respond to antibiotics, and patients are treated supportively until they recover. A significant number of patients with LaCrosse Encephalitis will be left with long term problems due to their illness.

Obviously, we want to avoid these illnesses as much as possible. Based on expert recommendations, I routinely recommend using an insect repellent with DEET to my patients. Reasonable parents are extremely unlikely to use enough “bug spray” to cause any toxicity to their children and the risk of getting an illness from a mosquito bite in later summer is very real. Always use insect repellents in a well ventilated area, and do not spray them on the face.