Mosquitoes are one of life’s annoyances, slender, skinny-legged tormentors primed to bite you, buzz
through your precious sleep and crash your patio party. But occasionally, the nuisance turns noxious, causing illness or even death.
Disease spread by mosquito bites is not commonplace in Texas, but it does occur. Typically, the
biggest concern is the West Nile virus, says Dr. Keith Lamy, at Austin family practice medicine clinic.
Since 2002, Texas has had dozens or even hundreds of cases reported each year.
During a bad outbreak in 2012, Texas had 1,868 cases, including 153 in Travis County. Feverish
victims began showing up at clinics, suffering muscle weakness and tremors, and sometimes paralyzed
from brain inflammation. Six people in Travis County died, all of them 60 years or older.
Last year, Texas had 135 West Nile cases, resulting in six deaths.
Health officials expect outbreaks of West Nile to continue in Texas. Fortunately, most infected people do not show any signs of it. In other cases, people experience mild, flu-like symptoms, including fever, aches, skin rash, and swollen lymph glands. A small number of infected people—about one in 150—will develop a severe or even fatal illness, according to the CDC. Symptoms can last for days, weeks, or even become permanent. They include neck stiffness and muscle weakness, high fever, loss of vision, convulsions, numbness, coma, and paralysis.
People over 60 years of age are at greater risk, as are people with certain medical conditions, such as
cancer and diabetes.
No vaccines exist to prevent the virus, and there are no anti-viral medications for treatment.
There are also no vaccines or medicines to stop the Zika virus, which is usually caused by a mosquito
bite. An infected person may have no symptoms, or mild ones, such as fever, rash, aches, and pains.
But some cases can be severe and require hospitalization.
Zika is a serious risk for pregnant women, because it can cause a birth defect of the brain known as
microcephaly. Other potential problems include miscarriage, stillbirth, and other birth defects.
Although there have been a few cases of Zika caused by mosquitoes in Texas, typically you get the
disease by traveling to countries where the disease is prevalent. Besides mosquitoes, Zika can also
sometimes be spread by sexual contact or from a pregnant woman to her fetus.
Last year, the United States reported 452 Zika cases, and 437 of those were travelers returning from
areas affected by Zika. In Texas, five cases were believed to be from local mosquito-borne transmission, according to the CDC.
Texans should also be aware of two other mosquito-borne diseases that sometimes occur in the state.
No treatment medication occurs for either illness. Dengue fever is almost always transmitted by mosquitoes, and US cases typically occur when travelers visit countries where the virus is prevalent. In recent decades, however, a few outbreaks have occurred in the United States, including small ones in southern Texas in 2013 and 2005.
Symptoms usually begin 4 – 7 days after a mosquito bite. While some people have no symptoms,
others develop high fever, nausea, vomiting, pains, and other flu-like misery. In severe cases of
dangerous hemorrhagic fevers, victims can have intense abdominal pain, breathing problems, bleeding,
circulatory failure, and even death.
In recent years, Texas and other states have also reported cases of the chikungunya virus, almost always related to travel abroad. Most infected people will develop symptoms, which start 3-7 days after a mosquito bite. Fever and joint pain are typical, and headache, muscle pain, and swelling of the joints may occur. Newborns, the elderly, and those with certain medical conditions are at greater risk of developing severe and disabling symptoms.
International travelers should take precautions if they visit countries where mosquito-borne diseases
such as yellow fever, malaria, or Japanese encephalitis are prevalent. Vaccines are possible against
yellow fever, which typically causes flu-like symptoms but can cause more severe illness; as well as
Japanese encephalitis, which only rarely results in serious or fatal brain inflammation.
Malaria, meanwhile, has no vaccine and poses a threat in many tropical and subtropical parts of the
world. Travelers who come down with malaria may have fever, aches, shaking chills, nausea, and
vomiting, as well as anemia and jaundice. Without treatment, they may become severely ill with
kidney failure, seizures, mental confusion, coma, and death.
Fortunately, antimalarial drugs are available. If you plan to visit areas with malaria, consult with Dr. Lamy before your trip to review your options based on your age, medical history, and travel plans. You may need to allow 4-6 weeks before travel for the drugs to become effective and for special doses to be prepared.
Of course, whether you travel or stay in Texas, your best defense against illness is to keep mosquitoes
from biting you or breeding near you. Drain all pots, tires, and other sources of standing water around your property to get rid of places where mosquitoes can lay their eggs. And use bug repellent, screens, and protective clothing to reduce your risk of exposure.
And if you think you may be suffering from West Nile, Zika, or any other mosquito-borne disease,
schedule an appointment with Dr. Lamy to review your symptoms.