Relatively cold winter temperatures along with a cool and rainy spring have contributed to a fairly calm summer for West Nile Virus in Texas so far. As of August 13th only 27 cases have been reported across Texas. There has been one death, an elderly man in Montgomery County. Last year 183 cases were reported, 14 were fatal. There have been confirmed cases in and around Dallas, Harris and El Paso counties. A woman in Harris County developed a severe case, but she survived, although the disease has taken its toll on her.
But summer’s rising temperatures along with recent rainfall are creating ideal mosquito breeding environments across the state, and West Nile activity is increasing. A few cities and communities have discovered high counts of mosquitos that carry the virus and have ramped up public information campaigns as well as searching for mosquito breeding grounds and spraying on an as-needed basis. August is the peak month for West Nile virus.
West Nile Virus was first detected in the US in New York in 1999. It made its way along the eastern half of the country and was first confirmed in Texas in 2002. Today it can be found in 96% of counties across the 48 contiguous states. From 2002-2013, 4,253 cases of West Nile Virus disease have been reported in Texas. By far the worst year for West Nile in Texas was 2012. The potentially lethal illness resulted in 286 deaths across the United State including 1,890 human cases and 89 deaths in Texas. Especially hard hit were the Dallas/Fort Worth and Houston metro areas.
Most people who get West Nile virus show no symptoms. Those who feel sick usually experience flu-like symptoms that include fever, headache, nausea and joint pain. Although rare, the disease can cause serious encephalitis and meningitis and death. Although anyone at any age can be infected, people 50 and over and those with weakened immune systems are more at risk for severe disease and death due to West Nile Virus. There is no cure for the disease yet.
All of these diseases are spread through mosquitoes. They get the disease when they bite infected birds and then bite humans and other mammals, such as horses. It is also spread through blood transfusions; all donated blood in the US is screened for the virus for this reason. There is evidence that mothers can give her baby West Nile Virus when she is pregnant.
Along with West Nile Virus, Texans are at slight risk for a handful of other major arboviruses that affect humans: Saint Louis encephalitis virus, Eastern equine encephalitis virus, Western equine encephalitis virus, California serogroup viruses, and dengue virus. West Nile Virus accounts for 99% of the arborvirus illnesses in Texas.
In July the Texas Department of State Health Services confirmed the first case of chikungunya in Texas. The person who had this illness had returned from a trip to the Carribbean, where it is more widespread. This disease is causing concern because the mosquitoes that can transmit the virus are found in Texas. In August a mosquito caught in Houston tested positive for chikungunya. Also, a high number of people, as many as 90%, who are infected with the disease show symptoms.
Passerine birds, such as this grackle, are the most common birds in Texas. They are the hosts for West Nile Virus.
The Texas Department of State Health Services, the Centers for Disease Control and the American Medical Association agree that the best way to avoid West Nile Virus is to prevent mosquito bites.
Your best defense is to practice these four habits: