The Texas Department of State Health Services confirms Thursday the first case of West Nile virus has been recorded in the state for the 2015 season.
And batches of mosquitoes on Thursday tested positive for West Nile virus in Mesquite, Frisco and Dallas County.
The West Nile virus patient, who is in Harris County, has contracted the more serious neuroinvasive form of the disease.
As per usual, health officials are not releasing personal information about the patient due to confidentiality laws.
While the patient is not in North Texas, the diagnosis serves as a reminder for everyone to take precautions to minimize the risk of exposure to the mosquito-borne virus.
"We do know that Harris County has their first human case, and so that tells us Dallas County residents and the state of Texas need to be aware that it is mosquito season and to be prepared," said Zach Thompson, director of Dallas County Health and Human Services.
Cases of West Nile neuroinvasive disease typically occur in the late summer or early fall, and Texas is seeing its first human case more than a month earlier compared to 2014.
"Seeing the first human case is not a surprise," said Thompson. "But what it tells us is we need to prepare and use preventive measures."
In 2013, there were 183 human cases in Texas. In 2014, there were 379. But Thompson said there's no way to predict if this year will have a higher number of cases than last.
"The number of mosquitoes that we are going to see in terms of possible positive mosquitoes, who knows?" said Thompson. "In terms of possible human cases, it fluctuates."
With Texas' variety of climates, West Nile can be transmitted year round, outside of traditional peak seasons. Experts advise people take protective measures by utilizing the "4Ds" to reduce the risk of West Nile virus:
- DEET: All Day, Every Day: Whenever you’re outside, use insect repellents that contain DEET, picaridin or oil of lemon eucalyptus.
- DRESS: Wear long, loose and light-colored clothing outside.
- DRAIN: Remove all areas of standing water in and around your home.
- DUSK & DAWN: Limit outdoor activities during dusk and dawn hours when mosquitoes are most active.
Several cities and towns in North Texas have already begun spraying adulticide to kill mosquitoes.
The city of Frisco says crews will spray for mosquitoes Friday from 6-9 p.m. in a section of the Frisco Lakes golf course and a nearby wooded area that leads to Lake Lewisville.
Due to the incredibly wet spring in North Texas, some city leaders believe that will lead to an increase in mosquitoes. An increase in mosquitoes doesn't necessarily mean an increase in cases of West Nile virus however.
"Up to 80 percent of people who contract the virus don't get symptoms and won't even know they have it," said Dr. Tom Sidwa, state public health veterinarian and manager of DSHS's zoonosis control branch in a news release Thursday. "But those who do get sick can experience very serious effects ranging from fever to substantial neurological symptoms and even death."
Symptoms, if they appear, are fever, headache, nausea, body aches, swollen lymph nodes and skin rashes. Fewer than 1 percent of those infected with West Nile virus experience the more serious neuroinvasive form of the illness.
State health officials are also monitoring cases of another mosquito-borne virus, chikungunya, after seven Texas residents have been diagnosed with the disease this year after traveling to Central or South America.