In late May, a resident of Lantana became the first person since 2009 to contract the West Nile virus in Denton County, prompting area health officials to issue the usual recommendations and preventative measures.
Since then, two more human cases have been reported in the county – both in the City of Denton. All three people have been hospitalized.
Officials in neighboring Dallas and Tarrant counties also say human cases of West Nile virus have been discovered, and mosquitoes testing positive for West Nile virus have been found in multiple areas of Denton, Collin, Dallas, and Tarrant counties.
Sarah McKinney, public information officer for the Denton County Health Department, said that since municipalities handle the treatment of standing water where virus-carrying mosquitoes breed, people in unincorporated places like Lantana need to especially be on the offensive.
"We want to focus on prevention; we don't want any more people to contract West Nile, so the best way to do that is to prevent mosquito bites in the first place," she said.
Due to confidentiality laws, county officials have released little information on the West Nile patients' conditions.
The county continues to track West Nile, as physicians are required to report any new cases to the county within one week.
West Nile virus is normally spread through mosquito bites and very rarely through other blood interactions such as transfusions. There's no evidence it can be spread through casual contact. Thus, the best way to control its spread is to keep mosquitoes from breeding in standing water near residences and avoiding or repelling live mosquitoes with repellant containing DEET.
"Dump out standing water and avoid those times you're more likely to be bitten, or wear the appropriate clothing or repellent if you are going to be out," McKinney said. "With summer barbecues and whatnot, we're not going to give up all those, so we're going to be out when the mosquitoes are out -- we just have to be proactive."
Standing water can also be treated with briquets or "dunks" containing BTI, a bacterium which destroys mosquito larvae but is otherwise non-toxic to fish and other animals.
"If you have to have standing water, some people have small ponds, definitely check out those BTI briquettes," McKinney said. "I think that the local hardware stores all sell them."
Those over 50 and people with reduced immunity are at higher risk of contracting West Nile virus, and most people bitten by an infected mosquito will never develop symptoms.
Some may develop a mild set of symptoms, including fever, headache, nausea, vomiting, swollen lymph nodes, skin rashes and body aches.
Only one percent of those who are infected will develop the more serious symptoms.
Serious symptoms include high fever, severe headache, neck stiffness, disorientation, tremors, convulsions, vision loss and paralysis or numbness.
"What we're always reminding people is that at that phase, you'd be getting yourself checked out by medical personnel," McKinney said. "Even the milder symptoms, a lot of people would be going to their health care provider."
McKinney said that recent weather trends may have contributed to larger-than-usual insect populations this summer.
"That's our guess, that the reason is because we had a mild winter, and also all the rain we had in the spring. We can't really say for sure, but we're leaning that way," she said.
She said that the relatively early case is not cause for alarm.
"It is a little bit early, and the reason could be the milder winter and all the rain we had in the spring, however, having early cases doesn't mean we're going to have a heavy West Nile virus season," McKinney said.
For more information on avoiding West Nile, visit http://dentoncounty.com/HEART/WNV.