As health officials in Denton and Dallas counties reported more deaths from the West Nile virus Tuesday, Dallas County commissioners rejected a call for aerial mosquito spraying by a physicians group.
A Denton resident in his 90s who had underlying health conditions became the county's first West Nile fatality in 2012, officials said.
Meanwhile, Dallas County officials reported an eighth death, a resident who lived in northwest Dallas. The county's seventh death, reported Monday, was a resident from the Seagoville area. Both died of the more serious neuroinvasive form of the disease.
Tarrant County has seen 110 confirmed cases and one death, a Euless woman in her 60s who had other medical issues. It's the county's worst West Nile virus season since 2009, when three deaths and 32 cases were reported. No cases were reported in 2010 and only two in 2011.
As of Monday, the Texas Department of State Health Services had recorded 158 cases of the neuroinvasive form, the majority of them in Dallas-Fort Worth.
Other states where deaths have occurred include Arizona and Mississippi, according to the most recent figures on the website of the Centers for Disease Control and Prevention.
Medical Society letter
The Dallas County Medical Society sent a letter to Dallas County officials Monday saying that it supported the "immediate implementation of an aerial spraying plan to combat the historic outbreak of West Nile Virus in Dallas County."
The move came after the society's Community Emergency Response Committee held an emergency teleconference Sunday night and voted 13-0 to recommend the first aerial spraying since the mid-1960s.
Committee members felt that the measure should be taken in addition to the ongoing campaign urging residents to clear their property of standing water and to use mosquito repellant from dusk until dawn.
"All of these things need to be put in place," said the committee chairman, Dr. John Carlo.
He said the committee evaluated the number of confirmed cases, the number of sites found with mosquitoes carrying the illness and the fact that the West Nile season normally continues into October.
"Spraying has been used with success in other places without environmental damage," Carlo said.
Dallas County commissioners declined to act on the recommendation Tuesday.
A warmer-than-average winter that kept the mosquito population alive is believed to have helped cause the spike in West Nile cases this year.
People 50 and older are particularly susceptible to the virus, which can cause two illnesses -- the neuroinvasive form and the milder West Nile fever.
Tarrant County tests mosquitoes. Cities are responsible for preventive measures.
Euless' public works department, which handles the city's mosquito abatement, has been spraying every other week since April. In Benbrook, crews sprayed an area of the city the night of Aug. 1.
Arlington has not determined a need for spraying, which the city sees as a less-effective means of protection against mosquito-borne illnesses. Only two sites, or pools, have tested positive for infected mosquitoes, according to information from the county.
The city evaluates the need to spray based on the presence of a cluster of human cases and positive mosquito sampling in a targeted area.
Fire Chief Don Crowson told the City Council on Tuesday that Arlington has recorded 31 cases this year but no fatalities.
He said public education on preventative measures, such a using insect repellent and avoiding the outdoors at dusk and dawn, is key.
"We found that in most of the cases involving West Nile virus, the victims were not protected with spray," Crowson said.
Arlington is monitoring reported cases by ZIP code and deploying mosquito larvacide as necessary.
Crowson said the health community generally agrees that spraying is not the most effective way to tackle the problem because mosquitoes breed so quickly.
"Spraying is a one-time event. Within a couple of days, you have the issue occurring again," he said.
Staff writer Susan Schrock contributed to this report.
Patrick M. Walker,