Dallas Mayor Mike Rawlings declared a state of emergency due to the spreading of the West Nile Virus across Texas that has so far killed 14 people. The Dallas Mayor has also requested aerial spray of pesticides to control mosquitoes in the county.

“I think this is the right thing to do. I cannot have any more deaths on my conscience because we didn’t take action,” Rawlings said, according to The Dallas Morning News.

A total of 693 cases of West Nile Virus have been reported in 43 states as of mid-August, the Centers for Disease Control and Prevention said. Nearly half of the cases, 336, have occurred in Texas. Nationally there have been 26 deaths due to West Nile Virus. More than 80 percent of the cases have been reported from six states- Texas, Mississippi, Louisiana, Oklahoma, South Dakota, and California.

This has been the highest number of cases for West Nile Virus since 1999 when it was first detected in the U.S.

“The evidence is very compelling that it is time to expand on mosquito control efforts in our region," said Richardson Mayor Bob Townsend in a statement, The Dallas Morning News reports.

Aerial spraying has already been used in places like New York City and Sacramento, California, to control the spread of West Nile Virus, Reuters Health reports.

West Nile Virus spreads through mosquito bites. People usually show symptoms of the disease between 3 and 14 days after being bitten. Severe symptoms are rare and include high fever, headache, neck stiffness, convulsions, muscle weakness, vision loss, numbness and paralysis. Most of the infected people, about 80 percent of the cases, show no symptoms, CDC says.

Dallas City Hall has suggested that people worried about being exposed to aerial spraying should stay indoors to minimize contact.

Officials have said that because the chemical used in aerial spray breaks down in sunlight and water, no special precautions are suggested for swimming areas.

Aerial spraying schedule is available here.