The bite is back.

With the return of summer weather, come mosquitoes – and public health warnings.

“We just need to be vigilant and on the lookout,” said Erie County Health Commissioner Gale Burstein. “Mosquitoes are a summertime nuisance, but by taking a few simple steps, you can reduce your risk of being bitten and possibly contracting a mosquito-borne disease like West Nile Virus.”

West Nile Virus can lead to fever or other symptoms in 20 percent of those infected and in rare instances can be fatal.

Less than 1 percent of those infected become seriously ill, but the elderly or those already in poor health are most vulnerable.

So far this summer, there have been no reported cases of West Nile Virus in Erie County. No water pools have yet tested positive. There has not been a confirmed human case of the disease countywide since October 2012, Burstein said.

Burstein cautioned, however, the worst could come later in the summer.

“In reality, we see it in the late summer,” she said.

Of the dozen human cases of West Nile reported in Erie County two years ago – including a fatal case – seven cases were diagnosed in August, four as late as November and one in October. The three cases of infected humans in 2011 showed up in August and September.

“It’s July, so it’s a little early in the season to see human cases, but it doesn’t mean it can’t happen,” Burstein said.

So far statewide, one confirmed case of the virus has been reported, although not in a human, according to the federal Centers for Disease Control and Prevention.

The CDC reports that West Nile infections in mosquitoes or animals have been reported in 20 states, including New York. Twenty-nine cases of infected humans have turned up in 14 states as of last week, including a fatal case involving a 75-year-old man in Missouri last month.

Regarded “as one of the most deadly mosquito-borne diseases in the United States,” the virus was recently detected for the first time this year in Plymouth County, Mass.

Discovery of eastern equine encephalitis and West Nile viruses last year prompted officials in Chautauqua County to conduct aerial spraying in late August in the Jamestown area. Symptoms of EEE include high fever, stiff neck, headache and malaise, and it is lethal in an estimated 35 percent of cases when the virus affects the brain.

There were no reported illnesses associated with the West Nile Virus in Erie County last year or in 2010, although the virus was discovered in a pair of water pools in Amherst as early as July 17-18 last year – two of 17 pools in all that tested positive for the virus.

Burstein said weather plays a large role in the mosquito crop – and, by extension, the viruses associated with them – in any given summer.

“If it’s warm early in the season and it stays very warm, there are more and more opportunities for mosquitoes to propagate and more opportunity for West Nile Virus,” she said.

That’s why health departments remind the public to eliminate mosquito breeding grounds around their homes and yards. Such steps include ridding yards of standing water, moving water bowls for pets indoors and dumping standing water in bird feeders, tires and toys.

“We still have several months of warm weather where West Nile Virus could be identified in mosquitoes,” Burstein added. “So, it is always a good idea to be proactive in addressing potential problems.”