Summer flooding has contributed to conditions for mosquitoes to breed with 17 of the harmful insects testing positive for West Nile virus in Lycoming and Clinton counties thus far, according to the state Department of Environmental Protection.

From a local perspective, in Lycoming County, the department collected 365 mosquitoes, 99 of which were tested and 16 which produced positive test results for the virus. One mosquito was found to be positive for the disease in Chapman Township, Clinton County, according to the department data released Friday.

The primary culprit is the receding floodwaters, which are creating ideal conditions leading to the highest level of the virus since the disease was first introduced in 2000.

In Lycoming County’s analysis of the virus, one bird sample was collected, tested and produced no presence of the disease, nor has any veterinarian samples been positive, the department said.

One mosquito was found to be positive in Clinton County, but no birds or veterinarian samples, the department said.

Overall, local mosquito samples were obtained from the following communities between June 7 and July 19: Chapman Township, Clinton County; Jersey Shore; Lycoming Township; Mill Creek Township; Montoursville; Muncy Creek Township; Old Lycoming Township and Williamsport, according to the test information.

“There’s been one human case already, and our goal is for that to be the only one,” said Patrick McDonnell, department secretary. The virus has been found present in 51 counties.

Eliminate places for mosquitoes to lay eggs, use insect repellent — when possible, officials said. It is best to try to stop stagnant water from collecting in tire piles, drainage pipes, or bird baths, experts said. Bird species such as the ruffed grouse, the state bird, are getting hit hard by the bites of the mosquitoes, according to Matt Helwi, a department biologist.

Symptoms of the virus in humans may produce a mild flu and can lead to more complications such as swelling of the brain, muscle convulsions, coma, paralysis and death.

Since 2000, the disease has claimed 33 lives in the state.

More than 150 have been infected by the insect in the past six years.

The seriousness of the threat has resulted in the state adding another $140,000 to the West Nile program.

Department officials said they are monitoring a man in his 70s in Allegheny County who contracted the disease this year.