HAUPPAUGE — As Suffolk health officials investigate the first possible case of West Nile virus in the area, they are also advising residents to take precautions when it comes to mosquitoes carrying the virus. Commissioner of Health James Tomarken recommends reducing one's exposure to the insects as there is no way to tell which ones are carriers. Tomarken said a typical mosquito bite will produce local irritation, but urges residents to seek medical attention if one experiences symptoms such as headaches, chills and muscle aches.