Vanderburgh County Health officials say two more mosquito pools tested positive for West Nile Virus. That brings the total number of positive Vanderburgh county samples to six for the year. The West Nile Virus is a mosquito-born illness that can cause the brain to swell. It is sometimes fatal. Its a good idea to use insect repellent when youre outdoors, especially around dusk or dawn and dump out any standing water around your house.