West Nile virus is contracted from a mosquito. You can not get it from any other source. Holbrook is a West Nile positive town as are most towns. To help keep the mosquito population down, you should avoid having any free standing,stagnant water around your yard.( old tires, buckets, toys ext.) Also change bird waters daily. For free standing fish ponds or large puddles that take days to dry up, there is a mosquito dunk that can be purchased at most hardware stores that work well by killing larvae but will not harm fish or other animals. These also stay affective for about a month even if the area dries up for a little while then fills again.