Though there have been no recorded cases of mosquito-borne illnesses in Boston this year, the Boston Public Health Commission is warning residents to take simple precautions after a mosquito pool in Roxbury tested positive for the West Nile Virus.

In addition to wearing bug spray and long clothing to prevent bites, securing window and door screens in your home to prevent mosquitoes from getting indoors. West Nile has been reported in Boston every summer since 2000 and this summer’s case in Roxbury follows that trend.

To reduce the spread of mosquitoes, make sure items around your home do not collect water. Mosquitoes need water to breed and larvae can develop into adults in as little as a week.

West Nile is a rare but serious disease that often shows no symptoms but can occasionally cause headaches, fever, nausea, and vomiting lasting a few days to several weeks, according to the Boston Public Health Commission. Those over 50 are more likely to develop severe illnesses if they get West Nile.

For more information, contact the Boston Public Health Commission at bphc.org/mbi or 617-534-5611.