The Philadelphia Department of Public Health last Friday announced that it has identified the first human cases of West Nile virus in Philadelphia this year, with a confirmed count of four cases.

West Nile virus is widespread across the state, with the Pennsylvania Department of Environmental Protection recording mosquitoes carrying the disease in 46 of the 67 counties, including all counties in southeastern Pennsylvania. Two human cases of West Nile have also been identified in Allegheny County. Health department employees are working in various ways to control mosquitoes throughout Philadelphia, but in a news release they asked for the public’s help.

“We all have a role in preventing the spread of West Nile virus,” said Dr. Palak Raval-Nelson, Commissioner, Philadelphia Department of Public Health. “And it’s easy to do: Wear mosquito repellent and dump out standing water.”

West Nile virus is a neurologic infection spread by infected mosquitoes that bite humans. Most people infected with West Nile will not develop symptoms; however, one in five will develop fever and flu-like symptoms. One in 150 people will develop a severe West Nile infection that causes inflammation of the brain or spine, which can lead to death.

While people of any age can be infected with West Nile, those 50 years of age and older are at the highest risk for severe disease and death. The health department says that if you or a family member are experiencing unexplained headaches, weakness and fatigue, see your primary care provider. West Nile virus is not a communicable illness.

The health department’s vector control services program works every year to prevent mosquitoes through a variety of ways. So far this summer, it has treated more than 50,000 storm drain inlets with larvicide to stop mosquito breeding. Residents are encouraged to report mosquito problems to the health department by calling 215-685-9000. Reporting mosquitoes will trigger an inspection and, if appropriate, treatment.

The most effective way to prevent the spread of West Nile virus is to keep mosquitoes from breeding on your property. The city offers these tips to mosquito-proof your home and neighborhood:

• Anything that can hold water can breed mosquitoes, from soda bottle caps to discarded tires. Check your property for these sources of standing water and empty them.

• At least once or twice a week, empty water from flowerpots, pet food and water dishes, birdbaths, swimming pool covers, buckets, barrels, cans and any other items outside your home.

• Empty and store wading pools for kids on their side.

• Check for clogged rain gutters and clean them out.

• Remove unused tires and other items that could collect water.

• Aerate ornamental ponds or stock them with fish.

• Be sure to check for containers or trash in places that may be hard to see, such as under bushes or under your home.

• Keep well-fitted screens on both windows and doors.

• Call the health department’s mosquito complaint hotline at 215-685-9000 to report mosquito problems in your neighborhood.

Given that some mosquitoes will survive, there are steps residents can take to avoid being bitten:

• Wear insect repellent on exposed skin when outdoors. The insect repellent should contain one of the following ingredients: DEET, Picaridin, oil of eucalyptus, or PMD.

• When weather permits, wear long-sleeved shirts and long pants whenever you are outdoors.

• Consider staying indoors at dawn, dusk, and in the early evening, when mosquitoes are most active.