A male in his 50s is the first confirmed human West Nile Virus (WNV) infection in San Joaquin County this year. That, according to Dr. Julie Vaishampayan, Assistant Health Officer from San Joaquin County Public Health Services (PHS). The man’s health is being monitored in a hospital. To date in 2015, West Nile virus has been detected in 13 other California counties.

West Nile virus is most commonly transmitted to humans and animals through the bite of a mosquito infected with the virus. Hot weather, abandoned swimming pools and standing water create ideal conditions for the development of mosquitoes and the subsequent spread of the virus.

“It is very important that people take precautions to protect themselves and their families from mosquito bites,” advised Dr. Vaishampayan.

The San Joaquin Mosquito and Vector Control District has continued spraying for mosquitoes throughout the county, including several applications during the past week in and around the Escalon area. County officials earlier this month confirmed the presence of the virus in mosquito samples collected from the city.

WNV is influenced by many factors such as climate, the number and types of birds and mosquitoes in an area, and the level of immunity in birds to WNV. It is possible that the drought has contributed to WNV amplification by reducing sources of water for birds and mosquitoes. As birds and mosquitoes seek water, they are coming into closer contact, increasing transmission of the virus.

Most individuals who are infected with WNV will not experience any illness. About one in five people infected with WNV will develop West Nile Fever with symptoms of headache, fever and fatigue. However, some individuals – less than 1 percent – will develop serious neurologic illness such as encephalitis or meningitis.

Individuals 50 years of age and older have a higher chance of getting sick and are more likely to develop serious illness when infected with WNV. Studies also indicate that those with diabetes and/or hypertension are at greatest risk for serious illness.

Public Health Services officials recommend that individuals prevent exposure to mosquito bites and West Nile virus by following the “Four Ds”:

DEET – Apply insect repellent containing DEET, picaridin, oil of lemon eucalyptus or IR 3535 according to label instructions to keep mosquitoes from biting you. Apply repellents only to exposed skin and/or clothing. DEET can be used safely on infants and children two months of age and older.

DAWN AND DUSK – Mosquitoes that carry WNV tend to bite in the early morning and evening so it is important to wear repellent at this time. Make sure that your doors and windows have tight-fitting screens to keep out mosquitoes. Repair or replace screens with tears or holes.

DRESS – Wear clothing that reduces the risk of skin exposure to mosquito bites (i.e., long pants and long-sleeved shirts).

DRAIN – Mosquitoes lay their eggs on standing water. Eliminate all sources of standing water on your property, including flower pots, old car tires, rain gutters and pet bowls. If you have a pond, use mosquito fish or commercially available products to eliminate mosquito larvae. Neglected swimming pools are also prime habitat for mosquito development. The San Joaquin County Mosquito and Vector Control District is available to help with neglected pools in the prevention of mosquito development.

To request District service, call 209-982-4675, 1-800-300-4675 or visit the District website at www.sjmosquito.org.