A woman in her late 60’s is the first confirmed human West Nile Virus (WNV) infection in San Joaquin County this year. The announcement was made this week by Dr. Julie Vaishampayan, Assistant Health Officer from San Joaquin County Public Health Services (PHS). The woman’s health is being monitored in a hospital.

To date in 2016, West Nile Virus has been detected in 30 California counties. Last week, the San Joaquin County Mosquito Vector Control District reported the highest number of WNV positive mosquito samples detected in a week since the arrival of WNV in 2004. With these historical numbers, the threat of WNV infection to people significantly increases.

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.

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 the increase in WNV detection 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 one 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.

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.