The Kings County Health Department (KCHD) announced today that the first human case of West Nile Virus (WNV) in 2017 has been confirmed.  The last human case in Kings County was in 2016.  This is the first human case of WNV reported in the state of California in 2017.


According to Dr. Teske, Health Officer for Kings County, “We are anticipating a significant increase in the number of WNV cases because of all the rain this year.  It’s a perfect combination of a lot of water and warm weather.”  It is especially important to eliminate any standing water – no matter how small an amount – where mosquitos can breed.

Since the county’s first human case in 2005, there have been a total of 66 WNV cases, including four deaths.  The last case of WNV reported in Kings County was in 2016, with a total of eight cases reported in that year.

“West Nile virus activity in the state is increasing, so I urge Californians to take every possible precaution to protect against mosquito bites,” said California Department of Public Health (CDPH) Director and State Public Health Officer Dr. Karen Smith.

This year to date, West Nile virus activity has been detected in three dead birds, one each from San Mateo, Orange, and San Diego counties. Heavy rains this winter in California have contributed to an increase in mosquito breeding sites. It is not known what impact the wet weather may have on the actual virus transmission risk in humans. So far this season, West Nile activity is within expected levels.

West Nile virus is influenced by many factors, including climate, the number and types of birds and mosquitoes in an area and the level of West Nile immunity in birds. West Nile virus is transmitted to humans and animals by the bite of an infected mosquito. The risk of serious illness to most people is low. However, some individuals – less than 1 percent – can develop serious neurologic illnesses such as encephalitis or meningitis.

People 50 years of age and older, and individuals with diabetes or hypertension, have a higher chance of getting sick and are more likely to develop complications.

In 2016, California reported 442 human WNV cases, including 19 deaths.