The Southern Nevada Health District is reporting four new cases of West Nile virus, bringing the total in Clark County for 2019 to 16.

A 15th case of West Nile virus, which is spread by mosquitos, has been reported in Clark County this year. (Getty Images)

The Southern Nevada Health District is reporting four new cases of West Nile virus, bringing the total in Clark County for 2019 to 16.

One new case involves a man over 50 with the more serious neuroinvasive form of the illness. Two men and one woman, all under the age of 50, have confirmed cases of the non-neuroinvasive form of the illness. Of the 16 reported cases, 11 have had the more serious, neuroinvasive form of the illness, which can be fatal.

West Nile virus is transmitted through the bite of an infected mosquito. The health district encourages Southern Nevadans to take precautions such as wearing long sleeves and long pants and and using EPA-approved insect repellent.

The 16 cases puts the county on pace for one of the worst years for the illness since it was first detected here in 2004.

Clark County typically experiences 10 or fewer cases each year, with a high of 26 cases in 2009 and no cases reported in either 2010 or 2018.

Contact Mary Hynes at mhynes@reviewjournal.com or 702-383-0336. Follow @MaryHynes1 on Twitter.