/Mosquito Surveillance

Mosquito Surveillance

West Nile Virus, a mosquito borne disease, was first identified in Clark County in 2004. In response to this public health threat, the Southern Nevada Health District developed a Vector Surveillance program to survey mosquito populations for diseases including West Nile Virus (WNV), Western Equine Encephalitis (WEE), and Saint Louis Encephalitis (SLE).

Aside from disease status, mosquito surveillance is used to identify the type of mosquitoes breeding in the community. Emerging diseases like Zika virus, Chikungunya and Dengue are carried by mosquitoes. Keeping an eye on the type of mosquito species is very important as it can be an early warning for new disease introduction to Las Vegas.

Since 2004, the Vector Surveillance program has submitted over 150,000 mosquitoes to the Nevada Department of Agriculture for WNV, SLE, and WEE analysis. Of these, approximately 4,000 mosquitoes have tested positive for WNV, and although rare, WEE and SLE have also been identified in mosquito submissions.

The Health District’s remediation of mosquito breeding areas is limited to small, targeted treatments of areas identified when setting mosquito traps. These locations requiring long term abatement are referred to the Public Works, Parks and Recreation, and Code Enforcement offices within the six jurisdictional counterparts. To report a stagnant swimming pool, contact your local Code Enforcement office for remediation.

The Health District is the only entity in Clark County capable of monitoring mosquito populations across the six distinct jurisdictions within the county, including City of Las Vegas, unincorporated Clark County, City of Henderson, City of North Las Vegas, City of Mesquite and the City of Boulder City. If you are experiencing mosquito activity at your home, please contact our office at (702) 759-1633.

Annual reports detailing surveillance and control activities since 2004 can be found on the Health District’s web site at /news-info/statistics-surveillance-reports/vector-borne-and-zoonotic-diseases/.

Human Cases

West Nile Virus is a reportable disease in Clark County and, since 2004 the Office of Epidemiology has conducted 139 investigations relating to WNV. Of those 139 investigations, 106 were reported as either probable or confirmed cases of West Nile Fever (N=45) or West Nile Neuroinvasive Disease (N=61). There were 31 presumptively viremic blood donors, meaning the case tested positive for the virus in their blood, but had no symptoms of disease. Of the 106 cases with clinical illness, six were fatal. Historical human case data can be found on Health District’s web site at /news-info/statistics-surveillance-reports/west-nile-virus-surveillance/.

Contact Information

Phone: (702) 759-1633

Updated on: July 8, 2020

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