Surveillance Reports
West Nile Virus Surveillance Program
The Southern Nevada Health District’s Environmental Health Division works to reduce mosquito populations and control the spread of mosquito-borne disease.
The Southern Nevada Health District, in collaboration with the Nevada State Health Division, conducts West Nile virus testing of dead birds and mosquitoes.
The presence of dead birds may be a sign that West Nile virus is circulating between birds and the mosquitoes in an area.
Visit the West Nile Virus or Mosquito Control webpages to learn more or to report dead birds, green pools or mosquito infestation.
Rabies Surveillance
When there is human bite exposure, suspect animal specimens from the animal control agencies are submitted by the Environmental Health Division to the State Animal Disease Laboratory in Reno for analysis.
When found positive for rabies, the case is further investigated by health district staff with recommendations to those exposed and to treating practitioners.
Visit the Rabies webpage to learn more.
Baylisascaris procyonis (Raccoon Roundworm) Surveillance
Baylisascaris procyonis is a parasitic organism common to raccoons and transmittable to humans through ingestion of contaminated soil, water, or on objects that have been contaminated with raccoon feces.
Raccoon feces specimens are collected by the Environmental Health Division and U.S. Department of Agriculture and submitted to the Nevada Department of Agriculture Animal Disease Lab for testing.
In 2004, two of the 16 specimens collected tested positive for Baylisascaris procyonis.
To learn more, visit the Baylisascaris procyonis webpage.
Rodents Surveillance Program
The Roof Rat population continues to increase in Clark County, with people in over 30 zip codes reporting rats since 2003. With the increase of construction on the edges of town, the native Desert Wood Rat population has also been forced into urban areas.
The Rodent Surveillance Program at the Southern Nevada Health District includes disease testing and rodent prevention training to community groups, as requested. Urban and rural surveillance are two methods of gathering disease information on the current rodent population.
Extermination of rodents on private property is the responsibility of property owners. The health district does not offer rodent control or extermination services.
Urban Rat Surveillance
The Roof Rat is the most common urban rat found in Southern Nevada.
Environmental Health Specialists use live traps to collect a sample of the rat population around the valley based on resident complaints and historical data. Blood samples are tested for plague and Hantavirus. Fecal samples are tested for salmonella, shigella, and campylobacter bacteria. Rats are also combed for fleas, which can be carriers of disease. The fleas are sent to the U.S. Centers for Disease Control and Prevention for identification and testing for the presence of diseases.
Urban rat surveillance is conducted twice a year in the spring and fall. Since 2003, over 120 Roof Rats have been trapped and tested. All rats tested were negative for disease.
Rodent control is a community wide effort. If every property owner completed the Rodent Control Checklist PDF (222 KB/5 pages) the population of rodents in Southern Nevada would decrease.
To learn more about rodents and how to prevent infestations, visit the Rodent Pests webpage.
If you believe you have a rat infestation, contact your local pest control company. If you have any questions regarding rodent proofing your home, contact Vector Control at (702) 759-1633.
Rural Rodent Surveillance
The Desert Wood Rat is native to Southern Nevada and found in rural areas.
Working in cooperation with State and Federal agencies, environmental health specialists use live traps to collect a sample of the rodent population in rural areas used by humans, such as camp grounds, ranger stations, hiking trails, etc. Unlike the urban surveillance program, which only traps rats, rural surveillance tests all rodents captured for disease.
In this catch and release program, blood samples are collected and tested for plague and Hantavirus, and rodents are combed for fleas, which can be carriers of disease. While rural rodents have tested positive for plague and hantavirus, no humans have been infected.
The urban and rural surveillance program is performed to advise the public about locations where rodent diseases may be occurring in nature; especially at points that humans may come in contact with rodents while enjoying the rural environment.
The potential for disease is always present in our community as our urban areas are continuing to encroach upon the rural rodent population.
Visit the plague and hantavirus webpages to learn more about symptoms, treatment and prevention of these diseases.
To learn more about rodents and how to prevent infestations, visit the Rodent Pests webpage.
