With the recent storms, there is plenty of standing water throughout Riverside County and health officials are urging residents to empty outdoor containers that may have inadvertently filled with rain to prevent the spread of mosquito-borne illness.
Broken jars, old car tires, tin cans and other discarded items are some of the things that can collect rainwater and act as a breeding ground for mosquitoes in only a few days. Residents are being asked to survey their yards and property for sources of water and empty the containers, even if they hold only a few inches of water.
Many homeowners have collected rainwater to use to water landscape. While this is encouraged during this historic drought, there are some precautions you should take to eliminate these collection barrels from becoming a breeding ground for mosquitoes. Once the water is collected, the barrel or container should be covered with a tight-fitting lid or a mesh screen. It is important to not allow the mosquitoes access to the water to lay their eggs.
West Nile virus is among the illnesses that mosquitoes can spread. Each year there are a handful of human cases reported in Riverside County.
"While West Nile virus is rarely fatal, it can sometimes be serious, and it's not the only disease mosquitoes can carry," said Dr Cameron Kaiser, Riverside County public health officer. "The best way to avoid illness is to not get bitten in the first place."
The California Department of Public Health this week announced the first death in 2015 due to the virus. Riverside County has not reported any deaths since 2008. The virus is transmitted to humans and animals by the bite of an infected mosquito. The risk of serious illness to most people is low. Some individuals – less than one percent – can develop a serious neurologic illness such as encephalitis or meningitis.
Riverside County’s Environmental Health Vector Control Program and Public Health Department have a comprehensive surveillance program to monitor for the virus. The program includes testing suspect cases in humans, capturing and testing mosquitoes with potential for disease transmission and testing sentinel chickens. These surveillance techniques allow the vector control program to focus their mosquito control efforts.
It is possible that the drought has contributed to increased virus activity by reducing sources of water for birds and mosquitoes. As birds and mosquitoes seek water, they are coming into closer contact and amplifying the transmission of the virus.
According to state health officials, 33 counties have reported WNV activity so far this year, four more than this time last year and above the five-year average of 22. To date, 497 mosquito samples have tested positive for WNV, which exceeds the five-year average of 330.