Pests carry virus to Riverside

Areas of Riverside county sprayed due to presence of mosquitoes with West Nile Virus

Written by: Amelia Alvarado

Riverside County is at war with a dangerous foe. These pesky little creatures have always been here, but now they are armed with their weapon of choice the West Nile Virus and they’re prepared to bite at any time day or night.

The Northwest Mosquito and Vector Control District, a company dedicated to providing vector control services (mosquitoes, flies, rats, Africanized honey bees, black flies, midges) and occasionally other vectors of minor public health importance, has found a growing amount of West Nile virus activity in Riverside county this year.

Northwest Mosquito Vector control presented its research findings to the Riverside City Council on Oct. 6.

The results of the tests came from samples collected of deceased birds and captured mosquitoes. Areas where the tests were conducted were determined by reported human and animal cases in or near the area.

There have been 66 reported human cases, four being fatalities, in Riverside county, according to the government website westnile.ca.gov, which also posts statistics of animal fatalities.

This makes it the leading county in California with human related cases with Los Angeles county, being the second.

When members of the Northwest Mosquito and Vector Control District conduct these tests, the information can be gathered in a number of ways.

The most popular being what is called a red box, which is 6 feet tall, 6 feet deep and 3 feet wide and serves as a medium for the researcher to be able to walk in and suck the mosquitoes right off the wall.

A method of which Greg Williams, researcher for Northwest Mosquito and Vector Control District refers to as a “gold mine” in a YouTube video posted by the Press-Enterprise in which Williams gives a reporter a tour of the research facility.

In the video, Williams explains how from this method the samples they test not only tell them if they have the virus, but also what kind of infected animal or mammal they’ve fed on.

“This method is most useful because the data collected helps in narrowing down habitats and finding more virus activity,” Williams said.

This allows them to make efforts to sustain the virus and spray for any future outbreak.

Additional trapping methods, were used in the research conducted in Riverside County where positive indicators were found in the areas of Canyon Crest between Alessandro Boulevard, and Central Avenue, and north of Chicago Avenue, according to an email from Paul Davis, Riverside city council member of Ward 4.   

The way the virus can be spread starts with an infected bird who then gets bitten by an adult mosquito. The mosquito then becomes the carrier, the soldier with a mission to spread the infectious virus.

From there it attacks it’s unsuspecting victim. Most individuals infected with the virus may not experience any illness at all. Full information on the disease can be found at the Center for Disease Control website.

However, those who do become ill can experience flu-like symptoms such as fever, head and body aches, vomiting, diarrhea and a rash.

One in five infected people may experience these symptoms which can begin anywhere from four to seven days from the initial bite.

More severe cases can occur in less than 1 percent of people who become infected. They can develop serious neurological illnesses like meningitis or encephalitis, which is inflammation on the brain, spinal cord or surrounding tissue.

Symptoms of neurological illness can be high fever, headache disorientation, stiff neck, seizures, tremors or paralysis. Some of these effects can be permanent.

Recovering from the symptoms can take weeks even months. About 10 percent who develop neurological illness from the West Nile virus can die.

“The District will be treating the areas (where tests were conducted) with Aqua-Reslin which is approved for use in mosquito control by the U.S. EPA,” Davis said in an email issued to the city after the presentation by Northwest Mosquito and Vector Control District.

“Aqua-Reslin is a synergized permethrin formulation,” Michelle Brown, ecologist with the Northwest Mosquito and Vector Control District, said.  “Its active ingredients are permethrin and piperonyl butoxide, which poses low risk to humans and pets.”

On the early morning of Oct. 8, between the hours of 3-5 a.m. the infected areas were sprayed with Aqua-Reslin with the use of ground foggers.

“The Aqua Reslin is not chemically tested at the facility but has been through rigorous EPA testing through the years and has been approved and deemed safe to animals,humans and the environment,” Bill Van Dyke, Registered environmental health specialist and spokesman for the Northwest Mosquito and Vector Control District, said.

“There are no residual effects,” Dyke said. “The contact spray looses it’s potency within 10-15 minutes and has no chemical components that are long lasting killers.”

He went on to explain how the agency takes action protecting the environment by avoiding spraying any bees or anywhere bees are present.

“This is similar to a home fogging done to rid bugs or insects from the home,” Brown said.

Despite the assured safety of the spray, it was recommended to residents who were concerned that the spray could be harmful, to reduce exposure to pets and for residents to remain inside with the windows closed 30 minutes after the ground application.

“In fact Aqua-Reslin is even safer than a home fogging due to lack of chemical components in the reslin,” Dyke added.

“Our main focus and efforts are on the preventing and killing of the larvae before they become adults,” Brown said. “There is a now a new breed of mosquitoes found in Riverside County, capable of carrying the dengue fever otherwise known as the yellow fever that can bite during the day.”

This species of mosquito has been discovered in 12 other California counties including San Bernardino, according to Brown.

Though there haven’t been any reported cases of the Dengue fever, she said citizens should be aware and alert.

Citizens can take measures to avoid or otherwise prevent being infected by this virus. These include avoiding standing water and outdoor activities during mosquito peak hours, such as dawn and dusk.

Spraying insect repellent with the active ingredient DEET (N, N-diethyl-m-toluamide), picaridin (KBR 3023), oil of lemon eucalyptus [p-methane 3, 8-diol (PMD)] or IR3535, according to the instructions on the product label, is another way to prevent being stung by a deadly mosquito.

“Though we hope the initial treatments will be effective efforts to further prevent the disease from spreading will be made if necessary,” Brown said.

Additional information is available at westnile.ca.gov or 951-340-9792. Those who have been bitten or are experiencing any of the above symptoms should see a physician as soon as possible.