Health & Fitness

Break In West Nile Cases May Be Benefit Of Winter's Bounty

Santa Clara County Vector Control is expecting fewer cases of West Nile given the wet winter because birds and mosquitoes will separate.

West Nile is transmitted from birds to mosquitoes to humans.
West Nile is transmitted from birds to mosquitoes to humans. (Shutterstock)

SAN JOSE, CA — Despite the prolific water left as breeding grounds, the long, arduous winter may take the bite out of opportunities for the West Nile virus spreading this summer.

That's because more water sources create enough space for birds and mosquitoes to spread out in their own domain, Santa Clara County Vector Control District Manager Nayer Zahiri told Patch. Mosquitoes get West Nile from birds. The flying pests then give it to people.

During drought years, mosquitoes and birds are forced to share their water sources. It's like more people catching colds in the winter because we're sharing more confined spaces.

Find out what's happening in Campbellwith free, real-time updates from Patch.

For example, the county reported 17 positive cases of mosquitoes carrying the West Nile virus in 2014 at the peak of California's drought. More than 1,000 birds carried the disease.

Now most of the state is out of drought, according to the California Department of Water Resources.

Find out what's happening in Campbellwith free, real-time updates from Patch.

By contrast, the virus was transmitted to four mosquitoes in the county last year, while 22 birds tested positive. Last year, 10 people died from complications associated with the West Nile virus, according to www.westnile.ca.gov. This is a drop from 44 in 2017.

On a national scale, the Centers for Disease Control and Prevention reported the number of significant cases of West Nile cases has increased 1,537 with 137 deaths.

In California as of Jan. 8, the CDC has reported 204 cases of West Nile this year, while eight people have died from this blood-borne disease. Other states' numbers can be found here.

The West Nile virus is most commonly spread to people by the bite of an infected mosquito. No vaccines will prevent it, according to the CDC. About 1 in 5 people who are infected develop a fever and other symptoms, with 1 out of 150 of those infected developing a serious, sometimes fatal, illness. Using insect repellent and wearing long-sleeved shirts and pants to prevent mosquito bites is recommended.

So even with a break from West Nile cases expected this year, summer outdoor enthusiasts may still feel the sting from the sheer prevalence of more mosquitoes out enjoying winter's bounty — and human skin.

Mosquito Awareness Week was last week.

With that, the county's Vector Control District is reminding the public to be diligent about inspecting and maintaining their properties for stagnant water to reduce the risk of mosquito-borne diseases and their presence as a nuisance to people and animals.

Mosquitoes spread heart worm disease to dogs and cats. Pets should be checked for heart worm on an annual basis. Mosquitoes can lay their eggs in sources of water as small as a bottle cap and thousands of mosquitoes can emerge from just one abandoned swimming pool. Vector Control highly recommends homeowners dump and drain any standing water in their yards as well as report abandoned swimming pools and dead bird sightings.

“Establishing regular maintenance can protect ourselves and our loved ones from the health threats posed by mosquitoes," Zahiri said.

Here are a few suggestions to keep the pesky critters away:

  • Drain, remove or turn over anything that can hold water such as flowerpots, planter bases, bird baths, toys, cans, rain gutters, pet dishes, buckets, old tires and tarps
  • Do not allow the level of water in your swimming pool to fall below the pump circulation area
  • Request free mosquitofish to place in neglected pools and ornamental ponds
  • Report abandoned or neglected swimming pools as well as mosquito activity
  • Drill holes in tire swings and other containers, so they can drain
  • Clear roof gutters of debris
  • Change water in bird baths at least one time per week
  • Install tight fitting screens on doors and windows
  • Keep lids tight on rain water collection systems
  • Encourage neighbors to also eliminate standing water on their property

There is no magic remedy for mosquito aversion. They go with summer like barbecues and swimming. Zahiri did note they tend to be attracted to carbon dioxide, which would explain why they hang around a hiker's face on an upward ascent. Other determinants include a body's Ph level, temperature and skin color.

Either way, protecting one's body is one sure fire way to keep them off the skin and a person out of the emergency room.

The public is encouraged to report dead bird sightings by contacting the state West Nile Virus Hotline at 877-968-2473 or visiting www.westnile.ca.gov. To report an abandoned swimming pool, mosquito activity, or to request free mosquitofish, informational material or an educational presentation, the public may contact the district office by calling 408-918-4770 or filling out a service request online at SCCvector.org.


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