Mosquito control operation went as planned, vector control district says


The campaign to kill mosquitoes carrying the West Nile virus came to Menlo Park's Allied Arts neighborhood and parts of downtown on Sunday evening.

The spraying "went exactly as planned," said Megan Caldwell, a spokesperson for the San Mateo County Mosquito and Vector Control District.

With near-ideal weather conditions -- a light wind and a temperature inversion -- two specially equipped trucks, each carrying a driver and a navigator, traversed the area at a slow and constant speed.

The trucks fogged the streets with the insecticide etofenprox, which loses its insect killing power in about 15 minutes, Ms. Caldwell said.

A third person on each team accompanied the truck in a separate vehicle to control traffic.

With the light wind and the insecticide airborne and in atomized form, even mosquitoes away from the streets are expected to have succumbed, Ms. Caldwell said.

The vector control district is conducting a day-after follow-up procedure of setting mosquito traps, and will be publishing the results, she said.

The fogging is a consequence of the vector control district's discovery of West Nile virus in two dead birds found on Thursday, July 30, one on Creek Drive and the other on Cambridge Avenue, Ms. Caldwell said. The district had a window of 24 to 72 hours to act to control the insects.

While West Nile is a disease that primarily affects birds, it is potentially dangerous to humans, horses and other animals. But transmission requires a bite from an infected mosquito. It is not contagious.

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16 people like this
Posted by Alisa
a resident of Menlo Park: Central Menlo Park
on Aug 3, 2015 at 12:55 pm

Thank you very much! I am a big Mosquito attractor, and I really don't want to get a bite from a West Nile infected mosquito! Keep up the good work.

Pretty soon the mosquitos might carry Chickunguna, Dengue and Yellow Fever. I hope those diseases don't spread via mosquitos here, but I hear that these diseases are spreading.

Like this comment
Posted by Marc
a resident of another community
on Aug 3, 2015 at 7:46 pm

Funny. I just looked up the insecticide "etofenprox"on Wikipedia. The Wikipedia article does not say it loses its "insect killing power in 15 minutes. Quite the contrary. Look for yourself. Any explanation?

4 people like this
Posted by MG
a resident of Atherton: Lindenwood
on Aug 3, 2015 at 9:26 pm

Marc... what does wiki say about how long West Nile lasts?

15 minutes?

Like this comment
Posted by Marc
a resident of another community
on Aug 4, 2015 at 5:19 am

@MG. If you do not read the Wikipedia description of the insecticide, you will not know what it says. As to West Nile Virus, the Wikipedia article states quite a bit
It causes "severe" syptoms in less than 1 percent of infectees but no one wants to get it. The issue is whether spraying that insecticide over half of Menlo Park with a phony or at least misleading story about its "killing power" lasting only 15 minutes is a good answer. Apparently from the lack of comments on this story, few Menlo Parkers care at all.

Like this comment
Posted by Dave Boyce
Almanac staff writer
on Aug 4, 2015 at 10:54 am

Dave Boyce is a registered user.

Megan Caldwell described the insecticide as having a 4% concentration of etofenprox. The 15-minute effectiveness window was a combination of that concentration and the method by which it was applied, by an "ultra-low-volume" spraying device.

Wind is needed, but it must be light, Ms. Caldwell said. The atomizing allows the insecticide to hang in the air briefly enough to "drift laterally" so as to get the mosquitoes that are flying some distance from the street. Eight gallons covers 400 acres, she said.

16 people like this
a resident of Menlo Park: Central Menlo Park
on Aug 4, 2015 at 11:05 am

"in less than 1 percent of infectees"

Misleading. Or perhaps the the poster is not familiar with a concept called 'math'.

If we don't control how many Americans get West Nile, it's a real problem.

Let's say we fail to control outbreaks, and WN spreads through the Bay Area; skeeters would of course eventually hit everyone in the Bay Area. They are skeeters, that's their job. And they are good at it, especially if we give up controlling them.

One percent is an issue: 1% of the 7.5 million is 75,000 Bay Areans.

Not all at once, of course, because it would take a couple years of uncontrolled WN to spread. It may mutate, it may lessen, or not, who knows? And let's discount the allegedly "minor" symptoms for the 99% for the sake of discussion (as if when YOU get it, you will think it's MINOR? Oh yeah, sure, I believe you.)

Adding 75,000 patients to the medical system over a couple years will be a disaster.

Not counting the misery inflicted on those individuals and families. How many skeeter bites did you get as a kid?

Folks that don't want strategic, targeted spraying in their neighborhood to control such a disaster deserve a new name. NIMBY is taken.

How about NIMBYBISP?

(Not In My BackYard Because I'm a Selfish.....)

Kind of like the anti-vaxers, working on misleading information, and not wanting to be part of the community that all participate so everyone is protected.

How neighborly of you.

16 people like this
a resident of Menlo Park: Central Menlo Park
on Aug 4, 2015 at 11:12 am

1% for severe. Here's the "minor" symptoms that @Marc thinks are cool:

"West Nile fever (WNF), which occurs in 20 percent of cases, is a febrile syndrome that causes flu-like symptoms.[8] Most characterizations of WNF generally describe it as a mild, acute syndrome lasting 3 to 6 days after symptom onset. Systematic follow-up studies of patients with WNF have not been done, so this information is largely anecdotal. In addition to a high fever, headache, chills, excessive sweating, weakness, fatigue, swollen lymph nodes, drowsiness, pain in the joints and flu-like symptoms. Gastrointestinal symptoms that may occur include nausea, vomiting, loss of appetite, and diarrhea. Fewer than one-third of patients develop a rash."

@Marc: flu-like symptoms.

Do you get a flu shot during a bad 'flu year'? Or do you count on the vaccinated herd to protect you from viruses?

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