Update: Vector control discusses spread of West Nile virus

Roseville resident one of three in Placer County now recovering
By: Scott Thomas Anderson, The Press Tribune
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Placer County authorities are warning that the West Nile virus that’s been infecting birds and chickens in the area for months has now spread to humans. 

Three newly identified cases involve a Roseville resident and two Lincoln residents.

The Placer Mosquito and Vector Control District has known since late July that insects in the farming lands along western Roseville have been carrying West Nile.

According to the county’s public heath department, all three residents who contracted it became ill with meningitis, were hospitalized and tested positive for West Nile. All three are now reportedly recovering. One was a child.

Pat Orme, Placer County’s assistant director of community health, told the Presss Tribune in July that it’s important to know that West Nile virus is only a serious threat to humans in a minority of cases.

“About 80 percent of people who contract West Nile don’t have any symptoms at all,” Orme said. “Around 20 percent of people who have it will show mild symptoms, such as a low fever, headache, vomiting and possibly swollen lymph nodes. It’s less than 1 percent that experience major symptoms, which would be a high fever, severe headaches and neurological affects. It’s that 1 percent that needs to seek immediate medical attention.”

While data indicates that most individuals suffering from the West Nile virus recover on their own, Orme said pregnant women are at a higher risk and should take no chances.

“Women who are pregnant, or nursing mothers, should definitely see their doctors if they believe they might have any symptoms of this,” she said.

People suffering from diabetes and/or hypertension are also believed to be at greater risk for serious illness.

West Nile virus is transmitted by the bite of a mosquito, usually in the two weeks before illness.

When news broke Wednesday that human cases of West Nile had been identified in Placer County, the director of the county’s health and human services, Dr. Richard Burton, emphasized that infections are preventable.” These (human) cases, and the positive mosquitoes and birds found this season in western areas of the county, remind us all that we must take some simple precautions to avoid mosquito bites,” he said.

Placer County authorities recommend that individuals prevent exposure to mosquito bites and West Nile virus by practicing the “Three Ds” — DEET-type mosquito repellent, draining stagnant water sources and having an awareness at dusk and dawn. 

Insect repellent containing DEET, picaridin, oil of lemon eucalyptus or IR3535 can prevent West Nile-infected mosquitoes from biting, though it can only be used safely on infants and children 2 months of age and older.

Drainage is another important tactic. “Standing water can end up on peoples’ property from leaky hoses or broken sprinkler systems,” said Ada Barros, a representative from the Placer Mosquito and Vector Control District. “Plastic outdoor toys and play equiptment are also things that can cause pooling that people don’t always think about. We also recommend that bird baths and outdoor water dishes be changed every three days.”

Residents are encouraged to report all dead birds and dead tree squirrels on the state website or by calling toll-free (877) WNV-BIRD (968-2473).