A Lyon County resident is the first Nevadan in 2005 to have been diagnosed with West Nile virus, state health officials confirmed Wednesday.
The victim, who is under the age of 50, has developed West Nile encephalitis, a more severe form of the disease which can lead to a variety of harsh symptoms and even death.
The Nevada State Health Division declined to say what Lyon County area the victim is from. Health officials fear federal privacy laws could be violated by revealing the patient's location, saying such information could lead to the discovery of a person's identity. The case could be as far away as Fernley or Yerington, but it could also be right next door in Mound House.
Likewise, the state agency declines to be more specific than "over 50" or "under 50" with the ages of West Nile victims.
Age is a factor with West Nile virus. While the U.S. Centers for Disease Control says less than 1 percent of those infected will develop encephalitis, older victims are far more likely to make up that small faction. Younger people generally only experience a flu-like illness called West Nile fever.
"While serious symptoms of the (virus) are more common in people 50 years and over, this case shows that people under the age of 50 can also develop the severe form of the disease," said Nevada State Health Officer Dr. Bradford Lee.
Although the mosquito-borne virus that has been spread across the nation from New York to California by migrating birds affects only a tiny percentage of humans, health officials are urging Nevada residents to take precautions against the blood-sucking insects that spread it to humans, horses and other animals.
"I cannot stress enough the importance of practicing the preventative measures to reduce the chance of being bitten by mosquitoes," Lee said, recommending long-sleeved clothing, insect repellent and being aware of bug hot spots during dusk and dawn, when mosquitoes are most active.
The virus was first detected in Nevada last summer, in a dead crow found in Carson City, and the second year the disease is present in a state has generally been the year it has hit the hardest. Last year, 44 Nevada residents were diagnosed with the disease. No one died.
The virus caused much more damage to Nevada's horses, however.
More than 130 equine cases and 50 deaths were reported to the state last year. Virtually all of them could have been prevented, according to veterinarians.
"While there isn't a vaccine for humans, there is a vaccine available for horses, donkeys and mules," said State Veterinarian Dr. David Thain. "It you haven't vaccinated your equines, you need to vaccinate now."
Health officials earlier this year predicted a 2005 West Nile rate up to three times higher than in 2004.
So far this summer, the Lyon County resident, a mosquito pool in Fernley, three crows in Yerington, a finch near Elko and a horse in Silver Springs have all been found to have the disease.
To the west, two Californians have died so far this year, in 2004, the virus last killed 28 in California and 100 across the United States.
At least 31 Californians have been infected this year with the West Nile virus.
- Contact reporter Cory McConnell at cmcconnell@nevadaappeal.com or 881-1217. The Associated Press contributed to this report.