MERCED -- The year's first positive case of West Nile virus in mosquitoes was discovered this week, Merced County Mosquito Abatement District officials reported Wednesday.
Two groups of mosquitoes trapped in Merced were carrying the virus, according to Bruce Bondi, assistant manager of the Merced County Mosquito Abatement District.
The district traps groups of mosquitoes, usually a minimum of 15, and sends them to UC Davis for testing.
One of the groups that tested positive was found south of North Bear Creek, near 20th Street. The other was trapped by Davenport Park in Merced.
The mosquitoes were trapped earlier this month, but staff learned of the positive test results Monday, Bondi said.
Now that specific regions where West Nile is found have been identified, technicians will increase spraying efforts in those areas.
"That gives us a better picture of where we need to focus our efforts," Bondi said.
The district is planning to spray the areas this week, depending on weather conditions.
Bondi said the first case of West Nile virus in mosquitoes is usually discovered in August, but this year's higher temperatures could have contributed to the virus replicating at a faster pace.
No human cases of the virus have been reported in Merced County this year, he added.
In 2012 in Merced County, there were 13 reported cases of West Nile virus in people, the second-highest rate since 2005, when 28 cases were reported. In 2010 and 2011, there were four cases each, according to Inman.
Most people will not suffer any lasting health issues from a West Nile infection, but in rare cases the disease can lead to serious neurological problems or death. There is no treatment or vaccine for the illness, which is spread to humans by infected mosquitoes.
Officials urge the public to take action to fight mosquitoes and the potentially deadly diseases they spread.
Bondi reminded residents to prevent mosquito bites by avoiding going out at dusk; using repellents with DEET; wearing loose-fitting, long-sleeved clothing; and reporting standing water where mosquitoes can breed.
For more information, call the Merced County Mosquito Abatement District at (209) 722-1527.
Reporter Ramona Giwargis can be reached at (209) 385-2477 or firstname.lastname@example.org.