A dead bird found in Dublin last week tested positive for West Nile virus, marking the "first indication of active virus transmission" in the county this year, the Alameda County Mosquito Abatement District announced.
According to the district, the body of an American crow was recovered on Aug. 5 from the 6800 block of Ash Court in the city of Dublin, less than a half mile from Valley High School. Results from tests conducted at the district laboratory on Aug. 7 were positive for the virus.
More than 90 cases of West Nile -- which is spread to humans and animals through the bite of an infected mosquito and has no cure -- have been reported in California this year. The majority of them are dead birds (81) and 10 humans, plus 675 mosquito samples.
Roughly one in five people who contract West Nile virus will experience symptoms including fever, headache, vomiting, body aches or rash. Less than 1% will develop a more serious neurological illness such as meningitis or encephalitis. Adults over 50 and immuno-compromised individuals are at increased risk of serious complications.
The district said "dead birds play an important role in the district's ability to monitor West Nile virus activity in Alameda County" and that "public reporting of dead birds is vital to our surveillance program."
Mosquito monitoring and larval control efforts are being ramped up around the area where the infected dead bird was found. Fountains, buckets and tires -- "anything that can hold water for more than four days" -- are just a few of the types of places where the district said mosquitoes can breed.
"Every effort is being made to locate areas of standing water where mosquitoes may breed including but not limited to catch basins, storm drain systems, and swimming pools," officials said.
Residents can reduce the risk of contracting West Nile and other mosquito-borne illnesses by dumping or draining standing water on their property, limiting outdoor activity at dawn and dusk -- when mosquito activity is peak--and wearing long pants and long-sleeved shirts, as well as insect repellent with active ingredients like DEET, Picaridin, IR3535, or oil of lemon eucalyptus. Door and window screens should also be in good condition and free of any tears or holes.
Residents can also request mosquitofish from the district "for their fish ponds, horse troughs, or neglected swimming pools."
"Even though this summer is very different from what we normally experience, West Nile virus is still something we need to be concerned about," said General Manager Ryan Clausnitzer. "As we stay closer to home and spend more time outdoors we wish to remind residents to remove standing water from their property and protect themselves from mosquito bites by wearing repellent and long and loose clothing. While we are not detecting high numbers of mosquitoes in the area where the bird was found, there is an increased risk of West Nile virus with every mosquito bite."
The district also said horses are "very susceptible to West Nile virus" and that vaccines are available. Owners should contact their veterinarian about vaccination scheduling.
To learn more about West Nile virus, mosquitoes, or to request any district services, visit www.mosquitoes.org or call 510-783-7744. Call the Alameda County Public Health Department for information about West Nile virus symptoms, prevention or testing at 510-267-8001.