By Gig Connaughton, County of San Diego Communications Office
March 17, 2019 (Lakeside) - A dead Cooper’s hawk found in Lakeside has tested positive for West Nile virus, making it the first sign this year of the potentially deadly disease in San Diego County.
County Vector Control officials said people should remember to follow the County’s “Prevent, Protect, Report” guidelines—particularly to dump out standing water and to wear insect repellent—to protect themselves from mosquitoes that can transmit West Nile virus and other diseases, such as chikungunya, dengue and Zika.
Officials said the dead hawk had relatively low levels of West Nile virus in its tissues, suggesting that it was an old infection. However, they said it was a good reminder that West Nile virus, which first arrived in San Diego County in 2003, is established here and that people need to protect themselves from mosquitoes.
Last year was a relatively mild one for West Nile virus in San Diego County. One county resident tested positive for the disease and survived. However, as recently as 2015, 44 County residents tested positive and six people died. Across California in 2018, 215 people became infected with West Nile virus and 10 people died.
West Nile virus is mainly a bird disease, but it can be transmitted to humans by a number of species of mosquitoes — including Culex mosquitoes native to San Diego and, less effectively, by invasive Aedes aegypti mosquitoes — if they feed off an infected animal, mainly birds, and then bite people.
If people who become infected suffer symptoms, they are typically mild, including headache, fever, nausea, fatigue, skin rash or swollen glands. But in rare cases, West Nile virus can make people extremely ill and even kill them.
New Mosquito-Borne Illness Worries
Protecting against mosquitoes has become even more important for San Diego County residents in recent years. Since 2014, three types of day-biting, invasive Aedes mosquitoes have been found in San Diego County. All of these mosquitoes like to live and breed near people, in yards and even inside homes. All of them can potentially transmit diseases not naturally found here. Two of these species can potentially transmit chikungunya, dengue and Zika — but only if they first bite an infected person. In general, that means local invasive Aedes mosquitoes could only transmit those diseases if they found, and bit, San Diego County residents who got the disease while traveling and returned home still infected.
County officials said that people should help fight mosquitoes and potential illnesses by following the “Prevent, Protect, Report” guidelines.
Prevent Mosquito Breeding
Dump out or remove any item inside or outside of homes that can hold water, such as plant saucers, rain gutters, buckets, garbage cans, toys, old tires, and wheelbarrows. Mosquito fish, available for free by contacting the Vector Control Program, may be used to control mosquito breeding in backyard water sources such as unused swimming pools, ponds, fountains and horse troughs.
Protect Yourself From Mosquito Bites
Protect yourself from mosquito-borne illnesses by wearing long sleeves and pants or use repellent when outdoors. Use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Make sure screens on windows and doors are in good condition and secured to keep insects out.
Report Possible Mosquito Activity
Report increased mosquito activity, or neglected, green swimming pools and other mosquito-breeding sources, as well as dead birds — dead crows, ravens, jays, hawks and owls — to environmental health’s Vector Control Program by calling (858) 694-2888 or emailing firstname.lastname@example.org. Also report if you are being bitten by mosquitoes during daylight hours, or if you find mosquitoes that match the description of Aedes mosquitoes by contacting the Vector Control Program at (858) 694-2888.