On March 21, the laboratory staff did an annual rodent survey for hantavirus at San Bruno Mountain County Open Space Preserve and State Park. Out of the 43 rodents collected, 5 were positive for hantavirus for an infection prevalence of 11.6%. Results for plague are still pending. The laboratory will schedule a follow-up survey for hantavirus at San Bruno Mountain in the summer and are on-schedule to complete our annual survey for rodent-borne diseases at Montara Mountain in May.
The District has been awarded a grant to assist in surveillance of invasive Aedes mosquito surveillance. The grant funding comes from the Center for Disease Control and is administered by the nonprofit corporation Public Health Foundation Enterprises on behalf of the California Department of Public Health. The District plans to use the funds to greatly expand our efforts to detect and control invasive mosquito species.
The 2017 sentinel chickens are situated in their coops for the West Nile Virus season. The three coops are at Woodside, East Palo Alto and San Mateo and contain ten chickens each. Starting May 1, the chickens will be tested every two weeks for the mosquito-borne diseases West Nile Virus, Saint Louis Encephalitis, and Western Equine Encephalitis.
Some of you may have noticed a large number of insects in the air lately. Most of these are midges; harmless creatures that are a natural part of the ecosystem. But what is a midge and why are they here in such large numbers this year?