Dr. Justin Remais on how to protect yourself from this mosquito-borne disease
Dr. Justin Remais began studying West Nile virus following record breaking numbers of infections in California in 2014 and 2015. His team began piecing together the factors contributing to West Nile activity in neighborhoods across Southern California, predicting that changes to California’s climate might contribute to greater transmission in future decades, especially in coastal communities.
Now, as professor and chair of the Division of Environmental Health Sciences at the UC Berkeley School of Public Health, Dr. Remais is noting another sharp rise in California’s West Nile virus activity. The state has recorded more than 250 dead birds that tested positive for West Nile virus as of mid-July, a striking increase from just 50 recorded last year at this time. In Los Angeles County, there were 67 positive mosquito pools – a group of captured mosquitos that tested positive for the virus – compared to just 6 at this same time in 2025, a tenfold increase. Counties in Southern and Central California have recorded five human cases by mid-July, compared to three in 2025. We asked Professor Remais about West Nile virus, and what the public can do to protect themselves from this disease.
