Opinion: California faces rising danger of mosquito-borne diseases

West Nile virus is here to stay. Aedes mosquitoes, which can transmit Zika, have been found in 12 counties
East Bay Times
In the past year, California has experienced multiple public health crises. Last October, San Diego County health authorities declared an end to a Hepatitis A outbreak that killed 20 people and sickened nearly 600. That same month, health officials warned the public of a typhus outbreak in downtown Los Angeles. And now public health departments across the state are scrambling to prevent a widespread outbreak of measles.
But when most people think about mosquitoes, they consider them nuisances that cause itchy bites. They don’t think about the public health risk and potential for mosquito-borne disease transmission. However, the threat of mosquito-borne diseases, especially West Nile virus, is also very serious and must be a public-health priority.
That’s why I’m advocating for more state funding to support vector-borne-disease research, surveillance and data collection. It’s critical that mosquito- and vector-control professionals and public health officials have resources they need to track and predict the emergence of mosquito-borne diseases and efficiently respond.
At its annual meeting in June, the American Medical Association called for more funding and resources for education, improved surveillance and research on existing and emerging vector-borne diseases. This is likely due in part to findings of the U.S. Centers for Disease Control and Prevention that disease cases from mosquito, tick and flea bites tripled in the United States from 2004 to 2016.
AMA Board Member E. Scott Ferguson, M.D., said, “our country currently has limited capacity to properly control mosquitoes, ticks and other sources of vector-borne disease that are causing more and more people to become ill. In fact, approximately 80 percent of vector-control organizations lack the resources they need to prevent and control vector-borne diseases.”
This is true in California, which, according to the CDC, is one of the top states for mosquito-borne diseases. In 2018, West Nile virus activity was detected in 41 counties in California and there were 217 human West Nile virus disease cases, of which 154 were the more severe neuroinvasive form.
Looking back to 2003, there were only three human cases of West Nile virus and no fatalities. Since then there have been 6,799 human cases reported and 303 fatalities. While that number fluctuates each year, we know for certain West Nile virus is here to stay in California.
At-risk groups such as the elderly, homeless and those who are immunocompromised or have comorbidities such as diabetes are particularly susceptible to suffering from mosquito-borne disease complications.
Moreover, California is home to invasive Aedes mosquitoes, which can transmit Zika, dengue, chikungunya and other exotic viruses. Invasive Aedes have been identified in 12 California counties, primarily in Southern California. Mosquito- and vector-control professionals are waging a tough fight to prevent them from spreading north.
The professionals also face daunting challenges from wildfires, which have created new, unattended water sources — such as abandoned swimming pools, ornamental ponds, septic tanks, buckets and barrels — that serve as breeding grounds for mosquitoes. These new challenges are placing even greater resource constraints on mosquito control and public health agencies as they work to prevent the spread of mosquito-borne diseases.
Mosquito-borne-disease threats affect all Californians regardless of where you live or your socio-economic status. There are no vaccines for people against West Nile virus and other mosquito-transmitted viruses, such as St. Louis encephalitis and chikungunya. All of these are costly to treat and can have long-term health and financial consequences.
It is far more effective to invest in preventative public health approaches instead of incurring enormous costs after large mosquito-borne-disease outbreaks occur.
Assemblyman Bill Quirk, D-Hayward, is a retired nuclear physicist.