Mosquito-borne diseases are a real threat in California. Let’s manage the risk

Friday, May 18, 2018

Senator Richard Pan and Assemblymember Bill Quirk, Sacramento Bee

Since 2004, cases of disease spread by pests such as ticks, fleas, and mosquitoes have tripled nationwide. According to a new Centers for Disease Control and Prevention report, these vector-borne diseases increased in the U.S. from 27,388 in 2004 to 97,075 in 2016.

Around the world, diseases spread by mosquitoes alone kill hundreds of thousands of people each year. Here at home, we are working hard to track and control the spread of West Nile, St. Louis encephalitis, chikungunya, dengue, and Zika. Vaccines simply do not exist for most of these illnesses. Vector control is the best and only preventative defense against the health threats they pose.

California is one of the top states for mosquito-borne diseases. Last year, we had 553 confirmed human cases of West Nile virus disease, including 44 fatalities. This was the highest percentage of deaths in California from West Nile in 15 years. Since 2003, 6,582 Californians have been diagnosed with the virus and in more than half the cases the disease spread to the nervous system.

We are also facing emerging threats from the Zika virus. The invasive mosquitoes that carry Zika have already spread to nearly 200 cities. To date, local transmission of Zika has not been detected in California, although 651 cases of travel-related Zika infections have been confirmed since 2015. Travelers to Mexico and Latin America, especially pregnant women and their partners, should be aware that infection during pregnancy can cause devastating birth defects.

With so much risk from mosquito-transmitted diseases, it is imperative that public health departments and mosquito control agencies have the resources to expand surveillance and control programs. This includes technology to improve the state’s ability to identify developing threats.

In California, we have a flagship platform for data management, visualization, and analysis, known as the California Surveillance Gateway. CalSurv tracks and predicts where disease-spreading mosquitoes might emerge. UC Davis, the California Department of Public Health and local mosquito control agencies work together to provide real-time understanding of growing mosquito populations and mosquito-borne virus activity.

Since its inception in 2006, CalSurv has been funded through a patchwork of competitive academic research grants and some at-risk federal grants including NASA research on climate change. We don’t know if these funds are sustainable.

It is important that this essential system continues to be funded so that there is sustained collaboration among public health departments, vector control agencies, and the research community to enhance our detection and prevention capabilities. My bill, AB 2892 (Quirk), officially recognizes CalSurv as a critical surveillance program which protects public health. Together, we are also championing investments in research to help California prevent infectious diseases.

It is also crucial that Californians work to reduce mosquito breeding habitats at our homes and take precautions. This includes responsible outdoor water use and dumping and draining all standing water. Mosquitoes can breed in standing water – even a puddle in an empty tire can intensify the risk in residential areas. Additionally, residents should install screens on windows and doors and use insect repellent to keep mosquitoes from biting.

The CDC study was particularly alarming because the data only include cases reported to public health agencies; the actual rate of vector-borne disease is likely much higher. Every year, millions of international travelers and goods make their way through our state. All it takes is one invasive mosquito biting one infected traveler for these diseases to spread here. We need to be vigilant and ensure we have the resources to protect ourselves and our families.

Sen. Richard Pan, MD, MPH represents the 6th Senate District in Sacramento and Yolo counties. Assemblyman Bill Quirk represents the 20th Assembly District in Alameda County; senator.pan@sen.ca.gov, assemblymember.quirk@assembly.ca.gov.