Archived News


July 6, 2006

DAVIS--Mosquito research at the University of California, Davis is rising to new heights. NASA satellite data and remote imagery will be used to forecast the risk of West Nile virus and other mosquito-borne virus activity in California and eventually, the other Western states.

WilliamResearch entomologist and professor William K. Reisen of the UC Davis Center for Vectorborne Diseases has received a three-year, $1 million grant from the NASA Earth-Sun Science Applied Sciences Program, in which data from NASA satellites and earth ecosystem models will be integrated into the current statewide arbovirus surveillance systems. The grant is a collaborative effort linking NASA with UC Davis researchers, the California Department of Health Services (DHS), the MosquitoVector Control Association of California (MVCAC) and the Centers for Disease Control and Prevention (CDC).

"The purpose of this grant is to use NASA remote sensing products in conjunction with other surveillance measures of arbovirus activity to forecast the risk of arbovirus activity in California and other Western states," Reisen said.

"Using data collection, reporting and mapping schemes developed by the Environmental Assessment and Information Technology program at UC Davis, NASA Ames will incorporate landscape analysis from remotely sensed satellite imagery to help direct mosquito control efforts to prevent outbreaks of mosquito-borne pathogens such as West Nile virus."

Reisen said the collaboration will enable better monitoring and management of WNV, St. Louis encephalitis and western equine encephalomyelitis virus, all transmitted by Culex mosquitoes. The collaboration also may help researchers to keep tabs on other emerging viruses, Reisen said. "Research led by Dr. Aaron Brault and colleagues has shown that new genetic strains are introduced continually in California and that dramatic changes in arbovirus virulence have been linked to relatively minor changes in genetic structure. In addition, the products and systems developed may have applications for Homeland Security."

NASATitled "Integration of Remote Sensing into Mosquito-borne Encephalitis Virus Intervention Decision Support Systems," the grant is considered another weapon in the expanding arsenal to battle West Nile virus, which last year killed 19 people in California and infected more than 900 others. Officials also diagnosed 456 horses in the statewith the mosquito-borne disease; 200 of them died or were euthanized.

Said co-principal investigator Vicki Kramer, chief of the Vector-Borne Disease Section, California Department of Health Services: "The ongoing West Nile virus epidemic has heightened the need to effectively track pending and real-time risk for emerging vectorborne pathogens in California. Incorporating remotely sensed data into the current risk assessment component of the California Statewide Mosquito-borne Virus Surveillance and Response Plan (CMVSRP) will extend the current suite of ground-based environmental measurements, provide a much-needed spatial overview of ecosystem change, and possibly allow real-time integration with current NASA EcoCast model products."

Co-principal investigator Steve Mulligan, district manager of the Consolidated Mosquito Abatement District, Selma, and chair of the MVCAC Vector Control Research Committee, agreed. "The arrival of the West Nile virus and its rapid, epidemic spread throughout California highlights the need to accurately track pending and real-time risk for emerging vectorborne diseases in California." West Nile virus, which first surfaced in Uganda in 1937, invaded New York in 1999 and spread to California in 2002. The virus now threatens California’s 35.5 million population, its extensive horse industry (131,900 horses on 16,500 farms*) and its burgeoning economy, ranked the fifth largest in the world. Agriculture and tourism anchor the economy.

"Clearly, tracking the emergence, natural introduction or intentional release of mosquito-borne viruses is a public health and homeland security issue of great importance to the health and economic vitality of the United States," Reisen said.

CMVSRP is the primary decision support system used by state and local public healthofficials in California, including DHS and MVCAC, to manage mosquito-bornediseases. The Arbovirus Surveillance Network (ArboNET) is a national reporting and information system managed by CDC’s Division of Vector-borne Infectious Diseases in Fort Collins, Colo.

Reisen said the integration of data, especially climatic data, from NASA satellites andg round-based models should greatly help improve the CMVSRP and ArboNETsystems.

"Most agencies rely exclusively on surveillance data, which limits the ability of decisionmakers to focus available resources and proactively address potential problem areas in advance of disease outbreaks," Reisen said.

NASA’s Terrestrial Observation and Prediction System (TOPS) currently integrates data from satellite and ground-based observation networks to produce a comprehensive suiteof more than 30 variables describing land surface and ecosystem conditions. Information derived from satellites includes land and snow cover, surface temperature, vegetation density and vegetation productivity. Surface weather stations yield statistics for maximum and minimum temperatures, humidity, solar radiation and rainfall. Modeled fluxes indicate soil moisture and vegetation stress.

Under Reisen’s grant, TOPS data will be incorporated to drive models of mosquito abundance and produce seasonal forecast products for use in the CMVSRP and ArboNET systems.

Weekly summaries of current and predicted ecosystem conditions affecting mosquito abundance and virus transmission risk derived from NASA remote sensing data products and earth science models will be integrated into CMVSRP and ArboNET, Reisen said. "Using TOPS, we will produce 1-km resolution maps of mosquito abundance and virus transmission risk for California and the western United States, as well as maps of ecosystem and meteorological conditions related to mosquito abundance.

"Public health officials will have advance warning of potential hot spots and will have the data they need to identify new locations to place surveillance resources, including active case detection schemes to detect equine and human case clusters." Last year Sacramento County was the nation’s hot spot for West Nile virus activity.

In addition to Kramer and Mulligan, co-principal investigators are entomologist Bruce Eldridge, graduate student Christopher Barker and programmer Bborie Park, all of the Center for Vectorborne Diseases, UC Davis; public health specialist Theresa Smith, CDC, Fort Collins, Colo.; and research scientists Ramakrishna Nemani, Forrest Melton and Bradley Lobitz, all of NASA Ames Research Center, Moffett Field, Calif.

*Editor's note: The American Horse Council estimates that 698,000 horses live in California.

**To view selected publications, please visit:

Media contact:

Kathy Keatley Garvey, Communications
University of  California
Statewide Mosquito Research Program
Department of Entomology
396 Briggs Hall
One Shields Ave.
University of California, Davis
Davis, CA 95616
Phone: (530) 754-6894   Fax: (530) 752-1537

Web sites :

UC Mosquito Research Program 

Lanzaro Genetics Lab

UC Malaria Research and Control

UC Davis Center for Vectorborne Diseases