West Nile Virus Biology, Genetics & Clinical Research

NIAID conducts and funds basic and clinical research on

• West Nile Virus (WNV) biology and viral structure
• Ways the virus causes human disease and persists in the body
• Viral interaction with and transmission among humans, birds, and mosquitoes
• Processes underlying WNV emergence and ecological patterns in the United States
• Insecticide resistance

With NIAID support in 2001 and 2002, researchers found that hamsters and mice are good models for WNV in humans. As a result, golden hamsters and mice are now used to test the efficacy of WNV vaccine candidates and antiviral treatments. NIAID-supported researchers are studying the different ways the immune system responds to WNV and how these responses interact to affect infection. Scientists are also examining how WNV evolves and adapts to changing environments and the structural changes that occur to the virus when it replicates.

NIAID has long supported the World Reference Center for Emerging Viruses and Arboviruses (WRCEVA), located at the University of Texas Medical Branch at Galveston, which helps support research and outbreak investigations throughout the world. In response to the 2012 WNV outbreak in the United States, WRCEVA scientists sequenced several newly isolated WNV strains from Texas. Using genetic analysis, they compared different WNV strains to see if the virus has changed over time. In addition, the center has long provided research resources, such as viral isolates and reagents, to the scientific community. The center’s repository currently includes more than 500 WNV strains and isolates from across the globe.

In July 2012, in a NIAID-supported observational study of WNV patients in the Houston area, researchers at the Baylor College of Medicine discovered chronic kidney disease among 40 percent of patients long after recovery from acute disease. The study highlights the continuing need to investigate the pathology behind persistent infections, clinical outcomes, and treatment options.