Assessment of State, Local and National Capacity for Surveillance for West Nile Virus and Other Arboviral Infections in the US, 2004 and 2012

Wednesday, June 25, 2014: 11:36 AM
103, Nashville Convention Center
James L Hadler , Independent Consultant, Atlanta, GA
Dhara Patel , Council of State and Territorial Epidemiologists, Atlanta, GA

BACKGROUND:  West Nile virus (WNV) transmission was first recognized in the United States in August 1999.  In five years, WNV spread to the 48 contiguous states, resulting in 7,102 reported cases of neurological illness and 667 deaths through 2004, becoming the most commonly reported mosquito-borne disease in the U.S. As it spread, funding for WNV surveillance and prevention was appropriated by Congress and distributed though the CDC Epidemiology and Laboratory Capacity (ELC) cooperative agreements for emerging infectious diseases to all 50 states and six large cities/counties. In 2005, the Council of State and Territorial Epidemiologists (CSTE) conducted an assessment of ELC recipients about their capacity in 2004 and determined that all had well-developed WNV surveillance programs attributable to new funds and technical guidance from CDC, and that a national arboviral surveillance infrastructure had been established. Since 2005, annual federal funding for WNV surveillance has gradually decreased by 60%, despite broadening of ELC funding for WNV to include surveillance for other arboviruses as well. In 2012, the US had its most severe WNV season since 2003. In 2013, CSTE conducted another assessment of the ELC-supported WNV programs to determine the current state, local and national capacity to conduct WNV and other arbovirus surveillance, prevention and control.

METHODS: Using the 2005 assessment as a starting point, a workgroup developed a questionnaire to assess surveillance capacity for WNV and other arboviruses during 2012. In August 2013, the questionnaire was distributed electronically through the state epidemiologist to all 50 state health department WNV programs and through the local health department (LHD) epidemiologist or director to all 6 ELC-supported WNV programs in city/county health departments and to 24 additional LHDs with the highest cumulative WNV burden since 1999. 

RESULTS:  All 50 state health departments, all six ELC-funded LHDs and 15 high WNV-burden LHDs responded. Since 2004, staffing of dedicated 0.5-1.0 FTE WNV surveillance and laboratory positions has decreased 42% in ELC-supported jurisdictions. While all continue to conduct human WNV surveillance, fewer conduct active surveillance, mosquito surveillance, and test all mosquito pools for WNV. Most have stopped avian mortality surveillance, 45% test fewer human specimens, and fewer test human specimens for other arboviruses. To achieve “full capacity”, a 58% increase in FTEs is needed.  

CONCLUSIONS: Capacity for WNV surveillance and control has decreased substantially since 2004, compromising local and national ability to rapidly detect and respond to changes in WNV and other arboviral activity.