Assessment of Arbovirus Surveillance 13 Years after Introduction of West Nile Virus, United States.

Assessment of Arbovirus Surveillance 13 Years after Introduction of West Nile Virus, United States1 James L. Hadler, Dhara Patel, Roger S. Nasci, Lyle R. Petersen, James M. Hughes, Kristy Bradley, Paul Etkind, Lilly Kan, Jeffrey Engel Before 1999, the United States had no appropriated funding for arboviral surveillance, and many states conducted no such surveillance. After emergence of West Nile virus (WNV), federal funding was distributed to state and selected local health departments to build WNV surveillance systems. The Council of State and Territorial Epidemiologists conducted assessments of surveillance capacity of resulting systems in 2004 and in 2012; the assessment in 2012 was conducted after a 61% decrease in federal funding. In 2004, nearly all states and assessed local health departments had well-developed animal, mosquito, and human surveillance systems to monitor WNV activity and anticipate outbreaks. In 2012, many health departments had decreased mosquito surveillance and laboratory testing capacity and had no systematic disease-based surveillance for other arboviruses. Arboviral surveillance in many states might no longer be sufficient to rapidly detect and provide information needed to fully respond to WNV outbreaks and other arboviral threats (e.g., dengue, chikungunya). B efore 1999, there was no appropriated funding in the United States for arboviral surveillance, and many states had no arboviral surveillance systems (2). After the emergence of West Nile virus (WNV) in New York, New York, in 1999 (3), Congress appropriated annual funding to support WNV surveillance activities in affected states and large cities; funds were awarded to these areas through epidemiology and laboratory capacity (ELC) cooperative agreements from the Centers for Disease Control and Prevention. CDC collaborated with state, local health, and Author affiliations: Yale University School of Public Health, New Haven, Connecticut, USA (J.L. Hadler); Council of State and Territorial Epidemiologists, Atlanta, Georgia, USA (D. Patel, J. Engel); Centers for Disease Control and Prevention, Fort Collins, Colorado, USA (R.S. Nasci, L.R. Petersen); Emory University School of Medicine, Atlanta (J.M. Hughes); Oklahoma State Department of Health, Oklahoma City, Oklahoma, USA (K. Bradley); National Association of County and City Health Officials, Washington, DC, USA (P. Etkind, L. Kan) DOI: http://dx.doi.org/10.3201/eid2107.140858 academic partners to develop WNV detection, monitoring, and prevention guidance (4,5). By 2004, WNV had spread across the continental United States (6), and transmission to humans had been documented by multiple routes, including blood transfusions and organ transplantation (7– 10). That year, CDC distributed nearly $24 million to all states and 6 large city/county health departments for WNV surveillance and prevention. In 2000, CDC established ArboNET, a comprehensive national surveillance data capture platform to monitor WNV patterns. In 2003, CDC expanded ArboNET to include other arboviral diseases. ArboNET relies on a distributed surveillance system, whereby ELC-supported state and local health departments report data weekly on detection of arboviruses in humans, animals, and mosquitoes. CDC posts all data on the Internet with weekly updates (11). In 2004, the Council of State and Territorial Epidemiologists (CSTE) conducted a WNV surveillance capacity assessment and found that WNV surveillance programs were in place and well developed in jurisdictions receiving WNV surveillance funding (12). CSTE attributed the success of capacity development primarily to availability of federal funds and technical guidance from CDC. Annual funding for WNV and other arbovirus surveillance distributed through the ELC cooperative agreements has steadily decreased since 2006 to 39% of its 2004 zenith, reaching lows of $9.3 million in 2012 and in 2013 (R.S. Nasci, unpub. data). Concomitantly in 2012, the nation experienced the highest incidence of confirmed WNV neuroinvasive disease since 2003 and the highest number of confirmed deaths (286) for any year thus far (13). In addition to the continued challenge of WNV to financially stressed arbovirus surveillance systems, there is the growing threat of other arboviral diseases, such as dengue (14), chikungunya (15–17), and Powassan virus encephalitis (18). In August 2013, CSTE conducted another assessment of state and selected local health departments (LHDs) to 1 A shorter version of this report has been published previously (1). Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 21, No. 7, July 2015 1159 RESEARCH measure their current surveillance and staffing capacity for WNV and other arboviruses and compare findings with those from the 2004 assessment (19). Its objectives were to describe 1) national capacities for surveillance for WNV and other arboviruses in the 50 states and 6 ELC-funded LHDs in 2012 and changes since 2004; 2) surveillance capacities of LHDs with historically high WNV burdens but no direct federal funding and how they compare with those in ELC-supported LHDs; and 3) the outstanding needs to bring US arbovirus surveillance to full capacity. Methods The assessment tool was developed by a working group that included representatives from CSTE, the Association of State and Territorial Health Officials, the National Association of County and City Health Officials, the Association of Public Health Laboratories, the CDC Division of Vector-Borne Diseases, and Emory University. The working group developed the 2013 survey by modifying the 2004 assessment tool and adding unique questions that reflected new WNV surveillance, prevention, and control guidance (20) and assessed specific staffing needs, presence of Aedes aegypti mosquitoes, and effect of federal WNV surveillance funding reductions on WNV surveillance activities over the past 5 years. After pilot studies in 7 states and 4 LHDs, CSTE emailed the final state survey to the 50 state health departments and instructed key respondents to obtain relevant information from laboratory and mosquito surveillance and control staff, and complete the assessment online. The Epi Info Web Survey System was used to collect responses (21). CSTE used a similar process for distributing the assessment to 30 large city/county health departments that met at least 1 of 3 criteria: 1) receive supplemental WNV surveillance funding through the ELC grant (n = 6 [Washington, DC; New York, NY; Los Angeles County, CA; Chicago, IL; Houston, TX; and Philadelphia, PA); 2) had at least 100 cumulative reported cases of WNV neuroinvasive disease during 1999–2012 (n = 22, excluding 4 of the ELC-funded LHDs); or 3) had recent local dengue transmission (n = 2). The 2 assessments were analyzed separately. Frequencies of response to each question were examined in aggregate and by groupings of state health departments on the basis of whether they reported a need for additional staff. LHDs were (...truncated)