Diana Cervantes, MS, MPH Epidemiologist Tarrant County Public Health

Tarrant County: ~ 1.8 million citizens Ecology Culture Forrest to grassland prairies Urban to rural Culture Very little history of mosquito spraying WNV response began in 2002 Mosquito surveillance/testing (2003) Focus on surveillance and prevention awareness and education Open grassland, not as much shade compared to forest Culex quin urban high density TC no history of spraying, 5 cities that routinely spray prior to 2012 and then increased to 8-9 (2 cities areal spraying Haslet and S. lake in Denton partially)

Historical WNV Human Case Data Tarrant County, 2002-2011 WNV associated mortality: 1 in 2002; 7 in 2006; 3 in 2009

2012 Human case counts in Tarrant County* Total cases: 279 WNF -178 WNND - 101 Deaths - 11 Incidence rate per 100,000: 14.5 Cities with cases - 24 24 with cases Part or all (GP some in Dallas Co) of 41 cities in TC and there are unincorporated areas in TC we cover *For 2012 Arboviral season; Based on data reported as of 5:00 PM 02/22/2013

WNV Cases by Onset of Illness, Tarrant County, 2012 Average time from when a person became ill until the case was reported to TCPH was 17.7 days. Data source: Tarrant County Public Health

Use of Insect Repellent While Outdoors among Tarrant County WNV Cases, 2012* *Regardless of time spent outdoors; 2012 Arboviral season; Based on data from Tarrant County cases reported as of 11:00 AM February 21, 2013

Tarrant County Response Mosquito surveillance Resurgence of interest in participation TCPH LRN operated to capacity Adulticide application Varied among municipalities No generalized aerial spraying Targeted ground spraying effective IR was average among the metroplex counties…not the highest or the lowest Risk communication 32 mosquito surveillance participants down to 26 (fort worth and Arlington dropped out) but now participating again Prior to 2012, 5-6 cities spraying and then jumped to 8-9 Aerial spraying * Enhanced communication within TC and with 41 cities

Lessons learned Limitations of using human case data to drive control efforts Limitations of mosquito surveillance data program implementation No standard/structured trapping No historical trap data Effective communication is critical Stakeholders Media Public Local/regional partners Due to the culture in TC of now spraying, human cases drove the response in municipalities (mosquito collections, spraying). There is a need to focus on the front end and CONTROL of mosquito populations to prevent cases in addition to prevention due to the four D’s (Dusk/Dawn, drain, dress, DEET) Traps, no fixed locations: general numbers but traps mobile As with any surveillance program need to have a continuous loop of data collection, analysis, interpretation, dissemination

West Nile Neuroinvasive Disease CSTE Epidemiologic Case Definition Must meet Laboratory Criteria AND Clinical Criteria Clinical Criteria: Fever, (>100.4 or 38C) as reported by pt or HCP, AND Meningitis, encephalitis, acute flaccid paralysis, or other acute signs of central or peripheral neurologic dysfunction, as documented by a physician, AND Absence of a more likely clinical explanation NOTE: there is a great deal of variability (no standard) in determination of WNV fever versus WNND. In the case investigation form, are other agencies basing information ONLY as documented by a physician or also based on case reported signs/symptoms? What signs/symptoms or combination of signs/symptoms is DSHS using to

Recommendations for future response Review/revise response plans to increase mosquito pool surveillance operational plans to reflect surveillance data (mosquito data to drive response) communication plans Communications with those in the position to make decisions Increase number of traps and in fixed locations so that data can be used to inform control efforts. Communication to appropriate parties that can instigate response/change

Acknowledgements Tarrant County TX DSHS Environmental Health Epidemiology and Health Information TX DSHS Central Region 2/3 North Texas local public health