142nd APHA Annual Meeting and Exposition

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309551
West Nile Virus Infection, Harris County, Texas, 2002 to 2013

142nd APHA Annual Meeting and Exposition (November 15 - November 19, 2014): http://www.apha.org/events-and-meetings/annual
Sunday, November 16, 2014

Leann Liu, MD, MS , Disease Control and Epidemiology,Harris County Public Health & Environmental Services, Houston, TX
Diana Martinez, PhD, MPH , Disease Control and Medical Epidemiology, Harris County Public Health and Environmental Services, Houston, TX
Martin Reyna, MS , Mosquito Control, Harris County Public Health and Environmental Services, Houston, TX
Roberto Gorena, PhD , Disease Control and Medical Epidemiology, Harris County Public Health and Environmental Services, Houston, TX
Umair A. Shah, MD, MPH , Executive Director, Harris County Public Health and Environmental Services, Houston, TX
Objectives: This analysis aims to: 1) describe West Nile Virus infections (WNVI) in Harris County excluding Houston, Texas, 2002 to 2013; 2) explore the differences between neuroinvasive (WNVNI) and fever (WNVF) cases in regards to demographics and comorbidities; 3) analyze risk factors of hospitalization of WNVI.

Methods: Descriptive and analytic statistics were used to analyze the surveillance data of WNVI during the time period.

 Results: A total of 199 confirmed and probable infections were identified, including 149 WNVNI and 50 WNVF cases. Over 68% of them clustered in west and northwest of the county. The median age of patients was 54.8 (SE1.2) years; 62.8% were male. The onset of majority of cases (81.4%) concentrated in July to September. Overall, 75.4% of patients were hospitalized, and 4.5% died. In terms of personal protections, almost half (46.9%) patients reported never or rarely used mosquito repellent. The average age-adjusted incidence rate of WNVNI infection was 0.7 per 100,000. The time from onset of illness to testing of WNV was shorter in WNVNI cases than WNVF ones (8.8 vs 12.9 days, 95% CI of the difference 0.1-8.3, p=0.055). We did not detect statistically significant differences between WNVNI and WNVF cases in multivariate models adjusting for demographics and chronic disease(s). Neuroinvasive manifestation was found to be significantly associated with hospitalization (OR 22.6, 95% CI 7.9-65.1, p=0.000) after adjusting for demographics and chronic disease(s).

Conclusions: WNVI can significantly burden a community's population.  The public should be encouraged to heed public health messaging, including personal protection, particularly during peak seasons in these areas. Clinicians should be alerted of this endemic disease and consider testing and reporting as early as possible, especially in neuroinvasive patients.

Learning Areas:

Epidemiology

Learning Objectives:
Describe West Nile Virus infections (WNVI) in Harris County excluding Houston, Texas, 2002 to 2013; Analyze risk factors of hospitalization of WNVI

Keyword(s): Epidemiology, Surveillance

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have 24 years of experience in the field of Public Health, specifically in epidemiology, disease surveillance and data analysis. I provide programmatic oversight, technical expertise, and personnel supervision for the Epidemiology Program. I am directly involved in disease surveillance, analysis of large datasets and report writing. I am responsible for ensuring appropriate/timely response of the Epidemiology Program to public health emergencies and large scale outbreak investigations. The population served is approximately 2.1 million.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.