Environmental Health

One of the emerging priorities for the use of syndromic surveillance is for the monitoring of environmental health conditions. Heat-related illness (HRI) is of growing public health importance, particularly with climate change and anticipated increased frequency of heat waves. High ambient temperatures are responsible for significant morbidity and mortality, as was demonstrated during the 2003 heat waves in Europe that resulted in an estimated 45,000 excess deaths. A syndromic surveillance system that is able to detect early indications of excess HRI may start the public health response earlier, and thus reduce associated morbidity and mortality. Our research group is exploring the potential use of 911 medical dispatch data for the surveillance of HRI in Toronto. An important step in this assessment is exploring the association between temperature and 911 dispatch calls for HRI.

Objective

This paper describes the association between 911 medical dispatch calls for heat-related illness and maximum temperature in Toronto, Ontario during the summer of 2005.

When a chemical or biological agent with public health implications is detected in the City of Houston, analysis of syndromic surveillance data is an important tool for investigating the authenticity of the alert, as well as providing information regarding the extent of contamination.

Syndromic surveillance data in Houston is currently provided by the Real-Time Outbreak Disease Surveillance, which collects and synthesizes real-time chief complaint data from 34 area hospitals, representing approximately 70% coverage of licensed ER beds in Harris County. Data collected for each complaint includes patient home and work zip codes, allowing for geographic analysis of the data in the case of a localized environmental contamination.

Historically, when alerted to a contaminant in the Houston area, the Houston Department of Health and Human Services (HDHHS) has analyzed health data for each zip code in the geographic area of interest separately, a time-intensive process.

Recognizing the need for a more accurate and timely response to an environmental alert, HDHHS proposes aggregating zip codes into zones, based on coverage of population and areas of high risk. These “Surveillance Zones” will be used to quickly reference syndromic data in the event of a chemical or biological event.

Objective

This paper discusses the development of zones within the City of Houston in order to more quickly and accurately reference surveillance data in the case of chemical or biological events.

Heat related illness is the number one cause of human death in relation to extreme weather events in the United States, resulting in an average of 400 deaths per year over the past few decades. It is also expected that both the duration and intensity of these events will increase. The temperature of the surface is measurable from a number of space borne satellites and can be derived using a number of available algorithms. This type of data can be compared to census collected variables to determine the number of persons at risk for heat related morbidity and mortality within urban environments.

Objective

This paper describes a method of determining areas at risk during extreme urban heat events using remote sensing technologies, geographical information systems and artificial neural networks.

On December 14th, 2006, a severe windstorm in western Washington caused hundreds of thousands of residents to lose power. On December 15, 2006, there was a surge in emergency department (ED) visits for patients presenting with signs of acute carbon monoxide (CO) poisoning. A Public Health investigation was initiated following the storm to determine the extent of CO poisoning due to the windstorm. A retrospective analysis was later undertaken to evaluate how well our syndromic surveillance system was able to identify patients who presented to area EDs with carbon monoxide poisoning.

Objective

We evaluated the performance of our ED syndromic data for detecting visits associated with CO poisoning.

Since October 2004, the Indiana State Health Department and the Marion County Health Department have been developing and using a syndromic surveillance system based on emergency department admission data. The system currently receives standards-based HL7 emergency department visit data, including free-text chief complaints from 72 hospitals throughout the state. Fourteen of these hospitals are in Marion County, which serves the Indianapolis metropolitan region (population 865,000).

Objective

This paper describes how a syndromic surveillance system based on emergency department data may be leveraged for other public health uses.

A large event such as the Super Bowl that attracts over 120,000 visitors to an area within a short period of time has the potential to increase the risk of communicable diseases and environmental hazards in a community in addition to the possibility of a bioterrorist attack. Though Miami-Dade County Health Department has in place a syndromic surveillance system, additional public health measures were implemented to ensure the health and safety of all residents and visitors in the weeks surrounding the February 4th event.

OBJECTIVE

To identify unusual patterns of communicable diseases, health events or bioterrorism-related activity in Miami-Dade County immediately before, during and after Super Bowl XLI.

The Bioterrorism Surveillance Unit of the Los Angeles County (LAC) Department of Public Health, Acute Communicable Disease Control (ACDC) program analyzes Emergency Department (ED) data daily. Currently capturing over 40% of the ED visits in LAC, the system categorizes visits into syndrome groups and analyzes the data for aberrations in count and spatial distribution. Typical usage of the system may be extended for various enhanced surveillance activities by creating additional syndrome categories tailored to specific illnesses or conditions. This report describes how ED data was utilized for enhanced surveillance regarding: (1) a sustained heat wave in California that broke temperature and duration records, (2) a 30,000 gallon raw sewage spill that prompted the closure of two miles of beach, and (3) an alert to ACDC of a high school student who attended school while symptomatic for meningitis.

Objective

To describe enhanced surveillance provided by the LAC Department of Public Health’s syndromic surveillance system for monitoring health events in 2006.