2005 Model Practice Application (Public)

West Nile Virus and Vector-Borne Disease Surveillance Program

Dallas County Health and Human Services

The Environmental Health Division of Dallas County Health and Human Services began conducting mosquito-borne surveillance in 1966, as a response to an outbreak of St. Louis Encephalitis. However, in 2004 additional staff and resources significantly increased the efficiency of this program, thus enabling the program to better serve the citizens of unincorporated Dallas County and other local municipalities. The occurrence of West Nile virus (WNV) in Texas resulted in many human cases that caused several human deaths in 2002 and 2003.

To address this growing public concern, Dallas County Health and Human Services (DCHHS) implemented a WNV and Vector-borne disease program. The Environmental Health Division initiated a multi-disciplinary collaborative effort that involved the epidemiology, communicable disease, outreach workers, public information officer, GIS technicians and laboratory divisions of DCHHS to create county-wide surveillance program. This created a set of complementary action plans, intended to offer a consistent approach to prevent human cases of WNV and other vector-borne diseases. In addition, this program enabled local agencies in Dallas County to respond to vector-borne disease threats within their jurisdiction and it allowed them to take the necessary actions deem appropriate. With this infrastructure in place, DCHHS worked to increase communication and share resources to improve this practice.

Due to the spread of the WNV within the communities of Dallas County, DCHHS conducted a review of existing prevention and control resources available to address this threat. DCHHS became the lead agency in a WNV and Vector-borne disease program for matters related to epidemiology and other health issues. Local hospitals and health agencies assisted in reporting possible human cases of WNV to the communicable disease division of DCHHS. The epidemiology staff of DCHHS performed investigations of all reported human cases of WNV. The Environmental Health Division of DCHHS contacted local municipal health departments of all suspected and confirmed human cases on WNV originating within their jurisdictions of mosquito control. Local municipal vector-controlled programs conducted mosquito control procedures within their jurisdictions. Through the acquisition of innovative laboratory equipment, a mosquito-testing procedure was developed to support its existing Integrated Mosquito Management Program.

An association of local health departments collected mosquitoes that were tested for the presence of WNV by utilizing a DNA analysis known as RT-PCR (Real Time Polymearse Chain Reaction) by the DCHHS laboratory. DCHHS collected all test results of positive human, mosquito, and bird samples and tabulated this data into a collaborative e-mail data based that was utilized by all participants of the program. Positive samples were plotted and mapped using GIS technology for use at DCHHS weekly press conferences. The key to making this procedure work efficiently was the creation of a GIS Technician position. This person bridges the gap from data collection to data reporting. In the past, there was no uniform format of data collection, nor a single site of storing the data. Any data that was collected was mapped with push-pins or stickers. Furthermore, the pins represented block ranges or zip codes. Under the current procedures, surveillance for mosquito traps and other samples employed GPS units to create a uniform data file for storing this information. GPS units provided accurate coordinates of sites that were transferred to software and plotted using a map printer. This allowed DCHHS staff to target control activities and public information campaigns. In addition, these maps were used for press conferences, media press releases, and maps of treatment areas to inform stakeholders of activities in their neighborhood. These press conferences provided communication to all stakeholders concerning WNV information. Environmental Health and Older Adult Services of DCHHS provided outreach programs to educate targeted audiences of the potential risk, prevention, and personal protection from the West Nile Virus.

DCHHS was responsible for regional coordination of surveillance efforts, sharing of information and expertise among adjacent health jurisdictions involved in the WNV and Vector-borne disease surveillance program. An interdepartmental infectious disease program was formed by DCHHS to provide a coordinated effort between state and local health departments and hospitals to efficiently share information about WNV. Thirty-one local governments in Dallas County were the primary stakeholders and many participated in working together in order to gather and develop information for their respective constituencies. Collaboration of all participants was required to plan and implement their roles as designated representatives in regards to mosquito control. Local public health agencies were responsible for reassuring provisions of preventive activities to reduce the risk of WNV in their community. Education, communication, and maintaining local media contacts were important functions of all participating governmental agencies. Other departments within municipalities such as public works, code enforcement, and planning and development were important in the implementation of the program. Nonprofit and grassroots organizations provided outreach services through educational presentations designed to reach the senior citizens of all communities.

Existing medical, epidemiological, and environmental health staff of DCHHS was utilized to create and implement a WNV and vector-borne surveillance program. DCHHS employed three seasonal, full-time mosquito technicians to assist in surveillance and testing program. GIS technicians, P.I.O. and laboratory supports were also provided by DCHHS. On going funding of equipment and supplies for the program were through support of contracting municipalities and DCHHS. As the program continues, additional fees may be required to assist in the support of mosquito testing costs incurred.

Objective I: Develop a Dallas countywide WNV and vector-borne disease surveillance program.

• Assemble all essential staff within DCHHS (administration, medical, epdemiology, environmental health)
  
  
• Gather input from other health and governmental agencies and designate roles.

Objective II: Education through public information and outreach programs.

• Educate senior citizen communities regarding the potential risk, prevention, and personal protection from WNV
  
  
• Provide information to the public through daily and weekly contact through local media outlets.

Objective III: Increase mosquito surveillance and develop an in-house mosquito testing program.

• Develop WNV testing procedures
  
  
• Implement contractual agreements between DCHHS and other municipalities
  
  
• Purchase surveillance and laboratory equipment
  
  
• Train staff in mosquito identification, data entry, GIS tools, and light cycler procedures
  
  
• Conduct mosquito collections (April-October)
  
  
• Report mosquito testing results to GIS technicians, Public Information Officer, and local stakeholders
  
  
• Conduct weekly press conferences
  
  
• Implement adequate control measures
  
  
• Conduct outreach campaigns in areas of WNV isolations
  
  
• Collaboratively share data / laboratory results and GIS maps with stakeholders