Integrated GIS Solution For Mosquito Control

Keven C. Boyd

The Richland County, South Carolina, GIS Department replaced the paper map/document work flow of the Vector Control Department with a GIS solution. First, an inventory of breeding sites, monitoring locations, and "at-risk" facilities (e.g., child care) was conducted using GPS. Second, historical documents were transferred to Access and Excel for quicker searches. Third, custom software for the iPAQ replaced paper field forms and a master database is updated from iPAQ back in the office. Fourth, by using Crystal Reports, status reports are now digital and e-mailed. Vector Control has created action plans for outbreaks, reduced paper work, and is completing more citizen requests.


Executive Summary:

The Geographical Information Systems (GIS) Department functions under the cumulative mandate of three entities: those of Richland County, the Information Technologies Department (IT), and GIS itself. Being part of Richland County, the GIS department inherits the responsibility of improving the quality of life for all its citizens by providing cordial, responsible services and assistance in a prompt and fair manner. Of these essential County services the IT Department is authorized to be the visionary force that reinvents, reengineers, and streamlines all County Government practices where technology is concerned. The result of which is a more efficient and effective Government that can utilize the time/cost savings to improve the quality of interaction between Richland County and its citizens. As part of the IT Department, GIS finds itself supporting the broader goals of the County and IT through specific applications of spatial data, statistical analysis of geographic data and information and applications of that data. The five main goals for the GIS Department are:

To build a framework of fundamental digital geographic data elements that support Richland County’s services to its citizens.

To coordinate all digital geographic data so that services rendered to citizens are efficient and improved over time.

Make geographic and related information available to citizens while protecting county investment in data development.

Empower County officials and employees by providing the tools, data, and information needed for answering practical problems, policy issues, and political questions that impact citizens.

Foster data sharing partnerships between government and private entities so that economic, environmental, public safely, and infrastructures are improved for citizens.

With these goals and mandates in mind, the GIS Department seeks to find and realize innovative ways to apply technology to existing county methods and procedures so that citizens benefit both directly and indirectly from a local government able to respond in the timeliest fashion.

Background Information:

Vector Control of Richland County is a joint venture managed by the county and the South Carolina Department of Health and Environmental Control (DHEC). DHEC staff are supported with County resources to secure health and sanitary conditions for the local community. Richland County Vector Control is charged with monitoring and reducing harmful vectors (i.e. disease and pests) and controlling mosquito populations. Their primary responsibility involves the weekly monitoring of mosquito populations in 54 zones that comprise Richland County, the collection of ancillary data (i.e. rain fall amounts, species type and gender, and breeding site conditions) that relate to future population size, and the treatment and reduction of mosquitoes that are found. By scrupulously monitoring breeding sites across Richland County, mosquito populations still in the pre-adult (larvae) stage can be treated and greatly reduced in number. Adult mosquito populations are also held in check through nighttime spraying. The daily work of Richland County Vector Control results in fewer mosquitoes that can function as a spreading source for disease (i.e. West Nile).

Initial Project Investigation:

Vector Control first approached the GIS Department for the creation of paper map products for their field workers. After conducting a brief interview with the Vector Control staff, it was apparent that a need existed within the department for more than just new maps. The Vector Control staff were using old paper maps that were cut out and placed into three-ring-binders which also held the information about mosquito breeding sites located on the maps. These maps and paper documents, while useful, were not allowing the staff to work as efficiently as possible as no two persons could use the documents or maps at the same time in the field. Vector Control also lacked the fundamental maps to determine if citizens requesting mosquito spraying were within the county or another municipality. To determine caller locations, employees had to make a 40-minute round-trip from their offices to the Administration building to locate addresses with a wall map. With limited resources and staff, Vector Control verified addresses once a week. Delays in address location often created a backlog of new requests during the busiest time of the year.

The greatest limitation of the manual system was the inability to create strategies for dealing with disease outbreak. There was no way to quickly collate 54 small maps and hundreds of paper documents to determine where all key breeding sites were located and factor in nearby At-Risk-Sites (ARS) such as elderly care facilities, schools, and child day care facilities. In the event of an outbreak of West Nile Virus, these would be the ARS whose populations would need to be notified. The GIS staff of Richland County quickly realized that in order to improve the citizen response time and incident handling, a complete data management and analysis solution was needed to accommodate Vector Control’s daily business practices.

Project Solution:

Phase One

A four-phase implementation plan was created to address the needs of Vector Control. In phase one, the 54 individual paper maps of the Vector Control zones were digitized using current street data. Monitoring locations where weekly observations are recorded were also digitized. The two were then combined with other existing Richland County data layers (municipal boundaries, county boundary, water features, census boundaries, and road networks) to recreate the Vector Control maps in digital form. Using ArcView software by Environmental Systems Research Inc. (Esri) all these layers were combined into an interactive map on the computer.

Phase Two

Phase two involved creating digital copies of all source paper maps of known mosquito breeding sites in Richland County using mapping grade Trimble ProXR Global Positing Systems (GPS) devices. Mapping-grade GPS data are accurate to within a few feet. Over the course of a summer, two students located all of the mosquito breeding sites within the County using GPS. All paper-based tabular data associated with each site were verified in the field and entered into a database.

Phase Three

Phase three involved locating all “At-Risk-Sites” (ARS) for mosquito transmitted diseases. These sites (schools, elderly care facilities and child day care facilities) contain concentrated populations that are most vulnerable during outbreaks of West Nile or similar diseases. Vector Control needed a way to locate these facilities in relation to the mosquito breeding sites. In the case of an outbreak, all ARS locations must be notified and targeted as primary treatment locations. The ARS were located using a combination of GPS devices and address location from lists complied from state and local agencies. From these data, three new layers were created. Schools, child day care, and elderly care facilities were added to the ArcView interactive map. With the inclusion of this new set of digital data, the Vector Control staff could view caller addresses as well as surrounding mosquito breeding sites, the location of ARS, and review all associated information within the database.

Phase Four

Phase four involved the creation of custom software for the Compaq IPAQ handheld Personal Digital Assistant (PDA). PDAs were selected to replace paper forms used by Vector Control to conduct field investigations. Prior to using PDAs, Vector Control staff had to fill out multiple paper forms in the field and transcribe information from them into several databases once they returned to the office. Many work hours were lost due to re-transcribing data, correcting for data entry errors, and forgetting to acquire the correct number and/or type of forms before leaving the office. Furthermore, the paper documents could not be easily analyzed for trends in mosquito breeding during single or multiple seasons.

Project Impact:

The advantages to the Vector Control Department at the end of phase one were: (1) each of the staff can now review any area on the map simultaneously without having to trade paper maps, (2) the address of a citizen requesting assistance can be entered and then the map will automatically move to the location allowing the staff to determine what municipally the citizen resides in, (3) any changes to existing Vector Control boundaries or additions/deletions of monitoring locations can be made in minutes and the digital map is immediately current, as opposed to using a paper map with dated information. (4) if any of the printed copies of the digital maps are lost, soiled, or torn they can be quickly reprinted.

The advantages to the Vector Control Department at the end of phase two were: (1) all known mosquito breeding sites can be displayed on the interactive map and all data associated with the sites can be reviewed by any staff member, (2) updates to the data can be made in minutes and is kept current through daily routines, (3) spatial relationships can now be derived concerning mosquito breeding sites (i.e. how many breeding sites within one mile of a citizen’s house are producing a high number of infected mosquito species), (4) when responding to citizen requests for mosquito spraying, breeding sites closest to an address can be located quickly and given extra treatment, thereby reducing mosquitoes at their breeding source.

The advantages to the Vector Control Department at the end of phase three were: (1) GPS devices provided Vector Control with ARS locations for inclusion in the ArcView interactive map. Locating all needed data layers is easy when staff need to respond to a citizen request for mosquito control. The resulting work order can be created and verified in a single step, (2) spatial relationships concerning breeding sites can now be expanded from phase two to include notification and preventative treatment around ARS locations as opposed to sorting through multiple paper documents and calling state offices to find out what are the closest ARS to the outbreak site (i.e. “If an outbreak of West Nile occurred at this location, what breading sites within 1 mile would be a spreading source? What are those breading sites like? What chemicals need to be used? What ARS locations, elementary schools and day cares, need to be notified?”).

The advantages to the Vector Control Department at the end of phase four were: (1) data entry errors are greatly reduced, (2) there is no longer a need for re-entering data collected in the field, (3) all data collected is now in a database which allows searching for specific pieces of information easer than using paper documents, (4) more time is spent conducting field investigation for citizens and less time re-doing paperwork.

Depth of Project Impact:

The four-phase technology solution for Vector Control’s business practices will directly impact their department in numerous ways. The greatest benefit results from the time saved in the reduced number of man-hours required to complete tasks. What once required multiple paper documents and maps, stored in various locations, is now available in one map and it’s associated databases. This directly affects the number of work orders that can be completed by each of the staff in the same amount of time, thereby improving their service to the citizens of Richland County.

A second impact is the increased depth of information that can be extracted from the ArcView interactive map in the areas of mosquito breading control and disease transmission. Being able to follow the spatial interaction between breeding sites and ARS locations allows Vector Control to begin developing strategies for preemptive treatment and mosquito suppression in the advent of disease outbreak. This directly relates to the SC DHEC mandate that Vector Control has of assuring the optimal level of health and sanitary conditions in which citizens live.

Unlike most GIS applications that require significant future data collection, the Vector Control project includes data maintenance within business procedures. Thus, data are constantly maintained and future collection efforts are limited. This construct promotes efficient data entry and error checking while minimizing long-range costs.

An additional positive impact is the data security that Vector Control now enjoys. Previously, all data were in the form of paper maps and documents. The conversion of all documents to digital data and maps allows resources to be backed-up within a Countywide computer security plan. This assures that any fire, water damage, theft, or storm damage to the Vector Control facilities will not permanently destroy their only data source. Had any of these accidents occurred before the technology improvements were completed, decades of mosquito breeding and control data useful for future modeling of breeding or analysis would have been lost. Protection of information in this fashion guarantees the citizens of Richland County that the employees responsible for mosquito control will always have available the full history of data with which to make decisions.

Project Metrics:

One of the mandates of the Richland County GIS Department is to empower officials and employees by providing the solution, tools, data, and information needed for their job-related tasks. The four-phase solution implemented by the GIS Department for Vector Control is an example of realizing mission objectives. However, the GIS Department roll as a “technology-facilitator” does not stop upon delivery of the solution or tools. The working relationship between Vector Control and GIS remains current through providing software training and answers to “help-desk” questions that arise during Vector Control daily routines. The GIS Department provides Vector Control with on-site computer hardware and software support as well as technical assistance with important tasks (i.e. data back-up) to ensure all work is completed as required.

The impact and benefits of changing the business practices of Vector Control will be monitored over the upcoming mosquito season. By evaluating the quantity and quality of data collected by Vector Control and by analyzing quarterly reports of help-desk work orders, Richland County expects to quantify the total cost savings of the new methods.


Keven Boyd
GIS Programmer / Analyst
Geographic Information Systems Department
2020 Hampton Street, Suite 3014
Columbia SC 29204
803.929.6140
www.richlandmaps.com