Lyme Disease Risk Assessment, Fort Stewart, Georgia, 25-28 April 1994 DEPARTMENT OF THE ARMY U.S. Army Environmental Hygiene Activity - South Fort McPherson, Georgia 30330-5000 [Seal of Department of Defense, United States of America] REPLY TO ATTENTION OF: HSHB-AS-P (40-5f) 2 December 1994 MEMORANDUM FOR Commander, Fort Stewart, Fort Stewart GA 31313 Commander, MEDDAC, Fort Stewart GA 31313 Subject: Lyme Disease Risk Assessment No. 16-08-A2AG-94, Fort Stewart, Georgia, 25-28 April 1994 1. REFERENCES. a. TIM No. 26, March 1990. Lyme Disease-Vector Surveillance and Control. b. TG No. 174, June 1991, Personal Protective Techniques Against Insects and Other Anthropods of Military Significance. c. TB MED 561, June 1992, Occupational and Environmental Health and Pest Surveillance. 2. AUTHORITY. a. The scheduling of this assessment was based on AEHA Form 250, Request for USAEHA Field Services, 20 December 1993. b. Conference Report on the National Defense Authorization Act for Fiscal Years 92 and 93, House Report 102-311, 102nd Congress, 1st Session, November 1991, p. 422. 3. PURPOSE. Lyme disease is one of several severe tick-borne diseases which pose health threats at military installations. These diseases, while seldom life-threatening, reduce the efficiency of affected military personnel and diminish the overall quality of life at installations. The purpose of collecting parasitic ticks was to provide a portion of the baseline data needed in the preparation of a definitive Lyme Disease Risk Assessment for Fort Stewart. The completed assessment can be used by supervisory personnel to minimize risks of Lyme disease to military and civilian personnel recreating or working at Fort Stewart. A "Fact Sheet, Protection from Ticks and Lyme Disease" is provided at Enclosure 5. 4. GENERAL. a. Survey Personnel. This risk assessment was conducted by Mr. Jack H. Chandler, Survey Officer, Entomologist, Entomological Sciences Division (ESD), U.S. Army Center for Health Promotion and Preventive Medicine (Provisional), Direct Support Activity-South (USACHPPM DSA-S). b. Personnel Contacted. A list of the personnel contacted is in Enclosure 1. c. Data Collection. (1) Small Mammal Trapping. Sherman, collapsible (small mammal) traps were placed in three promising woodland habitats and operated for three nights in order to capture parasitic ticks. No small mammals were collected from any of these traps. (2) Dry Ice Trapping of Ticks. Traps were operated at two locations as shown on Enclosure 3. Numerous lone star ticks were collected at each site. (3) Dragging for Ticks. Cloth drags were used during the early morning or evening hours at 28 sites in both wooded, edge and open habitats. See Enclosure 2 for a brief description of each of the sites where ticks were captured. The majority of these were along two major roads traversing Fort Stewart in a north-south and east-west direction. (4) Direct Immunofluorescent Assay (DIFA) of Ticks. Vials containing ticks were kept on ice and transported to Fort McPherson. The midgut contents of each tick was acetone fixed on individual wells of microscope slides. All preparations were then subjected to Fluorescein- Labeled, Affinity Purified Monoclonal Antibody and examined at 400 power under ultraviolet illumination to determine if they harbored Borrelia burgdorferi, the spirochete responsible for Lyme disease. The antibody used was a product of Kirkegaard and Perry Laboratories, Inc., of Gaithersburg, Maryland. Three or more strongly fluorescing spirochetes in a single preparation was regarded as positive. (5) Spirochete Rearing Trials. Several ticks were kept from each of four sites, surface sterilized and placed in tissue grinders along with some sterile growth media. These ticks were then macerated thoroughly. A portion of the resultant liquid was then pipetted into individual tubes containing sterile growth media (Barbour-Stoner-Kelley or BSK). The tubes were incubated for several weeks. The contents were viewed under darkfield illumination periodically to determine if spirochetes were present. At the conclusion of the rearing trials, portions of each tube were placed within individual wells of microscope slides and subjected to the DIFA procedure described above. 5. FINDINGS AND DISCUSSION. a. DIFA of Ticks. Only nymphal and adult lone star ticks, Amblyomma americanum (Linnaeus) were collected during this assessment. None of the tick midgut smears evaluated by DIFA were positive for the spirochete responsible for Lyme disease. b. Spirochete Rearing Trials. Fresh, sterile BSK medium is a light red color. This may change to a light pink or to various shades of yellow when spirochetes or other microorganisms are utilizing the media. Although the contents of many of the culture tubes changed color, no spirochetes were observed under darkfield illumination. Fluid withdrawn from these culture tubes at the end of the rearing trials were also negative for Borrelia burgdorferi when subjected to DIFA analysis. c. Preventive Medicine Service personnel were conducting an excellent surveillance program, including ticks. 6. CONCLUSIONS. No specimens of the black-legged tick (Ixodes scapularis) the known vector of Lyme disease were captured during this survey. Black- legged ticks have been captured on Fort Stewart and many of these were positive for the Borrelia burgdorferi the species responsible for Lyme disease. Although no positive ticks were identified during this survey, the potential for contracting Lyme disease and other tick-borne pathogens exists on the reservation. The lone star tick is very common on Fort Stewart and is a persistent biter which can transmit the pathogens causing Rocky Mountain spotted fever and tularemia. 7. RECOMMENDATIONS. Practice good personal protective measures, including the wearing of repellents when training or recreating in potential tick habitat at Fort Stewart. See Enclosure 4 for information on available repellents. Tick-Borne Disease Reduction measures are shown at Enclosure 3. 8. TECHNICAL ASSISTANCE. A "Fact Sheet, Protection from Ticks and Lyme Disease" is provided at Enclosure 5. The DSA-South will identify and test any ticks sent to this Activity for the presence/absence of spirochetes. Guidance and supplies for shipping ticks may be obtained by calling the Project Officer at DSN: 572-2564 or 572-2578. [signature] WILLIAM T. BROADWATER LTC, MS Commanding 5 Encls Enclosure 1 PERSONNEL CONTACTED SPC Jerry Acton, PVNTMED Specialist, PVNTMED Svc, Environmental Health, DSN 870-3050.#* CPT Carolyn Crider, Environmental Science Officer, Chief, Environmental Health, PVNTMED Svc., DSN 870-2390.#* SSGT Lutrica Hughes, NCOIC, Environmental Health, PVNTMED Svc., DSN 870-3050. MAJ Tom Logan, Cdr, 225th Medical Detachment (ENTO), DSN 870-3224. ---------- # Individual received an inbriefing. * Individual received an outbriefing. Enclosure 2 RESULTS OF TICK COLLECTIONS AT FORT STEWART, GEORGIA 25-28 APRIL 1994 PROJECT NO. 16-62-A2AG-94 [Data omitted - data summarized in above report] Enclosure 3 TICK-BORNE DISEASE RISK REDUCTION MEASURES 1. Emphasize public awareness programs to educate installation personnel and visitors on the potential for contracting tick-borne diseases such as Lyme disease and Rocky Mountain spotted fever and on personal protective measures which can be employed to minimize these risks. The USAEHA-S can provide brochures and other display materials. An informative VHS 0.5-inch audio-visual tape entitled "Lyme Disease - A growing threat" (PIN 504494) is available from the supporting Training Support Center (TSC). General Training Aid 8-5-56, Tick-Borne Diseases makes an excellent handout. Additional cards are available from USAEHA-S. An informative VHS 0.5-inch audio-visual tape about repellent application entitled "Application of the Arthropod Repellent System" (PIN 708575) and (TVT 8-232) is also available from the supporting TSC. 2. Submit any collected tick specimens (both field collected or ticks that have been removed from individuals) alive for identification and DIFA testing to USAEHA-S, Building 180, Fort McPherson, GA 30330-5000. USAEHA-S can provide directions and supplies for shipments of ticks. 3. Encourage individuals displaying Lyme disease symptoms such as febrile illness and rashes, to obtain prompt medical attention. 4. Stock Permethrin Arthropod Repellent (NSN 6840-01-278-1336, box of 12 cans), Insect Repellent Fabric Treatment (NSN 6840-01-334-2666, box of 12 bottles) and 3M [Trademark] Insect Repellent (NSN 6840-01-284-3982, box of 12 tubes) for distribution. Emphasize tick habitat avoidance and the proper wearing of clothing and use of repellents. 5. Identify high risk foci in cantonment areas via tick dragging/flagging, small mammal trapping, deer checks and the assaying of collected ticks for B. burgdorferi. Sampling should be performed in early summer when the ticks are active. Post DA Poster 40-5, and thereby identify high risk areas. 6. Avoid high tick population areas for troop training or recreation. Such areas can be identified by tick dragging or flagging prior to use. 7. Eliminate tick habitat in heavily used, infested areas (e.g., wooded recreation areas) by removing leaf litter and keeping grass mowed. Clearing should be performed during low-risk months (January/February) when the ticks are the least active. These measures will also discourage small mammals which may serve as hosts for the ticks. Thinning of trees and removal of brush will allow more sun penetration which will reduce the humidity level necessary for optimum tick survival. Prepare, as a contingency, to employ chemical control (use only approved pesticides) in the event that non-chemical control measures fail to reduce the tick population. 8. Follow installation professional wildlife biologist's recommendations to achieve annual deer harvest quotas in all training areas to ensure that the deer population is kept in check. Effective management of the deer population will reduce the associated tick population. --- [Trademark] 3M is a registered trademark of Minnesota Mining and Manufacturing Co., St. Paul, MN 55133 Enclosure 4 REPELLENTS 1. Several repellent products are available through the Defense General Supply Center (DGSC) or Self Service Supply System. When used in accordance with label directions and in conjunction with the proper wearing of the uniform, they provide personal protection against a wide variety of medically important insect/arthropod pests. Availability and current pricing can be obtained by calling the DGSC at DSN 695-4865: a. Insect/Arthropod Repellent Lotion (cream, 2 fluid ounces). The lotion, NSN 6840-01-284-3982, is not labeled for ticks, but will repel chigger mites and many biting flies. b. Permethrin Arthropod Repellent, Insect Repellent, Clothing Application (aerosol, 6 ounces) NSN 6840-01-278-1336. Seventy-five percent of the can is used to apply to the field uniform and the remainder is used to treat mosquito netting. The product provides protection from ticks and mosquitoes through six normal washings. c. Insect Repellent Fabric Treatment (liquid, 5.1 fluid ounces) NSN 6840-01-334-2666. The contents are added to 2 gallons of water and applied with the 2-gallon sprayer from a field sanitation kit at a pressure of 50 pounds per square inch to field uniforms, mosquito netting, and tent fabric to provide protection from ticks and biting flies and other insects. Since most sprayers are not equipped with the required pressure gauge (NSN 3740- 01-332-8746), it will be necessary to obtain a pressure gauge and filter (NSN 4330-01-332-1639), in order to complete the retrofitting. Proper application can provide protection for the normal life of the uniform, six washings of mosquito netting, and 6-9 months of treatment for tent fabric, depending on climate. d. Insect Repellent, Clothing Application IDAA kit, NSN 6840-01-345- 0237. One kit treats one complete battle dress uniform. Treatment lasts for repeated (30 or more) washings. Note: Dry cleaning will remove the treatment. Mark advice code "2B" (no substitutions) when ordering this kit. 2. Detailed directions for the use of these and other repellents can be found in the TG 174, Personal Protective Techniques Against Insects and Other Arthropods of Military Significance. An informative VHS 0.5-inch audio-visual tape about repellent application entitled "Application of the Arthropod Repellent System" (PIN 708575) and (TVT 8-232) is also available from the supporting TSC. 3. Do not use tick or flea collars. A toxic reaction can result. Humans have sweat glands in their skin that serve as an avenue for chemical absorption. Dogs on the other hand, respire by panting, lacking sweat glands, In addition, pets have a thicker hair barrier than most humans to protect then from direct contact with the collars. 4. The following practices enhance the effectiveness of protection when used in conjunction with repellents: - Cover as much exposed skin as possible. Consider loose fitting long- sleeved shirts in summer. - Tuck pants inside socks or boots to keep out ticks. - Wear light-colored clothing to make ticks easier to see. - Plan ahead and treat clothing with permethrin before your outdoor activity begins. Permethrin binds with fabric and is persistent through several washings. - Store treated clothing in a plastic bag to help preserve repellent effectiveness and identify treated clothing. 5. The U.S. Army Medical Department Tick-Borne Disease Card (7189) is available from the USAEHA-S, ESD. Enclosure 5 U.S. Army Environmental Hygiene Agency Entomological Sciences Division [picture of tick] Aberdeen Proving Ground, MD 21010-5422 FACT SHEET - PROTECTION FROM TICKS AND LYME DISEASE WHAT IT'S ALL ABOUT Soldiers and other personnel and dependents who live, train, work, or play in the field, share their environment with many forms of animal and insect life. Ticks may be abundant in both wooded and grassy areas. Several tick species are vectors or "transmitters" of Lyme disease. They include the deer tick, Ixodes dammini, in the Northeast and Midwest, and the western black-legged tick, Ixodes pacificus, in the West. Two other species, the Lone Star tick, Amblyomma americanum, and the black-legged tick, Ixodes scapularis, are prevalent across the South, and are potential vectors of Lyme disease. BE CONCERNED - BUT NOT ALARMED. Not all ticks carry Lyme disease, so a tick bite does not necessarily mean that disease will follow. In addition, prompt removal of a tick will lessen the chance of disease transmission. BUDDY UP When in the field, buddy up and routinely check for ticks every few hours or as frequently as possible. After returning indoors, remove your clothing and check your body carefully. Pay special attention to the hairy and/or warm, moist parts of the body. You can greatly reduce your chance of tick bite by following the DOD REPELLENT SYSTEM of wearing proper clothing and using both skin and clothing repellents: WEAR CLOTHING PROPERLY Blouse or tuck your uniform legs into your boots and wear your sleeves down. Civilians should tuck their pant legs into their socks, and their shirt into their pants. Light colored clothing makes it easier to spot ticks. USE REPELLENTS Apply deet repellent, NSN 6840-01-284-3982, to any exposed skin surfaces, and apply permethrin repellent spray, NSN 6840-01-278-1336, to your uniform or field clothing. Remember that permethrin is only for use on clothing, NEVER on skin. This combined use of repellents and proper wearing of clothing will provide nearly complete protection from tick bites. IF YOU ARE BITTEN If you find a tick embedded in your skin, DO NOT SQUASH OR BURN IT. Report to medical personnel to have the tick removed, or follow these guidelines: Use tweezers to grasp the tick's mouthparts as close to the skin as possible, and pull it straight outward. Pull slowly, firmly, and steadily. Be patient. The ticks central mouthpart called the hypostome is long and covered with barbs. This can make it difficult to remove. Wash the wound site and apply an antiseptic. Save the tick either in alcohol or frozen in a pill vial or plastic bag in case symptoms arise and identification of the tick becomes necessary. BE AWARE Be aware of the symptoms of Lyme disease. IF YOU HAVE BEEN IN AN AREA WHERE TICKS ARE FOUND AND YOU DEVELOP A RASH AROUND THE SITE OF THE TICK BITE OR FLU-LIKE SYMPTOMS (ACHES AND PAINS, HEADACHE, FEVER, EXTREME FATIGUE), ESPECIALLY DURING THE PERIOD FROM MAY THROUGH EARLY FALL, PROMPTLY SEE A PHYSICIAN FOR EVALUATION. REMEMBER... Wear trousers inside boots and sleeves down; use skin (deet) and clothing (permethrin) repellents; check your clothing and body as frequently as possible; remove attached ticks as soon as they are discovered; seek medical attention if symptoms develop. U.S. Army Center for Health Promotion and Preventive Medicine (Provisional) Direct Support Activity - South Entomological Sciences Division Fort McPherson, GA 30330-5000 FOR FURTHER INFORMATION CALL: DSN: 572-2564/2578