Lyme Disease Consultation, Fort Riley, Kansas, 24-27 November 1989 DEPARTMENT OF THE ARMY US Army Environmental Hygiene Activity-West Fitzsimons Army Medical Center Aurora, Colorado 80045-7010 [Seal of Department of Defense, United States of America] REPLY TO ATTENTION OF: HSHB-AW-P (40-5f) 23 February 1990 MEMORANDUM FOR Commander, U.S. Army Health Services Command, ATTN: HSCL-P, Fort Sam Houston, TX 78234-6000 SUBJECT: Lyme Disease Consultation No. 16-66-0502-90, Fort Riley, Kansas, 24-27 November 1989 1. AUTHORITY. AEHA Form 250-R, Health Services Command, 12 July 1989. 2. PURPOSE. Our purposes for performing this Lyme disease consultation were to survey for vector species of Lyme disease and to determine the prevalence of the infective agent, Borrelia burgdorferi, in ticks and white-tailed deer, Odocoileus virginianus. See Enclosure 1 for other assistance that can be obtained from the U.S. Army Environmental Hygiene Activity-West. 3. GENERAL. a. Dr. Lester D. Hale, and SPC Kerry O. McKinley, the Survey Officers, discussed findings with key personnel at Fort Riley. See Enclosure 2 for a list of personnel contacted. b. The study involved collecting ticks and blood samples from deer brought to the field check-out station during routine hunter check-in procedures. Ticks and serum specimens were collected and sent by overnight express to the U.S. Army Environmental Hygiene Agency (USAEHA) laboratory, Aberdeen Proving Ground, for tick identification and Lyme disease assay. c. Technical assistance was provided to the Safety and Health Offices on Lyme disease educational programs. Further, a slide presentation on Lyme disease that included the chronology, geographic distribution, tick vectors, causal agent, hosts, clinical manifestations and symptoms, and personal protective measures against this disease was given to Fort Riley personnel. 4. BACKGROUND. a. Lyme disease, first recognized in 1975 in Old Lyme, Connecticut, is now recognized as the most common tick-borne illness in the United States. The etiological or causal agent of this bacterial disease is a spirochete B. burgdorferi, which is transmitted to humans and animals by the bite of an infected tick. Primary vectors of Lyme disease vary and include the deer tick, also known as the bear tick, Ixodes dammini, in the east, northeast, and midwest; the western black-legged tick, Ixodes pacificus, in the west; and the black-legged tick, Ixodes scapularis, in the southeastern United States. The Lone Star tick, Amblyomma americanum, is also known to transmit Lyme disease. Borrelia burgdorferi has been found in the American dog tick, Dermacentor variabilis; however, transmission of Lyme disease to animals by this tick has not been demonstrated under laboratory conditions. For this reason, this tick is not currently considered a vector of Lyme disease. The American dog tick, however, is the principal vector of Rocky Mountain Spotted Fever (RMSF). There could be a potential risk of Fort Riley personnel becoming infected with RMSF by being bitten by American dog ticks. b. Fort Riley is located adjacent to Junction City, Kansas, in the northeastern part of the state. The installation contains 96,806 acres and includes parts of three counties (Clay, Geary, and Riley) within its boundaries. In general, the installation is situated on a gently rolling, grassy plateau transversed by streams which, in certain areas, have caused relatively dramatic changes in elevation through erosion. The lowest point of the installation is 1,040 feet at Camp Funston, while the highest point is approximately 1,400 feet atop Artillery Hill. There are four basic communities of vegetation occurring on the installation: grassland, woodland, shrub-land and previously farmed land which is being allowed to return to nature. c. The deer population, before the hunt, was estimated by Fort Riley Fish and Wildlife biologists at approximately 1,000 deer. During 1989, 125 deer were harvested during this 3-day hunt, and there was a total of 240 deer harvested during the entire deer-hunting season. Automobile accidents killed 13 deer during 1989. d. According to Fort Riley Health Clinic personnel, there were 5 cases of Lyme disease reported in the state of Kansas for 1988. Most of these cases were National Guardsmen who attended summer camp at Fort McCoy, Wisconsin. State data were not available for the occurrence of Lyme disease in 1987 or 1989. Two soldiers, however, were diagnosed as having positive titers for Lyme disease at Fort Riley, one in 1988 and another in 1989. Both soldiers (one in 1988 at Breakneck Lake, and the other in 1989 at Camp Forsuth) were bitten by unidentified ticks on Fort Riley. These soldiers reported not having traveled for 90 days prior to being diagnosed with Lyme disease. e. General Lyme disease information and personal protective measures against this disease are presented in Enclosure 3. 5. FINDINGS AND DISCUSSION. a. Tick and blood samples. (1) There were 125 deer examined for ticks during the 3-day hunt: 60 deer were examined on Friday, 37 on Saturday, and 28 on Sunday. Examiners spent from 5 to 10 minutes on each deer concentrating search efforts for ticks on the ears, head, neck and shoulders. All of the ticks collected from each deer were counted and placed in an individual vial. The ticks were sent via overnight express to the USAEHA Aberdeen laboratory for species identification and examination for B. burgdorferi. (a) All ticks examined by the USAEHA Aberdeen laboratory personnel were found to be negative for the etiological agent, B. burgdorferi. (b) The most common tick found on deer during this survey was the winter tick, Dermacentor albipicus. There were 473 winter ticks collected: 239 adult males, 134 adult females, 99 nymphs, and one larva. There were only 23 dog ticks, D. variabilis, collected from deer: 18 were adult females, 4 adult males, and 1 nymph. The primary tick vector of Lyme disease, I. dammini, was not found on white-tailed deer examined during the survey. (c) Ticks were collected from 73.6 percent (92/125) of the deer examined. The number of ticks collected from each deer ranged from 1 to 17. The average number of ticks collected per animal for each of the five hunting areas was 2.3 for Area 1, 3.7 for Area 2, 4.6 for Area 3, 4.1 for Area 4, and 5.4 for Area 5. See Enclosure 4 for map of the hunting areas. The largest average number of ticks per animal were on the deer in Area 5, the area located closest to the cantonment and housing areas. (2) There were 65 blood samples taken from deer during the 3-day hunt: 17 blood samples were taken on Friday, 26 on Saturday, and 22 on Sunday. Each blood sample was centrifuged, and the serum was decanted and put into a 2 ml screw cap micro-tube for Lyme disease assay at the USAEHA Aberdeen laboratory. The results from these tests will be forwarded in a separate report. b. A Lyme disease coordinator had not been designated to oversee the Lyme disease program at Fort Riley. The Lyme disease coordinator should be involved in the training of military and civilian personnel in personal protective procedures, surveillance and reporting of the disease, and coordination of all Lyme disease efforts with appropriate military, State, and county offices. The Lyme disease coordinator should also review any Kansas Department of Health reports or bulletins for cases of Lyme disease in the counties surrounding Fort Riley. c. Suspected cases of Lyme disease occurring on Fort Riley were being reported by Preventive Medicine Services (PVNTMED Svc) personnel to the Office of the Surgeon General via Report of Selected Condition (MED 16). d. The PVNTMED Svc personnel had given out some information to troop commanders concerning Lyme disease. However, a continuing educational program on tick-borne diseases was not being provided to unit representatives. Once unit representatives are trained, they can then brief incoming troops on personal protective measures against tick bites. 6. CONCLUSIONS. Fort Riley staff personnel and hunters were exceptionally receptive to information on Lyme disease education and personal protective measures for personnel. There is the possibility that Lyme disease will occur on Fort Riley. During this survey, two species of ticks, D. albipictus and D. variabilis, were collected from deer; no known tick vectors of Lyme disease were collected on Fort Riley. Even though the bacterium B. burgdorferi, was not found in ticks assayed, it is believed that personnel stationed and/or training on Fort Riley may be at a low risk of becoming infected with Lyme disease. A Lyme disease coordinator should be designated to oversee the Lyme disease program. A potential risk of becoming infected with RMSF exists for personnel bitten by American dog ticks. 7. RECOMMENDATIONS. The following recommendations are based on good pest management practices: a. Provide Lyme disease information or briefings to representatives of units training on Fort Riley. b. Designate a Lyme disease coordinator that will oversee the Lyme disease program. c. Review Kansas Department of Health reports for cases of Lyme disease in the counties surrounding Fort Riley. [signature] RONALD J. RAKICKAS LTC, MS Chief, Entomological Sciences Division 4 Encls Enclosure 1 TECHNICAL ASSISTANCE Technical advice and/or consultation on pest management problems, to include on-site assistance, may be obtained by telephone from our Activity, AUTOVON 943-8090. Please inform your Major Command Pest Management Consultant if you desire to request on-site assistance from our Activity. Other services with which we can assist you are as follow: 1. Entomological laboratory support 2. Environmental laboratory support 3. Hazardous waste management 4. Industrial hygiene management 5. Medical systems safety and health 6. Sanitation and hygiene 7. Wastewater management 8. Water supply management 9. Worksite hazards management For assistance in any of the above-listed programs, please call: Environmental Health and Engineering Division - AUTOVON 943-8881 - Industrial hygiene: Field sanitation and hygiene: potable, recreation and wastewater quality: hazardous waste management: document/design reviews. Environmental Laboratory Division - AUTOVON 943-8288 - Routine and emergency analysis of water, soil, and occupational health-related samples. During non-duty hours, calls will be recorded by an answering machine and returned the next day. Many additional environmental services are available from our parent organization, the U.S. Army Environmental Hygiene Agency, and are described in AEHA Pamphlet 4C-2, Directory of Services (published annually). We will gladly coordinate with our parent organization to provide for any additional services you request and which we cannot provide. Enclosure 2 PERSONNEL CONTACTED 1. Mr. Herb Abel* Fish and Wildlife Biologist Fish and Wildlife Branch Natural Resources Division, DEH AUTOVON 856-6211 2. Mr. Scott Klinger Chief, Fish and Wildlife Branch Natural Resources Division, DEH AUTOVON 856-6211 3. CPT Ronald D. Phillips* Environmental Science Officer PVNTMED Svc AUTOVON 856-7511 4. Mr. Tom C. Stoalabarger Deputy Director of Engineering and Housing AUTOVON 856-3906 5. Mr. William Wildman Environmental Technician PVNTMED Svc AUTOVON 856-7471 -------------------- * Individual received an exit briefing Enclosure 3 GENERAL LYME DISEASE INFORMATION AND PERSONAL PROTECTIVE MEASURES Lyme disease is a multi-systemic bacterial disease which is transmitted to man and animals generally via the bite of an infected tick. The disease progresses in man from an early stage involving a rash [erythema chronicum migrans or erythema migrans (EM)], malaise, fever, neck stiffness, flu-like illness, and several other general symptoms to a secondary stage characterized by neurological, or cardiologic abnormalities. Intermittent or transient arthritis and chronic debilitating neurologic disturbance are typically seen in the third stage of the illness and can last months to years in duration. Not all patients present the entire range of symptoms. Many individuals apparently become asymptomatic, although it is not clear whether this necessarily indicates elimination of the causative organism from the patient. Serologic findings are used to corroborate clinical evidence of the disease, but should not be relied upon as diagnostic of Lyme disease. Early antibiotic therapy is effective in reducing likelihood of further symptoms, although failures to alleviate symptoms with antibiotic therapy have been reported. Tetracycline and its derivatives are the current drugs of choice in treatment for adults, and penicillin and its derivatives for children. The spirochete resides in the midgut of ticks, primarily of the genus Ixodes. The organism is transmitted to a mammal host via the tick's salivary secretions during ingestion of a blood meal. The white-footed mouse and other small mammals are particularly important hosts for the larval and nymphal ticks, and participate in the natural transmission cycle of the spirochete. Infected nymphal ticks pass the infection to white- footed mice, or other mammals in the early spring. These infected mammals then transmit the bacterium to the next generation of larval ticks which feed on them. Ticks are generally encountered in wooded and grassy settings where they seek hosts while waiting on low-lying vegetation. Some stages of ticks are very small, making it difficult to see them on military field uniforms. Frequent inspection of the garments for ticks while in the field is necessary to prevent later tick attachment. Attached ticks must be removed as soon as possible, using tweezers to grasp the tick at the skin surface and gently pulling the tick away from the skin. Care should be taken not to squeeze the tick's body contents into the wound. Use of repellents such as DEET provide only limited protection against tick attachment. Permethrin repellents applied as a 0.5 percent aerosol spray to clothing provide a high level of repellency (due to toxic effects against ticks); however, permethrin is currently not available for use under existing Kansas State laws. Use of permethrin spray would be possible only after State application for a local use permit under section 24 (c) of the Federal Insecticide Fungicide and Rodenticide Act (FIFRA), or under national or military registration for this particular product. Enclosure 4 FORT RILEY MAP [Map omitted]