Lyme Disease Risk Assessment No. 16-NF-3100-95, Naval Submarine Base- New London, Groton, Connecticut, 23-28 April 1995 DEPARTMENT OF THE ARMY U.S. Army Center for Health Promotion and Preventive Medicine Direct Support Activity-North Fort George G. Meade, Maryland 20755-5225 [Seal of Department of Defense, United States of America] REPLY TO ATTENTION OF: MCHB-AN-ES (40-5f) MEMORANDUM FOR Commander, Naval Submarine Base-New London, Groton, CT SUBJECT: Lyme Disease Risk Assessment No. 16-NF-3100-95 1. A copy of the subject report with Executive Summary is enclosed. 2. Additional direct support in the fields of pest management, pesticide risk management, water supply management, wastewater management, hazardous waste management, worksite hazards management, healthcare hazards management, ergonomic evaluation, sanitation and hygiene, and installation industrial hygiene management is available, and may be requested from USACHPPM, DSA-North at DSN 923-6502/5281/6205, or commercial (301)677-6502/5281/6205. FOR THE COMMANDER: [signed by] RICHARD N. JOHNSON MAJ, MS Chief, Entomological Sciences Division ----- DEPARTMENT OF THE ARMY U.S. Army Center for Health Promotion and Preventive Medicine Direct Support Activity-North Fort George G. Meade, Maryland 20755-5225 [Seal of Department of Defense, United States of America] EXECUTIVE SUMMARY PEST MANAGEMENT STUDY NO. 16-NF-3100-95 LYME DISEASE RISK ASSESSMENT FOR NAVAL SUBMARINE BASE-NEW LONDON, GROTON, CT 23-28 April 1995 1. PURPOSE. This study assesses the risk for military and civilian personnel of contracting Lyme disease on Naval Submarine Base-New London, Groton, CT while engaged in outdoor activities. Additionally, this was a preliminary survey to assess the risk of contracting Hantavirus Pulmonary Syndrome (HPS). 2. RESULTS. During this survey, 34 Lyme disease (LD) vector ticks, Ixodes scapularis Say (=deer ticks), were collected. Eighteen ticks were adults; of these 2/18 (11%) were positive for Borrelia burgdorferi, the LD causal agent. None of the 20 mouse sera tested positive for the presence of antibodies against Sin Nombre Virus (SNV), the causal agent of hantavirus pulmonary syndrome (HPS), or related hantaviruses. 3. RISK. The risk of contracting LD at Naval Submarine Base-New London, Groton CT is High based on the results of this survey and information from the Connecticut Department of Health (CDH). The risk of contracting HPS is Low. 4. RECOMMENDATION. All military, civilian, and dependent personnel using Naval Submarine Base-New London for outdoor training or recreation should use personal protective measures, as addressed in Appendices D, E, F of this report. Deer ticks removed from people should be analyzed for the Lyme disease pathogen to aid in determining an appropriate treatment protocol. CDC Guidelines for the prevention of occupational exposure to rodents and rodent excreta should be followed, as addressed in Appendices G, H, I of this report. Periodically perform additional surveys (every two to three years) to update the local assessment of Lyme disease and Hantavirus Pulmonary Syndrome. ----- DEPARTMENT OF THE ARMY U.S. Army Center for Health Promotion and Preventive Medicine Direct Support Activity-North Fort George G. Meade, Maryland 20755-5225 [Seal of Department of Defense, United States of America] REPLY TO ATTENTION OF: MCHB-AN-ES (40-5f) 22 August 1996 LYME DISEASE RISK ASSESSMENT NO. 16-NF-3100-95 NAVAL SUBMARINE BASE-NEW LONDON, GROTON, CT 23-28 April 1995 1. REFERENCES. See Appendix A. 2. AUTHORITY. AEHA Form 250, DoD Lyme Disease Surveillance Program, Armed Forces Pest Management Board, October 1994 3. PURPOSE. To assess the risk of Lyme disease (LD) to Naval Submarine Base-New London (NSB-NL) personnel by performing tick trapping, examining mice for tick vectors of LD, especially Ixodes scapularis Say, and to assay ticks for evidence of the LD etiologic agent Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. A preliminary survey for the presence of hantavirus was conducted as a corollary to the LD survey. This assessment was conducted in accordance with Department of Defense Directive (DoD Dir.) 4150.7. 4. GENERAL. a. Risk Definition. The term "risk", as used in this report, is a non-statistical evaluation of qualitative and quantitative information on LD locally. To the extent available, information evaluated included the following elements: (1) History of LD in the area, (2) The presence of the principal tick vector of LD (I. scapularis) and host populations needed to sustain viable populations of this vector, (3) The presence of the LD-causing spirochete (B. burgdorferi) in the local tick population, and (4) The presence of antibodies against B. burgdorferi in the blood serum of local mammal hosts. Once gathered, this information was used to help determine the general relative risk level as follows: Low - Some elements of the LD cycle have been identified nearby, but not on the installation. Moderate - Some elements of the LD cycle have been identified from the installation or human cases of LD have been reported from the local area. High - All elements of the LD cycle have been found (are present) on the installation. b. Personnel Contacted. The purpose and methodology of this survey were discussed with Mr Dick Conant, Environmental Department, NSB-NL. Further coordination and assistance was provided through HMC Johnson, Lead Chief Petty Officer, Preventive Medicine Department, NSB-NL. c. Survey Conduct. Samples were collected by Dr. Harold Harlan, Direct Support Activity-North (DSA-North). He was assisted, in part, by HM2 Anchia, NSB-NL Preventive Medicine Department. Methods included small mammal trapping, dry-ice trapping, and tick dragging on the Naval Submarine Base-New London, using a protocol developed by DSA-North and materials provided by this Activity. Ticks were later assayed for the presence of B. burgdorferi via direct and indirect fluorescent antibody (DFA/IFA) techniques at this Activity. Mouse sera were assayed for the presence of antibodies against Sin Nombre Virus and other related hantaviruses by Western Blot method by personnel of the University of New Mexico School of Medicine. d. Technical Assistance. Technical assistance or further informal advice may be abtained by contacting the Chief, Entomological Sciences Division, this Activity, commercial (310)677-5281/6502 or DSN 923- 5281/6502, ext 250. 5. LYME DISEASE RISK a. Lyme disease (LD) is a multi-symptomatic infectious disease caused by the spirochete, Borrelia burgdorferi Say [sic], which is transmitted to humans by the bite of an infected tick. This disease is usually called Lyme disease or Lyme arthritis in the United States. Over the past few years, it has become the most prevalent arthropod- borne disease in North America. Its geographic range is expanding and the number of reported cases has continued to rise nearly every year since 1989. b. The number of LD cases reported to the U.S. Centers for Disease Control and Prevention (CDC), by the Connecticut Department of Health (CDH), have increased almost every year since 1985; however, the last reported year exhibited a decrease with 2,030 cases in 1994, and 1,493 cases in 1995 (reference 8, Appendix A). The lack of a rapid, sensitive, reliable, and cost-effective diagnostic test for LD results in proactive treatment before case confirmation and, consequently, under-reporting. The increased burden of reports on medical treatment facilities may also be a factor. Personnel concerned with LD prevention and control should not assume that human risk of LD has changed based solely on numbers of reported cases. c. Epidemiologic information from the CDH indicate that there were 458 cases and 316 cases reported from New London County (in which NSB-NL is located) in 1994 and 1995, respectively. The Naval Hospital reported 2 cases in 1994 and 10 cases in 1995. Over the last 10 years, Connecticut physicians have been reporting generally increasing numbers of human LD cases to CDH. 6. HANTAVIRUS RISK. a. Inhalation or ingestion of rodent urine and feces seem to pose the greatest health risk to people. Risk is increased when rodent droppings or urine are aerosolized in enclosed space such as buildings, bunkers, warehouses, etc. Personnel moving equipment, cleaning buildings, or otherwise disturbing deposited urine or feces may be at risk if not adequately protected. Direct contact with rodent droppings and urine may also be a means of transmitting the virus to humans. b. Service members participating in training maneuvers that involve disturbing rodent habitat are at risk of acquiring hantavirus infection. However, personnel training, working, or participating in events outdoors with adequate ventilation appear to be at low risk of acquiring hantavirus infection. This is due to a number of factors: infected rodent excreta is less concentrated; winds will dissipate any aerosolized virus; approximately 30 minutes exposure to direct sunlight will inactivate any viable hantavirus particle; and the density of field rodents outdoors is much less than that encountered indoors. People who can be considered at a higher risk might include pest controllers, wildlife biologists, contractors, plumbers, electricians, carpenters, maintenance workers, buildings inspectors, and workers involved in cleaning or demolition of old or little used buildings, etc. c. The number of positive or negative rodents may vary from location to location, from species to species, and from one time of the year to another. This, the percentages of positive rodents from any particular trapping location may not represent the risk over the entire area. 7. METHODS. a. Small mammal collection and examinations. Small mammals were trapped, under the authority of Connecticut Department of Environmental Protection Permit No. 9595003, using Sherman Live Traps (H.B. Sherman Traps, Inc., Tallahassee, FL). The animals were anesthetized and then examined about the eyes, ears, necks, and posterior for the presence of ticks. If ticks were detected, they were pulled off using fine-tipped forceps, placed into plastic vials, and forwarded to this Activity (DSA- North) for identification and possibly further testing. b. Serum collection and testing. All animals were anesthetized before blood samples were obtained through cardiac puncture method. The blood was drawn and placed into small plastic vials, labeled, frozen, and shipped to this Activity on dry ice (-32 degrees C). These blood samples were later shipped, on dry ice to Dr. Brian Hjelle, University of New Mexico. They were tested via Western Blot method (reference 9, Appendix A) to detect the presence of antibodies that the mice may have developed against Sin Nombre Virus (SNV), the Hantavirus Pulmonary Syndrome (HPS) causal agent, or related hantaviruses. c. Tick collection and testing. Ticks were collected along trails and along forest edges through the use of tick drags and dry ice traps. They were returned to this Activity, identified, and assayed via DFA/IFA techniques, as detailed by Piesman et al. (1986; reference 8, Appendix A) for the presence of B. burgdorferi. 8. RESULTS. (Also see Appendices B and C) a. A total of 18 adult I. scapularis were collected by tick drag or dry ice traps. The initial screening of ticks by DFA assay revealed 3 ticks tested positive for Borrelia spp. When these ticks were further assayed by IFA assay, 2 tested positive (11%) for B. burgdorferi. A total of 12 nymph and 3 larval I. scapularis were collected from six of 20 mice examined. Of these 2 nymphal ticks were positive for only Borrelia spp. b. None of the 20 mouse serum samples collected, tested positive for antibodies against SNV or related hantaviruses. 9. DISCUSSION. Lyme disease is endemic in Connecticut and occurs naturally on NSB-NL. The proximity of NSB-NL to Old Lyme, the original focus of the disease, should help focus the attention of personnel on NSB-NL to the threat of LD. The number of cases seen at the Naval Hospital and in the surrounding community justifies continued LD (and other tick-borne disease) surveillance and prevention efforts at Groton. Although no evidence of hantavirus was found in the mice assayed, we cannot rule out its presence on the installation. Hantavirus infection is a voluntarily reported disease in Connecticut; to date no cases have been reported in the state. Human cases of HPS have been diagnosed from New York State, caused by the NEW-YORK-1 strain of the virus. Guidelines published by the CDC should be followed by personnel with the potential for occupational exposure to rodents and rodent excreta. 10. CONCLUSIONS. Recent human LD cases seen by the Naval Hospital and those reported from New London County in which Groton is located, confirmed collections of the vector ticks in nearby counties, plus presence of B. burgdorferi in 11% of the adult I. scapularis collected on Groton, all support the conclusion that the risk of contracting LD on Naval Submarine Base-New London, Groton, CT is High. Periodic surveys for the presence of hantavirus in the rodent population on the installation would help to monitor the level of threat that this pathogen may exhibit in the future. 11. RECOMMENDATIONS. a. Periodically remind and retrain all military, civilian, and dependent personnel at [Naval Submarine Base-New London] who use the installation concerning the information on repellents which is contained in Appendices D, E, F of this report. b. Follow U.S. Centers for Disease Control and Prevention guidelines to minimize potential exposure to hantavirus, as provided in Appendices G, H, I of this report. c. Assist this Activity, or take other steps, to ensure the conduct of periodic (suggested 2-3 years) surveys of deer, small mammals, ticks, and evidence of the presence and prevalence of B. burgdorferi and other rodent and tick-borne diseases, to determine the risk level of contracting LD and HPS at NSB-NL, Groton. d. Have person with a history of tick bite or exhibiting symptoms report to Haval Hospital NSB-NL, Groton, CT. Physicians are required to report cases to the CDH Epidemiology Program at (860)509-7994. Hantavirus infection is voluntarily reportable to the CDH. 12. ADDITIONAL ASSISTANCE. Additional direct support in the fields of pest management, pesticide risk management, water supply management, wastewater management, hazardous waste management, worksite hazards management, health care hazards management, ergonomic evaluation, sanitation and hygiene, and installation industrial hygiene management is available, and may be requested from USACHPPM, DSA-North at DSN 923- 6502/5281/6205, or commercial (301)[677-]6502/5281/6205. [signed by] RICHARD N. JOHNSON MAJ, MS Chief, Entomological Sciences Division ----- APPENDIX A REFERENCES 1. AR 40-5, Preventive Medicine, 15 October 1990. 2. DoD Directive 4150.7, Department of Defense Pest Management Program, 24 October 1983. 3. Armed Forces Pest Management Board Technical Information Memorandum No. 26, Lyme Disease: Vector Surveillance and Control, March 1990. 4. Lyme Disease Surveillance Summary, Vol. 4, No. 3, Centers for Disease Control and Prevention, February 1995. 5. Oliver, J.H., M.R. Owsley, H.J. Hutcheson, A.M. James, C. Chen, W.S. Irby, E.M. Dotson, and D.K. McLain. 1993. Conspecificity of the ticks Ixodes scapularis and Ixodes dammini (Acari: Ixodidae). J. Med. Entomol., 30(1): 54-63. 6. Piesman, J., T. N. Mather, S.R. Telford III, and A. Spielman. 1986. Concurrent Borrelia burgdorferi and Babesia microti infection in nymphal Ixodes dammini. J. Clin. Microbiol. 24: 446-447. 7. Barbour, A. G., S. L. Tessier, and W. J. Todd. 1983. Lyme disease spirochetes and ixodid tick spirochetes share a common surface antigenic determinant defined by a monoclonal antibody. Infect. Immunol., 41: 795-804. 8. Lyme Disease Surveillance Summary, Centers for Disease Control and Prevention, Vol. 45 No. 23, 14 Jun 96. 9. Yamada, T., B. Hjelle, B. Lanzi, R. Morris, B. Anderson, S. Jenison. 1995. Antibody responses to Four Corners hantavirus in the deer mouse (Peromyscus maniculatus): identification of an immunodominant region of the nucleocapsid protein. J. Virol. 69: 1939-1943. ----- APPENDIX B DATA SUMMARY SHEET DOD LYME DISEASE RISK ASSESSMENT NAVAL SUBMARINE BASE-NEW LONDON GROTON, CONNECTICUT 23-28 April 1995 # Mice Examined 20 # Mice With Ixodes scapularis[1] 6 # Mice With Other Ticks Species 13 # Human Lyme Disease Cases 1994, New London Co.[2] 458 # Human Lyme Disease Cases 1995, New London Co. 316 # Human Lyme Disease Cases 1994, Connecticut[3] 2030 # Human Lyme Disease Cases 1995, Connecticut 1493 ------------------------------------------------------------------------ 1 Ixodes dammini Spielman, Clifford, Piesman, and Corwin and Ixodes scapularis Say were synonymized by Oliver et al. (1993). 2 New London County, CT includes all areas on Naval Submarine Base-New London from which Mice were sampled in this study. 3 Based on reference 8, Appendix A, of this report. ----- APPENDIX C TICK TESTING AND SERUM TESTING RESULTS NAVAL SUBMARINE BASE-NEW LONDON 23-28 April 1995 Table C-1. Ixodes scapularis ticks collected from small mammals, tick drags and dry ice traps were tested via DFA[1] for Borrelia spp. and further tested via IFA for B. burgdorferi. ------------------------------------------------------------------------ STAGE/SEX[2] # Collected # Tested # +Borrelia spp. # +B. burgdorferi Males 9 9 0 - Females 9 9 3 2 Nymphs 12 12 2 0 Larvae 3 3 0 - ------------------------------------------------------------------------ TOTAL 34 34 5 2 ------------------------------------------------------------------------ 1 Direct Fluorescent Antibody (DFA) and Indirect Fluorescent Antibody (IFA) testing method (see reference 6, Appendix A) 2 Adults (males and females) collected by tick drags and dry ice traps, numphs and larvae collected from white-footed mice (Peromyscus leucopus). Table C-2. Blood samples taken from live-trapped white-footed mice (Peromyscus leucopus) and tested for the antibodies against hantavirus[1]. ------------------------------------------------------------------------ # Mice Collected # Tested # + hantavirus # + SNV[2] # + NY-1[3] 20 20 0 - - ------------------------------------------------------------------------ 1 Screened via Western Blot Assay (see reference 9, Appendix A) 2 Sin Nombre Virus (strain of hantavirus) 3 New York - 1 (strain of hantavirus) ----- APPENDIX D Lyme Disease Risk Reduction Measures 1. Emphasize public awareness programs to educate troops, family members, civilian employees and visitors on personal protective measures and Lyme disease (and other tick-borne diseases). Methods should include, but not be limited to: a. Distribution of printed Lyme disease handouts, such as "tick- borne diseases" cards (GTA-8-5-56), pamphlets, and fact sheets. b. Notifications in the installation newsletter, local media, and post electronic media (e.g., closed-circuit TV), especially prior to the high-risk months (April-July). c. Making the following videos available for general viewing: "Lyme Disease: A Growing Threat (FAUPIN No. 504494DD, Army TVT No. 8-196) and "Application of the Arthropod Repellent System" (No. 708575, Army TVT No. 8-232). 2. Submit tick specimens (both field-collected ticks and those removed from individuals) alive for identification and DFA testing to USACHPPM, DSA-North, Fort Meade, Maryland 20755-5225. 3. Stock Permethrin Arthropod Repellent (NSN 6840-01-278-1336, box of 12 cans for $36.99), and 3M[1] Insect Repellent (NSN 6840-01-284-3982, box of 12 tubes, $29.30) for distribution. Emphasize tick habitat avoidance, proper wearing of clothing, and use of repellents. 4. Report all confirmed and suspected cases of Lyme disease [e.g., suspicious febrile illnesses, arthralgias, rashes, (Erythema Migrans)] through proper channels to both military and civilian public health authorities. 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 (or other human pathogens). Sampling should be done in early summer when I. scapularis nymphs (the life stage responsible for most human Lyme disease infections) actively seek hosts. Post DA Poster 40-5, to 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. Case-by-case surveillance is necessary due to the patchy distribution of I. scapularis and most other human disease vector ticks. 7. Eliminate tick habitat in heavily used, infested areas (e.g., wooded recreation areas) by removing low brush and leaf litter. Tick infestations should be verified via tick flagging/dragging prior to habitat modification. Clear such sites in low-risk months (i.e., January-February). 8. As a contingency, prepare to treat high-use areas with pesticides to reduce tick populations if surveillance yields large numbers of ticks (especially if any are found to contain human pathogens) and if non- chemical techniques (e.g., brush removal, mowing, raking) do not provide adequate control. -------------------------------------- 1 3-M is a registered trademark of Minnesota Mining and Manufacturing Co., St. Paul, MN 55133-3053. ----- APPENDIX E REPELLENTS 1. Several arthropod repellents 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 clothing, they provide personal protection against a wide variety of medically important insect/arthropod pests. Availability and current prices can be obtained by calling the DGSC at DSN 695-4865 or commercial (804) 790-4865. Repellents available for use are described below: a. Insect/Arthropod Repellent Lotion (cream, 2 fluid ounces), NSN 6840-01-0284-3982. This is for application to exposed skin, 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. Approximately 75% of one can should be applied to each field uniform, and the remainder used to treat other items (e.g., mosquito netting). This product provides protection from ticks and mosquitoes for a maximum of five weeks or five launderings. Apply more frequently if "buddy checks" reveal attached ticks. c. Insect Repellent, Fabric Treatment (liquid, 5.1 fluid ounces), NSN 6840-01-334-2666. The contents of one bottle are added to two gallons of water and applied with a 2-gallon sprayer (like the ones in field sanitation kits) at a pressure of 55 psi, to field uniforms, mosquito netting, or tent fabric to provide protection from ticks, biting flies, and other insects. Since many sprayers are not equipped with the required pressure gauge (NSN 3740- 01-332-8746), it may be necessary to obtain this type of pressure gauge and filter (NSN 4330-01- 332-1639), to retro-fit an available sprayer. Proper application, followed by complete drying of the fabric, can provide protection for the normal life of the uniform (180 days in the field), six launderings of mosquito netting, or 6-9 months effectiveness for treated tent fabric, depending on the climate of deployment site(s). 2. Detailed directions for the use of these and other repellents can be found in the U.S. Army Environmental Hygiene Agency Technical Guide (TG) 174, Personal Protective Techniques Against Insects and Other Arthropods of Military Significance, June 1991. 3. The "Tick-Borne Diseases" cards (GTA 8-5-56) should be ordered through normal military publications channels. Limited numbers of these cards may be obtained from the Entomological Sciences Division, USACHPPM, DSA-North, at DSN 923-5281 or commercial (301)677-5281. ----- APPENDIX F FACT SHEET - MOSQUITO AND TICK REPELLENTS 1. Repellents containing DEET (N,N-diethyl-3-methylbenzamide, formerly N,N-diethyl-m-tolumide) offer good protection against mosquitoes, and are made for application to skin. 2. Repellents containing Permethrin offer excellent protection against ticks, and are formulated for application to clothing. 3. DEET also offers protection against ticks, keeping them from attaching to treated skin (sometimes for long periods). Ticks do not generally attach in exposed areas, the primary areas to which DEET is to be applied (refer to any given product's label directions). 4. Permethrin, conversely, offers considerable protection against many mosquito species, but it can't be applied to exposed skin (refer to any given product's label directions), the main area(s) mosquitoes usually bite. Permethrin is useful for treating bed netting and tents. 5. Combined use of DEET on exposed skin (as for mosquito repellency) and Permethrin on clothing (as for tick repellency) offers maximum protection against both these (as well as many others). Always read and follow the label directions before using any compound. 6. Do NOT use flea or tick collars. A toxic reaction can result. Humans have many sweat glands in their skin that can serve as avenues for chemical absorption. Dogs (and cats), do not have sweat glands in their skin and cool themselves by panting. In addition, most breeds of these pets have a thick hair layer (barrier) whichprotects their skin from direct contact with collars. Humans have very limited hair covering. 7. Various lotion products claim protection against mosquitoes. Professional literature both supports and refutes benefits from lotions. Controlled tests have shown that mineral oil, a major component of most such lotion products, does reduce biting by several species of mosquitos on areas of treated skin. However, this reduction in biting is small when compared to the reduction by an wqual amount of DEET in concurrent tests by USDA labs. 8. Controlled tests have shown that products containing high concentrations of DEET (greater than or equal to 50%) do not offer greater protection than products containing 30-50% DEET. 9. The following practices enhance the effectiveness (degree of protection) against mosquitoes and ticks when used in conjunction with repellents: - Cover as much exposed skin as possible. Consider wearing loose- fitting long-sleeved shirts in summer. - Tuck pants legs inside tops of socks or boots. - Wear light-colored clothing to make ticks easier to see as they crawl. - Plan ahead and treat clothing with permethrin before starting your outdoor activity. Permethrin binds with fabric and is persistent through several detergent washings. ("Dry cleaning" will remove it immediately.) - Store treated clothing in a plastic bag to help preserve repellent effectiveness, and to help identify which clothing has been treated. ----- APPENDIX G ASSESSMENT AND REDUCTION MEASURES FOR HANTAVIRUS RISK 1. All personnel should be instructed on: how hantavirus is transmitted and maintained in the environment; the risk of acquiring hantavirus infection; preventive measures; symptoms of the disease; and when to seek medical attention. Personnel who have regular exposure to rodent droppings or urine are at high risk for hantavirus infection and should be identified. Any personnel exposed to rodent infested habitat indoors or outdoors that must seek medical assistance for symptoms of respiratory or renal distress should inform their health care providers(s) of possible exposure to hantavirus. A medical surveillance program for personnel at high risk should include a medical history, a physical examination with attention to the pulmonary and renal systems, medical clearance for respirator use, and baseline blood tests. A baseline serum sample for each worker at risk, drawn in a red-top tube, should be "on hold" and stored frozen (at -20 degrees C) for future analysis in the event it is needed. 2. Surveys of buildings and other structures which could harbor field rodent infectations should be done on a regular basis. Rodent-proofing measures should be instituted where needed (see Appendix F). 3. Contractors or personnel involved in cleaning rodent-infested buildings need to use the propoer personal protective equipment, and follow the proper cleanup procedures. To minimize the risk of hantavirus infection, personal protective equipment should be worn by those exposed to rodents or thier droppings/urine. This equipment includes respirators with high-efficiency particulate air (HEPA) filters, goggles, solvent-resistant gloves, coveralls, and boots. Detailed guidance on personal protection for various classes of potentially-exposed individuals against hantavirus infection was published by the CDC as a special report in the Centers for Disease Control and Prevention (CDC), Morbidity and Mortality Weekly Report, Hantavirus Infection - Southwestern United States: Interim Recommendations for Risk Reduction. Vol. 42, No. RR11, 30 July 1993. Also of interest are the USACHPPM Fact Sheets entitled, "Interim Recommendations for Reducing Risk of Hantavirus Infection", U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) 64-001- 0893, and, "How to Protect Your Home, Pet and Family from Hantavirus Infection", USACHPPM 64-002-0749, which provide additional guidance on this disease. ----- APPENDIX H GUIDANCE FOR CLEANING RODENT-CONTAMINATED BUILDINGS Areas with evidence of rodent infestations (i.e., rodent droppings, chewed material, etc.) should be thoroughly cleaned to reduce the likelihood of exposure to hantavirus-infected materials. Cleaning procedures must be performed in a manner that limits the potential for aerosolization virus particles. These procedures for cleaning rodent- contaminated buildings can be found in the publication "Hantavirus Infection-Southwestern United States: Interim Recommendations for Risk Reduction," published by the Centers for Disease Control and Prevention as a special report in Volume 42, No. RR-11, July 30, 1993, Massachusetts Medical Society, of the Morbidity and Mortality Weekly report. 1. All personnel involved in cleaning operations should wear protective equipment and clothing, respirators with high-efficiency particulate air (HEPA) filters, goggles, solvent-resistant gloves, coveralls, and boots. 2. In buildings where evidence of rodent activity is present, spray the floors and interior walls of the building with a general purpose disinfectant solution. Special attention must be given to dead rodents, rodent nests, droppings, food, or other items that have been contaminated by rodents; thoroughly soak these items with disinfectant and place them into a plastic bag. Use a dustpan and a broom to remove the soaked material. Do not attempt to remove dry contaminated materials with a vacuum or by sweeping. 3. Mop all floors with water containing a general-purpose disinfectant and a detergent. Clean carpets and upholstered furniture by steam cleaning or shampooing with commercial-grade equipment. Spray all buildings with dirt floors with a general-purpose disinfectant before use. Disinfect and remove rodent nests from furniture before decontaminating the furniture. The furniture which cannot be decontaminated should be disposed of by appropriate means in accordance with the installation medical practices. 4. Disinfect all work surfaces, storage cabinets, and drawers, etc., by washing them with a solution of water containing a general-purpose disinfectant and a detergent followed by an additional wiping-down with a disinfectant. 5. Launder any potentially contaminated clothing and bedding in hot water with a detergent. Items which cannot be laundered may be dry cleaned. 6. Seal the plastic bag(s) when full or when the cleanup is complete. Place the bags into a second plastic bag and dispose of as biological waste in accordance with the installation medical practices. ----- APPENDIX I RODENT CONTROL 1. Rodent infestations in storage buildings, warehouses, and other outbuildings can be controlled by the use of snap traps, glue boards, and anticoagulant bait stations. Snap traps and glue boards are more effective when placed along the walls and in rodent runways. Snap trap efficiency can be improved by placing two set traps parallel along the wall with the triggering mechanism set in opposite directions. In restricted spaces, the snap traps can be set perpendicular to the wall or opening with the triggering mechanism toward the wall or opening. Detailed information on commensal rodent control is outlined in the U.S. Army Environmental Hygiene Agency, Technical GUide 138, Commensal Rodent Control. 2. Preventive control is a very important aspect of rodent management. All buildings can be rodent-proofed by closing any openings 1/4-inch or greater in size to prevent rodent entry. Holes and cracks should be sealed with appropriate construction materials (i.e., quick- drying cement, reinforced wire mesh, or steel wool). The wire mesh and steel wool should be covered and sealed with a good grade of caulking compound. Filling holes and cracks with only a caulking compound is not a good method because the rodents can easily chew through the caulking compound. All doors on buildings should be kept closed. 3. Sanitation practices are essential in deterring rodents from entering buildings. All sources of food and water for rodents should be eliminated. This can be accomplished by denying rodents access by placing garbage in plastic bags, keeping the garbage container(s) covered, storing human and pet food in closed rodent-proof containers, and cleaning up all spilled food immediately. Special attention should be given to buildings where food is stored, eaten, or served. 4. Rodent surveillance should be conducted before occupying any infrequently used buildings. Prior to use buildings in recreation, training, or other areas should be surveyed for rodent activity by use of snap traps, glue boards and by looking for evidence of rodent infestations. Surveillance of occupied buildings should be conducted on a regular basis. Buildings used periodically should be reinspected monthly while in use, especially during the summer. -----