2nd Distribution, SAFETY--Preventing Hantavirus Disease To: " WRD Safety, Reston, VA ", " WRD Regional Safey Officers, Reston, VA " cc: "William G Shope Jr., Chief, Br. of Oper. Support, Reston, VA ", "Melvin Lew, Hydrologist, Reston, VA ", "Ronald V James, Research Chemist, Menlo Park, CA ", "Carole Nethaway, Secretary (OA), Reston, VA ", "Alice C Dilandro, Secretary (S), Reston, VA ", " WRD Archive File, Reston, VA " From: "Catherine L Hill, ACH/Operations, Reston, VA " Subject: 2nd Distribution, SAFETY--Preventing Hantavirus Disease Date: Thu, 30 Oct 1997 18:06:11 -0500 NOTE: At the present time, the most up-to-date distribution to all safety officers is safety_wrd@qvarsx.er.usgs.gov rather than the WRD distribution.so. Because the original WRD distribution.so on October 30, 1997, may not contain the most current list under this category, the following memorandum on Hantavirus prevention is being distributed a second time to safety_wrd and rso_wrd. ----------- In Reply Refer To: Mail Stop 405 MEMORANDUM October 28, 1997 To: District Chiefs Chief, Branch of Regional Research - ER, CR, WR Chief, Hydrologic Instrumentation Facility Chief, National Water Quality Laboratory Chief, Yucca Mountain Project Branch Chief, Research Hydrologist, CVO From: Catherine L. Hill /signed, Stephen Blanchard, Acting/ Assistant Chief Hydrologist for Operations Subject: SAFETY--Preventing Hantavirus Disease This memorandum serves as a reminder of the severity of the highly-fatal hantavirus disease, provides current information from the Centers for Disease Control and Prevention (CDC), and includes a generic district safety plan for prevention of hantavirus infection. In May 1993, a new type of hantavirus was identified for the first time in the United States. Rodents are the primary host for the virus that causes Hantavirus Pulmonary Syndrome (HPS). As of September 13, 1996, HPS has been confirmed in 145 case patients from 25 States (Attachment 1). Telephone numbers of the CDC State contacts have been included in Attachment 1 to provide direct contacts for specific HPS information in every State. The chances of getting the disease are very low, however, the consequences are very serious. Infected people usually show symptoms similar to the flu: high fever, muscle aches, chills, cough, and headache. Major symptoms such as severe pneumonia and respiratory distress, and swollen lungs filled with fluid, may not appear until the illness becomes life-threatening. Once infected, timely medical treatment increases the chance of recovery. The fatality rates so far are more than 50 percent, and there are no effective treatment methods or vaccines available. For Water Resources Division employees, the most probable exposure to the virus would be in disturbing rodent excreta or saliva in gaging stations. A memorandum from the Branch of Operational Support dated March 17, 1994, ("SAFETY--Hantavirus Infection Prevention") presents CDC recommended guidelines to minimize possible contact with the virus. Districts should call their local CDC contacts (Attachment 1) to determine appropriate methods for working in areas with few or no documented cases. In accordance with current CDC guidelines, eradicating all of the reservoirs of hantavirus hosts is neither feasible nor desirable. The best available approach for disease control and prevention is risk reduction through environmental hygiene practices that deter rodents from colonizing in the work environment. A generic district safety plan based on a July 1994 Utah District Plan and CDC guidelines for hantavirus infection prevention appears in Attachment 2. This plan can be modified to meet local conditions, and should be followed in areas where infected rodents are endemic. If you have any questions, please contact your regional safety officer. 2 Attachments This memorandum is being distributed via email only. cc distribution: Regional Hydrologists: NR, SR, CR, WR Safety Officers Regional Safety Officers Chief Hydrologist Assoc. Chief Hydrologist ACH, Research ACH, Technical Support ACH, Operations Chief, Br. Ops. Support Chief, Off. Ground Water Chief, Off. Surface Water Chief, Off. Water Quality Chief, NAWQA Chief, DODECA dilandro; mlfield; cpnelson; ccnethaw wrd-archive Attachment 1 Centers for Disease Control and Prevention Hantavirus State Contacts and Number of Hantavirus Pulmonary Syndrome Cases State Telephone No. No. Cases 1994-97 Total No. Cases AK 907-561-4406 0 0 AL 205-260-3433 0 0 AR 501-661-2817 0 0 AZ 602-230-5808 11 22 CA 510-540-2587 10 15 CO 303-692-2700 5 11 CT 203-566-4776 0 0 DC 202-727-0557 0 0 DE 302-653-2870 0 0 FL 904-922-8592 0 1 GA 404-657-2607 0 0 HI 808-586-4586 0 0 IA 319-335-4500 1 1 ID 208-334-2235 5 10 IL 217-782-2016 1 1 IN 317-633-0263 1 1 KS 913-296-5586 4 8 KY 502-564-4478 0 0 LA 504-568-4039 0 1 MD 410-225-6162 0 0 ME 207-287-1722 0 0 MA 617-522-3700 x189 0 0 MI 517-335-9629 0 0 MN 612-623-5249 1 2 MO 314-751-3334 0 0 MS 601-960-7725 0 0 MT 406-444-3986 3 5 NC 919-733-7544 0 1 ND 701-328-5262 0 5 NE 402-471-2122 0 0 NH 603-271-4657 0 0 NJ 609-292-4030 0 0 NM 505-841-2535 8 30 NV 702-688-1335 4 7 NYC 212-447-6220 0 0 NY 518-486-3845 1 1 OH 614-644-4659 0 0 OK 405-271-4060 1 1 OR 503-229-5882 4 5 PA 610-363-8500 0 0 RI 401-274-1011 1 1 SC 803-935-7061 0 0 SD 605-773-4970 2 5 TN 615-262-6374 0 0 TX 512-458-7676 8 9 UT 801-538-6191 5 10 VA 804-786-5142 1 1 VT 802-863-7335 0 0 WA 206-361-2914 12 13 WI 608-262-0248 1 1 WV 304-558-3530 x34 0 1 WY 307-777-7431 0 1 90 169 Attachment 2 U.S. Geological Survey, Water Resources Division District Hantavirus Infection Prevention Plan 1. GENERAL INFORMATION The first outbreak of Hantavirus infection occurred in the four corners geographical area where Arizona, New Mexico, Colorado, and Utah meet. The first known Hantavirus-related death was in May 1993. Since then and up to September 13, 1996, the Centers for Disease Control and Prevention (CDC) had logged 145 case patients in 25 States. The principal host and carrier of the virus is the common deer mouse, although other rodents also may be carriers. Human infection can occur when infected saliva or excreta are introduced into the body through principal routes of exposure, including inhalation, ingestion, or introduction into the eyes or through broken skin. A virus cannot survive without a host; however, it is uncertain how long the Hantavirus remains infectious once it is shed from an infected rodent. The district currently operates a number of gage houses that have been determined to be infested with mice. There are no certain treatments if contracted, and the current death rate, if contracted, is more than 50 percent. These conditions place personnel that routinely operate the gaging stations at risk for exposure to a virus that is best completely avoided. Although it may be impossible to completely eliminate exposure to mice, the district is issuing this plan in an effort to reduce the threat of infection by minimizing exposure to mice in gage houses. This plan outlines the procedures all district personnel should follow when disinfecting, cleaning, and sealing gage houses, which if infested, will be assumed infected. Gage houses are to be cleaned by teams of at least two people. Personnel should be medically able to engage in work activities described in this plan while wearing personal protective equipment. Personnel assigned to disinfect and clean gage houses must have necessary medical examinations, including a blood screen for Hantavirus antibodies. In addition to this plan, an orientation meeting will be held prior to its implementation to discuss the procedures outlined in the plan, to brief personnel about the hazards and the protection to be provided, and to address questions and concerns. This plan shall become effective when approval and signature are made by the district chief. 2. EQUIPMENT AND SUPPLIES The following equipment and supplies are needed and should be obtained before gage houses can be effectively disinfected, cleaned, and sealed. In addition, it is recommended that all solutions and their containers be clearly labeled identifying their names, expiration dates, and directions for use. (1) Respirator protection, including half-face air-purifying respirators equipped with a filter/cartridge combination (HEPA filters (purple) and organic vapor/acid gas cartridges (yellow)), as outlined in a separate District Respiratory Protection Program. (2) Personal protective clothing A. Coveralls (disposable, water-resistant Tyvek). B. Boots (waterproof). C. Goggles. D. Gloves (disposable, waterproof). (3) Disinfectant (bleach) for use in sprayers, wash basins, and tubs (including measuring cups or other means of ensuring an effective ratio to prevent use of an unnecessary amount of bleach). (4) Sprayers (hand-pressurized and pumped, 1-3 gallon capacity) for saturating inside of gage houses and any waste that will be buried, and for rinsing and disinfecting boots. (5) Dust pans (or shovels) that can be disinfected easily for removing dead rodents, droppings, nests, or other waste that will be buried. (6) Water jugs (5 gallon size) filled with potable water for personal wash water for hands and face and for additional water for mixing bleach solutions. (7) Water jug spigot (at least one per work crew) for jug to be used as personal wash station. (8) Wash basins (Rubbermaid dishpan type or pails, two per work crew) for disinfecting gloves and for soaking coveralls and spent filters with bleach solution before disposing. (9) Mild dish soap or Liquinox for washing hands, face, respirator facepiece, and goggles. (10) Paper towels for wiping areas that cannot be sprayed and for drying hands and face. (11) Ziplock-type reclosable plastic bags (1 gallon size) for storage of filters and disposal of spent filters. (12) Garbage bags for disposal of gloves, coveralls, and spent filters (after soaking in bleach solution), and for disposing general trash that does not require burial. (13) Hardware for sealing houses (to be determined by technicians). (14) Decon or other mouse poison. 3. KILLING THE VIRUS AND CLEANING THE GAGE HOUSE (1) Preparations A. Establish Zones The following zones should be established by using flagging, traffic cones, rocks, or other markers, to minimize transfer of potential contamination into clean areas such as vehicles and personal belongings, and to facilitate the work efforts. a. The Work Zone should include gage house, immediate surrounding area, and burial site. The burial site should be downwind from the gage house and removed enough from the river or stream that potential flooding will not be a concern. Personal protective equipment should be worn at all times in the Work Zone. b. THE WASH ZONE SHOULD ALWAYS BE LOCATED UPWIND FROM THE WORK ZONE. If this is impossible (i.e., directly upwind would put you in the middle of the river), remember that any location is better than directly downwind. The Wash Zone should provide a corridor for personnel to move from the Work Zone to the Clean Zone. If you progressed from the Work Zone to the Clean Zone, the Wash Zone should include, (i) Wash basin or pail with bleach solution, (ii) Space for removing personal protective equipment, (iii) Wash tub with bleach solution, (iv) Garbage bag, (v) Clean garbage bag laid flat on ground, table, or other surface for setting disinfected personal protective equipment that will be reused, (vi) Water jug with spigot and accessible soap and paper towels, (vii) Drinking water, (viii) Extras, such as potable water, more bleach, or filters that you might need while working. c. The Clean Zone also should be located UPWIND from the Work and Wash Zones. The Clean Zone should be removed enough that there is no chance that work activities will cross over into areas designated as "clean," such as vehicles. B. Prepare A Burial Site All rodent refuse must be disposed by burying; never discard in stream or as general trash. A hole, 2-3 feet deep, should be dug BEFORE personal protective equipment is donned. (Note: Work in personal protective equipment will be heavy, hot, and likely uncomfortable. Taking the time to make needed preparation before personal protective equipment is donned will greatly facilitate the cleaning process.) C. Dress For The Occasion Respiratory protection and personal protective clothing must be worn while mice-infested gage houses are disinfected and cleaned. a. Respiratory Protection Respiratory protection needed for the protection of Hantavirus infection includes air-purifying respirators equipped with HEPA filters (purple). A combination of HEPA filters with organic vapor/acid gas cartridges (yellow) will provide respiratory protection from chlorine gas, which is liberated from bleach, and must be used while disinfecting and cleaning gage houses. Respiratory protection operating procedures are outlined in the District Respiratory Protection Program and should be followed. For instance, it is easier to do negative and positive test fits first and then adjust the facepiece to have a comfortable but sealed fit. Adjusting the respirator is easier before having gloves on. Filters should be replaced any time during the cleaning effort when breathing becomes difficult or when chemicals such as disinfectants can be smelled. Spent filters should be disposed in plastic bags only after they have been soaked in bleach solution (discussed below). b. Personal Protective Clothing Personal protective clothing including coveralls, boots, goggles, hoods, gloves, and others, must be used during implementation of this plan. Coverall legs should be worn over the outside of the boots if possible. Only a small part of the boots will be exposed by wearing the coverall leg over the boot requiring minimal disinfection. Hoods on coveralls should be worn at least until gage house is saturated with bleach solution and obvious mice refuse removed. D. Prepare Disinfectant CDC has determined that the Hantavirus is easily killed by saturating contaminated areas with common household disinfectants. A solution of 2 cups of bleach to 1 gallon of water (1:8) is recommended in the March 17, 1994, WRD Memorandum and is to be the disinfectant used by the district. This bleach solution will be used in the wash zone discussed above to disinfect personal protective equipment and in sprayers to disinfect gage houses by saturating dead mice, excreta, nests, etc. Diluted bleach deteriorates more rapidly than concentrated bleach, and, therefore, may not be as an effective a disinfectant (D.W. Stephens, U.S. Geological Survey, written commun.,1995). Solutions should be mixed at the beginning of each day and discarded at the end of each day. Solutions should be replenished during the day when they get low and should be replaced if used to soak filters or coveralls. Never store diluted bleach in anything other than a tightly capped bottle (as opposed to a spray bottle), and never reuse the previous day's bleach solution that was used for washing personal protective equipment. NEVER MIX ANOTHER DISINFECTANT SPECIFICALLY AMMONIA, WITH BLEACH! THIS MIXTURE WILL RESULT IN THE LIBERATION OF TOXIC GASES! (2) Disinfecting And Cleaning Disinfect any obvious areas of mouse habitation first. Saturate dead rodents, excreta, nests, and any other obvious remnants thoroughly. Carefully remove any waste from gage house and deposit in hole for burial. Continue to saturate waste material in hole if needed. When all refuse has been deposited in the hole, refill the hole with the dirt that was removed. Continue disinfecting the gage house, by saturating all surfaces with bleach solution using the sprayer, if possible otherwise, wipe surfaces with paper towels dampened with bleach solution. Ventilate gage house before reentering to seal, to ensure that the chlorine gas liberated from the bleach has sufficiently dissipated. (3) Stopping Work It should always be assumed that the clothes and protective equipment you are wearing while disinfecting and cleaning the gage houses are contaminated. Care should be taken when you stop work, at any time for any reason, to appropriately disinfect protective equipment to prevent transfer of potential contamination to clean areas and personal clothing. NEVER REMOVE YOUR RESPIRATOR IN A POTENTIALLY CONTAMINATED AREA; ALWAYS LEAVE THE WORK ZONE FIRST. Remember the routes of exposure. Stopping for a drink of water without disinfecting your gloves makes the risk for ingesting contaminants high. Only under emergency conditions should protective equipment be removed before disinfecting. A. Leaving The Work Zone The following steps should be followed when you leave the Work Zone for any reason, even if it is only for a short period of time, such as getting a drink of water. ALWAYS EXIT THE WORK ZONE THROUGH THE WASH ZONE a. Disinfect gloves by dipping hands in dishpan with bleach solution b. Remove coveralls and place in washtub with bleach solution c. Disinfect gloves, as above d. Spray boots with bleach solution e. Remove goggles and wipe off EXTERIOR with paper towels dampened with bleach solution f. Disinfect gloves, as above g. Remove respirator and wipe off EXTERIOR with paper towels dampened with bleach solution, being very careful not to introduce any water into the filters (covers, however, should be wiped) h. Disinfect gloves, as above i. Remove gloves, and wash hands and face B. Day's End Or Completion Of Job The steps outlined below should also be followed at the day's end or upon completion of a job. a. Spray and wipe off any equipment that is used in the cleaning process, such as sprayers, with bleach solution, BEFORE removing any personal protective equipment. b. Break down wash line, disposing of bleach solution along exterior perimeter of gage house. c. Clean goggles and respirator facepiece thoroughly with soap and water. Follow the guidelines in the District Respiratory Protection Program, or in the manufacturer's instruction manual for cleaning the respirator. This could be done at the work site or at a more convenient place such as your home or motel room. Waiting until the next morning is not advisable as it may not be completely dry by the time you need to wear it. (4) Associated Hazards A. Hantavirus Infection If infected, symptoms typically develop within 2 to 4 weeks after exposure, although it may take up to 6 weeks. Early symptoms are similar to the flu and include high fever, muscle aches, chills, cough, and headache. As the disease progresses, the victim experiences severe pneumonia (hantavirus pulmonary syndrome) and respiratory distress. The lungs may swell and fill with fluid. If personnel involved in disinfecting and cleaning gage houses develop any of these symptoms described, at any time during or after the job, immediate medical attention should be sought and appropriate USGS personnel notified. B. Bleach The dangerous part of common household bleach (Ca(ClO)2) is the chlorine (Cl2) that is liberated as a gas when bleach is exposed to air. The Handbook of Toxic and Hazardous Chemicals and Carcinogens (Sittig, 1985) describes chlorine (Cl2) as "a greenish-yellow gas with a pungent odor. It is the most common of the four halogens which are among the most chemically reactive of all the elements. Chlorine reacts with body moisture to form acids. It is itself extremely irritating to skin, eyes, and mucous membranes." The greatest risk of exposure to chlorine gas is through inhalation and eye and skin contact. The concentration recommended by WRD of 2 cups of bleach to 1 gallon of water is a fairly concentrated solution. The solution should be used with care. The filter/cartridge combination (HEPA/organic vapors/acid gases (purple/yellow)) that will be issued for use with the half-face, air-purifying respirator facepiece will provide the respiratory protection needed for any liberation of chlorine gas while using the bleach solution. Contact with skin and eyes should not be a problem if personal protective clothing is worn. It is important to keep these hazards in mind, particularly when personal protective equipment is not being worn, for example when the wash line is disassembled. First aid for accidental contact should be administered and includes the following: a. Inhalation - Immediately move victim to fresh air. Administer artificial respiration, if needed. Seek immediate medical attention. b. Eye or skin contact - Irrigate eyes or skin with copious amounts of water. Seek immediate medical attention. C. Dehydration, heat exhaustion, heat stroke, and other physical hazards Personal protective equipment can be hot and cumbersome to work in. Personnel should be alert and aware of associated hazards such as, dehydration, heat exhaustion, and heat stroke, particularly when working during hot days. Although it may be time consuming and somewhat of a bother, personnel should make sure they pace themselves and take breaks as frequently as necessary. Personnel should be aware of other physical hazards inherent to the work environment, which may include cuts and snake and insect bites. 4. SEALING THE GAGE HOUSE Gage house and immediate surrounding area should be sufficiently disinfected, cleaned, and aired BEFORE sealing begins, such that sealing the gage house can progress without use of personal protective equipment. Procedure for sealing gage houses should be determined individually by technicians that operate them. Decon or other mouse poison should be placed inside cleaned and sealed gage houses. Use of mouse poison may become routine if it is determined to be a fairly effective deterrent, at least for nesting. 5. REVISITING THE SITES AND ONGOING EFFORTS If there is any evidence of mouse infestation when sites are subsequently visited, interim guidelines described in the March 17, 1994, WRD Memorandum will be followed until the gage house can be revisited, disinfected, and cleaned according to the guidelines described in this plan. Gage houses should be disinfected and cleaned, with additional attempts made to reseal the house, within a reasonable length of time. 6. REFERENCES (1) "Handbook of Toxic and Hazardous Chemical and Carcinogens," (2d ed.), p.217, by Sittig and Marshall, Park Ridge, N.J., Noyes Publications, 1985. (2) Water Resources Division Operations Memorandum No. 94.01, "SAFETY - Hantavirus Infection Prevention," March 17, 1994. (3) "Hantavirus Infection Prevention," U.S. Geological Survey, Water Resources Division. Utah District, July 27, 1994.