Message: #2661 - BPI Tech Brief #7 Date: 22 Mar 94 16:25:57 EST From: Mike Darwin <> Message-Subject: SCI.CRYONICS BPI TECH BRIEF #7 BPI TECH BRIEF #7 22 March, 1994 Copyright 1994 by Biopreservation, all rights reserved. As with Tech Brief #6 on assessment and identification of human cryopreservation patients this Tech Brief is a reprint of a chapter from our Level I Transport Manual. It is presented here both for criticism and comment and to serve as a starting point for the generation of community- wide standards for infection control during transport operations. Infection Control In the Standby and Transport Setting By Michael Darwin and Steven B. Harris, M.D. Introduction Infectious disease is any illness which can be transmitted from organism to organism. All infectious diseases fall into the class known as parasites: they live at the expense of the host organism by extracting energy and materials from the host's body. Disease organisms which are poorly adapted to their hosts rapidly kill or quickly provoke immunity (neutralization) in the host, and thus require a large population of susceptible individuals to infect in order to propagate and survive. Such diseases usually must spread rapidly and are known as epidemic diseases. Examples of epidemic diseases are polio, smallpox, Plague (Black Death), and the childhood diseases such as chicken pox and measles. The causes or "etiologic agents" of an infectious illness may be broadly divided into four classes: 1) Viruses and associated sub-viral particles (virion) of DNA and RNA; instructional material inside the cell's nucleus which in effect "tells the cells what to do.". Examples of viral etiologic agents (to name a very few) are influenza, polio, hepatitis A, B, and C, and the human immunodeficiency virus (HIV) the cause of Acquired Immunodeficiency Syndrome (AIDS). An example of a "sub- viral" etiologic agent is the Delta Particle which is a small piece of nucleic acid which is harmless alone, but when present in an individual suffering from Hepatitis B virus infection, greatly exacerbates the morbidity and mortality associated with the illness. Viruses and virions, unlike the other etiologic agents discussed below, are not capable of reproduction without a living host cell, in other words, they rely upon a host to provide most or all of the machinery for their reproduction. In fact, a virus is often nothing more than a carefully packaged set of instructions for making more virus (there are many exceptions to this generalization: the smallpox virus is large enough to see by "eye" with a high powered light microscope and contains many enzymes and complex structures which it uses to take over the host cell). The "package," consisting of an outer coat of specialized lipids or proteins, is designed to allow the virus to attach itself to, enter, and take control of the cell's metabolic machinery subverting it to the purposes of producing thousands of additional copies of the virus (usually resulting in the death of the infected cell). 2) Bacteria, protozoa, and fungi are capable of reproduction outside of living cells of other organisms . These organisms use the host's structure and nutrients as a food source to further their multiplication. Illnesses caused by these microorganisms are responsible for an enormous range of human disease and suffering. Leprosy, tuberculosis, the Plague , bacterial pneumonia, malaria, syphilis, and gonorrhea are but a few. 3) Multicellular parasites are more complex organisms such as mites (arthropods) and worms (helminths such as the Cestodes, Trematodes and Nematodes) which can also infect human beings and cause illness. Examples of such organisms encountered in the Developed Western World are scabies, and head, body, and public lice among the arthropods, and pinworm (enterobiasis), trichinosis and filariasis among the helminths. While illness caused by such muliticellular parasites is less common in developed countries than it was even a few decades ago, it is still common enough to be of some concern to the Transport Technician and to merit discussion of symptoms, and prophylaxis and treatment. Transmission of Infection Infectious agents may be found in many places in both the animate and inanimate environment which surrounds us. Transmission of infectious disease requires three factors: a source of infecting organisms (or reservoir), a means of transmission of the organism, and a susceptible host. These three factors may be imagined as three overlapping circles: *Illustration not included. Figure 15-1: Elements of infection. Source (Reservoir) Infectious agents may survive in a reservoir but may or may not multiply. Three common sources or reservoirs of infection are: people, fomites, and animals: People: The source of etiologic agents may be patients and may include persons with acute disease, persons in the incubation period of the disease, or persons who are colonized by infectious agents but who have no apparent disease. Patients may also become infected with their own microbial flora (such as bacteria normally present in the gut, on skin, and on mucous membranes). This is called endogenous infection. Fomites: The inanimate environment can also serve as a source of etiologic agents. Bedding, work surfaces, contaminated medical devices, door handles, and so on, can all carry infectious agents from viruses to insects. Animals and Insects: Fleas may transmit the Plague, ticks may transmit Rocky Mountain Spotted Fever, and skunks and bats serve as reservoir animals for rabies. Generally, animals and insects are not considered of any significance as a mode of disease transmission to the Transport Technician at this time, although acquisition of infestation with several species of insects from patients (scabies and the body louse) are of slight concern. Transmission: Transmission is the mechanism for transfer of an infectious agent from the source (reservoir) to a susceptible host. There are four main routes of transmission: Contact Routes: 1) Direct Contact: This involves direct physical transfer between an infected or colonized individual and a susceptible host. Examples of this are when a transport technician touches, intubates, suctions, surgerizes, or performs other procedures which put him/her in direct contact with the patient. Indirect Contact: This occurs when there is contact between the susceptible host with a contaminated object (usually inanimate) such as instruments, clothing, linens, dressings and so on. Droplet Contact: The occurrence of droplet contact is as a result of the production of aerosols of body fluids which are expelled or propelled from the source (usually the infected person) and which come into contact with the , skin, , conjunctivae, or other mucous membranes of a susceptible host. This mode is considered direct transmission since the droplets are usually large particles which settle out of the air on environmental surfaces within no more than three feet of the source. Examples of sources of aerosols are coughing, suctioning, operation of respiratory equipment, and aerosolization of body fluids mixed with air (such as bloody foam being withdrawn from an extracorporeal circuit) being discharged from a syringe into an open waste container. *Illustration not included. Figure 15-2: Transmission Via Droplet Contact: Aerosolization of infectious material during a sneeze. Note the mucous strings and relatively coarse particle size. Vehicle Route The vehicle route transmits infectious agents or their toxins through the following media: Food - as in salmonella and staph infections Water - as in giardia and legionellosis or Hepatitis A Drugs and IV Fluids - as in septicemia secondary to administration of a contaminated parenteral product. Blood: as in HIV, or Hepatitis B or C. Airborne Transmission Transmission of etiologic agents by the airborne route involves the creation of droplets or dust particles which are less than 5 microns in diameter. These particles are small enough to remain in the air currents in the ambient environment and get onto or into the susceptible host (conjunctiva, skin, or contact by inhalation). Volume of Innoculum The quantity of etiologic agent which is transferred usually affects the liklihood of subsequent infection. This will vary greatly from etiologic agent to etiologic agent. For instance, it is estimated that a single smallpox virus is capable of routinely causing infection. By contrast, many, many HIV particles are typically required to cause infection. Vector-borne Transmission This route of transmission involves an infectious agent which is transmitted to the susceptible host by an arthropod (insect). This is not a serious or common mode of disease transmission in the developed world. Host The so far unmentioned but by no means unimportant final element in the process of infection is the susceptible host. Susceptibility to a given infectious disease can and does vary greatly between hosts. Some hosts will easily become infected. Others will be resistant to infection. Still others will become infected and will experience mild or not clinically obvious illness. Others may become infected and serve as asymptomatic carriers of the disease. Age, general health, the presence of stress, trauma, wounds, nutritional status, and many other factors alone or in combination all may act to impact the host's susceptibility to a given etiologic agent. Finally, the genetic make-up of the host and past history of exposure to the etiologic agent or its antigens (such as vaccination) can have a profound effect on the likelihood of infection as well as on the course of the illness if infection occurs. Prevention of Infection Transmission of etiologic agents can only be inhibited by "breaking the chain" of events which lead to infection. Logically, the best place to do this is at the weakest link in this chain. 1) Patients with known infections should be identified promptly and their diseases assessed for the need for special precautionary measures. Inanimate sources of pathogens associated with caring for the patient can be addressed through disinfection or sterilization. In all but rare instances (which will be discussed briefly below) standard "Universal Precautions" which isolate the Transport Technician from contact with the patient's blood, secretions, and other body fluids will be sufficient to "break" the link at its weakest point, the point of transmission. With the emergence of HIV with its long, asymptomatic period and its unusual feature of infectivity throughout all 5 phases of the illness, it has become imperative to presume that all patients are HIV infected or carry other diseases, both blood borne and respiratory, which may not be clinically apparent at the time of standby or transport (such as Hepatitis B, C, or tuberculosis (TB)). 2) Interrupting the mode of transmission is the most frequently employed method of preventing the spread of infectious disease. Hand washing, wearing of masks, gloves and gowns, and disinfection of surfaces, linens and instruments are all examples of interrupting transmission. 3) Hand washing has consistently been shown to be the most effective single means of preventing transmission of etiologic agents. All personnel should wash their hands both before and after patient contact regardless of whether or not gloves have been worn. 4) Manipulation of the host's susceptibility is one of the more difficult factors to control. Vaccination and administration of products conferring passive immunity (such Hepatitis B immune globulin), and the use of chemotherapeutic prophylaxis (such as the administration of Ribavirin to personnel Transporting and perfusing HIV cases) may help boost host defenses. Proper nutrition and stress reduction are also important considerations and will be discussed in greater detail later.. However, these are downstream interventions and the best place to prevent infection is to prevent contact of the infectious agent with the host. 5) Isolation in the form of Universal Body Substance Precautions (UBSI) is to be practiced at all times during patient contact since they are the best way to break the chain of infection. The isolation precautions mandated in this manual are predicated on this concept. Diseases of Concern in the Standby/Transport Setting From the moment the Transport Technician first has contact with the patient it is important to be aware of the patient's medical history and to pay particular attention to the following diseases which are of special concern: (AIDS) Human Immunodeficiency Virus Infection. HIV is a lipid coated retrovirus (an RNA virus) which is transmitted through intimate contact with body fluid containing the virus. Examples of such contact which are of special concern to the Transport Technician are contact of mucosa or open wounds with blood or body secretions, needle sticks or cuts with instruments contaminated with infected blood or body fluid, conjunctival contact with blood or body fluid during suctioning, catastrophic rupture of the extracorporeal circuit, or aerosolization of blood/secretions during Thumper support in the presence of fulminating pulmonary edema, or contact with circulating water in the Portable Ice Bath (PIB) which is contaminated with body fluids. HIV is a disease with 6 stages beginning with infection and ending with complete compromise of the host's immune system and death. This first stage of the disease (infection) is sometimes (though not always) accompanied by flu-like symptoms; fever, malaise, sore throat... The disease infects T-lymphocytes, in particular "helper" T- lymphocytes either killing them or rendering them ineffective. When the population of helper T-cells drops below 400 per cubic mm of blood or about 1/2 of normal the infected individual becomes increasingly susceptible to attack by bacteria, viruses and malignancies which are normally kept in check by this arm of the immune system. Infection with single or multiple etiologic agents ensues eventually resulting in death from failure of one or more organ systems. HIV may also infect other body cells such as those in the central nervous system and gut, causing dementia and *Illustration not included. Figure 15-3: The Walter Reed Classification System chart show the progression of patients from exposure to HIV (WR-0) through stages of progressive immunocompromise ending with complete collapse of T4 cell function and death. The criteria by which patients are staged are shown in the 4th and 5th columns from the left and consist of T4 cell count and decay of the delayed hypersensitivity response (skin anergy: in other words failure of the patient to develop a local inflammatory response on the skin after cutaneous administration of common disease antigens such as measeles, mupms and so on). The chart below shows WR staging versus both T4 cell count and associated clinical changes (i.e., lymphadenopathy, opportunistic infections, etc.). intestinal failure. The mean incubation period for AIDS (the final stage of HIV disease) is believed to be 10.25 years. However, individuals have been to known to die of AIDS as early as 12 months after infection and to have remained healthy for as long as 17 years. Because HIV compromises the arm of the immune system most responsible for protecting the individual against tuberculosis (TB), this disease is epidemic amongst HIV infected individuals in the 3rd through 5th stages of the disease. Unlike HIV, TB is a highly communicable disease. TB will be discussed in great detail below, however it is worth mentioning here that all AIDS patients must be presumed to have concurrent TB infection since AIDS destroys the immune response used to detect the presence of TB infection. It is estimated that between 1/4th to 1/3rd of all AIDS patients are infected with TB; an increasing number with a strain of TB which is resistant to most antibiotics known to be effective at treating TB (so-called multi-drug resistant TB (MDR-TB)). HIV has been found in virtually all body fluids but is present in the highest concentration in semen, blood and cervical secretions. Although not common, it is a theoretical possibility that HIV may be transmitted through contact with any body fluid such as urine, saliva, tears, cerebrospinal fluid, peritoneal fluid, pericardial fluid, pleural fluid, synovial fluid, amniotic fluid and breast milk. While HIV has been found in saliva there are no documented cases of transmission by this route. Extensive studies involving the use of shared eating utensils, tooth brushes, and intimate oral contact between infected and uninfected persons have failed to demonstrate theses routes as a means of transmission. Because HIV is a lipid coated virus it is very fragile and does not survive long on environmental surfaces. Furthermore, its lipid coating makes it very susceptible to destruction by soaps and detergents. Thus, cleansing of environmental surfaces with detergents and disinfectants and hand washing are very effective at destroying the virus. *Illustration not included. Figure 15-5: Typical patient clinical course and T4 cell count as staged using the Walter Reed staging classification for HIV infection. Approximately 3 months after exposure the patient shows significant levels of virus in the blood. The T4 cell count drops and then rebounds in response to initial antibody production by the host. By about 9 months lymphadenopathy develops. At approximately 36 months after infection the T4 cell count has declined to below 400. At 68 months the patient became symptomatic with oral thrush. Twevele months later the patient experiences multiple opportunistic infections and at 83 months death occurs with a T4 cell count of essentially zero. (From Scientific American 259:4, 1988.) Risks Of Transmission Of special concern to the Transport Technician is the risk of acquiring HIV infection as a result of incidents of exposure or "breaks" in technique which may occur during the course of transport operations. The "good" news is that HIV is not very infectious compared to most other epidemic viral illnesses and in particular in comparison to Hepatitis A, B, and C. The Hepatitis viruses are by comparison thousands of times more infectious than HIV. The bad news is that HIV infection is generally presumed to carry a mortality rate of 100%. Thus, it is of paramount importance that the Transport Technician not become infected with HIV during the course of delivering cryopreservation care. The unbreached application of UBSI Precautions to be described below will virtually guarantee protection from transmission of HIV to transport staff. *Illustration not included. Figure 15- 4: The graphic above shows the wide variety of tissues which are currently known to be infected with the Human Immunodeficiency Virus (HIV). All cells which can be infected with HIV carry the CD4 molecule on the surface of their cells. However, accidents can and do happen and it is important that staff be aware of the risks they face in the event of an incident of exposure. While there is no way to know what the response of a given individual will be to exposure, the risks for statistical populations are known and they are as follows: 1) Needle Sticks/cuts with HIV contaminated sharp objects: This is by far the most serious and common source of exposure. It is estimated by the CDC that the risk of infection from this route is roughly 1 in 250. In other words, for every 250 people who experience this kind of contamination 1 will become infected with HIV. *Illustration not included. Figure 15-6: Recapping needles is strictly forbidden because of the obvious risk of needle-stick. 2) Conjunctival/Respiratory Contact With Aerosols or Blood: Good numbers for this route of transmission are not known. Personal communication with infectious disease physicians experienced in this area place the risk for conjunctival contact at between 1 in 500 and 1 in 1,000. The risk for respiratory contact is not known. 3) Blood Contact With Open Wounds (cuts, abrasions, etc.): Risks are not well established here although there have been several documented cases of transmission by this route amongst health care workers. It should be noted that the CDC has stated that the risk of infection from needle sticks is low. The author believes this statement to be hypocritical since the risk of acquiring HIV from needle sticks, puncture, or incision by other contaminated sharps, is the same as quoted for unprotected anal intercourse with an infected partner: a practice which the CDC defines as very high risk. Universal Body Substance Isolation Universal body substance isolation precautions (UBSI) are called "universal" for the simple reason that you must assume that all patients you care for are infected with HIV or one or more other blood or airborne pathogens. Since medical history, testing , and examination cannot reliably identify all patients infected with HIV and TB the following blood/body fluid and airborne disease precautions must be consistently used for all patients: From the time Standby begins all Transport Technicians who will have contact with the patient including being present in the room where the patient is being cared for must wear a mask at all times. Gloves must be worn for touching blood and body fluids, mucous membranes, tissues or non-intact skin of all patients. Gloves must be latex, not vinyl. Vinyl gloves are easily torn and rapidly develop microscopic holes which allow more than two times the penetration of bacteria and viruses than do latex gloves. *Illustration not included. Figure 15- 7: The Human Immunodeficiency Virus. Once transport operations begin all transport personnel must wear the following protective items at all times during transport operations: o Hand/skin protection consisting of nitrile glove liners with latex exam or surgical over-gloves. Personnel who will not be doing surgery must wear heavy-duty minimum 12 mil nitrile gloves with latex over-gloves. Surgical or other personnel requiring good "feel" or touch sensitivity may wear sheer 5 mil nitrile liners with surgical or latex exam over-gloves. o Respiratory protection consisting of either tie-on or cup- type surgical masks. o Eye protection consisting of goggles or full face shields. Personnel involved in perfusion operations or surgery must wear full face shields. o Body skin protection consisting of Tyvek suits which cover arms, trunk and legs. o Shoe covers must be worn to prevent contamination with ice water contaminated with body fluid which may accumulate on the floor during PIB leaks or movement of the patient out of the PIB. If the Tyvek clothing has integral shoe covers these are acceptable. Hands and other skin surfaces should be washed thoroughly with soap and water if contaminated with body fluids or blood. Hands should also be washed immediately after removal of gloves. Nitrile liner gloves should also be washed while on the hands (and left in place) if there is a need to discard the latex over-glove (such as when exiting the transport or operating area to a "clean" area or working on clean equipment). If possible all hand washing and skin cleansing should be carried out with an antimicrobial soap. Extreme care should be taken to avoid sticks or cuts from scalpels, needles or other sharp objects both during and after procedures and when cleaning instruments. To prevent needle-stick injuries needles should never be re- capped, purposely bent, or broken by hand, removed from syringes, or otherwise manipulated by hand. Immediately after use needles, scalpel blades, syringes and other disposable sharp objects must be placed in rigid walled, puncture resistant "sharps containers" for disposal. Locate the sharps container as close to the point of use as possible. Never lay a used needle or sharp down on any surface for any reason. Sharps must disposed of promptly. Transport Technicians who have lesions or weeping dermatitis should refrain from all direct patient contact and from handling contaminated patient care equipment until the condition is gone. Where possible Transport Technicians who are pregnant should refrain from involvement with invasive aspects of the procedure and should exercise special care to protect themselves during discharge of their duties. While pregnant women are not known to be at increased risk of contracting HIV in a healthcare or transport setting, the fact remains that if infection does occur their is significant risk of its prenatal or natal transmission to the fetus/infant. Although saliva has not been known to be responsible for HIV transmission it is capable of transmitting Hepatitis and other infectious agents. For this reason bag-valve resuscitators or other ventilation equipment providing isolation for the Transport Technician should always be available for use during transport operations. HIV Chemoprophylaxis and Surveillance Transport personnel involved directly in invasive surgical operations employing sharps under field conditions should be prophylactically treated with Ribavirin (Vilona) obtained from Mexico. While this drug is not an effective treatment for HIV infection because of its failure to cross the blood-brain barrier, it is the prophylactic agent of choice at this point. Zidovudine (AZT) should probably not be used for prophylaxis since most AIDS patients have received this drug during their illness and thus harbor Zidovudine resistant virus. The HIV chemotherapeutic agents ddI and ddC are unacceptable for prophylaxis due the high incidence of both mild (GI disturbances) and serious (pancreatitis) side effects. By contrast, Ribavirin, used for the short period of transport operations, and a brief window beyond, is very unlikely to produce serious side- effects. The following protocol of Ribavirin prophylaxis is indicated for surgical personnel involved in transport: When the patient becomes frankly agonal, at-risk team members should take a dose of 400 mg of Ribavirin (Vilona). Thereafter doses of 400 mg should be administered at 8 hour intervals for 48 hours after transport operations or other risk of exposure ceases. In the event of needle stick or other contamination or break in technique Ribavirin therapy should be continued for 14 days. Follow up serologic examination should then be conducted at 90 days, 6 months, and 12 months to rule out the possibility of infection. All Transport Team Members must have routine surveillance for the presence of HIV infection at 90 days and 6 months following transport operations when it is documented that HIV infection was present in the patient. (NOTE: all patients are serologically evaluated for the presence of HIV antibodies following cryopreservation..) *Illustration not included. Figure 15-8: Ribavirin for use in prophylaxis against HIV infection. Transport personnel with known exposure to HIV should continue Ribavirin prophylaxis for at least 2-weeks. The Technician should then be tested for HIV antibody at 6 weeks, three months, six months and one year. Until HIV seronegativity is firmly established (antibody seronegativity by ELISA at 1-year and/or antigen negativity by PCR at 6 months) the exposed individual should be counseled to avoid unprotected sexual contact and operate under the assumption that they are HIV infected and act to protect their sexual partners accordingly. Similarly, exposed individuals should refrain from blood, blood component, or semen donation, and females should defer pregnancy until absence of infection can be determined. Hepatitis A, B, and C Hepatitis A is a highly infectious form of hepatitis (liver inflammation/injury) which is transmitted primarily through oral-fecal contact (as in lack of or improper hand washing during food preparation) or by blood or salivary contact. It is most often a childhood disease with a peak incidence between the ages of 5-14 years. It has a short incubation period (15 to 50 days) usually causes little morbidity (though this is variable) and is only rarely associated with mortality (<0.5%). However, several caveats apply in this regard: pregnant and post menopausal women appear to have a more severe course of the illness and the morbidity rises for both males and females the later in life that infection occurs. The incidence of Hepatitis A is somewhat seasonal occurring mostly in Autumn or Winter. The clinical course is one of abrupt onset with anorexia, fever, nausea, vomiting, lassitude and sometimes right upper quadrant abdominal pain. Symptoms persist for several days to a week after which time jaundice (yellowing of skin and the whites of the eyes) appears if it is going to occur. Once jaundice occurs fever and associated symptoms usually decrease in severity. Jaundice is frequently accompanied by dark urine, and light or white colored stools. The onset of jaundice usually signals the beginning of recovery. The patient is infectious throughout the illness and often into convalescence which may be prolonged (lasting several weeks to months). The usual course of the disease is benign and recovery is almost always complete. Comparatively rarely the disease may become fulminant and the patient experience significant morbidity or even mortality. Patients recovered from Hepatitis A are believed to have lifetime immunity and do not develop carrier state. Hepatitis B and C Hepatitis B and C will be discussed together since the clinical course of both illnesses is roughly the same and it is believed that the incubation period, mortality and morbidity are also comparable. There are several important differences between Hepatitis B and C and Hepatitis A. The onset of B and C is slower, indeed often insidious, and the incubation time is far longer: 45 to 160 days. Not infrequently the first appearance of the disease is jaundice. However, fatigue, malaise, changes in urine color, and occasional febrile illness accompany initial manifestation of the illness. While the onset of Hepatitis B and C is slower with patients often being afebrile, the clinical course is much more serious than with Hepatitis A. Hospitalization is frequently necessary and the mortality may approach 10 % to 20% in some outbreaks. The symptoms of the illness: jaundice, malaise, anorexia, fever, white or cream-colored stools, and dark urine are much the same as with Hepatitis A. It should be noted that many individuals in the population have had Hepatitis A, B and/or C and have never manifested clinical symptoms. In the case of Hepatitis A it is believed that the ratio of asymptomatic (undiagnosed) cases to symptomatic cases is 10 to 1. For Hepatitis B and C the ratio is lower, possibly as low as 2 to 1 or 3 to 1. While the clinical course of Hepatitis B and C may run the gamut from virtually no symptoms to death, it is an unfortunate reality that the less severe the course of the illness, the more likely the illness is to become chronic and/or to result in carrier status for the infected individual. The chronic active form or Hepatitis B and C has a high mortality both from liver failure as a result of the direct action of the virus and from liver cancer associated with the chronic presence of the virus. Similarly, carriers of the B and C viruses have an approximately 100-fold greater risk of developing primarily carcinoma of the liver and of course they are a life-long source of infection to those with whom they come into intimate contact, or with whom they share needles or blood products. The primary routes of transmission of Hepatitis B and C are sexual contact, intimate personal contact (shared tooth brushes, or other hygienic utensils), contaminated needles or sharps (such as those used in IV drug abuse, ear piercing, and tattooing) and blood products. Hepatitis Precautions The UBSI techniques discussed above for use with HIV are also effective at protecting against all three varieties of Hepatitis. It is important to point out that unlike HIV, Hepatitis B is easily transmitted through routine contact such as bed bathing, kissing, and so on. Thus, Transport Technicians present in standby operations (particularly long standbys) who become involved in routine patient care should be especially vigilant when dealing with individuals infected with Hepatitis. The use of gloves, masks and cover gowns is required during all patient handing operations including turning, bathing, suctioning, and handling of linens soiled with body secretions. Hepatitis Prophylaxis A very safe and highly effective vaccine is available against Hepatitis B (HB vaccine). It is required that all transport personnel be immunized against hepatitis B using either of the commercially available vaccines (Recombivax or Engerix-B). Following vaccination the Transport Technician should be evaluated for anti-hepatitis B antibodies (anti- HBs) to ensure the presence of a sufficient titer of antibody to confer protection. In the event of documented exposure to Hepatitis A, a single dose of pooled gamma globulin (0.02 to 0.04 ml of 16% solution per kilo of body weight) should be administered intramuscularly as soon as possible after exposure. Exposed personnel must then be followed by the Suspension Team Medical Director or their own physician and development of any disease documented and reported as required by law. *Illustration not included. Figure 15-9: Hepatitis B vaccine is a safe, highly effective and nearly side-effect free product for protection against Hepatitis B. Personnel with documented exposure to Hepatitis B should be treated with Hepatitis B Immune Globulin (Hyper- Hep). The usual dose for adults is 1 ml administered intramuscularly. Simultaneously, the Team Member should be evaluated for anti-HB titer and if the titer is inadequate a booster dose of HB vaccine given. Personnel exposed to Hepatitis A or C should refrain from intimate contact with others (including sexual contact with or without use of a condom) until seronegativity for the antigen can be established or the maximum common incubation period has passed without evidence of seroconversion or illness. Mucocutaneous Herpes Herpes infections of the skin and/or mucous membranes are common in patients suffering immunocompromise from HIV, cancer, chemotherapy or advanced age. UBSI precautions should used to protect against transmission of these agents. The Herpes viruses cause a wide range of human illness but have a predilection for tissues derived from the embryonic ectoderm, usually infecting the skin and/or the nervous system. Herpes viruses are lipid coated but can persist for clinically relevant times on environmental surfaces. A rather unpleasant, albeit fascinating aspect of Herpes viruses, is their ability to establish latent infection after the initial invasion of the host. This characteristic can result in repeated symptomatic outbreaks of the illness even decades after initial infection. A brief summary of the most common Herpes viruses responsible for human diseases of concern to the Transport Technician is discussed below: Herpes Simplex viruses are the class of etiologic agents responsible for cold sores, and genital herpes. H. Simplex may infect the eyes, lips, mouth, anus, vagina, and occasionally the central nervous system. Infection with one or more varieties of H. Simplex is almost universal. UBSI precautions should be used when caring for patients with H. Simplex. The illness does not usually cause significant mortality except in immunocompromised hosts. Cytomegaloviruses (CMV) are among the most ubiquitous viruses infecting man. It is estimated that in the United States 60 % to 80% of the population is infected with one or more strains of CMV. The CMVs can cause a wide array of illness most of which are not serious. CMV mononucleosis is common. More serious forms of CMV such as CMV disease of the liver (CMV hepatitis), central nervous system, liver, kidneys, and lungs most often occur in immunocompromised hosts. CMV is not highly infectious and requires contact with body fluids. UBSI should be effective in preventing transmission of CMV in most cases. Epstein-Barr Virus (EBV) is the primary causative agent of infectious mononucleosis. The exact mode of transmission of EBV is unknown however, like CMV and the other herpes viruses, infection with EBV is ubiquitous. Certain strains of EBV in certain susceptible individuals seem to be responsible for, or at least closely associated with, several malignancies: including Burkitt's lymphoma, and carcinoma of the post-nasal space. While the route of transmission of EBV is as yet not well established (although it is often referred to as the "kissing disease"; an unproved theory!) it is clear that EBV is not very infectious, rarely results in serious illness, and with the use of UBSI precautions presents little risk to the Transport Technician. Varicella-Herpes Zoster is more commonly known as chickenpox, a benign disease of the skin usually seen in childhood. It commonly causes pustular eruptions on the skin and runs its course in 7-10 days. The incubation time is quite consistently between 15 and 18 days. In many individuals infected with H. Zoster the infection re-emergence late in life as shingles: an acutely painful lesion of the skin confined to the path of the infected underlying nerve and characterized by the same kind of papule with the same crusting progression observed in chickenpox. The exudate from these lesions is highly infectious. UBSI should be used in handing individuals exhibiting active H. Zoster disease. Typically H. Zoster is not a major concern for the Transport Technician since most have been previously infected and are thus immune to acute re- infection. The exception to this rule is adults who have not had previous H. Zoster infection (i.e., chickenpox). In the case of such immunologically naive individuals transport of patients with active H. Zoster infection should be avoided since infection with H. Zoster in the adult is more serious and can occasionally result in significant morbidity and even (rarely) death. While UBSI precautions should be used in H. Zoster infections it should be noted that in patients with extensive lesions these precautions may well fail to protect the immunologically naive Transport Technician; H. Zoster, much like smallpox, is highly infectious and even the slightest exposure to the etiologic agent is likely to produce disease (witness the near universality of infection in the global human population). Alternatively, the immunologically naive Transport Technician may choose to transport such a patient accepting the likelihood of subsequent infection and choosing to undergo therapy with Acyclovir (an oral antiviral of low toxcicity which is effective against Herpes viruses) to moderate the course of the illness. Prophylaxis with Acyclovir is also a possible option and may be decided upon by the Transport Technician and the Medical Director. Influenza Influenza is an acute, highly contagious disease that is almost always associated with fever and profound fatigue. Severe headache, myalgia and malaise accompanied by (usually) relatively mild respiratory symptoms is typical. The outcome is usually benign with the notable exceptions being the very young, the very old, and the immunocompromised. The usual cause of morbidity and mortality in these groups is viral and/or bacterial pneumonia with a few individuals succumbing to acute cardiomyopathy with resultant congestive heart failure. There are three types of influenza: A, B and C each of which is antigenically distinct and unrelated to the other. All three are lipid coated viruses all three are susceptible to chemotherapy with the antiviral Ribavirin. Additionally, early influenza A infection can be treated with two other antivirals, amantadine and rimantadine. A bivalent vaccine for influenzas A and B exists and it is recommended that transport personnel be immunized against influenza annually. Influenza is of particular concern to the Transport Technician for the following reasons: 1) It is highly infectious and UBSI precautions may fail to check its spread to staff caring for the patient. It is not inconceivable that most or all of the staff may contract the illness at once making patient care delivery problematic to say the least! 2) It has a very short incubation time (24-48 hours) so that staff may become ill with it before the end of standby, during transport, or during subsequent cryoprotective perfusion and cool down. 3) It is a prostrating and incapacitating illness which demands inactivity and bed rest. It cannot be "worked through". Failure to get adequate rest can result in exacerbation of the illness and serious complications. 4) It is a common cause of death in the elderly and immunocompromised patient; the prime patient population for cryopreservation. 5) Infection of Transport and Perfusion staff with influenza from a cryopreservation patient has already occurred and has resulted in serious compromise of key personnel to perform effectively in a patient safety threatening emergency which immediately followed the patient's cryopreservation. For these reasons Ribavirin and amantadine hydrochloride (another prophylactic chemotheraputic agent effective against influenza A) are maintained in the Transport Team Leader's ONK and may dispensed at the discretion of the Medical Director in the event that vaccination and UBSI fail to prevent staff infection. Meningitis/Encephalitis Meningitis with or without accompanying encephalitis may be caused by a wide range of viral and bacterial infections. Of most concern here are those caused by communicable viruses and the meningicocci. The virulence of these etiologic agents varies considerably. UBSI precautions as described above should be used. Chemoprophylaxis or Bioprophylaxis should be determined by the etiologic agent and the judgment of the Cryopreservation Team Medical Director as to their appropriateness. While the occurrence of an outbreak of meningicoccal meningitis in an institutional setting (camp, prison, military barracks) is often the cause of near hysteria, the fact is that the overall risk of transmission is very low and lower still in a medical setting where respiratory protection is in place. Most patients who have had 24 to 48 hours of antibiotic therapy for the disease will present no risk of transmission. Prophylaxis in the form of minocycline and rifampin (or other suitable agents) may be initiated by the Medical Director at his/her discretion based upon the virulence of the organism and the degree of exposure of the staff. Vaccination against several strains of meningicoccal meningitis is also an option and may be administered at the discretion off the Medical Director and Transport Team Member. Pneumococcal Pneumonia and Meningitis were until recently of little concern to the Transport Technician in the Transport setting. However this has begun to change with recent emergence of several strains of pneumococcus which are resistant to almost all antibiotics including the third generation cephalasporins, pennicillin and streptomycin. The only antibiotic effective in some cases against these organisms has been vancomycin administered in high doses. At such doses vancomycin is both nephro- and oto- toxic. There have been several deaths from these strains of pneumococcus and almost uniform severe morbidity (due largely to delays in diagnosis as a result of the failure of the illness to respond to conventional antibiotic therapy). Transport Technicians are at special risk of acquiring antibiotic resistant pathogenic pneumococcal organisms as a result of their contact with the elderly nursing home patients who have often had repeated courses of antibiotics for pneumococcal pneumonia. There is thus the risk that the Transport Technician may become carrier for such organisms and later succum to infection with antibiotic resistant pneumonia or meningitis. It is for this reason that all Transport Technicians are required to be vaccinated for pneumonia. Tuberculosis (TB) was once the leading cause of death in the United States and was known as the White Plague. It devastated generations of Americans. It is still the leading cause of death worldwide. The causative organism is Mycobacterium Tuberculosis a non-motile bacillus which is transmitted primarily by the airborne route. Humans are very susceptible to TB. In epidemics of TB resulting from contact with an open case of pulmonary tuberculosis (such as in a classroom or homeless shelter setting) 50 % to 70% of the exposed individuals will become infected although only a few will develop clinical disease during the first few years after infection. The age at which infection occurs has a significant relationship to the time at which subsequent active disease is likely to develop. While most associated with its pulmonary manifestations the disease may affect many organ systems. Tubercular disease located elsewhere than in the lung is referred to as miliary TB. Organs or tissues affected by miliary TB may include (but are not limited to): bones, joints, skin, bladder, kidneys, liver/gallbladder, lymphatic system, cervix, and most devastating, the brain and meninges. TB was once thought a thing of the past in U.S. and was of little concern to either the general population or to health care workers. Changes in the handling of the mentally ill (with the resultant creation of "street people") and the emergence of large numbers of immunocompromised individuals as a result of HIV infection have changed all that. The incidence of TB is climbing rapidly in the United States and, what is more troubling, there has emerged several strains of the organism which are resistant to virtually all currently available (and so far to all experimental) chemotheraputic agents. It is now estimated that as many as 10% of all TB infections in AIDS patients are of the multi-drug resistant variety. This is a very serious public health issue which, in this author's opinion, is not being addressed well in the United States. The U.S. strategy to controlling TB has long relied on surveillance with a skin test of tuberculin antigen (PPD or tine)(originally developed by the Bacilli's discoverer Robert Koch) to identify infected individuals and then treat them with a combination of drugs (usually Isoniazid and Rifampin) most commonly administered over a 12-month period. Unfortunately, due to poor or nonexistent follow-up on the part of U.S. public health authorities, particularly among the lower socioeconomic classes and "street people" has lead to the emergence of strains of the organism which are completely resistant to all currently available chemotheraputic protocols. Another distressing development is the growing population of immunocompromised individuals in whom active tubercular disease cannot be easily detected with the skin test. Unfortunately, tubercule bacilli are notoriously difficult to culture and this procedure is not only costly but not very effective in identifying active cases. These three developments: the resurgence of TB, the emergence of multi-drug resistant TB, and the presence of a growing reservoir of undetectable hosts for TB make it imperative that the Transport Technician protect his/herself against tuberculosis by every means available. *Illustration not included. Figure 15-10: A 12-year follow-up on children infected by a single school teacher (From: Hyge. Danish Med. Bull., 4:13, 1957). This is especially true since a significant percentage of patients presenting for cryopreservation have done so because of HIV infection. In fact, using the Alcor Foundation (the largest cryopreservation organization) experience as representative, 18% of all patients who have presented for cryopreservation after the beginning of the AIDS epidemic did so because of HIV disease. As has been previously noted, AIDS patients constitute a significant reservoir of TB. TB Precautions TB is spread by airborne particles (droplets or dust) and thus respiratory protection is of paramount importance. Masks should be worn by transport personnel at all times when caring for or standing by in the home of any patients with known tubercular disease or HIV. UBSI precautions should be used during transport. TB Prophylaxis It is urged that all Transport Technicians be vaccinated against TB with Bacillus Calmette Guerin (BCG). This vaccine is a live bacillus which is inoculated into excoriated or punctured skin. It confers immunity to subsequent TB infection in approximately 80% of those vaccinated with no prior history of TB. *Illustration not included. Figure 15-11: The effectiveness of BCG in preventing TB infection. An 80% rate of protection can be expected. In cases where prolonged contact with the patient is to occur (as during a lengthy standby in the patient's home) with a TB infected or likely TB infected individual Isoniazid in doses of 100 mg three times a day may be given during the period of standby, transport and for a minimum of two weeks following the conclusion of transport as prophylaxis against infection. Measles, Mumps, and Rubella are not normally serious concerns during transport of cryopreservation patients. Most Transport staff will have either had these childhood illnesses or been vaccinated against them. If the Transport technician believes s/he might not have had these illnesses NOW is the time to get vaccinated. Scabies, head and body lice are normally of little concern in the transport setting. Most patients presenting for cryopreservation will have been under medical care and will come from a socioeconomic background where such arthropod infestation is uncommon. The use of UBSI precautions is very effective in inhibiting transmission of these arthropods. If transmission does occur pediculosis (lice) may be treated by the application of any of a variety of inexpensive, highly effective over-the-counter preparations such as A-200. Scabies may be easily and effectively treated by any of several prescription insecticides such as Kwell. The Pregnant Transport Technician Because of the risk to both the mother and fetus posed by both the infectious agents, and chemotherapy to treat infection, pregnant women should be excluded from transports where there exists reasonable possibility of exposure to infectious disease. Disinfection and Cleaning of Equipment and Environmental Surfaces The first and most important rule in disinfection and cleaning of equipment and instruments is: avoid having to do it in the first place. Wherever possible use disposable equipment; particularly where such equipment will contact blood or be used in invasive procedures. Disconnect any disposable equipment from non-disposable equipment (suction lines, extracorporeal tubing, etc.) while wearing gloves, a mask, gown and shoe covers; sanitize or sterilize the non disposable equipment according to the guidelines following this Chapter, and properly dispose of the rest. Non critical items that do not ordinarily touch the patient or that touch only intact skin (such as blood pressure cuffs) rarely, if ever, transmit disease. Simple sponging, wiping, or washing with regular detergent is usually all that is required. Rinse with clear water and allow to air dry thoroughly. Wash the PIB, Thumper, and similar equipment with hot soapy water. All pieces of equipment that are first to be disinfected or sterilized should first be thoroughly cleansed to remove all organic matter (blood, tissue, saliva) and other residue. Patient care equipment that enters normally sterile tissue or that touches mucous membranes must be sterilized before each use and subjected to high level disinfection. Chemical sterilants that are registered with the U.S. Environmental Protection Agency (EPA) as "sterilants" may be used either for sterilization or for high-level disinfection. Also acceptable is a solution of household bleach diluted in water (concentrations ranging in 1:10 to 1:100) to disinfect equipment and surfaces. Clean all organic matter and other debris off of the equipment before disinfecting, and follow the manufacturer's instructions for disinfecting any equipment. Be sure to clean any visible blood and secretions out of all cracks and crevices. Disinfection and Cleaning of the Ambulance Extraordinary attempts to disinfect and/or "sterilize" the interior surfaces of the ambulance are unnecessary and liable to result in damage to upholstery and equipment. The environmental surfaces of the vehicle are rarely associated with transmission of disease. The most important aspect to minimizing the risk of disease transmission in the ambulance is general cleanliness, good housekeeping and organization. Do not allow trash in the form of medical disposables wrappers to accumulate. Keep working surfaces uncluttered and promptly clean up spills of any kind. Where body fluids have spilled use a Body Fluid Spill Clean Up Kit and wipe the surface down with a commercial disinfectant or bleach solution. Following completion of a transport the ambulance interior should be cleaned with soap and water and environmental surfaces wiped down with 1:100 solution of household bleach. Keep the vehicle well ventilated during cleaning. The following guidelines are recommended for cleaning the vehicle interior following completion of a case: Wear disposable gloves and eye protection during all cleaning and decontamination procedures. Remove any blood, body fluids, or other matter with paper towels or disposable linens; dispose of these properly and immediately. Whenever blood is found clean with a disinfectant or bleach solution. Transport Technician Prophylactic Health Recommendations Before the Transport Technician begins active duty s/he should: Receive a PPD skin test for tuberculosis, unless the individual has documentation of a previous significant reaction or vaccination with BCG. Persons with significant reactions on initial PPD screening should be followed in accordance with American Thoracic Society Guidelines. Contact the local Department of Health Services for further information and notify the staff physician. Show evidence of immunity to the following diseases: a) Measles by proof of appropriate immunization or history of disease or infection, or serologic evidence. b) Hepatitis B by proof of appropriate immunization or history of disease or infection, or serologic evidence. c) TB (if PPD negative) by immediate vaccination with BCG or proof of prior vaccination with BCG. d) Rubella by proof of appropriate immunization or serologic evidence of past disease. (History of disease is not sufficient). e) Tetanus, diphtheria and polio by proof of prior immunization. (Prior disease does not impart immunity). f) Influenza by vaccination. Be counseled on the importance of good nutrition and judicious micronutrient supplementation in improving resistance to infectious disease. It is especially important for any health requirements such as ongoing vitamin/mineral supplementation, prescription medications, and so on to be available and continued throughout transport operations. Transport of cryopreservation patients almost invariably results in marked stress both psychological and physiological to the Transport Technician. Interruptions in normal sleep-wake cycles and sleep deprivation are common. Dietary alterations (reliance on fast food or foodstuffs not commonly eaten at home), confinement for extended periods with colleagues and strangers, often in an alien home setting, the psychological demands of the terminally ill patient and family, plus the not infrequently present added stress of familial hostility and medical/legal complications all contribute to both physiological and psychological stress. It is now well understood that both these kinds of stress result in secretion of adrenalcorticoids and related steroid hormones which are markedly immunosuppressive even in the healthy individual, and further that such stress results in depletion of micronutrients due to both their increased metabolism and excretion (for instance serum levels of both vitamin C and the B vitamins decline markedly in humans and animals under stress. It is thus of added importance that the Transport Technician continue uninterrupted any nutritional or medical regime s/he is normally on during the period of Transport operations. Nutritional Supplementation Recommendations It is the recommendation of the Cryopreservation Team Medical Director that all transport personnel follow the supplementation regime recommended below during the course of standby and transport operations, or an equivalent regimen: o 1 capsule of Daily One multivitamin/multimineral supplement manufactured by Twinlabs, Inc. Females of reproductive age should use the iron containing version of this product. o 1,000 mg of vitamin C (time release is not necessary). It is recommended that this be acquired in single dose, film-tab or coated tablets, to ease consumption under field conditions. o 400 I.U. vitamin E. o 500 elemental magnesium in the form of magnesium oxide. The above supplements are available without a prescription from most health food stores and pharmacies. The Transport Team Leader will maintain a modest supply of these nutrients for distribution to team members, however it is urged that each team member maintain their own supply. Further, it is strongly urged that as a minimum Transport Team members carry on a program of nutritional supplementation such as the one outlined above on an ongoing basis since when an emergency is going to occur (inside or out of human cryopreservation activities) can never be predicted. Recommended Immunizations For Transport Technicians Before you participate in Transport Operations you must be immunized against the following infectious diseases. Immunization against TB is optional, however if immunization is declined a TB skin test (tine test) is required annually. o Hepatitis B vaccination (3 doses over 6 months). o Influenza vaccination (annually). o DPT (diphtheria/pertussis/tetanus) with a DT booster every 10 years. o Polio immunization. o Rubella (German Measles) vaccination. o Measles vaccination. o Mumps vaccination. o Pneumococcal pneumonia vaccination o Meningicoccal Meningitis vaccination. General Guidelines For Preventing the Transmission of Infectious Disease In addition to the specific precautions outlined above, the following general guidelines should be observed when transporting patients for human cryopreservation: Wash your hands thoroughly after the completion of your patient handling duties. If running water is not available, use a commercial germicidal hand rinse to clean your hands. If you need to clean or disinfect any equipment in the vehicle, thoroughly wash your hands again afterwards. Whenever possible, use disposable equipment and supplies, particularly on patients with known infectious disease. When you have finished, double-bag all used equipment in a red Biohazardous Waste Bag (red bag), seal it to prevent leakage, and transport it to the Biopreservation facility, hospital, mortuary or other facility which is authorized to dispose of biohazardous wastes. Maintain at hand a supply of disposable gloves, masks, hats, gowns and shoe covers at all times. Follow the procedures outlined above to dispose of any soiled gloves, masks, gowns or shoe coverings. Always wear disposable gloves when working with or cleaning up blood. Never retain disposables for clean-up and use in teaching, training or for any other purpose. Disposables are to be thrown away at the end of the transport with the only exception being in the case of equipment (disposable) malfunction where the device may need to be retained for subsequent medicolegal investigation. In the case of a device being retained for investigation of malfunction it should be double red bagged and returned to the facility for disinfection. If there is to be a delay in return the device should be refrigerated on ice taking care not to allow water to enter the red bags. The cooler the device is in should be clearly labeled with a Biohazardous Materials Trefoil. If refrigeration is not practical or possible, call the facility for an appropriate protocol of on-site disinfection (such as treating the device with Cidex or Sporocidin). Disassemble and disinfect all non disposable equipment after every use. Thoroughly clean equipment first to remove blood, vomitus, or other organic soil; then wash in a strong disinfectant and let the disinfected equipment soak (i.e., Cidex or Sporocidin). Bag all tissues, dressings, and other disposable paper items in double red bags and seal to prevent leakage (tie the bag or use a cable tie). If your clothing becomes soiled with body fluids remove it as soon as possible, bag it and label it, take a hot shower and wash with germicidal soap. Rinse thoroughly. Your clothing should be washed for at least 25 minutes in hot water containing a germicide which will not damage the fabric (Sanisol or other benzyl ammonium chloride containing detergent is acceptable). Dump any secretions, blood, or vomitus from suction devices down the drain, hopper or toilet at the hospital mortuary or Biopreservation facility (as appropriate) and wash thoroughly into the sewer system. If disposing of such wastes at Biopreservation they must first be admixed with bleach in an approximately 1:10 concentration (i.e., 1 volume bleach to 10 volumes liquid waste). Remove all equipment and linens from the ambulance and wash all ambulance surfaces contacted by the patient with Sanisol or similar product. Wipe down the vehicle walls with 1:100 bleach solution. Let the ambulance air-dry and restock it with clean supplies. After you have finished all cleaning of equipment and the ambulance, wash your hands again thoroughly. Document in the ambulance log-book that cleaning was done. Promptly report any suspected exposure, including the date and time of exposure, the type of fluid involved, the amount of fluid, and details of the exposure using the Exposure Incident Investigation Form. Disposal of Biohazardous (Infectious) Waste Federal and State law mandate stringent guidelines for the disposal of Biohazardous waste. It is very important to understand that the liability for such waste is perpetual , that it originates with the generator of the waste, and that the liability cannot ever be transferred. Thus, if an individual is injured by a sharp generated by Biopreservation 100 years after the sharp was generated, Biopreservation (if it is still in existence) is fully liable for any damages. Furthermore, this liability cannot be given away or bought by others. Thus, if you hand over a bag of Biohazardous waste to a hospital or mortuary and they improperly dispose of it (even after agreeing to dispose of it properly) Biopreservation and/or the Transport Technician are fully liable. *Illustration not included. Figure 15-12: Universal biohazard symbol: the Biological Hazard Trefoil. The biohazard trefoil must be present on all biohazardous/infectious waste containers. For this reason Biopreservation deals with a licensed and heavily insured Biohazardous waste hauler (TCI of Colton, Ca) to dispose of Biohazardous wastes. In the event the Transport Technician relies on a hospital or mortuary to dispose of such waste it is critical that it be determined that the waste will be handled appropriately. Sharps (except in out-of-state cases) must never be disposed of by handing off to a mortuary or hospital. All sharps must be transported back to Biopreservation for incineration with TCI. Transport is to be carried out in the ambulance in sealed sharps containers (use duct tape to close double close the lid, then place the sharps container inside two red Biohazardous waste bags and label appropriately). Bulk blood, suctioned fluids, excretions, and secretions can be carefully poured down a drain connected to a sanitary sewer. If it is possible and safe to do so, such wastes should first be mixed with bleach in a 1:10 ratio per the instructions above. Always wear a face-sheild whendisposing of such waste, in addition to gloves, gowns shoe covers and so on. *Illustration not included. Table 15-1: Comparison Of The Relative Effectiveness of Various Chemical Sterilants and Disinfectants Selected Bibliography 1) Comstock WG, et al: A controlled trial of community-wide isoniazid prophylaxis in Alaska. Amer Rev Resp Dis. 1976;95:935-42. 2) Occupational Health and Safety Administration: Occupational exposure to blood-borne pathogens final rule: 29 CFR Part 1910.1030. Washington D.C. Federal Register 1991;56. 3) Gerty RJ, ed: Hepatitis B. New York: Academic Press. 1985. 4) Green WC: AIDS and the immune system. Scientific American 1993;269:99-105. 5) Haffen BQ, Karren KJ, eds: Pre-Hospital Emergency Care and Crisis Intervention. Englewood Cliffs, New Jersey: Prentice Hall. 1992. 6) Joklik WK, Smith DT, eds: Zinsser Microbiology: 15th Edition. New York: Appleton-Century-Crofts. 1972: 454-469. 7) Pantaleo G, et al: HIV infection is active and progressive in lymphoid tissue during the clinically latent stage of the disease. Nature 1193;362:355-358. 8) Price RW, et al: The brain in AIDS: Central nervous system HIV-I infection and AIDS dementia complex. Science 1988;239:586-592. 9) Putnam RD, Langerman N: OSHA Bloodborne Pathogens Exposure Control Plan. Boca Raton: Lewis Publishers. 1992. 10) Redfield RR, Burke DS: HIV infection: The clinical picture. Scientific American 1988;259:90-298. 11) Redfield RR, et al: The Walter Reed staging classification for HLTV III-LAV infection. New Eng J Med 1986;314:131-32. 12) Riley RL, et al: Infectiousness of air from a tuberculuous ward. Amer Rev Resp Dis 1962;85:511.+ 13) Rose SL: Clinical Laboratory Safety. New York: Van Nostrand Rheinhold. 1984. 14) Tiollais P, Buendia MA: Hepatitis B virus. Scientific American 1991;264:116-123. 15) Weiss RA: How does HIV cause AIDS? Science 1993;260:1273-1279. 16) Zuckerman AJ, ed: Viral Hepatitis and Liver Disease. New York: Alan R. Liss, Inc. 1988. Page: 1