This report outlines recommendations for postexposure interventions to prevent infection with hepatitis B virus, hepatitis C virus, or human immunodeficiency virus, and tetanus in persons wounded during bombings or other events resulting in mass casualties. Persons wounded during such events or in conjunction with the resulting emergency response might be exposed to blood, body fluids, or tissue from other injured persons and thus be at risk for bloodborne infections. This report adapts existing general recommendations on the use of immunization and postexposure prophylaxis for tetanus and for occupational and nonoccupational exposures to bloodborne pathogens to the specific situation of a mass-casualty event. Decisions regarding the implementation of prophylaxis are complex, and drawing parallels from existing guidelines is difficult.#
Information included in these recommendations might not represent FDA approval or approved labeling for the particular product or indications in question. Specifically, the terms "safe" and "effective" might not be synonymous with the FDA-defined legal standard for product approval. This report does not include any discussion of the unlabeled use of a product or a product under investigational use with the exception of the discussions of: 1. use of antiretroviral medications for human immunodeficiency virus postexposure prophylaxis. 2. off-label use of tetanus toxoid, reduced diphtheria toxoid and acel lular pertussis vaccine (Tdap) in the following situations: a. the interval between tetanus and diphtheria toxoids vaccine (Td) and Tdap might be shorter than the 5 years indicated in the pack age insert, b. the interval between doses of Td might be shorter than the 5 years indicated in the package insert, c. a dose of Tdap may be administered to a person who has already received Tdap, d. a dose of Tdap may be administered to a person aged 64 years, and e. Tdap may be used as part of the primary series for tetanus and diphtheria.

# Introduction
Public health authorities must consider how to provide care to injured persons in the event of acts such as bomb ings that result in mass casualties. During 1980During -2005, of 318 acts of terrorism investigated by the Federal Bureau of Investigation (FBI) in the United States or territories, 208 (65%) involved attempted bombings; of these 208 attempts, 183 (88%) succeeded. The majority of these acts were committed by domestic extremist groups that inten tionally targeted property and did not cause deaths or injuries in persons; however, 19 bombings (10% of those that were successful) resulted in 181 deaths and 1,967 injured survivors. These figures do not include masscasualty incidents that occurred outside the United States and its territories or those that occurred on U.S. soil that were classified as crimes, accidents, unintended negligence, or terrorist incidents other than bombings (e.g., the 2,972 persons killed as a result of the terrorist attacks of Septem ber 11,2001). A total of 1,967 (91%) persons injured during terrorist bombings in the United States and approxi mately 12,000 (80%) persons injured during the terrorist attacks of September 11, 2001, survived (1).
Military health-care providers frequently must respond to mass-casualty events. During October 7, 2001 In August 2001, the Israeli health ministry announced that tissue from two suicide bombers had tested positive for evidence of hepatitis B virus (HBV) (2). A 2002 case report from Israel described evidence of hepatitis B virus in a bone fragment that had traumatically implanted into a bombing survivor (3). Traumatically implanted bone frag ments removed from five survivors of the 2005 London bombings were taken directly to forensic custody without testing for bloodborne pathogens (4) These observations support the potential for explosions to result in transmis sion of infections among persons injured during the event and indicate that emergency responders and health-care providers in the United States need uniform guidance on prophylactic interventions appropriate for persons injured in bombings and other events resulting in mass casualties. Wounds resulting from mass-casualty events require the same considerations for management as similar injuries resulting from trauma cases not involving mass casualties, including the risk for tetanus. In addition, exposure of wounds, abraded skin, or mucous membranes to blood, body fluids, or tissue from other injured persons (includ ing suicide bombers and bombing casualties) might carry a risk for infection with a bloodborne virus. Injured survi vors of mass-casualty events are at risk for infection with HBV, hepatitis C virus (HCV), or human immunodefi ciency virus (HIV) and for tetanus.
Decisions regarding the administration of prophylaxis after a mass-casualty event are complex, and drawing direct par allels from existing guidelines regarding prophylaxis against bloodborne pathogens in occupational or nonoccupational settings is difficult. Assessment of risk factors commonly used to estimate the need for prophylactic intervention might not be possible in the setting of response to a masscasualty event because responses to such events might over whelm local emergency response facilities, and medical response staff will be focused primarily on rendering life saving trauma treatments. Because no uniform guidance existed for posstexposure interventions to prevent bloodborne infections and tetanus among U.S. civilians or military personnel wounded during mass-casualty event, CDC convened a Working Group comprising experts in injury response, immunizations, bloodborne infections, tetanus, and federal-, state-, and local-level public health response to develop such guidance.
The recommendations in this report pertain only to bombings and other mass-casualty events and are not meant to supplant existing recommendations for other settings. In a situation involving a substantial number of casualties, the ability to assess medical and vaccination histories or the risks associated with the source of exposures might be limited, as might the supply of biologics. For this reason, in certain instances, the recommendations provided in this report differ from standard published recommendations for vaccination and prophylaxis in other settings. These rec ommendations are not meant to supplant existing recom mendations for other settings and apply only to the specific situation of an event involving mass casualties. In addition, the recommendations provided in this report are limited to issues regarding initial postexposure management for bloodborne pathogens and tetanus prophylaxis. Other pro phylactic measures that might be appropriate (e.g., use of antibiotics for the prevention of bacterial infection) are not discussed in this report.
Federal law requires the use of a Vaccine Information State ment (VIS) before the administration of vaccines against HBV or tetanus. VIS forms are available at http:// www.cdc.gov/vaccines/pubs/vis/default.htm. Whenever fea sible, a VIS form should be provided to patients or guard ians before vaccination.
Individual states set forth their own legal requirements as to what constitutes the nature of informed consent that might be required before certain medical interventions. In general, these statutes also provide for exemptions in emer gency circumstances. It is these state-specific laws that should guide response when informed consent would be applicable, but the circumstances of response to a masscasualty event might preclude adherence to standard informed consent processes. Emergency responders and health-care providers should consult with their legal coun sel for guidance regarding the relevant laws of their juris dictions in advance of any mass-casualty event.

# Methods
This report was developed through consultation among persons with expertise in immunization and other prophy lactic interventions against bloodborne and other infections, physicians who specialize in acute injury-care medicine (trauma and emergency medicine), and local, state, and federal public health epidemiologists. Thus, the recommen dations in this report represent the best consensus judg ment of expert opinion.
This report adapts existing recommendations on the use of immunization and postexposure prophylaxis in response to occupational and nonoccupational exposures to bloodborne pathogens in the United States to the specific mass-casualty event setting while acknowledging the diffi culty of drawing direct parallels. This adaptation also draws on guidance and practices developed previously and in use in the United Kingdom and Israel (2,(5)(6)(7).
These recommendations were adopted through a process of expert consultation and consensus development. First, CDC drafted proposed preliminary recommendations on the basis of relevant existing U.S. guidance and practices of Israel and the United Kingdom (2,5-7). These proposed recommendations were discussed by representatives of the U.S. and international trauma response community at a May 2006 meeting in Atlanta, Georgia; following this dis cussion, the initial draft was revised. A working group then was convened comprising CDC staff members with exper tise in injury response, tetanus, viral hepatitis, HIV infec tion, immunization and postexposure prophylaxis, and occupational safety and health, and representatives of the National Association of County and City Health Officials and the Council of State and Territorial Epidemiologists with experience in local and state level public health re sponse. This group worked through the draft section by section to revise, update, and refine the recommendations; this revised document was shared again with representa tives of the U.S. and international trauma response com munity for additional comment during a meeting in Atlanta, Georgia, in August 2007. Because this guidance met the requirements established by the Office of Management and Budget (OMB) for a Highly Influential Scientific Assess ment (HISA) (available at / omb/memoranda/fy2005/m05-03.html), the recommen dations underwent a final process of external review in addition to undergoing internal CDC review for scientific content. As part of the OMB HISA peer review, the docu ment was posted on CDC's website for public comment. An external expert panel subsequently reviewed and cri tiqued the document, the public comments, and CDC's response to those comments, and the document was revised a final time in response to the external review process.

# Bloodborne Pathogens of Immediate Concern
Although transfusions and injuries from sharp objects (e.g., needlestick) have been associated with the transmis sion of multiple different pathogens (8,9), three bloodborne pathogens merit specific consideration in mass-casualty situ ations: HBV, HCV, and HIV. All three viruses are endemic at low levels in the United States and can be transmitted by exposure of infectious blood to an open wound or, more rarely, to skin abrasions or through exposure to intact mucous membranes. These viruses also can be transmitted by similar exposures to other body fluids or tissues from infected persons. Infection risks and options for postexposure prophylaxis vary, depending on the virus and the type of injury and exposure. Because hepatitis A virus (HAV) is transmitted via the fecal-oral route and is not considered a bloodborne pathogen (10), HAV prophylaxis is not recommended during a mass-casualty event.
The information typically used in occupational settings to guide prophylactic intervention decisions (including the circumstances of the injury, background prevalence of dis ease, or risk for infection of the source of exposure) might not be as clearly interpretable or as readily available in a mass-casualty setting. For example, both the extent of exposed disrupted skin and the volume of blood contribut ing to the exposure might greatly exceed that of usual occupational exposures. In addition, injured persons might be exposed to blood from multiple other persons or to bio logic material from the body of a bomber or another injured person. The HBV, HCV, and HIV status of the source(s) usually will be unknown, and timely ascertain ment might not be practical. If the circumstance in which each victim was injured can be characterized, this informa tion can be used to assess the likelihood that an injured person was exposed to another person's blood. However, when such information is not readily available for persons injured during blast-related mass-casualty events, such blood exposure should be assumed.

# Hepatitis B Virus
The prevalence of chronic HBV infection in the United States is approximately 0.4%. Prevalence varies by race, ethnicity, age group, geographic location, and individual history of risk behaviors (11).
Newly acquired HBV infection often is asymptomatic; only 30%-50% of children aged >5 years and adults have initial clinical signs or symptoms (11). The fatality rate among persons with reported cases of acute symptomatic hepatitis B is 0.5%-1.0% (11). No specific treatment exists for acute hepatitis B. Acute hepatitis B infection fails to resolve and instead progresses to chronic HBV infection in approximately 90% of those infected as infants, 30% of children infected at age 5 years (11). Overall, approximately 25% of persons who become chronically infected during child hood and 15% of those who become chronically infected after childhood die prematurely from cirrhosis or liver can cer (11). Therapeutic agents approved by the U.S. Food and Drug Administration (FDA) for treating chronic hepa titis B can achieve sustained suppression of HBV replica tion and remission of liver disease for certain persons (11).
HBV is transmitted by percutaneous or mucosal expo sure to infectious blood or body fluids. Although hepatitis B surface antigen (HBsAg) has been detected in multiple body fluids, only serum, semen, and saliva have been dem onstrated to be infectious (11). Serum has the highest con centration of HBV, with lower concentrations in semen and saliva. HBV remains viable for 7 days or longer on environ mental surfaces at room temperature (11). Among suscep tible health-care personnel, the risk for HBV infection after a needlestick injury involving an HBV-positive source is 23%-62% (12). Prompt and appropriate postexposure prophylaxis (PEP) intervention reduces this risk. Many infections that occurred before widespread vaccination of health-care personnel probably resulted from unapparent exposures (e.g., inoculation into cutaneous scratches, lesions, or mucosal surfaces) (12).
Both passive-active PEP with hepatitis B immune globu lin (HBIG) combined with hepatitis B vaccine and active PEP with hepatitis B vaccine alone have been demonstrated to be highly effective in preventing transmission after exposure to HBV (12). HBIG alone has been demonstrated to be effective in preventing HBV transmission. However, since hepatitis B vaccine became available, HBIG is used typically (and preferentially) as an adjunct to vaccination (11). The major determinant of effectiveness of PEP is early administration of the initial dose of vaccine (or HBIG). The effectiveness of PEP diminishes the longer after expo sure it is initiated (12). Studies are limited on the maxi mum interval after exposure during which PEP is effective, but the interval is unlikely to exceed 7 days for perinatal and needlestick exposures (12). No data are available on the efficacy of HBsAg-containing combination vaccines when used to complete the vaccine series for PEP, but the efficacy of combination vaccines is expected to be similar to that of single-antigen vaccines because the HBsAg component induces a comparable antibody response (12). Antiviral PEP is not available for HBV.
A policy of liberal use of hepatitis B vaccine for PEP after bombings or in other mass-casualty situations is recom mended because of the high concentration of HBV in blood of infected persons, the durability of HBV in the environ ment, and the efficacy and relative ease of administration of vaccine (11). Such use is consistent with existing recom mendations for administering the hepatitis B vaccine series as PEP for persons (e.g., health-care personnel or sexual assault victims) exposed to a source with unknown HBV infection status (11,12). In general, PEP for HBV will be warranted for previously unvaccinated persons if wounds, nonintact skin, or intact mucous membranes might have been exposed to blood or body fluids from another person or persons. In a mass-casualty setting, failure to provide hepatitis B vaccination when needed could result in pre ventable illness, whereas unnecessary vaccination is unlikely to cause harm (11). Completion of primary vaccination at the time of discharge or during follow-up visits should be ensured for all persons who receive an initial hepatitis B vaccine dose as part of the acute response to a masscasualty event.
If hepatitis B vaccine is in short supply, assessing how likely a person is to have been vaccinated previously might be necessary. In general, hepatitis B vaccination rates are highest among children aged <17 years (80%-90%) and health-care personnel (approximately 80%) (Table 1) (13-15) (see Pathogen-Specific Management Recommen dations).

# Hepatitis C Virus
The prevalence of chronic HCV infection in the United States is approximately 1.3% (16). Prevalence varies by race/ ethnicity, age group, geographic location, and individual history of risk behaviors (16,17).
Persons with acute HCV infection typically either are asymptomatic or have a mild clinical illness. Antibody to HCV (anti-HCV) can be detected in 80% of patients within 15 weeks after exposure and in 97% of patients by 6 months after exposure. Chronic HCV infection develops in 75%-85% of infected persons. The majority remain asymptom atic until onset of cirrhosis or end-stage liver disease, which develops within 20-30 years in approximately 10%-20% of infected persons (17).
HCV is transmitted primarily through exposure to large amounts of blood or repeated direct percutaneous expo sures to blood (i.e., transfusion or injection-drug use). HCV is not transmitted efficiently through occupational expo sures to blood; the average incidence of anti-HCV seroconversion after accidental percutaneous exposure from an HCV-positive source is 1.8% (range: 0-7%), with one study indicating that transmission occurred only from hollow-bore needles (17). Transmission rarely occurs through mucous membrane exposures to blood, and in only one instance was transmission in a health-care provider attributed to exposure of nonintact skin to blood (18). The risk for transmission from exposure to fluids or tissues other than HCV-infected blood has not been quantified but is expected to be low. The exact duration of HCV viability in the environment is unknown but is at least 16-23 hours (19,20).
Immune globulin and antiviral agents are not recom mended for PEP after exposure to HCV-positive blood. No vaccine against HCV exists. In the absence of PEP for HCV, recommendations for postexposure management are intended to achieve early identification of infection and, if present, referral for evaluation of treatment options. No guidelines exist for administration of therapy during the acute phase of HCV infection. However, limited data indi cate that antiviral therapy might be beneficial when started early in the course of HCV infection. When HCV seroconversion is identified early, the person should be referred for medical management to a knowledgeable specialist (12,17).
Testing is not routinely recommended in the absence of a risk factor for infection or a known exposure to an HCVpositive source (17). However, current public health prac tice often does include advising testing for potential exposures to unknown sources (e.g., playground incidents involving needlestick or health-care exposures involving possible needle or syringe reuse or inadequately disinfected equipment). In the setting of a bombing or other masscasualty event, both the extent of exposed disrupted skin and the volume of blood contributing to the exposure might greatly exceed that of usual occupational exposures. Thus, baseline and follow-up HCV testing should be considered for persons injured during bombings or other masscasualty events whose penetrating injuries or nonintact skin are suspected to have come into contact with another person's blood or body fluids (see Pathogen-Specific Management Recommendations).

# Human Immunodeficiency Virus
The overall prevalence of HIV infection in the United States was estimated to be 311. 5  nursing home compared with residents of transitional hous ing associated with a drug treatment program). The prin cipal means of transmission in the United States is through sexual contact or through sharing of injection-drug use equipment with an infected person (21). Exposures also occur in occupational settings (principally among healthcare personnel) and infrequently can result in transmission.
Guidelines for the use of antiretroviral PEP in both occu pational and nonoccupational settings have been published previously (22)(23)(24), but these documents do not specifi cally address situations involving mass casualties.
Potentially infectious materials include blood and visibly bloody body fluids, semen, and vaginal secretions. Cere brospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid also are considered infectious, but the transmission risk associated with them is less well defined. Feces, nasal secretions, saliva, sputum, sweat, tears, urine, and vomitus are not considered infec tious unless visibly bloody. Exposures that pose a risk for transmission include percutaneous injuries, contact of mucous membranes, or contact of nonintact skin with potentially infected fluids (22)(23)(24).
In studies of health-care personnel, the average risk for HIV transmission has been estimated to be approximately 0.3% (95% confidence interval  = 0.2%-0.5%) after a percutaneous exposure to HIV-infected blood and approximately 0.09% (95% CI = 0.01%-0.5%) after a mucous membrane exposure. Transmission risk from nonintact skin exposure has not been quantified but is esti mated to be less than that for mucous membrane exposure. Risk following percutaneous exposure is correlated posi tively with exposure to a larger quantity of blood, direct penetration of a vein or artery, a deep tissue injury, or exposure to blood from a source person with terminal illness (25), presumably related to high viral load.
Use of PEP with antiretroviral medications, initiated as soon as possible after exposure and continuing for 28 days, has been associated with a decreased risk for infection fol lowing percutaneous exposure in health-care settings (22). PEP also is recommended following nonoccupational sexual and injection-drug use-related exposures (24). Because of the potential toxicities of antiretroviral drugs, PEP is rec ommended unequivocally only for exposures to sources known to be HIV-infected. The decision to use PEP fol lowing unknown-source exposures is to be made on a caseby-case basis, considering the information available about the type of exposure, known risk characteristics of the source, and prevalence in the setting concerned.
In the majority of instances involving bombings or other mass-casualty events, the working group concluded that the risk for exposure to HIV-infected materials probably is low and that therefore PEP is not indicated. On this basis, PEP is not routinely recommended for treating persons injured in mass-casualty settings in the United Kingdom (7). For the same reason, HIV PEP should not be adminis tered universally in mass-casualty settings in the United States unless recommended by the local public health authority. Such instances might occur for mass-casualty events in certain specific settings judged by public health authorities to be associated with higher risk for HIV expo sure (e.g., a research facility that contained a large archive of HIV-infected blood specimens). In the rare situation in which PEP is recommended, it should be initiated as soon as possible after exposure, and specimens from the exposed person should be collected for baseline HIV testing. How ever, PEP should not be delayed for the results of testing. If PEP is used, certain other laboratory studies also are indi cated. Consultation from health-care professionals knowl edgeable about HIV infection is ideal, and is particularly important for pediatric patients and pregnant women. All persons for whom HIV PEP has been initiated should be referred to a clinician experienced in HIV care for follow up.

# Tetanus
Clostridium tetani, the causative agent of tetanus, is ubiq uitous in the environment and distributed worldwide. The organism is found in soil and in the intestines of animals and humans. When spores of C. tetani are introduced into the anaerobic or hypoaerobic conditions found in wounds or devitalized tissue, they germinate to vegetative bacilli that elaborate toxin and cause disease. This now infrequent but often fatal disease has been associated with injuries to otherwise healthy persons, particularly during military con flicts. During 1998-2000, the case-fatality ratio for reported tetanus in the United States was 18% (26). Although tetanus is not transmitted from person to per son, contamination of wounds with debris might increase the risk for tetanus among persons injured in masscasualty settings. Proper wound care and debridement play a critical role in tetanus prevention.
Serologic tests indicate that immunity to tetanus toxin is not acquired naturally. However, protection against teta nus is achievable almost universally by use of highly immunogenic and safe tetanus toxoid-containing vaccines. The disease now occurs almost exclusively among persons who were not vaccinated adequately or whose vaccination histories are unknown or uncertain (27,28). Universal pri mary vaccination, with subsequent maintenance of adequate antitoxin levels by means of appropriately timed boosters, protects persons among all age groups.
The age distribution of recent cases and the results of serosurveys indicate that many U.S. adults are not protected against tetanus (29). The proportions of persons lacking protective levels of circulating antitoxins against tetanus increase with age; at least 40% of persons aged >60 years might lack protection. In the United States, tetanus is pri marily a disease of older adults (27,28). Children are much more likely to have received age-appropriate vaccination; rates for receipt of 3 doses among children aged 19-35 months exceed 96% (28). During 1992-2000, only 15 cases of tetanus were reported in the United States among children aged <15 years. Parental philosophic or religious objection to vaccination accounted for the absence of immune protection for 12 (80%) affected children (30). Foreign-born immigrants, especially those from regions other than North America or Europe, also might be relatively undervaccinated (29,31).
Available evidence indicates that complete primary vac cination with tetanus toxoid provides long-lasting protec tion. After routine childhood tetanus vaccination, the Advisory Committee on Immunization Practices (ACIP) recommends routine booster vaccination with tetanus toxoid-containing vaccines every 10 years. For clean and minor wounds, a booster dose is recommended if the patient has not received a dose within 10 years. For all other wounds, a booster is appropriate if the patient has not received tetanus toxoid during the preceding 5 years.
In the setting of acute response to a mass-casualty event, failure to provide a tetanus vaccination when needed could result in preventable illness, whereas unnecessary vaccina tion is unlikely to cause harm (26)(27)(28)(29)32,33). A substan tial proportion of patients in this setting might be unable to provide a history of vaccination or history of contraindications to tetanus toxoid-containing vaccines, and the majority of wounds sustained will be considered tetanus-prone because they are likely to be exposed to dirt or feces. Thus, a wounded adult patient who cannot con firm receipt of a tetanus booster during the preceding 5 years should be vaccinated with tetanus and diphtheria toxoids vaccine (Td) or tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap); adults aged >65 years should receive Td (26). Similarly, a child with an uncer tain vaccination history should receive a tetanus booster as age-indicated by the standard childhood immunization table (pediatric diphtheria and tetanus toxoids and acellu lar pertussis vaccine  if aged 11 years) (32,34).
ACIP recommends that patients without a complete pri mary tetanus series who sustain a tetanus-prone wound routinely receive passive immunization with tetanus immune globulin (TIG) and tetanus toxoid (33). In the setting of acute response to a mass-casualty event, many wounded patients probably will be unable to confirm pre vious vaccination histories, and thus TIG normally would be indicated. However, this might not be feasible in a masscasualty setting if supplies of TIG are limited. All decisions to administer TIG depend on the number of casualties and the readily available supply of TIG. If the supply of TIG is adequate, consideration might be given to providing both tetanus toxoid and passive immunization with TIG at the time of management of tetanus-prone wounds. TIG is indicated if completion of a primary vaccination series is uncertain for an adult or if prior receipt of age-appropriate vaccinations is uncertain for a child. If TIG is in short sup ply, it should be reserved for patients least likely to have received adequate primary vaccination. In general, this group includes persons aged >60 years and immigrants from regions other than North America or Europe who might be less likely to have adequate antitetanus antibodies and who thus would derive the most benefit from TIG (32).
The TIG prophylactic dose that is recommended cur rently for wounds is 250 units administered intramuscu larly (IM) for adult and pediatric patients. When tetanus toxoid and TIG are administered concurrently, separate syringes and separate sites should be used (35). In circum stances in which passive protection is clearly indicated but TIG is unavailable, intravenous immune globulin may be substituted for TIG. Postexposure chemoprophylaxis with antimicrobials against tetanus is not recommended.
ACIP recommends that adults and adolescents with a history of uncertain or incomplete primary vaccination com plete a 3-dose primary series for tetanus, diphtheria, and pertussis (26,(30)(31)(32)(33)(34). In the setting of acute response to a mass-casualty event, completion of the primary vaccina tion series of any vaccine provided initially during acute response during follow-up visits should be ensured at the time of discharge for inadequately vaccinated patients of all ages. Special precautions regarding management of preg nant women in the setting of emergency delivery have been identified (see Special Situations).

# MMWR August 1, 2008

# Recommendations Pathogen-Specific Management

# Risk Assessment
To determine appropriate actions in response to evalua tion of casualties of bombings or other mass-casualty events, health-care providers should
- assess individual exposure risk by categorizing the patient into one of three exposure risk categories (Box 1) that are numbered sequentially from the highest (cat egory 1) to the lowest (category 3) level of exposure risk and assign each person to the highest level risk category for which he/she qualifies, - identify the appropriate risk category-and pathogenspecific management recommendation(s) (Box 1), and - determine the appropriate action to take (see Patho gen-Specific Management Recommendations) in response to management recommendations. When evaluating management choices for casualties of bombings or other mass-casualty events, health-care pro viders should assume that exposure to blood from other injured persons is likely unless available information on the circumstances of injury suggests otherwise. Blast inju ries result occasionally in traumatic implantation of bone or other biologic material that is alien to the wounded per son. Testing of such matter is not recommended as a useful adjunct for clinical management of wounded persons. Pub lic health authorities can provide assistance in assessing exposure risk for affected groups of injured persons. Teta nus risk is not dependent upon blood exposure.

# Recommendations Hepatitis B Virus
Unless an injured person who is unable to communicate an accurate medical history or for whom medical records are not readily available is accompanied by a person able to function as a health-care proxy, responders should assume the absence of a reliable hepatitis B vaccination history and no contraindication to vaccination with hepatitis B vaccine (see Contraindications and Precautions). If administration of hepatitis B vaccine to a large number of persons after a mass-casualty event is anticipated to result in shortages of hepatitis B vaccine products, or if such shortages already exist, assistance with vaccine supply is available (see Vac cine Supply).

# Recommendation: Intervene:
- Persons for whom neither a reliable history of completed vaccination against HBV nor a known contraindica tion to vaccination against HBV exist should receive the first dose of the HBV vaccine series as soon as pos sible (preferably within 24 hours) and not later than 7 days after the event.  treatment to facilitate the ability of primary healthcare providers to evaluate and, if appropriate, initiate or complete age-appropriate vaccinations or vaccina tion series (Appendix 1).

# Recommendation: No action:
- No action is necessary to prevent HBV infection.

# Hepatitis C Virus
Recommendation: Consider testing:
- Testing should be considered when an HCV-infected source is known or thought to be likely on the basis of the setting in which the injury occurred or exposure to blood or biologic material from a bomber or multiple other injured persons is suspected. - Public health authorities can provide assistance in assessing exposures and therefore treatment for affected groups of injured persons. A decision to perform test ing of specific persons might be made on the basis of the judgment of the treating physician and the prefer ences of the individual patient; testing during a fol low-up referral might be a more feasible logistical option in the setting of response to a mass-casualty event. If a decision is made to perform testing: - baseline testing for anti-HCV and alanine aminotrans ferase (ALT) should be performed within 7-14 days of the exposure; - follow-up testing for anti-HCV and ALT should be performed 4-6 months after exposure to assess seroconversion, preferably arranged as part of discharge planning; - HCV RNA testing should be performed at 4-6 weeks if an earlier diagnosis of HCV infection is desired; and - positive anti-HCV with low signal-to-cutoff value should be confirmed using a more specific supplemen tal assay before communicating the results to the patient; and - persons who are tested or are identified as a candidate for testing regarding exposure to HCV while undergo ing evaluation or treatment in immediate response to a mass-casualty event should be discharged with a refer ral for follow-up and written information on pre discharge treatment (Appendix 1).

# Recommendation: Generally no action:
- Exposure of mucous membranes to blood from a source with unknown HCV status generally poses a minor risk for infection and does not require further action.
- However, in settings in which exposure to an HCVinfected source is known or thought to be highly likely, testing for early identification of HCV infection fol lowing mucous membrane exposure may be consid ered. The decision to perform testing should be made on the basis of the judgment of the treating physician and the preference of the individual patient.

# Recommendation: No action
- No action is necessary to prevent HCV infection.

# Human Immunodeficiency Virus
Recommendation: Generally no action: option unless a decision to administer PEP has been made (35).
- In

# Recommendation: No action:
- No action is necessary to prevent HIV infection.

# Tetanus
All persons who sustain tetanus-prone injuries in masscasualty settings should be evaluated for the need for teta nus prophylaxis. Tetanus-prone injuries include but are not limited to puncture and other penetrating wounds with the potential to result in an anaerobic environment (wounds resulting from projectiles or by crushing) and wounds, avul sions, burns, or other nonintact skin that might be con taminated with feces, soil or saliva.
All persons who are not accompanied by either medical records or a health-care proxy and whose ability to com municate an accurate medical history is uncertain for any reason should be deemed to lack a reliable tetanus toxoid vaccination history and to have no contraindication to vac cination with tetanus toxoid (see Contraindications and Precautions). If compliance with recommendations is an ticipated to result in a shortage of tetanus toxoid products or TIG, assistance with product supplies is available (see Vaccine Supply).

# Recommendation: Intervene:
- Appropriate wound care and debridement are critical to tetanus prevention. - Age-appropriate vaccines should be used if possible.
However, in a mass-casualty setting, this might not be possible, and any tetanus vaccine formulation might be used, because the tetanus toxoid content is adequate for tetanus prophylaxis in any age group. In this set ting, the benefit of supplying tetanus prophylaxis out weighs the potential for adverse reactions from formulations from a different age indication.

# Recommendation: No action:
- No action is necessary to prevent tetanus. Exposure to blood or other bodily fluids generally is not considered a risk factor for tetanus. - However, responders or persons engaged in debris clean up and construction are candidates for prophylaxis even if they do not sustain any wounds. When feasible, as a routine public health measure, tetanus toxoid vaccina tion with Tdap or Td should be offered to all persons whose last tetanus toxoid-containing vaccine was received >10 years previously and who either are responders or are engaged in either debris clean-up or construction and who thus might be expected to encounter further risk for exposure (36)(37)(38)(39).

# Vaccine and Antitoxin Supply
Adherence to these recommendations might increase the acute demand for tetanus toxoid-containing vaccine, TIG, and hepatitis B vaccine beyond the available local supply. In that event, local authorities might have to rely on local and state health departments, mutual aid agreements, or commercial vendors to supplement the supply of needed biologic or pharmaceutical products. If a local authority's capacity to respond to an emergency is exceeded and other local or regional resources are inadequate, local and state public health jurisdictions can, through their established communication channels for health emergencies, work with CDC and others as appropriate to assist with product short ages.
CDC's Strategic National Stockpile (SNS) maintains bulk quantities of pharmaceutical and nonpharmaceutical medi cal supplies for use in a national emergency. Tetanus tox oid, tetanus immune globulin, and hepatitis B vaccine are not included in the stockpile formulary. However, SNS has purchasing agreements for acquiring medical materials in large quantities, subject to commercial availability. CDC maintains stockpiles of pediatric vaccine products purchased by the Vaccines for Children Program that might be used to assist state, territorial, and tribal health departments in meeting emergent local demands for vaccines. CDC also can work with manufacturers and with state and local health authorities to assist with supply of vaccines that are not available in either the SNS or other CDC vaccine stock piles.

# Counseling Hepatitis B and C Viruses
Persons undergoing postexposure management for pos sible exposure to HBV-or HCV-infected blood do not need to take any special precautions to prevent secondary trans mission during the follow-up period (12,17). The exposed person does not need to modify sexual practices or refrain from becoming pregnant. An exposed nursing mother might continue to breastfeed. However, exposed persons should refrain from donating blood, plasma, organs, tissue, or semen until follow-up testing by the health-care provider has excluded seroconversion (12,17).

# Human Immunodeficiency Virus
Persons known to be exposed to HIV should refrain from blood, plasma, organ, tissue, or semen donation until followup testing by the health-care provider has excluded seroconversion. In addition, measures to prevent sexual transmission (e.g., abstinence or use of condoms) should be taken, and breastfeeding should be avoided until HIV infection has been ruled out (22).

# Special Situations When HIV PEP is Initiated
HIV PEP should be considered only under exceptional circumstances. In the rare event that HIV PEP is consid ered, it should be initiated as soon as possible after expo sure. The patient should be counseled about the availability of PEP and informed about the potential benefits and risks and the need for prompt initiation to maximize potential effectiveness. If PEP is thought to be indicated on the basis of exposure risk, administration should not be delayed for HIV test results.
In the rare event that HIV PEP is administered, speci mens should be collected for baseline HIV testing on all patients provided with PEP using a blood or oral fluid rapid test if available; otherwise, conventional testing should be used. Testing should be discussed with the patient if the patient's medical condition permits. Procedures for testing should be in accordance with applicable state and local laws. PEP can be initiated and test results reviewed at follow-up. If the HIV test result is positive, PEP can be discontinued and the patient referred to a clinician experienced with HIV care for treatment.
If PEP is administered, the health-care provider also should obtain baseline complete blood count, renal func tion, hepatic function tests, and, in women, a pregnancy test. Because efavireniz might be teratogenic, it should not be administered until pregnancy test results are available (12,22). Otherwise, test results need not be available before PEP initiation but should be reviewed in follow-up.
Selection of antiretroviral regimens should aim for sim plicity and tolerability. Because of the complexity of selec tion of HIV PEP regimens, consultation with persons having expertise in antiretroviral therapy and HIV transmission is August 1, 2008 strongly recommended. Resources for consultation are avail able from the following sources:
- local infectious diseases, hospital epidemiology, or occupational health consultants; - local, state, or federal public health authorities; - PEPline at / PEPline.html, telephone 888-448-4911; - HIV/AIDS Treatment Information Service at http:// aidsinfo.nih.gov; and - previously published guidance (see Information Sources). Nevirapine should not be included in HIV PEP regi mens because of potential severe hepatic and cutaneous toxicity. Efavirenz should not be used if pregnancy is known or suspected because of potential teratogenicity (12,22).
PEP should be started as soon after exposure as possible and continue for 4 weeks. For ambulatory patients, a starter pack of 5-7 days of medication should be provided, if pos sible. Alternatively, for hospitalized patients, the first dose should be taken in the emergency department, and followup orders should be written for completion of the course in the hospital.
Patients on PEP should be reassessed for adherence, tox icity, and for follow-up of HIV testing (if rapid testing was not available at baseline) within 72 hours by an infectious disease consultant. Patients continuing on PEP should have follow-up laboratory evaluation as recommended previously (22)(23)(24), including a complete blood count and renal and hepatic function tests at baseline and at 2 weeks postexposure, and HIV testing at baseline, 6 weeks, 3 months, and 6 months postexposure.
Persons begun on HIV PEP should be discharged with written instructions and a referral to ensure follow-up care with a clinician experienced with HIV care and informa tion on the age-appropriate dose and schedule (Appendix 1).

# Simultaneous Administration
When tetanus toxoid and TIG are administered concur rently, separate syringes and separate anatomic sites should be used (40). Hepatitis B vaccine and tetanus toxoidcontaining vaccines might be administered at the same time using separate syringes and separate sites (36).
Treatment with an antimicrobial agent generally is not a contraindication to vaccination (40). Antimicrobial agents have no effect on the responses to vaccines against tetanus or hepatitis B.

# Administration of Blood Products
The administration of hepatitis B vaccine or tetanus toxoid-containing products does not need to be deferred in persons who have received a blood transfusion or other blood products.

# Pregnancy
Pregnancy is not a contraindication to vaccination against hepatitis B. Limited data suggest that a developing fetus is not at risk for adverse events when hepatitis B vaccine is administered to a pregnant woman. Available vaccines con tain noninfectious HBsAg and should cause no risk for infection to the fetus (11).
Pregnancy is not a contraindication for HIV PEP. How ever, use of efavirenz should be avoided when pregnancy is known or suspected (11,22).
Pregnant adolescents and adults who received the most recent tetanus toxoid-containing vaccine >5 years previ ously generally should receive Td in preference to Tdap when possible (41).

# Responders and Other Personnel
Responders and persons engaged in debris removal or construction often are at risk for incurring wounds through out the duration of response and clean up work. As a rou tine public health measure, health-care providers should offer tetanus toxoid vaccination to all response workers who do not have a reliable history of receipt of a tetanus toxoidcontaining vaccine during the preceding 10 years, regard less of whether the health-care visit was for a wound (38,39). Such persons might encounter potential exposure situations throughout the duration of their work in response to a masscasualty situation.
Health-care personnel, emergency response, public safety and other workers (e.g., construction workers and equip ment operators) who are injured and exposed to blood while providing assistance after a mass-casualty event should be managed according to existing guidelines and standards for the management of occupational exposures (10,22,42). Health-care personnel and first responders whose activities involve contact with blood or other body fluids should have been previously vaccinated against HBV and tetanus (12,22).

# Contraindications and Precautions

# Hepatitis B Vaccine
Hepatitis B vaccination is contraindicated for persons with a history of anaphylactic allergy to yeast or any vaccine component (11). On the basis of CDC's Vaccine Study Datalink data, the estimated incidence of anaphylaxis among children and adolescents who received hepatitis B vaccine is 1 case per 1.1 million vaccine doses distributed (95% CI = 0.1-3.9) (11). Persons with a history of serious adverse events (e.g., anaphylaxis) after receipt of hepatitis B vac cine should not receive additional doses. Vaccination is not contraindicated in persons with a history of multiple scle rosis, Guillain-Barre syndrome, autoimmune disease (e.g., systemic lupus erythematosis or rheumatoid arthritis), or other chronic diseases (11).

# Antiretroviral Therapy
Nevirapine should not be included in HIV PEP regi mens because of potential severe hepatic and cutaneous toxicity. Efavirenz should not be used if pregnancy is known or suspected because of potential teratogenicity (12,22).

# Preparations Containing Tetanus Toxoid
The only contraindication to preparations containing tetanus toxoid (TT, Td, or Tdap) is a history of a neuro logic or severe allergic reaction following a previous dose. Local side effects alone do not preclude continued use (26,30,31). If a person has a wound that is neither clean nor minor and for which tetanus prophylaxis is indicated, but also a contraindication to receipt of tetanus toxoidcontaining preparations, only passive immunization using human TIG should be administered.

# Reporting Adverse Events Vaccine Adverse Events Reporting System
Any clinically significant adverse events that occur after administration of any vaccine should be reported to the Vaccine Adverse Events Reporting System (VAERS) even if causal relation to vaccination is uncertain. The National Childhood Vaccine Injury Act requires health-care provid ers to report to VAERS any event listed by the vaccine manufacturers as a contraindication to subsequent doses of the vaccine or any event listed in the Reportable Events Table (available at ) that occurs within the specified period after vaccination. VAERS reporting forms and information can be requested 24 hours a day at telephone 800-822-7967 or by accessing VAERS at . Web-based reporting also is avail able, and providers are encouraged to report adverse events electronically at . htm.

# Reporting Adverse Events Associated With Antiretroviral Drugs and TIG
Unusual or severe toxicities believed to be associated with use of antiretroviral agents or TIG should be reported to FDA's MEDWATCH program (/ medwatch) at MedWatch, HF-2, Food and Drug Admin istration, 5600 Fishers Lane, Rockville, MD 20857; telephone 800-332-1088.

# National Vaccine Injury Compensation Program
The National Vaccine Injury Compensation Program (NVICP) was established by the National Childhood Vac cine Injury Act and became operational on October 1, 1988. Intended as an alternative to civil litigation under the tra ditional tort system (in that negligence need not be proven), NVICP is a no-fault system in which persons thought to have suffered an injury or death as a result of administra tion of a covered vaccine may seek compensation. Claims may be filed on behalf of infants, children and adolescents, or by adults receiving VICP-covered vaccines. Other legal requirements (e.g., the statute of limitations for filing an injury or death claim) must be satisfied to pursue compen sation. Claims arising from covered vaccines must be adju dicated through the program before civil litigation can be pursued. The program relies on a Reportable Events

# Tetanus is a potentially fatal disease that ...
A. has been associated with injuries to otherwise healthy persons. B. rarely occurs among persons known to be adequately vaccinated. C. in the United States, might be more likely among older adults, foreign-born immigrants from regions other than North America or Europe, or children whose parents object to vaccination. D. all of the above.

# Which of the following statements is true?
A. Failure to provide a tetanus vaccination when needed could result in preventable illness, while unnecessary vaccination is unlikely to cause harm. B. Failure to provide a hepatitis B virus vaccination when needed could result in preventable illness, while unnecessary vaccination is unlikely to cause harm. C. Postexposure prophylaxis against HIV infection usually should be given to all victims of bombings and similar mass casualty events. D. A. and B.

# Which statement about administration of TIG is true?
A. The currently recommended TIG prophylactic dose is 250 units intramuscularly (IM) for adult and pediatric patients. B. When tetanus toxoid and TIG are given concurrently, separate syringes and separate sites should be used. C. If passive protection is clearly indicated, but TIG is unavailable, intravenous immune globulin (IVIG) may be substituted for TIG. D. If TIG is in short supply, use should be reserved for patients least likely to have received adequate primary vaccination (persons aged 60 years or older, immigrants from regions other than North America or Europe, and children of parents who object to vaccination. E. All of the above.

# Information Sources
Recommendations for immediate prophylactic interven tions have been summarized (Table 2). Recommendations for issues that might arise in association with immediate prophylactic intervention also have been summarized (Table 3).
In addition to the guidance provided in these recom mendations, information on specific vaccines or other pro phylactic interventions also is available (Box 2). ACIP recommendations regarding vaccine use are published by MMWR. Electronic subscriptions are available free of charge at . Printed subscrip tions are available at Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 9235, telephone 202-512-1800.

# BOX 2. Online information sources

# Vaccines
Advisory Committee on Immunization Practices (ACIP) recommendations, available at http:// www.cdc.gov/vaccines/pubs/ACIP-list.htm.
CDC vaccines and immunization website, available at . American Academy of Pediatrics (AAP) Red Book, available at . Downloadable Vaccine Information Statements, available at / default.htm.

# Childhood, adolescent and adult immunization tables
Harmonized childhood, adolescent and adult immunization tables, available at / vaccines/recs/schedules/default.htm.

# ACCREDITATION

# Continuing Medical Education (CME).
CDC is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. CDC designates this educational activity for a maximum of 2.5 hours in category 1 credit toward the AMA Physician's Recognition Award. Each physician should claim only those hours of credit that he/she actually spent in the educational activity.

# Continuing Education Unit (CEU). CDC has been reviewed and approved as an

# Goal and Objectives
The goal of this report is to provide uniform guidance on prophylactic interventions appropriate for persons injured in bombings and similar events resulting in mass casualties. Upon completion of this educational activity, the reader should be able to 1) describe the indications for hepatitis B vaccine during response to a bombing or a similar mass-casualty event, 2) describe the indications for tetanus toxoid-containing vaccines during response to a bombing or a similar mass-casualty event, 3) describe the issues that should influence a decision to initiate postexposure prophylaxis against human immunodeficiency virus infection during response to a bombing or a similar mass-casualty event, 4) describe the issues that should influence a decision to initiate testing to evaluate for infection with hepatitis C virus during response to a bombing or a similar mass-casualty event, and 5) list the mechanisms for accessing assistance in the United States if adherence to these guidelines results in an acute shortage of vaccines during response to a bombing or a similar mass casualty event.
To receive continuing education credit, please answer all of the following questions.