Transmission of Mycobacterium tuberculosis is a recognized risk in health care facilities. The magnitude of the risk to HCWs varies considerably by the type of health care facility, the prevalence of TB in the community, the patient population served, the HCW’s occupational group, the area of the health care facility in which the HCW works and the effectiveness of TB infection-control interventions. The risk may be higher in areas where patients with TB are provided care before diagnosis and initiation of TB treatment and isolation precautions (e.g., in clinic waiting areas and emergency departments) or where diagnostic or treatment procedures that stimulate coughing are performed. Nosocomial transmission of M. tuberculosis has been associated with close contact with persons who have infectious TB and with the performance of certain procedures (e.g., bronchoscopy, endotracheal intubation and suctioning, open abscess irrigation and autopsy). Sputum induction and aerosol treatments that induce coughing may also increase the potential for transmission of M. tuberculosis. Personnel in health care facilities should be particularly alert to the need for preventing transmission of M. tuberculosis in those facilities in which immunocompromised persons (e.g., HIV-infected persons) work or receive care—especially if cough-inducing procedures, such as sputum induction and aerosolized pentamidine treatments, are being performed.

Transmission and Pathogenesis

M. tuberculosis is carried in airborne particles, or droplet nuclei, that can be generated when persons who have pulmonary or laryngeal TB sneeze, cough, speak or sing. The particles are an estimated 1 to 5 μm in size and normal air currents can keep them airborne for prolonged time periods and spread them throughout a room or building. Infection occurs when a susceptible person inhales droplet nuclei containing M. tuberculosis and these droplet nuclei traverse the mouth or nasal passages, upper respiratory tract and bronchi to reach the alveoli of the lungs. Once in the alveoli, the organisms are taken up by alveolar macrophages and spread throughout the body. Usually within two to ten weeks after initial infection with M. tuberculosis, the immune response limits further multiplication and spread of the tubercle bacilli; however, some of the bacilli remain dormant and viable for many years. This condition is referred to as latent TB infection. Persons with latent TB infection usually have positive purified protein derivative (PPD)-tuberculin skin-test results, but they do not have symptoms of active TB, and they are not infectious.

In general, persons who become infected with M. tuberculosis have approximately a 10% risk for developing active TB during their lifetimes. This risk is greatest during the first two years after infection. Immunocompromised persons have a greater risk for the progression of latent TB infection to active TB disease; HIV infection is the strongest known risk factor for this progression. Persons with latent TB infection who become co-infected with HIV have approximately an 8 to 10% risk per year for developing active TB. HIV-infected persons who are already severely immunosuppressed and who become newly infected with M. tuberculosis have an even greater risk for developing active TB.

The probability that a person who is exposed to M. tuberculosis will become infected depends primarily on the concentration of infectious droplet nuclei in the air and the duration of exposure. Characteristics of the TB patient that enhance transmission include:

• disease in the lungs, airways or larynx

• presence of cough or other forceful expiratory measures

• presence of acid-fast bacilli (AFB) in the sputum

• failure of the patient to cover the mouth and nose when coughing or sneezing

• presence of cavitation on chest radiograph

• inappropriate or short duration of chemotherapy

• administration of procedures that can induce coughing or cause aerosolization of M. tuberculosis (e.g., sputum induction).

Environmental factors that enhance the likelihood of transmission include:

• exposure in relatively small, enclosed spaces

• inadequate local or general ventilation that results in insufficient dilution and/or removal of infectious droplet nuclei

• recirculation of air containing infectious droplet nuclei.

Characteristics of the persons exposed to M. tuberculosis that may affect the risk for becoming infected are not as well defined. In general, persons who have been infected previously with M. tuberculosis may be less susceptible to subsequent infection. However, reinfection can occur among previously infected persons, especially if they are severely immunocompromised. Vaccination with Bacille of Calmette and Guérin (BCG) probably does not affect the risk for infection; rather, it decreases the risk for progressing from latent TB infection to active TB. Finally, although it is well established that HIV infection increases the likelihood of progressing from latent TB infection to active TB, it is unknown whether HIV infection increases the risk for becoming infected if exposed to M. tuberculosis.

Epidemiology

Several TB outbreaks among persons in health care facilities have been reported recently in the United States. Many of these outbreaks involved transmission of multidrug-resistant strains of M. tuberculosis to both patients and HCWs. Most of the patients and some of the HCWs were HIV-infected persons in whom new infection progressed rapidly to active disease. Mortality associated with those outbreaks was high (with a range of 43 to 93%). Furthermore, the interval between diagnosis and death was brief (with a range of median intervals of 4 to 16 weeks). Factors contributing to these outbreaks included delayed diagnosis of TB, delayed recognition of drug resistance and delayed initiation of effective therapy, all of which resulted in prolonged infectiousness, delayed initiation and inadequate duration of TB isolation, inadequate ventilation in TB isolation rooms, lapses in TB isolation practices and inadequate precautions for cough-inducing procedures and lack of adequate respiratory protection.

Fundamentals of TB infection control

An effective TB infection-control programme requires early identification, isolation and effective treatment of persons who have active TB. The primary emphasis of the TB infection-control plan should be on achieving these three goals. In all health care facilities, particularly those in which persons who are at high risk for TB work or receive care, policies and procedures for TB control should be developed, reviewed periodically and evaluated for effectiveness to determine the actions necessary to minimize the risk for transmission of M. tuberculosis.

The TB infection-control programme should be based on a hierarchy of control measures. The first level of the hierarchy, and that which affects the largest number of persons, is using administrative measures intended primarily to reduce the risk for exposing uninfected persons to persons who have infectious TB. These measures include:

• developing and implementing effective written policies and protocols to ensure the rapid identification, isolation, diagnostic evaluation and treatment of persons likely to have TB

• implementing effective work practices among HCWs in the health care facility (e.g., correctly wearing respiratory protection and keeping doors to isolation rooms closed)

• educating, training and counselling HCWs about TB

• screening HCWs for TB infection and disease.

The second level of the hierarchy is the use of engineering controls to prevent the spread and reduce the concentration of infectious droplet nuclei. These controls include:

• direct source control using local exhaust ventilation

• controlling direction of airflow to prevent contamination of air in areas adjacent to the infectious source

• diluting and removing contaminated air via general ventilation

• air cleaning via air filtration or ultraviolet germicidal irradiation (UVGI).

The first two levels of the hierarchy minimize the number of areas in the health care facility where exposure to infectious TB may occur, and they reduce, but do not eliminate, the risk in those few areas where exposure to M. tuberculosis can still occur (e.g., rooms in which patients with known or suspected infectious TB are being isolated and treatment rooms in which cough-inducing or aerosol-generating procedures are performed on such patients). Because persons entering such rooms may be exposed to M. tuberculosis, the third level of the hierarchy is the use of personal respiratory protective equipment in these and certain other situations in which the risk for infection with M. tuberculosis may be relatively higher.

Specific measures to reduce the risk for transmission of M. tuberculosis include the following:

1.    Assigning to specific persons in the health care facility the supervisory responsibility for designing, implementing, evaluating and maintaining the TB infection-control programme.

2.    Conducting a risk assessment to evaluate the risk for transmission of M. tuberculosis in all areas of the health care facility, developing a written TB infection-control programme based on the risk assessment and periodically repeating the risk assessment to evaluate the effectiveness of the TB infection-control programme. TB infection-control measures for each health care facility should be based on a careful assessment of the risk for transmission of M. tuberculosis in that particular setting. The first step in developing the TB infection-control programme should be to conduct a baseline risk assessment to evaluate the risk for transmission of M. tuberculosis in each area and occupational group in the facility. Appropriate infection-control interventions can then be developed on the basis of actual risk. Risk assessments should be performed for all inpatient and outpatient settings (e.g., medical and dental offices). Classification of risk for a facility, for a specific area and for a specific occupational group should be based on the profile of TB in the community, the number of infectious TB patients admitted to the area or ward, or the estimated number of infectious TB patients to whom HCWs in an occupational group may be exposed and the results of analysis of HCW PPD test conversions (where applicable) and possible person-to-person transmission of M. tuberculosis. Regardless of risk level, the management of patients with known or suspected infectious TB should not vary. However, the index of suspicion for infectious TB among patients, the frequency of HCW PPD skin testing, the number of TB isolation rooms and other factors will depend on the level of risk for transmission of M. tuberculosis in the facility, area or occupational group.

3.    Developing, implementing and enforcing policies and protocols to ensure early identification, diagnostic evaluation and effective treatment of patients who may have infectious TB. A diagnosis of TB may be considered for any patient who has a persistent cough (i.e., a cough lasting for longer than 3 weeks) or other signs or symptoms compatible with active TB (e.g., bloody sputum, night sweats, weight loss, anorexia or fever). However, the index of suspicion for TB will vary in different geographic areas and will depend on the prevalence of TB and other characteristics of the population served by the facility. The index of suspicion for TB should be very high in geographic areas or among groups of patients in which the prevalence of TB is high. Appropriate diagnostic measures should be conducted and TB precautions implemented for patients in whom active TB is suspected.

4.    Providing prompt triage for and appropriate management of patients in the outpatient setting who may have infectious TB. Triage of patients in ambulatory-care settings and emergency departments should include vigorous efforts to identify promptly patients who have active TB. HCWs who are the first points of contact in facilities that serve populations at risk for TB should be trained to ask questions that will facilitate identification of patients with signs and symptoms suggestive of TB. Patients with signs or symptoms suggestive of TB should be evaluated promptly to minimize the amount of time they are in ambulatory-care areas. TB precautions should be followed while the diagnostic evaluation is being conducted for these patients. TB precautions in the ambulatory-care setting should include placing these patients in a separate area apart from other patients and not in open waiting areas (ideally, in a room or enclosure meeting TB isolation requirements), giving these patients surgical masks to wear and instructing them to keep their masks on and giving these patients tissues and instructing them to cover their mouths and noses with the tissues when coughing or sneezing. Surgical masks are designed to prevent the respiratory secretions of the person wearing the mask from entering the air. When not in a TB isolation room, patients suspected of having TB should wear surgical masks to reduce the expulsion of droplet nuclei into the air. These patients do not need to wear particulate respirators, which are designed to filter the air before it is inhaled by the person wearing the mask. Patients suspected of having or known to have TB should never wear a respirator that has an exhalation valve, because the device would provide no barrier to the expulsion of droplet nuclei into the air.

5.    Promptly initiating and maintaining TB isolation for persons who may have infectious TB and who are admitted to the inpatient setting. In hospitals and other inpatient facilities, any patient suspected of having or known to have infectious TB should be placed in a TB isolation room that has currently recommended ventilation characteristics (see below). Written policies for initiating isolation should specify the indications for isolation, the person(s) authorized to initiate and discontinue isolation, the isolation practices to follow, the monitoring of isolation, the management of patients who do not adhere to isolation practices and the criteria for discontinuing isolation.

6.    Effectively planning arrangements for discharge. Before a TB patient is discharged from the health care facility, the facility’s staff and public health authorities should collaborate to ensure continuation of therapy. Discharge planning in the health care facility should include, at a minimum, a confirmed outpatient appointment with the provider who will manage the patient until the patient is cured, sufficient medication to take until the outpatient appointment and placement into case management (e.g., directly observed therapy (DOT)) or outreach programmes of the public health department. These plans should be initiated and in place before the patient’s discharge.

7.    Developing, installing, maintaining and evaluating ventilation and other engineering controls to reduce the potential for airborne exposure to M. tuberculosis. Local exhaust ventilation is a preferred source control technique, and it is often the most efficient way to contain airborne contaminants because it captures these contaminants near their source before they can disperse. Therefore, the technique should be used, if feasible, wherever aerosol-generating procedures are performed. Two basic types of local exhaust devices use hoods: the enclosing type, in which the hood either partially or fully encloses the infectious source, and the exterior type, in which the infectious source is near but outside the hood. Fully enclosed hoods, booths or tents are always preferable to exterior types because of their superior ability to prevent contaminants from escaping into the HCW’s breathing zone. General ventilation can be used for several purposes, including diluting and removing contaminated air, controlling airflow patterns within rooms and controlling the direction of airflow throughout a facility. General ventilation maintains air quality by two processes: dilution and removal of airborne contaminants. Uncontaminated supply air mixes with the contaminated room air (i.e., dilution), which is subsequently removed from the room by the exhaust system. These processes reduce the concentration of droplet nuclei in the room air. Recommended general ventilation rates for health care facilities are usually expressed in number of air changes per hour (ACH).

This number is the ratio of the volume of air entering the room per hour to the room volume and is equal to the exhaust airflow (Q, in cubic feet per minute) divided by the room volume (V, in cubic feet) multiplied by 60 (i.e., ACH = Q / V x 60). For the purposes of reducing the concentration of droplet nuclei, TB isolation and treatment rooms in existing health care facilities should have an airflow of greater than 6 ACH. Where feasible, this airflow rate should be increased to at least 12 ACH by adjusting or modifying the ventilation system or by using auxiliary means (e.g., recirculation of air through fixed HEPA filtration systems or portable air cleaners). New construction or renovation of existing health care facilities should be designed so that TB isolation rooms achieve an airflow of at least 12 ACH. The general ventilation system should be designed and balanced so that air flows from less contaminated (i.e., more clean) to more contaminated (less clean) areas. For example, air should flow from corridors into TB isolation rooms to prevent spread of contaminants to other areas. In some special treatment rooms in which operative and invasive procedures are performed, the direction of airflow is from the room to the hallway to provide cleaner air during these procedures. Cough-inducing or aerosol-generating procedures (e.g., bronchoscopy and irrigation of tuberculous abscesses) should not be performed in rooms with this type of airflow on patients who may have infectious TB. HEPA filters may be used in a number of ways to reduce or eliminate infectious droplet nuclei from room air or exhaust. These methods include placement of HEPA filters in exhaust ducts discharging air from booths or enclosures into the surrounding room, in ducts or in ceiling- or wall-mounted units, for recirculation of air within an individual room (fixed recirculation systems), in portable air cleaners, in exhaust ducts to remove droplet nuclei from air being discharged to the outside, either directly or through ventilation equipment, and in ducts discharging air from the TB isolation room into the general ventilation system. In any application, HEPA filters should be installed carefully and maintained meticulously to ensure adequate functioning. For general use areas in which the risk for transmission of M. tuberculosis is relatively high, ultraviolet lamps (UVGI) may be used as an adjunct to ventilation for reducing the concentration of infectious droplet nuclei, although the effectiveness of such units has not been evaluated adequately. Ultraviolet (UV) units can be installed in a room or corridor to irradiate the air in the upper portion of the room, or they can be installed in ducts to irradiate air passing through the ducts.

8.    Developing, implementing, maintaining and evaluating a respiratory protection programme. Personal respiratory protection (i.e., respirators) should be used by persons entering rooms in which patients with known or suspected infectious TB are being isolated, persons present during cough-inducing or aerosol-generating procedures performed on such patients and persons in other settings where administrative and engineering controls are not likely to protect them from inhaling infectious airborne droplet nuclei. These other settings include transporting patients who may have infectious TB in emergency transport vehicles and providing urgent surgical or dental care to patients who may have infectious TB before a determination has been made that the patient is non-infectious.

9.    Educating and training HCWs about TB, effective methods for preventing transmission of M. tuberculosis and the benefits of medical screening programmes. All HCWs, including physicians, should receive education regarding TB that is relevant to persons in their particular occupational group. Ideally, training should be conducted before initial assignment and the need for additional training should be re-evaluated periodically (e.g., once a year). The level and detail of this education will vary according to the HCW’s work responsibilities and the level of risk in the facility (or area of the facility) in which the HCW works. However, the programme may include the following elements:

• the basic concepts of M. tuberculosis transmission, pathogenesis and diagnosis,
  including information concerning the difference between latent TB infection and active
  TB disease, the signs and symptoms of TB and the possibility of reinfection

• the potential for occupational exposure to persons who have infectious TB in the
  health care facility, including information concerning the prevalence of TB in the
  community and facility, the ability of the facility to properly isolate patients who have
  active TB, and situations with increased risk for exposure to M. tuberculosis

• the principles and practices of infection control that reduce the risk for transmission of
  M. tuberculosis, including information concerning the hierarchy of TB infection-control
  measures and the written policies and procedures of the facility. Site-specific control
  measures should be provided to HCWs working in areas that require control
  measures in addition to those of the basic TB infection-control programme.

• the importance of proper maintenance for engineering controls (e.g., cleaning UVGI lamps and ensuring negative pressure in TB isolation rooms)

• the purpose of PPD skin testing, the significance of a positive PPD test result and the importance of participating in the skin-test programme

• the principles of preventive therapy for latent TB infection; these principles include the indications, use, effectiveness and the potential adverse effects of the drugs

• the HCW’s responsibility to seek prompt medical evaluation if a PPD test conversion
  occurs or if symptoms develop that could be caused by TB. Medical evaluation will
  enable HCWs who have TB to receive appropriate therapy and will help to prevent
  transmission of M. tuberculosis to patients and other HCWs.

• the principles of drug therapy for active TB

• the importance of notifying the facility if the HCW is diagnosed with active TB so that contact investigation procedures can be initiated

• the responsibilities of the facility to maintain the confidentiality of the HCW while
  ensuring that the HCW who has TB receives appropriate therapy and is non-
  infectious before returning to duty

• the higher risks associated with TB infection in persons who have HIV infection or
  other causes of severely impaired cell-mediated immunity, including (a) the more
  frequent and rapid development of clinical TB after infection with M. tuberculosis, (b)
  the differences in the clinical presentation of disease and (c) the high mortality rate associated with multiple drug resistant-TB in such persons

• the potential development of cutaneous anergy as immune function (as measured by CD4+ T-lymphocyte counts) declines

• information regarding the efficacy and safety of BCG vaccination and the principles of PPD screening among BCG recipients

• the facility’s policy on voluntary work reassignment options for immunocompromised HCWs.

10.    Developing and implementing a programme for routine periodic counselling and screening of HCWs for active TB and latent TB infection. A TB counselling, screening and prevention programme for HCWs should be established to protect both HCWs and patients. HCWs who have positive PPD test results, PPD test conversions or symptoms suggestive of TB should be identified, evaluated to rule out a diagnosis of active TB and started on therapy or preventive therapy if indicated. In addition, the results of the HCW PPD screening programme will contribute to evaluation of the effectiveness of current infection-control practices. Because of the increased risk for rapid progression from latent TB infection to active TB in human immunodeficiency virus, HIV-infected or otherwise severely immunocompromised persons, all HCWs should know if they have a medical condition or are receiving a medical treatment that may lead to severely impaired cell-mediated immunity. HCWs who may be at risk for HIV infection should know their HIV status (i.e., they should be encouraged to voluntarily seek counselling and testing for HIV antibody status). Existing guidelines for counselling and testing should be followed routinely. Knowledge of these conditions allows the HCW to seek the appropriate preventive measures and to consider voluntary work reassignments.

11.    ll HCWs should be informed about the need to follow existing recommendations for infection control to minimize the risk for exposure to infectious agents; implementation of these recommendations will greatly reduce the risk for occupational infections among HCWs. All HCWs should also be informed about the potential risks to severely immunocompromised persons associated with caring for patients who have some infectious diseases, including TB. It should be emphasized that limiting exposure to TB patients is the most protective measure that severely immunosuppressed HCWs can take to avoid becoming infected with M. tuberculosis. HCWs who have severely impaired cell-mediated immunity and who may be exposed to M. tuberculosis may consider a change in job-setting to avoid such exposure. HCWs should be advised of the legal option in many jurisdictions that severely immunocompromised HCWs can choose to transfer voluntarily to areas and work activities in which there is the lowest possible risk for exposure to M. tuberculosis. This choice should be a personal decision for HCWs after they have been informed of the risks to their health.

12.    Employers should make reasonable accommodations (e.g., alternative job assignments) for employees who have a health condition that compromises cell-mediated immunity and who work in settings where they may be exposed to M. tuberculosis. HCWs who are known to be immunocompromised should be referred to employee health professionals who can individually counsel the employees regarding their risk for TB. Upon the request of the immunocompromised HCW, employers should offer, but not compel, a work setting in which the HCW would have the lowest possible risk for occupational exposure to M. tuberculosis.

13.    All HCWs should be informed that immunosuppressed HCWs should have appropriate follow-up and screening for infectious diseases, including TB, provided by their medical practitioner. HCWs who are known to be HIV-infected or otherwise severely immunosuppressed should be tested for cutaneous anergy at the time of PPD testing. Consideration should be given to retesting, at least every 6 months, those immunocompromised HCWs who are potentially exposed to M. tuberculosis because of the high risk for rapid progression to active TB if they become infected.

14.    Information provided by HCWs regarding their immune status should be treated confidentially. If the HCW requests voluntary job reassignment, the privacy of the HCW should be maintained. Facilities should have written procedures on confidential handling of such information.

15.    Promptly evaluating possible episodes of M. tuberculosis transmission in health care facilities, including PPD skin-test conversions among HCWs, epidemiologically associated cases among HCWs or patients and contacts of patients or HCWs who have TB and who were not promptly identified and isolated. Epidemiological investigations may be indicated for several situations. These include, but are not limited to, the occurrence of PPD test conversions or active TB in HCWs, the occurrence of possible person-to-person transmission of M. tuberculosis and situations in which patients or HCWs with active TB are not promptly identified and isolated, thus exposing other persons in the facility to M. tuberculosis. The general objectives of the epidemiological investigations in these situations are as follows:

• to determine the likelihood that transmission of and infection with M. tuberculosis has occurred in the facility

• to determine the extent to which M. tuberculosis has been transmitted

• to identify those persons who have been exposed and infected, enabling them to receive appropriate clinical management

• to identify factors that could have contributed to transmission and infection and to implement appropriate interventions

• to evaluate the effectiveness of any interventions that are implemented and to ensure that exposure to and transmission of M. tuberculosis have been terminated.

16.    Coordinating activities with the local public health department, emphasizing reporting and ensuring adequate   discharge follow-up and the continuation and completion of therapy. As soon as a patient or HCW is known or suspected to have active TB, the patient or HCW should be reported to the public health department so that appropriate follow-up can be arranged and a community contact investigation can be performed. The health department should be notified well before patient discharge to facilitate follow-up and continuation of therapy. A discharge plan coordinated with the patient or HCW, the health department and the inpatient facility should be implemented.

Back

The common product shared between circuses and amusement and theme parks is creating and providing entertainment for the public’s enjoyment. Circuses can take place in a large temporary tent equipped with bleachers or in permanent buildings. Attending a circus is a passive activity in which the customer views the various animal, clown and acrobatic acts from a seated position. Amusement and theme parks, on the other hand, are locations where customers actively walk around the park and can participate in a wide variety of activities. Amusement parks can have many different types of rides, exhibits, games of skill, sales booths and stores, grandstand shows and other types of entertainment. Theme parks have exhibits, buildings and even small villages that illustrate the particular theme. Costume characters, who are actors dressed in costumes illustrating the theme—for example, historical costumes in historic villages or cartoon costumes for parks with a cartoon theme—will participate in shows or walk around among the visiting crowds. Local country fairs are another type of event where activities can include rides, animal and other side shows, such as fire-eating, and agricultural and farm animal exhibitions and competitions. The size of the operation can be as small as one person running a pony cart ride in a parking lot, or as large as a major theme park employing thousands. The larger the operation, the more background services that can be present, including parking lots, sanitation facilities, security and other emergency services and even hotels.

Occupations vary widely as do the levels of skills required for individual tasks. People employed in these activities include ticket sellers, acrobatic performers, animal handlers, food service workers, engineers, costume characters and ride operators, among a long list of other workers. The occupational safety and health risks include many of those found in general industry and others that are unique to circuses and amusement and theme park operations. The following information provides a review of entertainment-related hazards and precautions found within this segment of the industry.

Acrobatics and Stunts

Circuses, in particular, have many acrobatic and stunt acts, including high-wire tightrope walking and other aerial acts, gymnastic acts, fire-juggling acts and displays of horsemanship. Amusement and theme parks can also have similar activities. Hazards include falls, misjudged clearances, improperly inspected equipment and physical fatigue due to multiple daily shows. Typical accidents involve muscular, tendon and skeletal injuries.

Precautions include the following: Performers should receive comprehensive physical conditioning, proper rest and a good diet, and show schedules should be rotated. All equipment, props, rigging, safety devices and blocking should be carefully reviewed before each performance. Show personnel should not perform when they are ill, injured or taking medication which may affect required abilities to safely meet the needs of the show.

Animal Handling

Animals are most commonly found in circuses and county fairs, although they can also be found in activities such as pony rides in amusement parks. Animals are found in circuses in wild-animal training acts, for example, with lions and tigers, horse riding acts and other trained animal acts. Elephants are used as show performers, rides, exhibits and work animals. In country fairs, farm animals such as pigs, cattle and horses are exhibited in competitions. In some places, exotic animals are displayed in cages and in such acts as snake handling. Hazards include the unpredictable characteristics of animals combined with the potential for animal handlers to become overly confident and let their guard down. Serious injury and death are possible in this occupation. Elephant handling is considered one of the most dangerous professions. Some estimates indicate there are approximately 600 keepers in the United States and Canada. During the course of an average year there will be one elephant handler killed. Venomous snakes, if used in snake-handling acts, can also be very dangerous, with possible fatalities from snake bites.

Precautions include intense and ongoing animal-handling training. It must be instilled in employees to remain on their guard at all times. The use of protected contact systems is recommended where keepers work alongside animals capable of causing serious injury or death. Protected contact systems always separate the animal handler and the animal by means of bars or closed-off areas. When animals perform on stage to live audiences, noise and other stimuli conditioning must be a part of the required safety training. With venomous reptiles, proper anti-venom antidotes and protective equipment such as gloves, leg guards, snake pincers and carbon dioxide bottles should be available. Care and feeding of animals when they are not being exhibited also requires careful attention on the part of the animal caretakers to prevent injury.

Costume Characters

Costume characters acting the role of cartoon figures or historical period characters often wear heavy and bulky costumes. They can act on stages or mingle with the crowds. Hazards are back and neck injuries associated with wearing such costumes with uneven weight distribution (figure 1). Other exposures are fatigue, heat-related problems, crowd pushing and hitting. See also “Actors”.

Figure 1. Worker wearing a heavy costume.

William Avery

Precautions include the following: Costumes should be correctly fitted to the individual. The weight load, especially above the shoulders, should be kept at a minimum. Costume characters should drink plenty of water during periods of warm weather. Interaction with the public should be of short duration because of the stress of such work. Character duties should be rotated, and non-costumed escorts should be with characters at all times to manage crowds.

Fireworks

Fireworks displays and pyrotechnics special effects can be a common activity (figure 2). Hazards can involve accidental discharge, non-planned explosions and fire.

Figure 2. Loading pyrotechnics for fireworks show.

William Avery

Precautions include the following: Only appropriately trained and licensed pyrotechnicians should detonate explosives. Storage, transportation and detonation procedures must be followed (figure 3). Applicable codes, laws and ordinances in the jurisdiction where operating must be adhered to. Pre-approved personal safety equipment and fire extinguishing equipment must be at the detonation site where there is immediate access.

Figure 3. Bunker storage for fireworks.

William Avery

Food Service

Food can be bought at circuses and amusement and theme parks from individuals with trays of food, at vendor carts, booths, or even restaurants. Hazards common to food service operations at these events involve serving large captive audiences during high periods of demand in a very short period of time. Falls, burns, cuts and repetitive motion trauma are not uncommon in this occupational classification. Carrying food around on trays can involve back injuries. The risks are increased during periods of high volume. A common example of injury occurring in high-volume food service areas is repetitive motion trauma that can result in tendinitis and carpal tunnel syndrome. One example of a job description where such injuries occur is an ice-cream scooper.

Precautions include the following: Increased staffing during high-volume periods is essential to the safety of the operation. Specific duties such as mopping, sweeping and cleaning should be addressed. Precautions for repetitive motion trauma: regarding the example given above, using softer ice cream can make scooping less strenuous, employees can be regularly rotated, scoops can be warmed to promote easier penetration of the ice cream and the use of ergonomically designed handles should be considered.

Scenery, Props and Exhibits

Stage shows, exhibits, booths, artificial scenery and buildings must be built. Hazards include many of the same hazards as found in construction, including electrocution, severe lacerations, and eye and other injuries associated with the use of power tools and equipment. The outdoor building and use of props, scenery and exhibits increases the potential hazards such as collapse if construction is inadequate. Handling of these components can result in falls and back and neck injuries (see also “Scenery shops” in this chapter).

Precautions include the following: The manufacturer’s warnings, safety equipment recommendations and safe operating instructions for power tools and machinery must be followed. The weight of props and their sections should be minimized to reduce the possibility of lifting-associated injuries. Props, scenery and exhibits designed for outdoor use must be reviewed for wind load ratings and other outdoor exposures. Props designed for use with live loads should be appropriately rated and the built-in safety factor verified. Fire rating of the material should be considered based on the intended use, and any fire regulations that may be applicable must be followed.

Ride Operators and Maintenance Personnel

There are a wide variety of amusement park rides, including Ferris wheels, roller coasters, water flume rides, looping boats and aerial tramways. Ride operators and maintenance personnel work in areas and under conditions where there are increased risks of serious injury. The exposures include electrocution, being struck by equipment and caught in or between equipment and machinery. Besides the rides, ride and maintenance personnel must also operate and maintain the associated electrical power plants and transformers.

Precautions include an effective programme that can reduce the potential for serious injury in a lock out, tag out and block out procedure. This programme should include: personally assigned padlocks with single keys; written procedures for working on electrical circuitry, machinery, hydraulics, compressed air, water and other sources of possible energy release; and tests to ensure that the energy supply has been shut off. When more than one person is working on the same piece of equipment, each person should have and use his or her own lock.

Travelling Shows

Circuses and many amusement rides can travel from one location to another. This can be by truck for small operations, or by train for large circuses. Hazards include falls, severed body parts and possible death during erection, dismantling or transportation of equipment (figure 4). A particular problem is expedited work procedures, resulting in skipping time-consuming safety procedures, in an effort to meet play date deadlines.

Figure 4. Erecting an amusement park ride with a crane.

William Avery

Precautions include the following: Employees must be well trained, exercise caution and follow manufacturer’s safety instructions for assembly, dismantling, loading, unloading and transportation of the equipment. When animals are used, such as an elephant to pull or push heavy equipment, additional safety precautions are required. Equipment such as cables, ropes, hoists, cranes and fork-lifts should be inspected before each use. Over-the-road drivers must follow highway transportation safety guidelines. Employees will require additional training in safety and emergency procedures for train operations where animals, personnel and equipment travel together.

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Bullfighting, or the corrida as it is commonly called, is popular in Spain, Spanish-speaking countries in Latin America (especially Mexico), southern France and Portugal. It is highly ritualized, with pageants, well-defined ceremonies and colourful traditional costumes. Matadors are highly respected and often begin their training at an early age in an informal apprenticeship system.

Rodeos, on the other hand, are a more recent sports event. They are an outgrowth of skills contests between cowboys illustrating their everyday activities. Today, rodeos are formalized sports events popular in the western United States, western Canada and Mexico. Professional rodeo cowboys (and some cowgirls) travel the rodeo circuit from one rodeo to another. The most common rodeo events are bronco riding, bull riding, steer wrestling (bulldogging) and calf roping.

Bullfights. Participants in a bullfight include the matadors, their assistants (the banderilleros and picadors) and the bulls. When the bull first enters the arena from the bull pen gate, the matador attracts its attention with a series of passes with his large cape. The bull is attracted by the movement of the cape, not the colour, since bulls are colour-blind. The matador’s reputation is based on how close he gets to the horns of the bull. These fighting bulls have been bred and trained for centuries for their aggressiveness. The next part of the bullfight involves the weakening of the bull by mounted picadors placing lances in the bull, and then banderilleros, working on foot, placing barbed sticks called banderillas in the bull’s shoulder in order to lower the bull’s head for the kill.

The final stage of the fight involves the matador trying to kill the bull by inserting his sword blade between the shoulder blades of the bull into the aorta. This stage involves many formalized passes with the cape before the final kill. The greater the risks taken by the matador, the greater the acclaim, and of course the greater the risk of being gored (see figure 1). Bullfighters generally receive at least one goring per season, which could involve as many as 100 bullfights per year per matador.

Figure 1. Bullfighting.

El Pais

The primary hazard facing the matadors and their assistants is being gored or even killed by the bull. Another potential hazard is tetanus from being gored. One epidemiological study in Madrid, Spain, indicated that only 14.9% of bullfighting professionals had complete anti-tetanus vaccination, while 52.5% had suffered occupational injuries (Dominguez et al. 1987). Few precautions are taken. The mounted picadors wear steel leg armour. Otherwise, the bullfighting professionals depend on the training and skills of themselves and their horses. One essential precaution is adequate planning for onsite emergency medical care (see “Motion picture and television production” in this chapter).

Rodeos. The most hazardous common rodeo events are bronco or bull riding and steer wrestling. In bronco or bull riding, the purpose is to stay on the bucking animal for a predetermined time. Bronco riding can be either bareback or with a saddle. In steer wrestling, a rider on horseback attempts to throw the steer to the ground by diving off the horse, grabbing the bull by its horns and wrenching it to the ground. Calf roping involves roping a calf from horseback, jumping off the horse and then hog-tying the front and back legs of the calf together in the shortest possible time.

Besides the rodeo contestants, those at risk include the pickup riders or outriders, whose role is to rescue the thrown rider and capture the animal, and the rodeo clowns, whose job is to distract the animal, especially bulls, to give the thrown rider a chance to escape (figure 2). They do this while on foot and dressed in a colourful costume to attract the animal’s attention. Hazards include being trampled, being gored by the bull’s horns, injuries from being bucked off, knee injuries from jumping off the horse, elbow injuries in bronco and bull riders from holding on to the animal with one hand and facial injuries from bulls tossing their heads back. Injuries also occur from bronco or bull riders being smashed against the sides of the chute while waiting for the gate to open and the animal to be released. Severe injuries and fatalities are not infrequent. Bull riders sustain 37% of all rodeo-related injuries (Griffin et al. 1989). In particular, brain and spinal cord injuries are of concern (MMWR 1996). One study of 39 professional rodeo cowboys showed a total of 76 elbow abnormalities in 29 bronco and bull riders (Griffin et al. 1989). They concluded that the injuries were a result of constant hyperextension of the arm gripping the animal, as well as injuries in falls.

Figure 2. Rodeo clown distracting a bull from a fallen rider.

Dan Hubbell

The main way of preventing injuries lies in the skills of the rodeo cowboys, pickup riders and rodeo clowns. Well-trained horses are also essential. Taping elbows and wearing elbow pads has also been recommended for bronco and bull riding. Safety vests, mouth guards and safety helmets are rare, but becoming more accepted. Face masks have occasionally been used for bull riding. As in bullfighting, an essential precaution is adequate planning for on-site emergency medical care.

In both rodeos and bullfighting, of course, the animal keepers, feeders and so on are also at risk. For more information on this aspect, see “Zoos and aquariums” in this chapter.

Back

Sports activities involve a great number of injuries. Precautions, conditioning and safety equipment, when used properly, will minimize sports injuries.

In all sports, conditioning year round is encouraged. Bone, ligaments and muscles respond in a physiological fashion by gaining both size and strength (Clare 1990). This increases the athlete’s agility to avoid any injurious physical contact. All sports requiring weightlifting and strengthening should be under the supervision of a strength coach.

Contact Sports

Contact sports such as American football and hockey are particularly dangerous. The aggressive nature of football requires the player to strike or tackle the opposing player. The focus of the game is to possess the ball with the intent of physically striking anyone in one’s path. The equipment should be well-fitting and offer adequate protection. (figure 1). The helmet with appropriate face mask is standard and is critical in this sport (figure 2). It should not slide or twist and the straps should be applied snugly (American Academy of Orthopedic Surgeons 1991).

Figure 1. Snug fitting football pads.

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Source: American Academy of Orthopedic Surgeons 1991

Figure 2. American football helmet.

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Source: Clare 1990

Unfortunately, the helmet is sometimes used in an unsafe manner whereby the player “spears” an opponent. This can lead to cervical spine injuries and possible paralysis. It can also lead to careless play in sports like hockey, when players feel they can be more free with the use of their stick and risk slashing the face and body of the opponent.

Knee injuries are quite common in football and basketball. In minor injuries, an elastic “sleeve” (figure 3) which provides compressive support may be useful. The ligaments and cartilage of the knee are prone to stress as well as impact trauma. The classic combination of cartilage and ligamentous insult was first described by O’Donoghue (1950). An audible “pop” may be heard and felt, followed by swelling, if there are ligament injuries. Surgical intervention may be needed before the player may resume activities. A derotational brace may be worn post-operatively and by players with partial tear of the anterior cruciate ligament but with enough intact fibres able to sustain their activities. These braces must be well padded to protect the injured extremity and other players (Sachare 1994a).

Figure 3. Patella cut-out sleeve.

Huie, Bruno and Norman Scott

In hockey, the velocity of both the players and the hard hockey puck warrants the use of protective padding and helmet (figure 4). The helmet should have a face shield to prevent facial and dental injuries. Even with helmets and protective padding to vital areas, severe injuries such as fractures of extremities and spine do occur in football and hockey.

Figure 4. Padded hockey gloves.

Huie, Bruno and Norman Scott

In both American football and hockey, a complete medical kit (which includes diagnostic instruments, resuscitation equipment, immobilization devices, medication, wound care supplies, spine board and stretcher) and emergency personnel should be available (Huie and Hershman 1994). If possible, all contact sports should have this available. Radiographs should be obtained of all injuries to rule out any fractures. Magnetic resonance imaging has been found to be very helpful in determining soft tissue injuries.

Basketball

Basketball is also a contact sport, but protective equipment is not worn. The focus of the player is to have possession of the ball and their intent is not to strike the opposing players. Injuries are minimized due to the player’s conditioning and speed in averting any hard contact.

The most common injury to the basketball player are ankle sprains. Evidence of ankle sprains has been noted in about 45% of players (Garrick 1977; Huie and Scott 1995). The ligaments involved are the deltoid ligament medially and the anterior talofibular, posterior talofibular, and calcaneofibular ligaments laterally. X rays should be obtained to rule out any fractures which may occur. These radiographs should include the entire lower leg to rule out a Maisonneuve fracture (VanderGriend, Savoie and Hughes 1991). In the chronically sprained ankle, use of a semi-rigid ankle stirrup will minimize further insult to the ligaments (figure 5).

Figure 5. Rigid ankle stirrup.

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Finger injuries may result in ruptures of the supporting ligamentous structures. This can result in a Mallet finger, Swann Neck deformity and Boutonierre deformity (Bruno, Scott and Huie 1995). These injuries are quite common and are due to direct trauma with the ball, other players and the backboard or rim. Prophylactic taping of ankles and fingers helps minimize any accidental twisting and hyperextension of the joints.

Facial injuries (lacerations) and fractures of the nose due to contact with opponents’ flailing arms or bony prominences, and contact with the floor or other stationary structures have been encountered. A clear light-weight protective mask may help in minimizing this type of injury.

Baseball

Baseballs are extremely hard projectiles. The player must always be cognizant of the ball not only for safety reasons but for the strategy of the game itself. Batting helmets for the offensive player, and chest protector and catcher’s mask/helmet (figure 6). for the defensive player are required protective equipment. The ball is hurled at times in excess of 95 mph, sometimes resulting in bone fractures. Any head injuries should have a full neurological work-up, and, if loss of consciousness is present, radiographs of the head should be taken.

Figure 6. Protective cather's mask.

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Huie, Bruno and Norman Scott

Soccer

Soccer can be a contact sport resulting in trauma to the lower extremity. Ankle injuries are very common. The protection that would minimize this would be taping and the use of a semi-rigid ankle stirrup. It has been found that the effectiveness of the taped ankle diminishes after about 30 minutes of vigorous activities. Tears of the anterior cruciate ligament of the knee are often encountered and most likely will require a reconstructive procedure if the player wishes to continue participating in this sport. Anterior medial tibial stress syndrome (shin splints) is extremely common. The hypothesis is that there may be an inflammation to the periosteal sleeve around the tibia. In extreme situations, a stress fracture may occur. The treatment requires rest for 3 to 6 weeks and the use of non-steroidal anti-inflammatory drugs (NSAID), but high-level and professional-level players tend to compromise the treatment once the symptoms diminish as early as 1 week and thus go back to the impact activity. Hamstring pulls and groin pulls are common in the athletes who do not permit enough time to warm and stretch the musculature of the legs. Direct trauma to the lower extremities, particularly the tibia, may be minimized with the use of anterior shin guards.

Skiing

Skiing as a sport does not require any protective equipment, although goggles are encouraged to prevent eye injuries and to filter out the sun’s glare off the snow. Ski boots offer a rigid support for the ankles and have a “quick-release” mechanism in the event of a fall. These mechanisms, although helpful, are susceptible to circumstances of the fall. During the winter season, many injuries to the knee resulting in ligament and cartilage damage are encountered. This is found in the novice as well as the seasoned skier. In professional downhill skiing, helmets are required to protect the head due to the velocity of the athlete and the difficulty of stopping in the event the trajectory and direction are miscalculated.

Martial Arts and Boxing

Martial arts and boxing are hard contact sports, with little or no protective equipment. The gloves used on the professional boxing level are, however, weighted, which increases their effectiveness. Head guards at the amateur level help soften the impact of the blow. As with skiing, conditioning is extremely important. Agility, speed and strength minimize the combatant’s injuries. The blocking forces are deflected more than absorbed. Fractures and soft tissue insults are very common in this sport. Similar to volleyball, the repetitive trauma to the fingers and carpal bones of the hand results in fractures, subluxation, dislocation and ligamentous disruptions. Taping and padding of the hand and wrist may provide some support and protection, but this is minimal. Studies have shown that long-term brain damage is a serious concern for boxers (Council on Scientific Affairs of the American Medical Association 1983). Half of a group of professional boxers with more than 200 fights each had neurological signs consistent with traumatic encephalopathy.

Horse Racing

Horse racing at the professional and amateur levels requires a riding helmet. These helmets offer some protection for head injuries from falls, but they offer no attachment for the neck or spine. Experience and common sense help minimize falls, but even seasoned riders can sustain serious injuries and possibly paralysis if they land on their head. Many jockeys today also wear protective vests since being trampled under horses’ hooves is a major risk in falls and has resulted in fatalities. In harness racing, where horses pull two-wheeled carts called sulkies, collisions between sulkies has resulted in multiple pile-ups and serious injuries. For hazards to stable hands and others involved in handling the horses, see the chapter Livestock rearing.

First Aid

As a general rule, immediate icing (figure 7), compression, elevation and NSAIDs following most injuries will suffice. Pressure dressings should be applied to any open wounds, followed by an evaluation and suturing. The player should be removed from the game immediately to prevent any blood-borne contamination to other players (Sachare 1994b). Any head trauma with loss of consciousness should have a mental status and neurological work-up.

Figure 7.  Cold compressive therapy.

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Physical Fitness

Professional athletes with asymptomatic or symptomatic cardiac conditions may be hesitant in disclosing their pathology. In recent years, several professional athletes have been found to have cardiac problems that resulted in their deaths. The economic incentives of playing professional-level sports may inhibit athletes from disclosing their conditions for fear of disqualifying themselves from strenuous activities. Carefully obtained past medical and family histories followed by EKG and treadmill stress tests prove to be valuable in detecting those who are at risk. If a player is identified as a risk and still wishes to continue competing regardless of the medical-legal issues, emergency resuscitative equipment and trained personnel must be present at all practices and games.

Referees are present not only to keep the flow of the game going but to protect the players from hurting themselves and others. Referees, for the most part, are objective and have the authority to suspend any activity should an emergency condition arise. As with all competitive sports, emotion and adrenaline are flowing high; the referees are present to help the players harness these energies in a positive fashion.

Proper conditioning, warm-up and stretching prior to engaging in any competitive activity is vital to the prevention of strains and sprains. This procedure enables the muscles to perform at peak efficiency and minimizes the possibilities of strains and sprains (micro-tears). Warm-ups may very well be a simple jog or callisthenics for about 3 to 5 minutes followed by gentle stretching out of the extremities for an additional 5 to 10 minutes. With the muscle at its peak efficiency, the athlete may be able to quickly manoeuvre away from a threatening position.

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