Bloodborne pathogens and sports

INTRODUCTION — The bloodborne pathogens of greatest concern for potential transmission during sporting competition include human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). The epidemiology of these pathogens in sport, prevention of bloodborne infection in sport, and the screening and management of such infections in athletes are reviewed below. The diagnosis and management of specific bloodborne infections are reviewed separately. (See "Management of nonoccupational exposures to HIV and hepatitis B and C in adults" and "Epidemiology, transmission, and prevention of hepatitis B virus infection" and "Epidemiology and transmission of hepatitis C virus infection".)

EPIDEMIOLOGY AND TRANSMISSION RISK

Overall risk — The transmission of bloodborne infections during sport is rare [1]. Bloodborne pathogens of concern for potential transmission in sport include human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). All three may cause symptomatic or asymptomatic acute infections. Once contracted, HIV is a lifelong illness, but the disease can be well controlled with medication and proper medical care. Acute HBV and HCV infections may spontaneously clear, but a variable number of individuals go on to develop chronic infection and remain infectious to others. (See "Acute and early HIV infection: Clinical manifestations and diagnosis" and "The natural history and clinical features of HIV infection in adults and adolescents" and "Epidemiology, transmission, and prevention of hepatitis B virus infection" and "Hepatitis B virus: Overview of management" and "Epidemiology and transmission of hepatitis C virus infection" and "Overview of the management of chronic hepatitis C virus infection".)

There is a theoretical risk of bloodborne infections being transmitted during sports from the bleeding or exudative skin wounds of an infected athlete to other athletes via injured skin or mucous membranes. Although data is limited, the general consensus is that the likelihood of such transmission is extremely low [1-4]. Combative sports (eg, boxing, mixed martial arts) represent the highest theoretical risk, because of the higher rates of bleeding injuries and prolonged close-body contact [5]. Although not the equivalent of sanctioned combative sports, such as boxing and mixed martial arts, street fights entail a risk of HIV and HCV transmission, as documented in case reports [6-8]. HBV transmission has been documented in Japan in five members of a high school sumo wrestling club [9].

The prevalence of bloodborne pathogens among athletes has not been studied extensively. A 1995 study evaluated the prevalence of HBV infection among South Australian football (soccer) players and found no difference with a group of blood donors of the same age [10]. A 2008 study examined the prevalence of HCV among 208 former professional and amateur Brazilian football (soccer) and basketball players and reported an overall prevalence of 7.2 percent, with values of 11 percent among professionals and 5.5 percent among amateurs [11]. The study found a close correlation between the use of injectable stimulants and HCV infection rates. Athletes who did not inject such drugs had a prevalence of only 0.6 percent, suggesting that sport participation itself had little to do with the relatively high overall prevalence rates. A 2011 study involving 420 male wrestlers and 205 volleyball and soccer players found no evidence that participation in wrestling entailed higher rates of HBV or HCV transmission compared with low- to moderate-contact sports [12].

HIV transmission in sports — There are no well-documented, confirmed reports of HIV transmission during sport. The theoretical risk for transmission of HIV during National Football League (NFL) matches has been calculated to be less than 1 per 85 million game contacts [13]. This estimate was calculated using the following data: (a) estimated prevalence of HIV among athletes; (b) risk of percutaneous HIV transmission in health care; and (c) risk of a bleeding injury in American football. However, this calculation may overestimate the risk because it involves extrapolation from reports of needlestick injuries, which are likely to pose a much greater risk than sport-related skin injuries [14]. Although not the equivalent of sanctioned combative sports such as boxing and mixed martial arts, street fights entail a risk of HIV transmission, as documented in case reports [6,7]. Of note, transmission risk is lower if the HIV-infected athlete is being treated. (See "HIV infection: Risk factors and prevention strategies".)

Hepatitis B virus transmission in sports — HBV transmission has been adequately documented in Japan in five members of a high school sumo wrestling club [9] and in 11 members of a Japanese university American football team [15]. In addition, over a six-year period, a cluster of 568 cases of HBV infection was documented in Swedish cross country track finders (a type of orienteering) [16]. Transmission was thought to occur from skin wounds, as many track finders had scratches and skin lacerations, but regulations requiring that participants wear protective clothing (eg, long sleeves and pants) did not prevent a subsequent outbreak. Morbidity and mortality from these cases of HBV is unknown.

The concentration of HBV in blood is higher than HIV. In addition, HBV is resistant to drying, ambient temperatures, simple detergents, and alcohol, and can remain stable on environmental surfaces for at least seven days [17]. Hence, transmission of HBV can occur via inanimate objects and the risk of HBV transmission during sport is greater than that of HIV, assuming the population participating has not been immunized against HBV. There are no published estimates of the risk of HBV transmission during sport, but extrapolation from NFL-based reports gives an estimate of one transmission in every 850,000 to 4.25 million game contacts [18].

Hepatitis C virus transmission in sports — There are no reports of HCV transmission due to sports participation. HCV transmission has been documented after a bloody fight, but again, such activity is not the equivalent of sanctioned combative sports [8]. No published estimates of theoretical risk of HCV transmission in sports have been published.

Other pathogens — No other common pathogens are of concern for direct transmission during sport. Malaria and Zika, while important infections to protect against during athletic competition in particular regions, are not transmitted through the type of person-to-person contact that occurs in sport. (See "Prevention of malaria infection in travelers" and "Zika virus infection: An overview", section on 'Prevention'.)

PREVENTION OF TRANSMISSION OF BLOODBORNE PATHOGENS IN THE ATHLETIC SETTING — Although the risk of transmission for any bloodborne pathogen in the athletic setting is extremely small, standard precautions (previously known as “universal precautions”) should be followed by anyone providing care to athletes, and wounds and playing surfaces should be managed appropriately [19,20]. All personnel who may care for injured or bleeding athletes should be properly trained in first aid and standard precautions. Standard precautions are discussed in detail separately. (See "Infection prevention: Precautions for preventing transmission of infection".)

The following guidelines, adapted from a handbook published by the National Collegiate Athletic Association (NCAA) of the United States, are based on expert opinion but are reasonable for use (with modifications as necessary) in any sports setting to help protect against the transmission of bloodborne pathogens to competitors and caretakers:

Equipment and care providers

●All necessary equipment and supplies for treating injured and bleeding athletes should be prepared in advance and readily available to the clinicians providing care. Equipment for managing open wounds and contaminated playing surfaces should include the following:

•Personal protective equipment (PPE): minimal protection includes gloves, goggles, mask, and fluid-resistant gown if there is a chance of splash or splatter

•Antiseptic solutions for cleaning wounds

•Antimicrobial wipes

•Bandages, dressings and all material needed to apply them (eg, tape, scissors, athletic sleeves or mesh to cover bandages)

•Additional medical equipment needed for treatment (eg, topical antibiotic ointment)

•Antiseptic cleaning solutions for contaminated surfaces (eg, appropriately diluted bleach)

•Towels and cloths for cleaning contaminated surfaces

•Appropriate disposal container for “sharps” (eg, needles, syringes, scalpels) that is appropriately labeled

•Waste receptacles appropriate for soiled equipment, uniforms, towels, and other waste

●Personnel managing an acute blood exposure should follow standard precautions and presume all blood is infectious. Gloves (and other PPE as necessary) should be worn for direct contact with blood or other body fluids. However, emergency care should not be delayed if gloves are not immediately available—a bulky towel can be used to cover the wound, with the athlete themselves applying pressure until gloves can be obtained. Gloves should be changed after treating each individual. After removing gloves, caretakers should wash their hands.

●All needles, syringes, or scalpels should be carefully disposed of in an appropriately labeled “sharps” container. Medical equipment, bandages, dressings and other waste should be disposed of according to a written protocol. The specifics of such protocols will vary according to local resources, but important concepts remain consistent [21]. The key components of such a protocol include the following:

•Review of standard precautions

•Use of appropriate personal protective equipment

•Identification of potential infectious waste

•Collection of infectious waste in appropriate containers

•Transportation of infectious waste to an appropriate disposal facility

During events, bloody uniforms or other contaminated linens should be disposed of in a designated container to prevent contamination of other items or personnel. At the end of competition, such linen should be laundered and dried according to appropriate protocol; hot water at temperatures of at least 71°C (160°F) for 25-minute cycles should be used.

Care of the athlete

●Preparations before training or competition – Pre-event preparation includes proper care of preexisting wounds, abrasions, or cuts that may be a source of bleeding or a port of entry for bloodborne pathogens or other infectious organisms. These wounds should be covered with an occlusive dressing that will withstand the demands of competition [20]. Likewise, care providers with healing wounds or dermatitis should have these areas adequately covered to prevent transmission to or from a participant. Athletes may be advised to wear more protective equipment (eg, athletic sleeve) on high-risk areas, such as elbows and hands.

The bandage covering any open wound or pre-existing exudative skin lesion must have an outer layer(s) that are impermeable (eg, to other fluids), impenetrable (ie, not easily punctured), and unremovable (so-called IIU principle), given the likely forces applied and equipment used with a given sport. Athletic trainers or their equivalent are best qualified to create bandages that meet these requirements. A variety of products are available to meet these needs; however, the most common materials at hand that can achieve these goals easily and inexpensively are thick layers of plastic, such as from a biohazard bag, covered by duct tape applied to both the plastic cover and the athlete’s skin.

A number of effective techniques may be used to secure bandages. One reasonable approach involves using four layers as follows (picture 1):

•First layer – Non-adherent wound cover (eg, Telfa pad)

•Second layer – Absorbent pad (eg, standard gauze)

•Third layer – Occlusive, impermeable cover (eg, plastic bag/biohazard bag material)

•Fourth layer – Self-adherent, water and sweat-resistant tape (eg, Coban or Powerflex tape)

If specialized tapes are not available for the fourth (external) layer, duct tape may be used, although it is not ideal for skin perhaps. Any skin irritation caused by duct tape can be treated symptomatically following the event.

●Management of injuries sustained during training or competition – For injuries sustained during competition, bleeding must be stopped and any open wound covered with a dressing sturdy enough to withstand the demands of activity before an athlete may continue participating in practice or competition. The methods for applying such bandages are the same as those used prior to sporting events to prevent exposure. Participants with active bleeding should be removed from an event as soon as the injury is recognized. Athletes should report a bleeding wound to trainers or medical personnel immediately. Return to play is determined by appropriate medical staff and sport officials. Any participant whose uniform is partly or completely saturated with blood must change the uniform before returning to play.

Different sports have added rules to accommodate bleeding athletes in order to minimize interruptions to the contest and to avoid penalizing teams for acting safely to reduce the risk of transmitting infection. As an example, there are rules for “blood time” in wrestling: any contestant who is bleeding is charged with “blood time” (a modification of a standard time-out; time-outs for injuries not involving bleeding are limited in number) [22-24]. The number of blood timeouts is left to the discretion of the referee. The total time allotted may be limited in some settings (eg, 5 minutes in American high schools) but is left to the discretion of the official at the college and international levels. The time needed to clean surfaces and equipment is not counted against any limits. In football (ie, soccer), law 5 of the FIFA laws of the game states that any player bleeding from a wound must leave the field of play and may not return until the referee is satisfied that the bleeding has stopped [25]. There is no specified time limit on treatment and a player is not permitted to wear clothing with blood on it.

●Management of exposed but uninjured athlete – If blood or body fluids are transferred from an injured or bleeding athlete to the intact skin of another athlete, the event must be stopped, the skin cleaned with antimicrobial wipes to remove gross contaminate, and the athlete instructed to wash with soap and water as soon as possible. Chemical germicides intended for use on environmental surfaces should never be used on athletes’ skin. If the exposure involves exposure non-intact skin, eyes, mouth, mucous membranes, or parenterally (under the skin), standard post-exposure procedures should be followed. (See "Prevention of hepatitis B virus and hepatitis C virus infection among health care providers", section on 'Wound care' and "Management of health care personnel exposed to HIV", section on 'Initial actions following exposure'.)

●Follow-up care – In addition to the care provided at the time of injury or exposure, athletes should be provided with appropriate follow-up as indicated. Following any incident in which an athlete is exposed to blood or other potentially infectious materials on non-intact skin, eyes, mouth, mucous membranes, or parenterally (under the skin), the athlete should have a proper medical evaluation as part of their follow-up. Information about post-exposure counseling and prophylaxis can be found in several UpToDate topics. (See "Management of nonoccupational exposures to HIV and hepatitis B and C in adults" and "Prevention of hepatitis B virus and hepatitis C virus infection among health care providers", section on 'Post-exposure management'.)

Disinfecting playing surfaces — The regulations for nearly all sports stipulate that playing surfaces contaminated by blood or other body fluids be cleaned before play is resumed. The following steps should be observed when cleaning playing surfaces and equipment [26].

●All individuals responsible for cleaning and disinfection of blood spills or other potentially infectious materials (OPIM) should be properly trained on procedures and the use of standard precautions.

●Supplies necessary for cleaning and disinfecting hard surfaces contaminated by blood or OPIM should be assembled in advance and readily available during sporting events. Items should include PPE (as described above), supply of absorbent paper towels or disposable cloths, red plastic bags with the biohazard symbol or other appropriate waste receptacles according to facility protocol, and properly diluted tuberculocidal disinfectant or freshly prepared bleach solution diluted (1:100 bleach/water ratio).

As most spills of blood and other bodily fluids at athletic events are relatively small, a 1:100 ratio of bleach to water is used; in the rare event of a large blood spill (eg, hockey skate lacerates an artery), a 1:10 ratio of bleach to water would be appropriate.

●Management of contaminated surfaces includes the following steps:

•Individuals cleaning surfaces don disposable gloves.

•Visible organic material (eg, blood) is removed by covering with paper towels or disposable cloths. Soiled towels or cloths are placed in an appropriate waste receptacle according to facility protocol. Additional towels or cloths are used to remove as much organic material as possible from the surface and placed in the waste receptacle.

•Contaminated surfaces are sprayed or washed with a properly diluted chemical germicide used according to the manufacturer’s instructions for disinfection and then wiped clean. A properly diluted tuberculocidal chemical germicide or freshly prepared bleach solution diluted 1:100 is suitable. Soiled towels are placed in a waste receptacle.

•Cleaners remove gloves and wash their hands.

•Dispose of waste according to facility protocol or relevant state regulations. In the United States, guidelines promulgated by the Occupational Safety and Health Administration (OSHA) and the Centers for Disease Control and Prevention (CDC) are appropriate [20].

Other steps and vaccinations — It is reasonable (and reassuring to athletes and the general public) that all bleeding in the athletic setting be treated carefully and with appropriate regard for safety [5]. Given reports of the transmission of bloodborne pathogens during bloody fights in the non-sports setting, rules forbidding activities such as biting, scratching, punching, or other unsportsmanlike conduct that may lead to bloody contact should be strictly enforced. (It is recognized by the author that punching is obviously a part of combative sports, such as boxing and mixed martial arts.)

The hepatitis B vaccine is highly effective and many countries provide universal neonatal HBV vaccination. For athletes not already vaccinated, we recommend that those participating in sports associated with a relatively higher risk for transmission of bloodborne pathogens (eg, boxing, wrestling) receive the HBV vaccination. However, no major sporting organization requires vaccination. (See "Hepatitis B virus immunization in adults".)

SCREENING — The consensus among published guidelines is that athletes do not require routine testing for bloodborne pathogens [1]. We concur. No major sports or health organization, including the International Olympic Committee (IOC), International Federation for Sports Medicine (FIMS), World Health Organization (WHO), Fédération Internationale de Football Association (FIFA), United States Centers for Disease Control (CDC), Canadian Academy of Sport and Exercise Medicine (CASEM), American College of Sports Medicine (ACSM), National Collegiate Athletic Association (NCAA), National Basketball Association (NBA), National Football League (NFL), Major League Baseball (MLB), and National Hockey League (NHL), recommends routine screening, whether mandatory or voluntary, for bloodborne pathogens among athletic participants [1-4,20].

Voluntary testing for athletes and non-athletes alike should be encouraged when appropriate according to public health guidelines. Any testing should be conducted by certified testing facilities, provide comprehensive pre- and post-test counseling, and help patients gain access to appropriate healthcare if testing is positive [27-31].

Despite universal recommendations against routine mandatory testing, some organizations that oversee combative sports involving close physical contact and increased risk of blood exposure, such as boxing, wrestling, and mixed martial arts, have required athletes to participate in preparticipation testing for bloodborne pathogens. Such organizations include the International Federation of Associated Wrestling Styles, International Boxing Federation, International Amateur Boxing Association, Association of Ringside Physicians, and various state boxing commissions in the United States [5,32]. According to some organizations, athletes who test positive for HIV, HBV, or HCV may not participate in competitive bouts.

MANAGEMENT — Athletes with acute infections who are symptomatic (eg, febrile, lethargic) or whose health is compromised (eg, weak, dehydrated, malnourished, significantly immunocompromised) should not engage in intense exercise or sport. Appropriate treatment and recovery from the acute illness is necessary before an athlete may return to play. In addition, athletes with active secondary organ damage from an infection (eg, hepatic or splenic enlargement, impaired renal function, cardiomyopathy) should not participate in intense exercise or sport. Once such damage has resolved, the athlete should be reassessed before returning to play.

Athletes infected with HIV, HBV, or HCV who remain asymptomatic and in good general health without evidence of immunologic deficiencies can exercise without restrictions and in most cases may participate in athletic competition without restrictions or modifications [1,33]. However, there are some exceptions, primarily involving combative sports. As an example, the National Collegiate Athletic Association (NCAA) suggests that any athlete who develops a chronic HBV infection and is e-antigen positive should be removed indefinitely from competition and practice of combative sports involving sustained close-contact (ie, wrestling in the case of the NCAA) due to the small but realistic risk of transmitting the disease [20]. We believe this approach is reasonable when such chronic infectious states (eg, chronic HBV infection with e-antigen positive) come to light as part of a standard medical work up for suspected illness; we do not believe routine screening is needed for asymptomatic athletes including those involved in combative sports. It is worth emphasizing here that standard precautions against the transmission of infectious disease should be followed by all athletes in all competitions. (See 'Screening' above and 'Prevention of transmission of bloodborne pathogens in the athletic setting' above.)

Despite the statements of multiple international sports organizations and the exceedingly rare instances of documented transmission of bloodborne infection during sport, several regulatory bodies that oversee combative sports, such as boxing and mixed martial arts, require athletes to participate in preparticipation testing for bloodborne pathogens and athletes who test positive are prohibited from competition. Such organizations include the International Federation of Associated Wrestling Styles, International Boxing Federation, International Amateur Boxing Association, Association of Ringside Physicians, and various state boxing commissions in the United States [5].

Athletes with a known bloodborne infection and an open wound may participate in practice and competition provided the wound is completely covered with a bandage sufficiently secure to withstand the rigors of the sport in question. This holds true for all sports, although no practice guidelines are available for any sport. No medications are recommended specifically to reduce the risk of transmission during sport, but appropriate treatment is recommended and the general risk of transmission is reduced among patients with HIV who are receiving treatment. (See 'Care of the athlete' above and "HIV infection: Risk factors and prevention strategies".)

Athletes infected with bloodborne pathogens should be under the care of physicians with appropriate expertise; newly infected athletes should receive appropriate counseling. Athletes receiving treatment for such infections are not restricted from participation provided the treatment is not causing problematic side effects, such as dizziness or weakness. The management of these infections is continually changing and the reader is referred to the UpToDate topics concerning specific diseases. (See "Acute and early HIV infection: Treatment" and "Primary care of adults with HIV" and "Hepatitis B virus: Overview of management" and "Overview of the management of chronic hepatitis C virus infection".)

There is no evidence that exercise and training of moderate intensity are harmful to the health of athletes infected with bloodborne pathogens [20,33,34]. What little data exist on the effects of intense training on such athletes shows no evidence of health risks. However, no studies have investigated the effects of long-term intense training and competition at an elite level on the health of HIV-, HBV-, or HCV-infected athletes. Likewise, there is no evidence that particular medications or other treatments may reduce any theoretical risks posed to infected athletes by intense training. Monitoring of such athletes is prudent until the results of relevant studies are available.

SUMMARY AND RECOMMENDATIONS

●Pathogens – Bloodborne pathogens of concern for potential transmission during sporting competition include human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV); however, the transmission of bloodborne infections during sport is rare. There are no well-documented, confirmed reports of HIV or HCV transmission during sport. (See 'Epidemiology and transmission risk' above.)

●Prevention and management of exposures – Although the risk of transmission for any bloodborne pathogen in the athletic setting is extremely small, standard precautions (previously known as “universal precautions”) should be followed by anyone providing care to athletes, and wounds and playing surfaces should be managed appropriately whenever contamination (eg, blood) occurs. The basic steps for standard precautions, care of athletes with open wounds, and disinfection of playing surfaces are reviewed in the text. (See 'Prevention of transmission of bloodborne pathogens in the athletic setting' above.)

●Screening for infection – The consensus among prominent international sports and health organizations is that athletes do not require routine testing for bloodborne pathogens. We concur with this approach. Nevertheless, some regulatory bodies for combative sports (eg, boxing, mixed martial arts) require screening of participants. (See 'Screening' above.)

●Management of infected athletes – Published evidence about the risks and appropriate care of infected athletes is scant, but based on the available evidence and our clinical experience, we suggest the following guidelines for athletes infected with bloodborne pathogens:

•Athletes with acute infections who are symptomatic (eg, febrile, lethargic) or whose health is compromised (eg, weak, dehydrated, malnourished, significantly immunocompromised) should not engage in intense exercise or sport.

•Athletes with active secondary organ damage from an infection (eg, hepatic or splenic enlargement, impaired renal function, cardiomyopathy) should not participate in intense exercise or sport.

•Athletes who remain asymptomatic and in good general health without evidence of immunologic deficiencies can exercise without restrictions and in most cases may participate in athletic competition without restrictions or modifications.

•Athletes with a known bloodborne infection and an open wound may participate in practice and competition provided the wound is completely covered with a bandage sufficiently secure to withstand the rigors of the sport in question.

•Any athlete who develops a chronic HBV infection and is e-antigen positive should be removed indefinitely from competition and practice of combative sports. (See 'Management' above.)

●Exercise for infected, asymptomatic athletes – Exercise and training do not appear to be harmful to the health of asymptomatic athletes infected with bloodborne pathogens. However, information about the effects of long-term, intense training on infected athletes is limited and we suggest that such athletes be monitored regularly.