ABC of Sports Medicine: Infections in sport

Herpes gladiatorum (“scrumpox”)

This condition caused by the herpes simplex virus is one of the most contagious of all infections, and outbreaks in sports clubs are common. Scrumpox is traditionally associated with rugby football; the presence of skin lesions combined with the abrasive effects of facial stubble while scrumming facilitate transmission of infection. Other causal combat sports include judo and wrestling. Infection may also be spread readily by sharing towels or equipment.

Treatment requires the use of acyclovir, a specific antiviral available as a cream or tablets. Prevention depends on maintaining high standards of personal hygiene and excluding infected players until successfully treated.

Scrumpox may also be due to bacteria (streptococci or staphylococci) or fungi (Trichophyton or Microsporum). Impetigenous forms of scrumpox are due to Streptococcus pyogenes or Staphylococcus aureus; erysipelas, the least common form, is potentially the most serious, with treatment requiring the use of antibiotics; tinea barbae spreads similarly to other forms of scrumpox, requiring treatment with fungicidal creams or tablets.

Tetanus

Of all sport related infections, tetanus is potentially the most serious. Infection is caused by Clostridium tetani, the spores of which may frequently contaminate sports fields. Penetrating or “dirty” wounds facilitate bacterial growth and the production of neurotoxin. In Scotland within the past few years two rugby players and one soccer player developed tetanus from cuts acquired during play; only one of them survived. Treatment, other than for milder cases, requires intensive care providing sedation using curare-like drugs and life support facilities. Administration of antitoxin (specific antitetanus immunoglobulin) is necessary to neutralise any unbound toxin present, and penicillin is usually also required to eliminate any live bacteria capable of producing further toxin.

All wounds that are deep or dirty require early prophylactic treatment with thorough cleaning and debridement where necessary, complemented by penicillin and tetanus toxoid or antitoxin, depending on the immunisation status of the individual. Tetanus is readily preventable by active immunisation, with boosting doses recommended at 10 year intervals. For rugby and soccer players and other athletes, however, who may be exposed frequently to potentially contaminated outdoor surfaces, boosters every five years should be considered while they are still participating actively.

Other wound infections

Any wound or abrasion may be infected by a range of bacteria (for example, Staphylococcus, Streptococcus, Pseudonomas), which may be present in the playing arena or changing room, on clothing or equipment, on the skin, or in the respiratory tract of otherwise healthy carriers.

Water related infections

Water sports can pose infection hazards to various body sites or organs such as the eye (conjunctivitis, acanthamoebic keratitis), ear (otitis externa), skin (folliculitis), intestine (giardiasis, cryptosporidiosis), liver or kidneys (leptospirosis), or lungs (legionellosis), particularly if played in natural or unchlorinated waters.

Vector borne infections

Bites of insects (such as ticks, mosquitos, etc) may cause a range of diseases in areas where Lyme disease, malaria, and other vector borne infections such as tick borne encephalitis, yellow fever, or Japanese B encephalitis are prevalent. Cross country runners and orienteers may be particularly vulnerable. Lyme disease is caused by Borrelia burgdorferi acquired via bites from infected ticks of the Ixodes spp, occurs worldwide including Europe and the British Isles, and was originally identified in the United States where I dammini was the main vector. I ricinus ticks are widespread throughout the British Isles, particularly in woodland and bracken covered areas of the Scottish highlands, Wales, East Anglia, and the New Forest, where cases of Lyme disease have been reported.

In changing rooms

The shower and bathing areas of changing rooms, where athletes are crowded in a warm, moist atmosphere, are highly conducive to the transmission of a wide range of respiratory infections (influenza, sore throats) and fungal infections (tinea pedis, etc) or verrucas. Though most of such infections are merely nuisances, influenza not only incapacitates one person but can spread readily to fellow athletes, affecting performance and causing depletion of teams or cancellation of events. In addition, in a mistaken attempt to compete or to “not let the side down,” affected athletes may try to “run off” their flu, the effects of which may be counterproductive to the team and potentially dangerous to the individual.

The damaging effects of certain viral infections on cardiac muscle is well recognised. Influenza type A virus has been isolated from the myocardium of people who died after flu-like illnesses, and its effects on the metabolism of heart muscle has been shown experimentally in mice. Myocarditis caused by Chlamydia pneumoniae (TWAR (Taiwan acute respiratory disease) agent) was shown to have caused sudden death in an elite Swedish orienteer. Other microorganisms, particularly enteroviruses (coxsackieviruses A and B, echovirus), parainfluenza virus, cytomegalovirus, and Mycoplasma pneumoniae and bacteria such as Streptococcus group A and B burgdorferi, are also known for their myocardiopathic effects.

The longer term debilitating effects of some viral infections such as influenza, measles, chickenpox, infectious mononucleosis, and the coxsackievirus group of enteroviruses have become recognised as being associated with the chronic fatigue syndrome. Particular attention has been given to the Epstein-Barr virus and the coxsackievirus group, both of which are known to affect muscle and nerve tissue.

The expansion of air travel has made accessible more countries worldwide in which a myriad of infections no longer present in Europe are still prevalent. Only smallpox has been eradicated on a global basis. The most common problems likely to be encountered outside western Europe, North America, and Australasia are gastrointestinal infections (“travellers' diarrhoea,” salmonellosis, dysentery), viral hepatitis A, etc. In addition, the potential of contracting poliomyelitis in developing countries should not be underestimated.

During travel abroad

Despite intensive efforts towards eradication, malaria has been increasing in recent years in Africa, Asia, and South and Central America in parallel with resistance of the mosquito vector to insecticides. In areas of South East Asia, South America, and Africa, strains of Plasmodium falciparum have developed resistance to chloroquine and other drugs, presenting further problems in prophylaxis and treatment.

Respiratory illnesses are also particularly common among air travellers (who are exposed to airborne infection in crowded aircraft, airport terminal buildings, or hotels) and are compounded by the dehydrating effects of the low humidity in aircraft.

Relaxing in or around a swimming pool or whirlpool may result in exposure to a range of environmentally acquired diseases, particularly respiratory or fungal infections. Other leisure time activities may result in a sexually transmitted disease. Of these both hepatitis B and HIV infection have the potential of being acquired through any one of sport related situations, although the relative risks vary from very low while actively participating in sport to increasingly likely as a consequence of some leisure time activities.

Hepatitis B virus (HBV)

Infection is most usually acquired through contact with infected blood (via shared needles, needlestick injuries, etc) or by sexual spread from a carrier of the disease. Chronic carriers, detectable by the presence of hepatitis B surface antigen in their blood, rarely have a recognisable illness yet they can remain infectious for many years. The main emphasis in sport is on improving overall hygiene standards rather than imposing undue restrictions on known HBV carriers. Such people need not categorically be excluded from participating in sport. Injuries, cuts, or grazes that bleed are nevertheless potential sources of infection and should be cleaned and securely covered immediately.

The risk of acquiring hepatitis B during sporting activities is small, but infection via contaminated thorn-pricks during orienteering events and among barefoot runners has been reported.

HIV infection

Although considerably less readily transmissible, the modes of acquiring HIV are virtually identical to those of HBV. In the United States, HIV antibody testing is mandatory in some states for all boxers, while in other states ringside “seconds” are required to wear plastic gloves.

Several instances of direct bloodborne person to person spread of HIV infection within families have been reported in the United States. While the risk of acquiring HIV infection is low, seroconversion was reported from Italy in 1990 in a previously healthy soccer player with no admitted risk factors, whose head had collided with an opponent's (an injecting drug user known to be HIV positive), resulting in both players bleeding copiously.

With this one apparent exception, there remains to date no evidence worldwide of the transmission of either HIV or HBV infection while participating in sport. Cuts or abrasions during sporting activity clearly require immediate attention and bleeding to be controlled before players return to the field of play. In rugby union, the laws of the game require that “a player who has an open or bleeding wound must leave the field of play until such time as the bleeding is controlled and the wound covered or dressed,” with a temporary replacement being permitted. More recently, the International Rugby Football Board has prepared guidelines specific to bloodborne infections and contact sports.

Preventive measures

A wide range of prophylactic measures (vaccines, toxoids, immunoglobulin, antimalarial drugs, etc) are available against many infections. Most athletes nowadays should have had a basic course of tetanus toxoid in childhood, with booster doses at regular intervals to maintain effective immunity. Influenza vaccines should also be considered, although immunity is poorly maintained and repeat doses are required frequently.

Specific advice on prophylaxis, in particular against malaria, is always necessary for overseas travel outside western Europe, North America, and Australia. Vaccines are available against typhoid, hepatitis A, and hepatitis B infections and should be considered for athletes competing in areas of the world (South America, Africa, the Far East, etc) where disease is endemic. Cholera vaccine, however, is now regarded as being ineffective in providing adequate protection. Vaccines are also available for some vector borne infections such as yellow fever (tropical Africa and South America), Japanese B encephalitis (Far East), and tick borne encephalitis (central Europe, some areas of Scandinavia) but may not always be necessary for short stay visitors or at certain altitudes or seasons of the year. There is no vaccine for Lyme disease, and the value of protective clothing and repellent creams in preventing insect bites generally cannot be overstated.

Preventing infection in sport depends on many factors, among which maintaining good standards of personal and environmental hygiene are of paramount importance. Showering is always preferable to communal baths. Buckets and sponges are no longer acceptable and should be replaced by disposable wipes.

In recent years excellent guidelines on hygiene in sport for athletes have been produced by various organisations in the United Kingdom, including the Sports Council of Wales, the Scottish Sports Council, and the Health Education Authority. The Scottish Sports Council has also prepared a more comprehensive review entitled “Infections and sports.”

Recommended further reading

G R McLatchie, ed. Essentials of Sports Medicine. 2nd ed. Edinburgh: Churchill Livingstone, 1993:112-25. E Walker, G Williams, F Raeside, eds. ABC of Healthy Travel. 4th ed. London: BMJ Publishing Group, 1993.

The photograph of a scrum is reproduced with permission of the Glasgow Herald/Evening Times and that of an injured player with permission of Colorsport. The table on prophylaxis against tetanus was adapted from Immunisation Against Infectious Disease. London: HMSO, 1992.

Clark Sharp is consultant epidemiologist at Ruchill Hospital, Glasgow, and honorary medical advisor of the Scottish Rugby Union.

The ABC of Sports Medicine has been edited by Greg McLatchie, visiting professor of sports medicine and surgical sciences at the University of Sunderland, consultant surgeon at Hartlepool General Hospital, and director of the National Sports Medicine Institute, London. This paper has been edited in conjunction with Clyde Williams, professor of sports science at the University of Loughborough.