Sports Medicine: Just the Facts

CHAPTER 103 • THE ATHLETE WITH HIV 603

concentrations in tears, sputum, saliva, and urine but

it is not considered to be highly infectious in these

forms unless they are blood tinged. No HIV has been

found in sweat (LeBlanc, 1993).

• Primary routes of transmission include intimate
  sexual contact; parenteral exposure to blood, blood
  products, or blood containing body fluids; and
  materno-fetal transmission.


• HIV is not transmissible through casual contact,
  swimming pools, mosquitoes, saliva, sweat, tears,
  urine, feces, and inanimate objects (i.e., wrestling
  mats, toilet seats, and sinks) (Dorman, 2000).

DIAGNOSIS

SCREENING TESTS

• HIV antibodies are low or absent in the first few
  weeks of infection. They may not be produced until
  6 weeks after infection and in some instances may not
  be detectable until up to 6 months after infection. This
  is referred to as the “window period.” Therefore, anti-
  body testing following possible exposure is recom-
  mended at 6 weeks, 3 months, 6 months, and 1 year.


• The most commonly used screening test is the
  enzyme-linked immunosorbant assay(ELISA). This
  test can identify HIV antibodies in the blood with a
  sensitivity of up to 99.5% (ELISA tests have also been
  developed to identify HIV antibodies in saliva or
  urine). The specificity of the ELISA test, however, is
  lower and may lead to false positive results.
  Therefore, a positive ELISA must be confirmed with
  further testing.


• In standard laboratories, if the ELISA test is positive
  it is automatically repeated. Two positive ELISA tests
  are routinely then confirmed by the Western Blot test,
  which identifies antibodies to proteins of a specific
  molecular weight. It is only after these confirmatory
  tests are positive that an HIV antibody test should be
  reported as being a positive test.

FOLLOW-UP TESTING

• The viral load test is performed via polymerase chain
  reaction (PCR) or branched DNA (bDNA) testing and
  can detect the HIV virus in the blood. Some viral load
  tests are sensitive enough to detect as few as five or
  less copies of HIV in the blood.


• Although it can be used for diagnostic purposes in
  some instances, the viral load test is commonly used
  in the known HIV positive patient to help assess prog-
  nosis and help manage therapy. It is usually suggested

that a baseline measurement be obtained and then the

test be rechecked within 2–8 weeks of initiating or

changing treatment. It can then be followed every 3–4

months.

•Viral genotype and phenotypic resistance assays can

also help guide specific antiretroviral therapy.

•T-cell tests can identify the CD4 count and the

CD4:CD8 ratio in the blood. This information can be

used to assist with managing treatment and initiating

prophylaxis therapy for opportunistic infections.

ATHLETE SPECIFIC CONCERNS

EFFECTS OF HIV ON THE ATHLETE

EXERCISE AND THEIMMUNERESPONSE

INHEALTHYATHLETES

• According to the theory of psychoneuroimmunology,
  any stress may be capable of altering immune func-
  tion. Exercise is one such stress.


• Immunologic changes with exercise include white
  blood cell (WBC) increases with brisk exercise,
  which may even occur with heavy exertion of only
  30 s. Polymorphonuclear neutrophils(PMNs), mono-
  cytes, lymphocytes, and natural killer cells also
  increase. This increase is caused by increased cardiac
  output; displacement of WBCs from reserve pools in
  the lung, liver, and spleen; and an increase in epi-
  nephrine, which evokes granulocytosis and lympho-
  cytosis. The function of natural killer cells may also
  increase as a result of the release of cytokines during
  exercise. This response falls off if a person becomes
  accustomed to an exercise bout, suggesting that the
  response is the result of stress and not the inherent
  effects of exercise itself.


• The lymphocytosis of exercise is brief and after exer-
  cise the lymphocyte count will fall within 5 min. A
  further delayed fall to below baseline occurs over the
  next hour due to the effects of cortisol, which after
  exercise is no longer opposed by epinephrine. Counts
  return to baseline within 24 h.


• Conversely, a leukocytosis and delayed rise in PMNs
  is mediated by cortisol, which releases PMNs from
  bone marrow. This returns to baseline in about 24 h.
  Strenuous exercise may also evoke an acute phase
  reactant response and activate complement, and
  release tumor necrosis factor, interferons, interleukins,
  and other cytokines (Eichner and Calabrese, 1994).


• Chronic exercise can have a negative effect on immune
  function if there are prolonged periods of intense train-
  ing. Natural killer(NK) cell count and leukocyte func-
  tion has been shown to decline in swimmers and
  runners during periods of intense training. Overtraining