2-33. HEPATITIS
Hepatitis is a disease caused by a virus that damages the liver. In severe cases,
liver necrosis (death of tissue) is common. The two types of distinguishable hepatitis
are infectious hepatitis (Type A) and serum hepatitis (Type B). Infectious hepatitis is
usually spread by fecal contamination of food or drink. It has an incubation period of
about 30 days. Serum hepatitis can be spread by punctures of the tissue with needles
and dental scalers that have come in contact with contaminated blood or serum. It has
a much longer incubation period (perhaps several months) than infectious hepatitis.
The risk of infection is greater between patients than between patient and dental
specialist. All dental specialists should be tested and immunized against Type B
hepatitis if they are not already immune.
2-34. TUBERCULOSIS
Tuberculosis is caused by a nonsporeforming bacillus bacteria, Mycobacterium
tuberculosis. Cross-infection most likely occurs by droplet transmission. Active
tuberculosis infects the individual with a virulent (a strong disease-causing organism)
strain of bacteria that the patient cannot ward off by natural means. Inactive
tuberculosis occurs when the bacteria are walled off by the fibrous tissue. Even though
the Tine and the Mantoux tests detect the presence of circulating antibodies, these tests
do not tell whether the infection is active or inactive. A positive test result merely
indicates either a present or previous infection with the tuberculous bacteria. A positive
test result should always be reported to the dental or medical officer. Tuberculosis of
the oral mucosa occurs if wounds or erosions become infected by tubercle bacilli
contained in the sputum. The oral lesions vary greatly in their appearance. The tongue
is the most frequent site for these lesions. Antibiotics are effective in the treatment of
certain types of tuberculosis. However, multi-drug resistant strains have been
discovered recently. Outbreaks of tuberculosis have occurred in areas with a high HIV
population.
2-35. ACQUIRED IMMUNODEFICIENCY SYNDROME
Acquired immunodeficiency syndrome (AIDS) is a severe condition caused by
infection with the human immunodeficiency virus (HIV). Infected patients may have a
variety of manifestations ranging from no symptoms at all to severe immunodeficiency
and life-threatening secondary infectious diseases. There are three stages to this
disease--asymptomatic infection HIV, AIDS-related complex (ARC), and AIDS. The
serum test for the HIV antibody is not necessarily "positive" in all three stages of HIV
infection. In stage one (defined here as infection with HIV), the mean conversion time
to a positive serum antibody test following introduction of the virus is thought to be
about 42 days, but may be longer since the test will not be positive until sufficient
antibodies are present. Therefore, a patient infected with HIV may not show up as HIV
positive even though there is risk of transmission of the virus during an exchange of, or
contact with, infected body fluids. The HIV damages both the immune and the
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