0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22
1460 Tuberculosisand arthritis (chronic, monoarticular, involving large, weight bear-
ing joints); genitourinary – renal (back pain, fever, dysuria), prostate,
epididymis, endometrium, ovaries; gastrointestinal – small bowel,
particularly ileocecal area (fever, pain, diarrhea, obstruction), but
colon, duodenum, stomach, liver and peritoneum (fever, weight loss,
abdominal pain over several weeks) can also be involved; pericardi-
tis (acute presentation with tamponade or chronic constrictive with
shortness of breath, pleural effusions, ascites)tests
■Definitive diagnosis made by culturingM. tuberculosisfrom invol-
ved tissue; growth on solid media in 6–8 weeks; radiometric media
(Bactec) positive in 1–2 weeks depending on inoculum
■Pulmonary – 3 sputums on successive days; sputum induction or
bronchoscopy may be needed if cough nonproductive; early morn-
ing gastric aspirate and blood cultures (up to15% positive) may be
helpful; direct nucleic amplification test on sputum of smear nega-
tive cases, with high or intermediate likelihood of disease, has sen-
sitivity of 40–70%
■Extra-pulmonary – must obtain tissue or fluid for culture; negative
culture does not exclude disease; pleural, peritoneal, pericardial,
joint and cerebrospinal fluids positive in only 25–50% of cases; pres-
ence of granulomas suggestive, but not diagnostic, of M. tuberculo-
sis (non-tuberculous mycobacteria, fungi, other bacteria also cause
granulomas)
■Chest x-ray in primary tuberculosis usually shows infiltrate in upper
lobes, hilar and/or paratracheal adenopathy; pleural effusion less
common; in reactivation tuberculosis nodular infiltrates or cavities
in the posterior segment or the upper lobe or superior segment or
lower lobe in 70%; infiltrates in other areas in 30%
■Infected tuberculous fluid classically exudative with lymphocytic
predominance and low glucose, but great deal of variability
exits
■Tuberculin skin test (PPD) positive in 75% with active infection; neg-
ative test does not exclude disease; positive test may reflect previous,
inactive disease
Latent TB infection (LTBI) previously diagnosed by PPD. Now, whole
blood interferon-gamma assays are available that require only one visit
and are not subject to reader interpretation. Not yet validated in all
groups.