High sensitivity and specificity of acid-fast microscopy for diagnosis of pulmonary tuberculosis in an African population with a high prevalence of human immunodeficiency virus.

Laboratories in low-income countries report that acid-fast microscopy is insensitive and nonspecific. We demonstrate that for a Ugandan population with high prevalences of tuberculosis and human immunodeficiency virus infection, acid-fast microscopy is highly sensitive (93.1%) and specific (100%) when performed by trained technologists in a carefully controlled manner using established techniques.

Polymerase chain reaction of secA1 on sputum or oral wash samples for the diagnosis of pulmonary tuberculosis.

Background: Nucleic acid amplification tests are sensitive and specific for identifying Mycobacterium tuberculosis in sputum smear-positive populations, but they are less sensitive in sputum smear-negative populations. Few studies have assessed their performance among patients infected with HIV, and no studies have assessed their performance with oral wash specimens, which may be easier to obtain than sputum samples.

Methods: We performed a prospective study involving 127 adults from 2 populations who were undergoing evaluation for respiratory complaints at Mulago Hospital in Kampala, Uganda.