Serological screening for tuberculosis in the community: an evaluation of the Mycodot procedure in an African population with high HIV-2 prevalence (Republic of Guinea-Bissau)

ABSTRACT

The immuno-dot-blot assay MycoDot, which detects lipoarabinomannan (LAM) antibodies, was evaluated for the serological diagnosis of active pulmonary tuberculosis in patients in a rural community in the Republic of Guinea-Bissau. Sera from 269 adults (age > 15) and 33 children (age < 5) were assayed for antibodies in a blind manner and the results compared to the clinical status of tuberculosis. The assay had a specificity and a sensitivity of 92.4 per cent and 63.0 per cent respectively, when applied to the adult population. In HIV-2 infected individuals (27/269), the specificity and sensitivity of the assay were similar, 94.7 per cent and 62.5 per cent respectively. The assay did not provide high sensitivity for the diagnosis of tuberculosis in children. Sera from patients with leprosy cross-reacted with the antigen of the assay. It is concluded that this easily performed assay may be useful for the presumptive diagnosis of tuberculosis in adult populations in rural areas of developing countries where routine screening is not readily available.