Childhood tuberculosis and its early diagnosis.

Traditional methods for laboratory diagnosis of tuberculosis are unsatisfactory, especially for children, in whose specimens mycobacteria are usually sparse. Recent changes in tuberculosis epidemiology in developed countries, including a large increase in incidence in children from certain ethnic minorities, have prompted interest in newer diagnostic methods. Liquid-based culture detection systems offer improved sensitivity and speed of diagnosis, although the time taken for detection of growth is still upwards of 1 week. Nucleic acid amplification techniques offer more rapid results, but perform best on smear-positive samples; sensitivities may be as low as 50% in smear-negative specimens. Although these newer techniques are widely used in some developed countries, in others, they are not perceived as offering sufficient benefit to justify their routine use. The diagnostic accuracy of mycobacteriophage and serologic methods is insufficient to justify their wide use even in developing countries. Despite recent developments, there is still no panacea for diagnosis of childhood tuberculosis.