Diagnosis of tuberculosis in children using fluorescence microscopic examination of gastric washings

In a clinical setting where malnutrition and far-advanced tuberculosis are common, experience with fluorescence microscopy of gastric washings was evaluated in 536 specimens. These specimens were obtained from 191 Haitian children whose illness was difficult to diagnose. Using the culture of gastric washings as a disease indicator, the prevalence of positive specimens was 24 per cent. The sensitivity, specificity, and predictive value were 58 per cent, 95 per cent, and 81 per cent, respectively. The agreement (J statistic) was +53 per cent. Combining the results of several series showed no differences in the sensitivity and specificity between fluorescence microscopy of gastric washings and fluorescence microscopic examination of sputum specimens. Among 49 children with positive fluorescence microscopy of gastric washings, pulmonary tuberculosis was bacteriologically confirmed in 85 per cent. Positive fluorescence microscopy of gastric washings was more frequent among children with far-advanced and miliary disease than children with less severe disease. The sensitivity and specificity of fluorescence microscopy of gastric washings make it a useful diagnostic tool in childhood tuberculosis, particularly in the presence of negative cutaneous reaction to purified protein derivative, extensive disease, or severe malnutrition.