Background: Inflammatory diarrhoea (ID) resulting from Shigella, Salmonella, Campylobacter and Entamoeba histolytica requires specific diagnosis for therapy. Differentiation between ID and non-inflammatory diarrhoea (NID) is often not clinically possible. A faecal occult blood test (FOBT) correlates with faecal leucocytes. Lactoferrin indicates an inflammatory process as a marker for faecal leucocytes. We evaluated diagnostic values of lactoferrin latex agglutination test (LT) either alone or in combination with FOBT, correlating with stool microscopy and microbiology in differentiating ID from NID.
Methods: The study population constituted patients enrolled in 2% systematic sampling of patients under Diarrhoeal Disease Surveillance System of Dhaka Hospital, ICDDR,B.
Results: Between July and November 2002, 594 patients were enrolled; evaluation of FOBT and LT were done in 448/594 (75%) patients from whom either a single enteropathogen (315/594, 53%) or no pathogen (133/594, 22%) were identified and 146 were excluded for multiple pathogens. Invasive and non-invasive pathogens were isolated from 24% and 76% of the patients. FOBT and LT were positive in 40% and 39% of the samples. The sensitivities, specificities, PPVs, NPVs, and accuracies of FOBT were 55, 63, 24, 87 and 62%, and LT were 52, 64, 23, 86 and 62%, respectively.
Conclusion: FOBT and LT are not useful in differentiating ID from NID in diarrhoeal patients in Dhaka, Bangladesh.