The importance of diagnosing infectious invasive diarrhea early is obvious and fecal leukocyte examination first and occult blood testing later are the two important potential screening tests for acute diarrhea of invasive bacterial origin. In recent years, lactoferrin, a glycoprotein present in the specific granules of the neutrophils is used to screen by latex agglutination assay in stool specimens for invasive diarrheal pathogens.
Objective: We would like to evaluate the value of fecal lactoferrin agglutination assay, fecal leukocyte and fecal occult blood tests in invasive diarrheal diseases. Also we would like to compare fecal lactoferrin agglutination assay with other screening tests in the diagnostic approach.
Method: We assessed 386 children with acute diarrhea for stool culture, fecal lactoferrin, leukocyte and occult blood from March, 1999 to February, 2000.
Results: In 98 (25.4 %) cases enteroinvasive bacteria or Entamoeba histolytica (1 case) were documented. Salmonella species were isolated in 63 (64%) cases, Shigella species and C. jejuni in 27 (28 %) and (7 %) were isolated respectively. In study group, occult blood, fecal leukocyte and fecal lactoferrin were detected in 148 (38.3 %), 67 (17.4 %) and 116 (30.1 %) respectively. In 98 patients with enteroinvasive pathogens were documented, occult blood, fecal leukocyte and fecal lactoferrin were detected in 56 (57 %), 61 (62 %) and 87 (89%) respectively.
Conclusions: Fecal lactoferrin agglutination assay is a useful screening test for invasive infectious diarrhea and also selective tests for specimens for stool culture. Fecal lactoferrin agglutination assay has a high positive predictive value, and also has a higher negative predictive value, so if it is negative, there is no invasive pathogens as a cause of diarrhea with very high probability.