FECAL LACTOFERRIN, FECAL LEUKOCYTES AND OCCULT BLOOD IN THE DIAGNOSTIC-APPROACH TO CHILDHOOD INVASIVE DIARRHEA

Objective. To compare fecal screening tests in the diagnostic approach to childhood invasive diarrhea. Setting and patients. We assessed 125 consecutive children with acute diarrhea for fecal lactoferrin, fecal leukocytes and occult blood hom November, 1995, to June, 1996. Result s. Lactoferrin showed a greater overall sensitivity than fecal leukocy tes or occult blood for detecting invasive pathogens. Combinations of lactoferrin or fecal leukocytes and of lactoferrin or occult blood or both yielded sensitivities and negative predictive values close to 100 %, being superior to all other combinations. All patients with full br east-feeding and mixed feeding had a positive lactoferrin test with a 1:50 dilution used as the cutoff. In controls without diarrhea being e xclusively bottle-fed, 3 of 15 (20%) still showed a positive lactoferr in result at the dilution of 1:50, This compared with 15 of 15 (100%) positive results among controls fully breast-fed, 14 of 15 (93%) among controls predominantly breast-fed and 11 of 15 (73%) among control ch ildren predominantly bottle-fed. Conclusions. This study confirms the usefulness of lactoferrin testing testing as a negative predictor. Bre ast-feeding lowers the specificity of the test but does not alter the sensitivity. Fecal lactoferrin may be viewed as the screening test of choice to avoid expensive stool cultures in the diagnostic approach to invasive diarrhea.