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 from November, 1995, to June, 1996. RESULTS: Lactoferrin showed a greater overall sensitivity than fecal leukocytes 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 breast-feeding and mixed feeding had a positive lactoferrin test with a 1:50 dilution used as the cutoff. In controls without diarrhea being exclusively bottle-fed, 3 of 15 (20%) still showed a positive lactoferrin 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 children predominantly bottle-fed. CONCLUSIONS: This study confirms the usefulness of lactoferrin testing as a negative predictor. Breast-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.

Cyclospora cayetanensis associated with watery diarrhoea in Peruvian patients.

Acid-fast, coccidian-like bodies (Cyclospora cayetanensis) were identified over the last 18 months in the stools of seven Peruvian patients suffering from diarrhoea. The follow-up of two patients revealed a watery, self-limited diarrhoea, which lasted for up to four weeks. The organism was simultaneously identified in the diarrhoeal stools of three members of the same family who drank unchlorinated canal water and in the stools of a duck bred by this family. The organism was not found in the faecal samples of 50 healthy subjects and 10 ducks bred by families without known diarrhoea cases. These findings, albeit preliminary, may be suggesting that besides consumption of untreated water, additional modes of transmission such as contact with domestic animals may be important in this disease. Further studies are needed to assess whether this disease behaves as a zoonotic condition and to ascertain the relative importance of symptom-free subjects in person-to-person transmission of the organism.