Comparison of Methods for Detection of Blastocystis Infection in Routinely Submitted Stool Samples, and also in IBS/IBD Patients in Ankara, Turkey

BACKGROUND: This study compared diagnostic methods for identifying Blastocystis in stool samples, and evaluated the frequency of detection of Blastocystis in patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). RESULTS AND DISCUSSION: From a set of 105 stool specimens submitted for routine parasitological analysis, 30 were identified as positive for Blastocystis by the culture method. From that group of 30 positives, Lugol's stain, trichrome staining, and an immunofluorescence assay identified 11, 15, and 26 samples as positive respectively. Using culture as a standard, the sensitivity of Lugol's stain was 36.7%, trichrome staining was 50%, and the IFA stain was 86.7%. The specificity of Lugol's stain was 91%, trichrome staining was 100%, and the IFA stain was 97.3%. In the group of 27 IBS and IBD patients, using all methods combined, we detected Blastocystis in 67% (18/27) of the patients. Blastocystis was detected in 33% (2/6) of IBD patients and 76% (16/21) of IBS patients. For comparison, trichrome staining alone, the method most frequently used in many countries, would have only identified Blastocystis infection in 29% (6/21) of the IBS patients. No parasitic co-infections were identified in the IBS/IBD patients. Most Blastocystis-positive IBS/IBD patients were over 36 with an average length of illness of 4.9 years. CONCLUSIONS: Most IBS patients in this study were infected with Blastocystis. IFA staining may be a useful alternative to stool culture, especially if stool specimens have been chemically preserved

Detection of Cryptosporidium spp and other intestinal parasites in children with acute diarrhea and severe dehydration in Rio de Janeiro Detecção de Cryptosporidium spp e outros parasitas intestinais em crianças com diarréia aguda e desidratação grave no Rio de Janeiro

The objective of the present study was to estimate the frequency of infection by Cryptosporidium spp and other intestinal parasites in dehydrated children with gastroenteritis who were admitted to a pediatric hospital. Stool examinations from 218 children were performed. Cryptosporidium spp was identified in eighteen out of 193 stool samples (9.3%) subjected to safranin-methylene blue staining. Giardia lamblia was detected in ten out of 213 (4.7%) samples examined via the direct or Ritchie methods. Other parasites identified were Ascaris lumbricoides (4.2%), Blastocystis hominis (1.4%), Entamoeba coli (0.9%), Entamoeba histolytica/Entamoeba dispar (0.5%), Endolimax nana (0.5%), Trichuris trichiura (0.5%) and Enterobius vermicularis (0.5%).<br>O objetivo do presente estudo foi estimar a freqüência das infecções por Cryptosporidium spp e outros parasitas intestinais em crianças desidratadas com gastroenterite, internadas em um hospital pediátrico. Exames de fezes de 218 crianças foram realizados. Cryptosporidium spp foi detectado em 18 de 193 (9,3%) amostras fecais submetidas à coloração pela safranina/azul-de-metileno. Giardia lamblia foi detectada em dez de 213 (4,7%) amostras submetidas ao exame direto ou ao método de Ritchie. Também foram identificados Ascaris lumbricoides (4,2%), Blastocystis hominis (1,4%), Entamoeba coli (0,9%), Entamoeba histolytica/Entamoeba dispar (0,5%), Endolimax nana (0,5%), Trichuris trichiura (0,5%) and Enterobius vermicularis (0,5%)