Background: A mass Entamoeba histolytica infection recurred despite repeated treatments with metronidazole at a rehabilitation institution for individuals with intellectual impairments. Methods: Diloxanide furoate was administered to improve intractable intestinal amoebiasis after a recurring amoebic infection that tends to occur via coprophagy in mentally disabled individuals infected with E. histolytica at an institution (the prevalence rate and positive serology rate were 38.2 and 67.1%, respectively). The therapeutic effect of the drugs was judged by microscopic stool examination and an E. histolytica antigen detection kit. Results: The mass infection was eliminated through the administration of metronidazole and subsequent use of diloxanide furoate. Conclusions: Combination therapy successfully cured and prevented transmission of the mass E. histolytica infection at the institution.

Clinical usefulness of C-425, a native human immunoglobulin liquid preparation for intravenous injection, was studied in combination with antibiotics in severe bacterial infections in a double blind group comparison using an alkylated human immunoglobulin liquid preparation (Polyglobin, A.gamma G) as a reference drug. The following results were obtained: 1. C-425 or A.gamma G was administered to a total of 117 patients, of whom 89 patients, 45 in C-425 group and 44 in A.gamma G group, were included in the present analysis of efficacy and usefulness. Analysis of safety of the drugs included a total of 113 patients, 58 in C-425 group and 55 in A.gamma G group. 2. Efficacy and usefulness were graded according to a visual analog scale (VAS). 3. Mean efficacy values with standard deviations of VAS value were calculated at 52.0 +/- 34.9 for the C-425 group, and 47.2 +/- 34.8 for the A.gamma G group. The respective medians were 59.0 and 61.0. The Mann-Whitney U-test revealed no significant differences between the two groups. When those with VAS values of 50 or above were regarded as cases of effective treatment, the efficacy rates of the two groups were also practically comparable. 4. Side effects were not observed in either drug group. 5. Mean usefulness values with standard deviations were 52.3 +/- 34.9 for the C-425 group, and 47.9 +/- 35.0 for the A.gamma G group. The respective medians were 60.0 and 61.0. The Mann-Whitney U-test revealed no significant differences between the two groups. When the cases with VAS values of 50 or above were regarded as cases of useful treatment, there were no significant differences in the utility rates between the two groups. From these results, C-425 was considered to be useful for treating severe bacterial infections when used combined with antibiotics.