In the present work, assays were performed to compare the efficacy of hypochlorous acid, chlorine dioxide, and ozone in the inactivation of Cryptosporidium oocyst in public water supply from Brazilian South conditions. Experiments were carried out in samples containing 2 x 10(4) oocysts/ml of C. parvum purified from feces of experimentally contaminated calves. An in vitro excystation method was used to evaluate oocysts' viability and to determine the inactivation rates of hypochlorous acid at 2 ppm, chlorine dioxide at 1, 2, and 5 ppm, and ozone at the doses of 0.18, 0.24, 0.36, 0.48, and 1.44 mg/l. By using hypochlorous acid, the maximum inactivation rate obtained was 49.04% after 120 min. Chlorine dioxide at 5 ppm inactivated 90.56% of oocysts after 90 min of contact. Ozone was the most effective product, rendering an inactivation of 100% with the concentration of 24 mg/l. Resistance of Cryptosporidium to the usual disinfectants and the need for more effective water treatments to prevent waterborne diseases in Brazil are discussed in this manuscript.

We describe the finding of unizoic cysts of Isospora belli in lymphoid tissues of a Brazilian patient with AIDS, and discuss the possibilities of their drug resistance, they being the cause of relapses, and of being an indication for the existence of intermediary or paratenic animal hosts.

Resumo Introdução Manipuladores de alimentos que trabalham em hospitais frequentemente fornecem alimentos a indivíduos com imunidade reduzida, os quais são mais suscetíveis à aquisição de doenças infecciosas de origem alimentar. Objetivo O objetivo deste trabalho foi avaliar a presença de enteroparasitos e coliformes termotolerantes nas mãos dos manipuladores de alimentos de um hospital de ensino de Uberaba, Minas Gerais. Método Foram analisadas amostras das mãos de 44 manipuladores de alimentos de um hospital de ensino. Os coliformes termotolerantes foram contados pelo método do Número Mais Provável, a partir de amostra obtida por esfregaço. O conteúdo subungueal foi submetido à análise parasitológica, observado em microscópio. Resultados 15,9% (7/44) das amostras foram positivas para ocorrência de coliformes termotolerantes e 9,1% (4/44) dos conteúdos subungueais foram positivos para protozoários intestinais (3 Blastocystis spp. e 1 Giardia spp.). Conclusão Os resultados indicam contaminação das mãos dos manipuladores de alimentos e predisposição à veiculação de agentes patogênicos por essa via, ressaltando a importância de uma conscientização dos manipuladores de alimento quanto à higiene pessoal e dos alimentos, bem como a utilização de medidas preventivas.

This report describes the presence of Isospora belli unizoic cysts in mesenteric lymph nodes and of gametocytes in the gallbladder epitelium of a 26 year-old Brazilian male patient with Acquired Immune Deficiency Syndrome. This patient had received treatment for several times with sulfamethoxazole-trimethoprim. It is discussed the significance of I. belli tissue cysts as possible foci of resistance of the parasite and their association with the infection relapse even post-treatment with anticoccidian medication.

The authors describe a case of peritoneal enterobiasis presenting as necrotizing granuloma, in a adolescent with tumor of the ovarian endodermic sinus. The diagnosis was established through biopsy of peritoneal nodule, during laparotomy for staging system of ovarian cancer. Granulomatous nodules due to parasites could simulate metastasis, and cause confusion in the staging system for cancer.