Evaluation of a novel kit (TF-Test) for the diagnosis of intestinal parasitic infections.

Intestinal parasitic infections are currently a source of concern for Public Health agencies in developing and developed countries. Since three ovum-and-parasite stool examinations have been demonstrated to provide sensitive results, we designed a practical and economical kit (TF-Test) that is now commercially available (Immunoassay Com. Ind. Ltda., São Paulo, Brazil). This kit allows the separate collection of three fecal specimens into a preservative solution. The specimens are then pooled, double-filtered, and concentrated by a single rapid centrifugation process. The TF-Test was evaluated in four different laboratories in a study using 1,102 outpatients and individuals living in an endemic area for enteroparasitosis. The overall sensitivity found using the TF-Test (86.2-97.8%) was significantly higher (P<0.01) than the sensitivity of conventional techniques such as the Coprotest (NL Comércio Exterior Ltda, São Paulo, Brazil) and the combination of Lutz/Hoffman, Faust, and Rugai techniques (De Carli, Diagnóstico Laboratorial das Parasitoses Humanas. Métodos e Técnicas, 1994), which ranged from 48.3% to 75.9%. When the above combined three specimen technique was repeated with three specimens collected on different days, its sensitivity became similar (P>0.01) to that of the TF-Test. The kappa index values of agreement for the TF-Test were consistent (P<0.01), being higher and ranking in a better position than conventional techniques. The high sensitivity, cost/benefit ratio, and practical aspects demonstrate that the TF-Test is suitable for individual diagnosis, epidemiological inquiries, or evaluation of chemotherapy in treated communities.

Detection of IgM antibodies to Schistosoma mansoni gut-associated antigens for the study of the dynamics of schistosomiasis transmission in an endemic area with low worm burden

Dados de prevalencia e incidencia da esquistossomose foram estimados, acompanhando-se um grupo de escolares residentes em area rural do municipio de Itariri (Sao Paulo, Brasil), por um periodo de 2 anos, com cinco inqueritos, um a cada semestre, realizados no primeiro semestre de cada ano entre marco e abril e no segundo, entre setembro e outubro. O hospedeiro intermediario do Schistosoma mansoni na area e a Biomphalaria tenagophila. A infeccao pelo S. mansoni foi determinada pelo metodo parasitologico de Kato-Katz, atraves do exame de tres laminas, e os resultados analisados comparativamente aos da reacao de imunofluorescencia para deteccao de anticorpos IgM (RIF-IgM). Foram encontrados nos cinco inqueritos indices de prevalencia de 8,6 por cento, 6,8 por cento, 9,9 por cento, 5,8 por cento e 17,2 por cento pelo metodo parasitologico...