As parasitoses provocadas por protozoários ou helmintos patogênicos afetam mais de dois bilhões de pessoas no mundo. Considerando os problemas gerados por infecções parasitárias e a necessidade do uso correto dos medicamentos prescritos, o objetivo deste trabalho foi detectar a freqüência de infecção por enteroparasitos e o uso de agentes quimioterápicos em crianças moradoras na periferia de Porto Alegre, RS, Brasil. Foram analisadas noventa e seis crianças em idade pré-escolar, que realizaram o exame parasitológico de fezes e que fizeram uso de antiparasitários. A eficácia do tratamento foi avaliada pelo exame parasitológico repetido seis meses após o tratamento. O mesmo teste diagnóstico foi utilizado para avaliar a cura que foi definida como a ausência de ovos e cistos nas fezes. Das crianças estudadas, 79 (82,3%) estavam infectadas com um ou mais parasitas, os mais prevalentes foram Ascaris lumbricoides, Trichuris trichiura e Giardia lamblia. Os antiparasitários mais utilizados foram mebendazol (86% das prescrições) e metronidazol (30,3%) de acordo com a prevalência da infecção. A porcentagem de cura das 79 crianças estudadas após 6 meses do tratamento foi 65,3% para A. lumbricoides e 66,1% para T. trichiura. Este estudo sugere que um programa de educação continuada voltado para a prevenção e tratamento das infecções parasitárias tem se mostrado uma ferramenta útil na erradicação destas patologias.

Parasitic infections caused by intestinal protozoan and helminths affect more than two billion people worldwide and chemotherapy is the most commonly used therapeutic procedure. Considering the problems created by parasitic infections and the incorrect use of drugs, the aim of this work was to detect the frequency of enteroparasites infection and to estimate the use of chemotherapeutic agents in children living in the periphery of the city of Porto Alegre, RS, Brazil. Ninety-six preschool age children, who had parasitological exams and who used antiparasitic drugs, were analyzed. The efficacy of treatment was evaluated by stool examination repeated six months after treatment. The same diagnostic test was used to evaluate parasitological cure, which was defined as absence of eggs and cysts in the stool. From these children, 79 (82.3%) were contaminated by some species of parasite, the most prevalent were Ascaris lumbricoides, Trichuris trichiura and Giardia lamblia. The most commonly used drugs were mebendazole (86% of prescriptions) and metronidazole (30.3%). The cure rate in the 79 children, examined 6 months after treatment, was 65.3% for A. lumbricoides and 66.1% for T. trichiura. This study suggests that a continuous education program regarding the prevention and treatment of parasitic infections is an essential tool for their eradication.

Shape variations of strains of Trichomonas vaginalis were demonstrated by scanning electron microscopy (SEM) following inoculation on McCoy cell monolayers and after interaction with human erythrocytes. The parasites adhered to both cells and presented amoeboid forms, with pseudopodia-like extensions. Several amoeboid organisms swam freely over the cell monolayers and produced aggregates. These unusual forms of the urogenital flagellate may be a response to the composition of the culture medium and may play an important role in the pathogenic process of T. vaginalis.

Tetratrichomonas didelphidis (Hegner and Ratcliffe 1927) Andersen and Reilly 1965 is a flagellate protozoan from the intestine, cecum and colon of Didelphis marsupialis Linnaeus, 1758. The prevalence of T. didelphidis in opossums D. albiventris was studied in the Botanical Garden, Porto Alegre City in the southernmost Brazilian State, Rio Grande do Sul, Brazil. T. didelphidis was found in seven of eight cultures of swabbed rectums, representing a prevalence of 87.5% in D. albiventris. In the present investigation it was observed that the T. didelphidis found in the intestine content of D. albiventris had the same morphological characteristics as those previously described by other authors in the D. marsupialis, being probably the same protozoan species in both host species.