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  Backgrand & Objective: Enterobius vermicularis is a common helminthic infection and its prevalence in Iran is 25 to 92 percent.The aim of this study was to determine the prevalence of E. vermicularis infection among children going to daycare centers in Ardabil.

  Methods : This cross-sectional study was carried out in 2003 on 400 children who were selected from 10 daycare centers using Graham's scotch adhesive tape technique. A questionnaire was filled for every subject and the results were analyzed by Chi-square test.

  Results : The prevalence of enterobiosis in the children under study was 18.3%. The highest rate (21.62%) was observed among 3-4 year-old children and the lowest rate (16.19%) was seen among 5-6 year-old ones. The infection rate of males and females were 16.4% and 21.2%, respectively. Prevalence of enterobiosis in children of illiterate mothers (54.5%) was higher compared to literate mothers (12.4%) (p< 0.05).

  Conclusions : In order to prevent this infection, health education especially for illiterate parents or those who have lower level of education is necessary.

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  Background & Objectives: Infection with Toxoplasma gondii can cause severe illness when transmitting to fetus or when it is reactivated in immune-suppressed persons. The aim of this study was to determine the prevalence of antibodies against toxoplasma gondii in women referring to laboratory of health center for medical examinations before marriage.

  Methods: This descriptive cross-sectional study was performed on 504 samples collected from women in Arabil, Iran, in 2002. The samples were studied by indirect immunofluorescent assay (IFA) for determination of IgG and IgM antibodies to toxoplasma.

  Results: The seroprevalence of IgG antibody at a titer of ³ 1:20 was 34.7%. The highest antibody titer frequency was observed in 1:20 titer (11.7%) and the lowest belonged to 1:3200 (0.4%) and 1:6400 (0.4%) titers. 20 persons (4%) showed IgM antibody against Toxoplama gondii. No statistically significant differences were observed between the prevalence of antibodies on the one hand and age and history of contact with cat or domestic animals on the other.

  Conclusion: since 65.3% of these women in Ardabil were seronegative, health education is required to omit the risk factors, especially during the pregnancy.

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  Background & Objectives: Intestinal infestation is among the most common infections in the world, being responsible for considerable morbidity and mortality. The objective of this study was to determine the prevalence of intestinal infestation and related risk factors among students of primary schools in Ardabil.

  Methods: This cross-sectional and descriptive study was conducted in 24 primary schools of Ardabil in 2003. A total of 1070 school children between 7-13 years of age (527(49.3%) boys and 543(50.7%) girls) took part in this study. Fecal specimens were collected by random sampling and were examined for ova, larva and cysts of intestinal parasites using direct wet mount and formalin-ether concentration methods.

  Results: A total of 1 0 species were identified, Giardia lamblia (14.2%), Blastocystis hominis (10.2%) and Entamoeba coli (4.1%) were the most common parasites, respectively, the over all prevalence rate for at least one parasite was 27.7%. There was no statistically significant difference in prevalence of parasites by sex, age, class grade and rate of infection (p>0.06).

Conclusion: This study indicated that there is a high rate of intestinal infestation rate among primary school students. So health education about personal hygiene is necessary for the students and their parents, especially mothers.

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 Background & Objectives: Cryptosporidium is an intracellular – extracytoplasmic parasite that has taken much attention in last 20 years as a clinically important human pathogen. Cryptosporidial infection can be transmitted from fecally contaminated food or water and from animal-human or human-human contact. In immunocompromised persons, the illness is much more severe such as debilitation, fatigue, cholera-like diarrhea, severe abdominal cramps, low-grade fever, severe weight loss and Anorexia. Because there was no regional study about cryptosporidiosis in Ardabil, we carried out this survey to determine the prevalence of cryptosporidiosis among the children hospitalized in Ardabil.

 Methods: This descriptive and analytical study was carried out on 371 patients in Sabalab and Aliasghar hospitals of Ardabil between 2004 and 2005. A questionnaire was filled for each patient. Stool samples were examined by concentrated formal - ether method and stained with modified Ziehl-Neelson method. The data were analyzed with SPSS (ver 11) using Chi-square test.

  Results: We analyzed 371 stool samples from children with diarrhea. Cryptosporidium oocysts were detected microscopically in 15 samples. Its prevalence was 4.04% in infected patients. 66.7% of the infected ones were at the age of 6 to 24 months, 20% 25-48 months, and 13.3% 49-72 months.

 Condusion: Because cryptosporidiosis was more prevalent at the age of 6-24 months, health education is more necessary for their mothers.