Prevalence of intestinal parasitic infections among primary school attending students in Barandooz-Chay rural region of Urmia, West Azerbaijan province, Iran in 2008

Department of Parasitology and Mycology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran. Department of Environmental Health, Faculty of Public Health, Urmia University of Medical Sciences, Urmia, Iran. Department of Microbiology and Parasitology, Faculty of Medicine, The Persian Gulf Tropical and Infectious Diseases Research Center, Bushehr University of Medical Sciences, P. O. Box 3631, Bushehr, Iran.


INTRODUCTION
Intestinal parasitic infections are still a serious public health problem in the world.It is estimated that some 3.5 billion people are affected, and 450 million are ill as a result of these infections, the majority being children (WHO, 1998).The high prevalence in children is attributed to many factors, particularly the social and economical situation of the individuals, which is the important cause of the prevalence of intestinal parasites, in addition to environmental, poor sanitary and personal hygiene (Scolari et al., 2000).
years in Iran, the high prevalence of intestinal parasites in school children have been widely reported in many areas (Fallah et al., 2004;Hazrati et al., 2006).
The aim of this study was to determine the prevalence of intestinal parasitic infections in Urmia city from 7 to 14 year old school children and its relation to the education of parents, age, family and environmental factors related to intestinal infections.

MATERIALS AND METHODS
The design used for the study was a cross-sectional design.This study was conducted at nine primary schools, chosen by randomized cluster sampling, from urban areas of Urmia city (the capital of West Azerbaijan province), located in the Northwest of Iran.The sample size was calculated on a prevalence of 40%

RESULTS
The

DISCUSSION
The overall prevalence of intestinal parasites in Barandooz-Chay area of Urmia was 42.5%, which was much lower than the prevalence in the rural area of Silvana (52.6%), the southwest region of Urmia (Mostaghim et al., 2005).The results of the present investigation indicated that the total prevalence of intestinal protozoa infection was 31.6% among students of Barandooz-Chay area in Urmia and the prevalence of  intestinal helminthes infection was 10.9% in the primary school children.The results of a study, which was completed by Hazrati Tappeh in 2005, showed that prevalence of protozoan infection was 28.4% in Nazloo (a region also in the Northwest part of Urmia).The prevalence of the protozoan parasites was 10.3% for G. lamblia and 10% for E. coli, being the two most common infections, as was observed in the Nazloo region in Urmia (Hazrati et al., 2006).A comparison of the prevalence indicated that G. lamblia with 20.5%, E. coli with 14.6% and B. hominis with 13.3% were higher than other infections in Urmia, and this was estimated because the socioeconomic and environmental conditions were lower.
Abundance of helminthes infections was reported for E. vermicularis (24.9%), H. nana (1.14%) and A. lumbricoides (0.28%), by Mostaghim et al. (2005).Another study by Hazrati et al. (2006) reported infections for E. vermicularis (28.4%) and H. nana (0.4%), while the present study indicated infections for E. vermicularis (10.6%) and H. nana (0.2%).Low prevalence of E. vermicularis in this study might be due to the fact that the socioeconomic and environmental conditions were better.Several studies until 2004 in Hamadan city, west of Iran, have showed that prevalence of A. lumbricoides was higher, in comparison with other states.In those years, the mean infection rate of A. lumbricoides was 19.5% Years (Fallah et al., 2004).In this study, infection of A. lumbricoides was not reported in Barandooz-Chay, which was as a result of the avoidance of human fertilizers used by farmers.In 2004, Okyay et al. (2004) worked on the prevalence of intestinal parasites among primary school children in Aydin, a city in the western part of Turkey.The results showed that 145 (31.8%) were infected with one or more intestinal parasites.The most common was E. vermicularis with 83 (18.2%) infected children, the second was G. lamblia with 49 (10.7%)infected children and the third was E. coli with 36 (7.9%) infected children.
In the present study, infection of protozoan, especially G. lamblia, is higher than helminthes infections.
The results of this study indicate high prevalence of some intestinal protozoa, especially G. lamblia, and a great amount of helminthes in the area.In contrast, based on the present study and other studies in various areas, the intestinal parasite infections in the world is one of the most important health indexes.In spite of its different prevalence in various societies and ages due to decrease or eradication, intestinal protozoan infections, especially giardiasis and amebiasis, are very important problems that societies are suffering from.High prevalence of G. lamblia in Barandooz-Chay region, in comparison with other parts of Iran, shows a necessity for more studies and a derivation of a solution for the problem.

Table 1 .
Number of family members and education of parents' related prevalence of intestinal parasitic infections.

Table 2 .
Number of family members and related education of fathers and mothers.Stool samples of each student were collected in labeled plastic vials without preservatives.They were examined for intestinal parasites by wet mount and formalin-ether sedimentation techniques, and cellophane tape was used to detect Enterobius vermicularis infection.Data were analyzed using SPSS 11 for windows pocket program.
d=0.05, at a confidence level of 95%.So, the calculated study population size was 405.The school lists, for all children in grade one to four, in all nine primary schools in Urmia city were prepared.A total of 405 primary school children were randomly selected from the lists of nine schools.The questionnaire contained age, gender, residence, education and occupation of parents, number of family and water supply.

Table 1 .
Significant relation, observed in the education of parents and number of family members, is given in Table2.The age prevalence of intestinal protozoan and intestinal parasitic infections are shown in Figures1 and 2, respectively.