Background: Pinworm or Oxyuris (Order: Nematoda) is the most common nematode parasite in humans. One of the most frequent parasitic diseases in kindergartens, school-going children, and in places where many people live together is Oxyuriasis or Enterobiosis. The aim of this study was to determine the prevalence of Oxyuris contamination among kindergarten and primary school students of Babol city, Mazandaran province, Iran.
Keywords: Enterobiosis , Iran, kindergarten, nematode, pinworm, primary schools
Parasitic diseases till now, have been accounted as one of the diseases caused due to unhygienic conditions in many countries around the world. Pinworm or Oxyuris (Order: Nematoda) is the most common nematode parasite in human beings. Regarding climatic conditions, this parasite can live in all conditions but in cold and moderate regions because of favorable temperature is common, especially in crowded families. One of the most frequent parasitic diseases in kindergartens, school-going children, and in places where many people live together is Oxyuriasis or Enterobiosis.
Oxyuris has worldwide distribution and in Iran, the prevalence of it was reported as 25-29%. Signs of Oxyuris contamination include stomachache, headache, itching, paleness, diarrhea, and abdominal cramps accompanied with anorexia in children. Also, in some children complications such as agitation, madness, and nervousness can be seen. Oxyuriasis is not dangerous but can produce perinea itchiness during night time. This is when the pregnant female of the Oxyuris lays its eggs, which contain larvae that die soon after. It is infrequent that the Enterobius vermicularis emigrates to the vagina, producing vulvo-vaginal itchiness or toward the urethra, causing a urine infection. Secondarily, vulvo-vaginitis can be produced by scratching the genital region. 
Diagnostic methods of Oxyuris includes using Graham method (Scratch test), observation of eggs in samples taken from beneath of nails and finding adult worms in feces of patients.  The aim of this study was to determine the prevalence of Oxyuris contamination among kindergarten and primary school students of Babol city, Mazandaran province, Iran.
This study was done as a cross-sectional study in 2009, on 30 schools, including 10 kindergarten and 20 primary schools (10 schools for girls and 10 schools for boys) located in rural and urban regions of Babol.
During this study which was done on 702 students, first in an explaining meeting with students’ parents, they got to know this disease and its significance in public health. Then correct method of sampling was taught to them, a scotch test tape with two slides and a questionnaire requesting personal information, including age, gender, and location of residence, were given to them. They were asked to take samples from their children, in the morning before defecation. The samples were transferred to the parasitology laboratory of Babol Medical University and were observed by light microscope with magnification of 10× and 40×. The collected data were analyzed by SPSS statistical software and Chi-square test.
This study was done on 702 students of Babol kindergarten and primary schools. Among them 352 (50.1%) were boys and 350 (49.9%) were girls. All of the studied children were in the age group of 4-7 years. According to the location of residence, 313 (44.6%) were in urban areas and 389 (55.6%) were in rural areas. From the total 702 investigated children, 234 (33.33%) were positive and were infected by pinworm, including 101 (43.16%) boys and 133 (56.84%) girls [Table 1].
Based on gender, no statistically significant difference was seen (P > 0.05). According to dwelling location, 80 (34.18%) of the contaminated children were in the city, whereas 154 of them (65.82%) were in rural areas, which was statistically significant (P < 0.05).
Parasitic infections are seen in different parts of the world in various ratios. The distribution of these infections depends on the principles and standards of hygiene in the society, economic conditions of the society, and climatic conditions of the area. Then, investigation and determination of parasites of every region and their prevalence in that region are essential for controlling them. Oxyuriasis is one of the most significant parasitic diseases of childhood. 
In previous years, in Iran, several studies were done related to this disease. Abedi et al. (2002) reported that from 133 specimens which were taken from kindergarten schools of Isfahan, only 2.38% were positive, which is the lowest infection rate described in Iran.  In another study done by Daryani et al. (2003), in Ardebil city, pinworm infection rate of 18.3% was reported.  Also, a study done in 1995 in Urmia, Iran, by Valizadeh et al., reported an infection rate of 37.64% for oxyuriasis, which was the same as the present study but a little more.  In Kashan in 1999, Talari et al during a study on kindergartens of this city reported that the rate of oxyuriasis was 19.5%. 
Several studies were done on pinworm infection in Iran, such as Maraghi et al in 1999 in Ahwaz reported that infection rate was 34.6% in Iran.  In Zahedan, Sharifi et al reported pinworm infection rate of 31.8%  and Maghrebi et al reported a rate of 40% in Tehran.  These findings are similar to the present study.
In other countries, including South Korea and Argentina, pinworm infection rates of 25%.  and 43.4%  were reported, respectively.
In the present study, oxyuriasis was observed in girls more than in boys (P < 0.05). This is in line with Talari et al.’s study results,  whereas Lee et al reported that pinworms were more in boys. Pinworm prevalence was more in individuals settled in rural areas may be due to lower hygiene level and more crowded families, which are favorable conditions for incidence of this parasite.
Ismaeli et al reported that pinworm infection rate in rural children was more than that in urban children, in Golestan province.  These findings, in line with the present study, reported that the rate of infection in kindergartens and primary schools of rural areas was more than that in the urban areas.
Considering the data obtained from this study, because oxyuriasis infection rate in kindergarten and primary school children of Babol was high and this disease is highly contagious, it is suggested that oxyuriasis be described in parent-teacher meetings for increasing the knowledge of families about this disease and regular scotch test done on children to diagnose the disease and treat the infected children and their whole family.
The authors thank Mr. Javad Mosavi for his support in carrying out the present study.
Source of Support: None, Conflict of Interest: None