Introduction

Giardia lamblia has a global distribution, causing an estimated of 2.8 × 108 cases per annum (Lane and Lloyd 2002), and is the most common intestinal parasite of humans in the developed countries. About 200 million people in Asia, Africa, and Latin America have symptomatic giardiasis, with some 500,000 new cases reported each year (WHO 1996).

Human-to-human transmission of G. lamblia can occur indirectly through the accidental ingestion of the cysts in contaminated water or food or, directly, in the environments where hygiene levels may be compromised. Environments such as disadvantaged community settings and daycare centers are conducive to direct person-to-person transfer and thus favor the high frequency of transmission of Giardia (Hoque et al. 2002; Hopkins et al. 2002).

Giardiasis is also one of the most important parasitic infections in Iran, but no health education studies on the effectiveness of hygienic health practices of the population is yet available.

Materials and methods

In this study, 420 children (aged 9 and 12 years) were randomly selected from two female primary schools in the same area in south Tehran. The children and their families were living under similar cultural and social conditions. All the children were examined for parasite infection with the formalin–ether concentration method. The infection rate of G. lamblia was 18.1% (76 children) in both schools. The case group selected included 30 children from the school no.1 with Giardia infection. The same number of children with Giardia infection was selected from school no. 2 with as the control group. All 60 children were treated and cured of Giardia. The case group and their mothers were separately covered by the health education programs that included washing hands with soap, cutting nails, washing vegetables, and making the families knowledgeable about giardiasis and its effects on their children. All the programs were performed by health education methods, e.g., poster, video film, face-to-face meetings, and pamphlets. The control group had not undergone any health education program. Three months later, a triple stool examination was done in both groups to check reinfection.

Results

In this study, 93.1% of fathers and 96.3% of mothers in both groups had only high school education. Of the mothers in the case and control groups, 86.2% and 83.8%, respectively, were not aware of their children’s infection. Furthermore, more than 82% of mothers in both groups had no information about giardiasis and its control methods.

After implementation of the health education programs, the mean of the mother’s awareness about controlling of giardiasis increased from 6.54% to 27.16% (p = 0.00001). The control group had no variation in this item because they had not undergone any health education. The increase in the awareness of the mothers in the case group demonstrates the effectiveness of health education programs. The mean of children’s information about giardiasis and its methods of control in the case and control groups before implementation of the health education programs was 4.76% and 4.86%, respectively, but after the implementation of the programs, it increased to 16.3% in the case group but remained at 4.86% in the control group (p = 0.00001).

In this study, the children chosen in both groups had a 100% infection rate by Giardia. After being treated by a pediatrician, both groups were cured of the Giardia infection. After implementation of health education programs, the rate was 23.3% in the case group but 86.7% in the control group, indicating a significant difference between the two groups (p < 0.05; Table 1).

Table 1 Prevalence of Giardia infection in the children in both groups before and after the implementation of the health education programs
Full size table

Discussion

G. lamblia has a global distribution, causing an estimated of 2.8 × 108 cases per annum (Lane and Lloyd 2002). Its simple life cycle involving an environmentally resistant cyst provides ample opportunities for the parasite to be transmitted directly from one individual to another or indirectly through contamination of the environment or food (Hoque et al. 2002). Esrey et al. (1991) have documented that children infected with parasites progressed slowly in school and lagged behind in all the anthropometric values, such as body height, weight, and thorax circumference (Anderson and May 1991; Egger et al. 1990; Mohamed et al. 2004; Raj et al. 1996). Children with parasite infections are prone to immunodeficiency, increased acute respiratory diseases, increased risk of urinary infections, allergy, bronchial asthma, appendicitis, infertility, and vulvovaginitis in girls (Moore et al. 2001; Van den Biggelaar et al. 2004).

Common characteristics of Giardia markedly influence the epidemiology of these infections: (1) The infective dose is low for the parasite; (2) the cysts are immediately infectious when excreted in feces and can be transmitted by person-to-person contact; (3) the cysts are remarkably stable and can survive for weeks to months in the environment; and (4) environmental dispersal can lead to the contamination of drinking water and food. The death triangle of poor hygiene, inadequate sanitation, and lack of access to safe drinking water claims the lives of 6,000 children each day, mostly in the developing countries (WSSCC 2004). There is a lack of evidence on how improved hygiene can help to reverse such grim figures and contribute to the well-being of children, because it is more difficult to measure the effectiveness of hygiene promotion programs than water and sanitation interventions (Almedom et al. 1997; Carneiro et al. 2002; Curtis et al. 1993; Luby et al. 2004).

In this study, two groups of case and controls were selected and there were no significant differences in terms of the mothers’ age, parents’ education, fathers’ occupation, mothers’ awareness of their children’s infection, and mothers’ information about giardiasis and its control methods. The obtained results also showed that 86.2% and 83.8% of the mothers’ case and control groups, respectively, had no awareness of their children’s infection, indicating that giardiasis is a hidden infection without any clinical symptoms. It is suggested that the Health Ministry should inform the children and the families in this regard.

By implementation of health education programs, the infection rate in the case group was 23.3% and 86.7% in the control group. This result shows that health education programs played a key role in the prevention of Giardia infection.