Yemen's schoolchildren are reported to have a high prevalence of intestinal parasites. The findings of this study revealed that the overall proportion of intestinal parasites detected among participants was 48%. This finding is lower than reported in a previous study conducted in Yemen that documented the frequency rate of parasite infection at 58.7% in Hadramowat [11], 90% in Al-Mahweet [16], 62.7% in Ibb [14], 73.25% in Hajjah [17], 61.85% in Sana’a [18], 51.26% in Taiz [19], and 61.85% in Amran [20]. Moreover, this finding is reported lower in different countries: 29.4% in Ethiopia [21], 46.2% in Egypt [3], 15% in Ghana [22], and 5.3% in Saudi Arabia [23].
The difference in prevalence rate may be attributed to variations in geographical locations, study population, sample size, hygienic condition, socio-economic status, food consumption behavior differences, and diagnostic methods employed by the participants.
This finding revealed a significant association between intestinal parasitic infection and the type of school, with the public having a significantly higher prevalence rate compared to private schools (57% vs. 39%; P = 0.011).
The present finding showed that male participants had considerably greater proportions of parasitic infections than did female participants, with a statistical difference (P = 0.010). This outcome is supported by similar previous studies conducted in Yemen [16, 24]. This may be referred to as the habitat behavior of boys in contributing to their fathers’ agricultural activities, which allows them to remain outside for a long time outside the home daily and makes them more exposed to intestinal parasitic infection than females.
Regarding the age group, the age group of 11–15 years showed a greater rate of parasitic infections compared to the age range of 7–10 years. This finding is in disagreement with early reports conducted in different nations that documented that lower-age children had a higher rate of IPI compared to older-age children [13, 25–27].
In this result, children with parents who had primary certificates had a considerably higher rate of parasite infection. This result is similar to the report by Alshahethi et al. [28], which revealed statistically significant higher prevalence rates of E. histolytica among children with uneducated parents than those with educated parents in Amran city.
Education is considered an important social determinant of health. Also, a strong association between educational status and health has been recognized. The effect of education is to create better overall self-awareness of personal health and make healthcare more accessible. Well-educated people have better health, as reflected in the low levels of mortality, morbidity, and disability. Education helps promote health equity, sustain healthy lifestyles and positive choices, nurture relationships, and enhance personal, family, and community well-being [29].
The prevalence of parasite infection is significantly greater in children who use treated water than in those who use untreated water. These results are in disagreement with the work of previous studies that acknowledged the higher prevalence of intestinal parasites among those who drink untreated water [16, 25, 30]. The source of drinking water appeared to play a great role in increasing the chance of getting an intestinal parasite infection; hence, children who used water from the pond accounted for a relatively high number of positive cases. This might be due to the contamination of water and food with human waste during open-field defecation [21].
The rate of parasite infection in this study was higher among people who consumed unwashed fruits and vegetables. These results are in consonance with earlier reports showing that eating unwashed vegetables was significantly associated with protozoa infection among examined children [3, 21].
Furthermore, a significant increase in intestinal infection was observed in the current study among participants who didn't wash their hands after defecation and trimmed their nails, which was consistent with the results previously reported elsewhere [21, 32]. This could be attributed to the lack of removal of accumulated dirt containing parasite eggs in fingernails, which could serve as a source of infection [33]. Moreover, it suggests that unwashed hands and dirty fingers are liable to harbor parasite ova or cysts, thus increasing the risk of infection. Pit-latrines without slabs and shared pit-latrines with slabs were significantly associated with IPIs. This finding was consistent with another study [34].
In developing countries, it has been well documented that contaminated hands play a major role in the transmission of facal-oral, and washing hands before eating or after evacuation has been reckoned as a secondary barrier [35]. The major factors associated with the prevalence of pathogenic organisms in Yemen are poor hygienic practices, environmental contamination with fecal, the lack of safe water, and health awareness resulting from a high level of poverty [7, 36–40].
According to the current findings, E. histolytica was the most common parasite (25%) detected among children, followed by G. lamblia (13.5%), E. coli (12%), E. vermicularis (10%), and H. nana (6.5%). The results are in consonance with those of other workers who reported that the most predominant parasite found in schoolchildren was E. histolytica, G. lamblia, A. lumbricoides, T. trichiura, H. nana, S. mansoni, A. duodenale, E. vermicularis, and S. stercoralis [12, 14, 16, 17].
In a different study by Hailu and Ayele [27], showed the predominant parasites were A. lumbricoides, E. histolytica, and H. nana. Similarly, E. histolytica and A. lumbricoides were the most predominant parasites, followed by E. vermicularis, G. lamblia, Cryptosporidium parvum, Heterophyes heterophyes, and H. nana [2]. The distribution and prevalence of various species of intestinal parasites differ from region to region because of several environmental, social, geographical, and other factors.
Regarding clinical signs and symptoms, the observation of this result revealed that all participants who had diarrhea, blood in the stool, abdominal pain, fever, cough, muscle pain, itchy skin, and weight loss had a significant prevalence of intestinal parasites. All participants who had diarrhea had a significant prevalence of intestinal parasites, with a statistically significant difference (P = 0.000). These data were consistent with the results previously reported in other studies [13–14].