This was the first report that revealed the prevalence of E. vermicularis infections among children who live in rural areas of Southern Thailand through detection using the scotch tape technique. In this study, the overall prevalence of E. vermicularis infections at 5.79%, which lower than in previous studies conducted in other regions of Thailand. This discrepancy may partly be due to the study setting and source population difference. The prevalence of pinworm infections at percentages ranging from 7.81–38.82% [19–21, 27, 28, 30], 11.30–50.90% [18, 29], and 7.25–45.38% [22–25] in the central, northeast, and northern region of Thailand, respectively.
However, according to these, the prevalence of E. vermicularis infections in Thailand tends to be decreased over the past three decades may mainly be due to the sanitary environment and healthcare access has been greatly improved by urbanization.
Our study revealed that boys were more highly infected with E. vermicularis than girls, which was also observed in previous studies [9, 12]. Higher infection rates among boys may be due to boys involved in more activities, close contact with other children, and poor personal hygiene than girls. Among the age groups, children 3 to 6 years of age were more at risk to be infected with E. vermicularis, which is consistent with previous studies [13, 29, 30]. This could be because they have more group activities together, take naps together during the day on the floor mat, and poor personal hygiene than older children.
Three main factors that are often involved in E. vermicularis infections among children are family background, living conditions, and personal hygiene. In the present study, children with mothers who had a primary level of education had a higher risk of infection. This finding was similar to those reported previously [1, 13] and it may be explained by mothers who had low education levels; thus, they did not have accurate knowledge of pinworm infection are a principal caretaker of children. Meanwhile, some previous reports have suggested that parents’ knowledge about enterobiasis might be one of the most important risk factors for enterobiasis in children [11, 14]. In addition, children who had younger/older siblings were more highly infected with E. vermicularis than those who had not and these findings were similar to those reported previously [1, 12, 17]. These results suggested that new infection or reinfection may occur in the family among children who are in constant close contact over long periods of time. Further, it seems that their resident including parents or caretakers should be investigated and treated.
Previous reports suggested that inadequate personal hygiene can increase the risk of enterobiasis in children [1, 11, 13–15]. In our study, children who did not frequently wash their hands after using toilet facilities were more at risk to be infected with pinworms. This finding was similar to those reported previously [1, 14], indicating that direct infection by hand from anus to mouth might occur, and additionally it also causes of distribution into the surrounding environment. Moreover, children who sucked their fingers were more at risk to be infected with E. vermicularis, which was consistent with other studies [11, 15]. Interestingly, we found that children who kept their fingernails long were more at risk to be infected with pinworms, which is consistent with a previous study . It could be due to pinworm eggs that may thus be transferred from contaminated hands to mouth. Finally, in our study, these findings indicate that finger-oral route remains the most important avenue for E. vermicularis transmission.