Oral and dental hygiene are crucial factors in maintaining overall health and well-being. Neglecting basic oral care practices not only harms the teeth and gums but also significantly elevates the risk of heart disease, cancer, and diabetes (Dörfer et al., 2017). The oral cavity, along with the teeth, serves as the primary digestive organ in the human body. From a scientific perspective, the initial breakdown of food commences in the mouth, facilitated by oral enzymes and tooth movement (Gift and Atchison, 1995). Given these insights, any malfunctions in the oral cavity and teeth can lead to severe digestive and functional complications (Wu et al., 2016). Thus, the maintenance of oral and dental hygiene is crucial and can potentially lead to significant systemic issues (Wu et al., 2016). Data from the World Health Organization reveals that despite the emphasis on oral health, a significant portion of the global population, especially children, struggle with dental and gum diseases, a predicament that is widespread among underprivileged segments of society (Sadida et al., 2021).

Maintaining optimal oral health is a crucial component of overall well-being, particularly for children, and holds even greater significance for those with special health requirements (Kilian et al., 2016). Despite the heightened prevalence of dental issues among individuals with disabilities or illnesses, they often receive inadequate oral care compared to the general population (Mishu et al., 2022). Researches indicated that dental treatment stands as the most neglected health necessity among disabled individuals. Therefore, the principal objective of dental care provision for this demographic should prioritize preventive measures to address dental diseases, necessitating meticulous planning and effective service delivery (Peres et al., 2019). Intellectual disability (ID) is a genetic condition characterized by substantially below-average intellectual functioning and deficiencies in adaptive behavior (Chelly et al., 2006). This condition typically emerges in childhood and is distinguished by diminished intelligence and adaptive skills (Chelly et al., 2006).

Entamoeba gingivalis and Trichomonas tenax are anaerobic parasites found in the human oral cavity (Bonner et al., 2014; Marty et al., 2017). These parasites can be transmitted through saliva, contaminated food containers, drinking water, and other means (Bonner et al., 2014; Marty et al., 2017). They typically inhabit the upper regions of the digestive system, including the mouth, teeth, gum margins, and spaces between teeth, as well as the respiratory tract (Arpağ and Kaya, 2020; Eslahi et al., 2021). While traditionally considered benign microorganisms by many dentists, recent studies have linked these parasites to oral conditions like periodontal disease, gingivitis, and osteomyelitis (Bao et al., 2020; Yaseen et al., 2021; Azadbakht et al., 2022). Children with ID often face challenges in maintaining proper oral hygiene due to their motor, sensory, and intellectual impairments, which can lead to compromised oral health; therefore, there is a need to enhance the oral health status of these populations and establish an effective system for administering preventive interventions. Here, we aimed to evaluate the prevalence of E. gingivalis and T. tenax among children with ID in Lorestan province, in Western Iran through parasitological and molecular methods.

Today, it has been proven that the maintaining optimal oral health is a critical aspect of overall well-being, especially for children, and is of particular importance for individuals with special health needs (Gift and Atchison, 1995). Since, children with intellectual disability often face challenges in maintaining proper oral hygiene due to their motor, sensory, and intellectual impairments, which can lead to compromised oral health; therefore, there is a need to enhance the oral health status of these populations and establish an effective system for administering preventive interventions. Here, we aimed to evaluate the prevalence of Entamoeba gingivalis and Trichomonas tenax among children with ID in Lorestan province, in Western Iran through parasitological and molecular methods.

The present study showed that the total prevalence of the E. gingivalis and T. tenax was 40.5% and 42.8% by microscopic and PCR methods, respectively. Among positive samples, 61.9% and 38.1% children were positive for E. gingivalis and T. tenax, respectively. In a study conducted by Sharifi et al. (2020) on 315 adolescents in Kerman province, Iran, it was found that 9.2% and 11.4% tested positive for E. gingivalis and T. tenax through culture and PCR methods, respectively (Sharifi et al., 2020). Additionally, Mehr et al. (2015) demonstrated that the prevalence of T. tenax among individuals with Down syndrome and periodontitis in Tabriz, Iran was 18.8% as determined by PCR analysis (Mehr et al., 2015). Azadbakht et al. (2023) reported that among hemodialysis patients in Lorestan province, Western Iran, the frequencies of E. gingivalis and T. tenax were 17.1% and 14.5%, respectively (Azadbakht et al., 2023). Furthermore, Kooshki et al. (2023) observed that in children with cancer from Lorestan, Iran, the prevalence of E. gingivalis and T. tenax was 25.5% and 31.1% based on microscopic and PCR methods, respectively (Kooshki et al., 2023). The difference in the prevalence of these oral cavity parasites are likely influenced by factors such as the study population, sample size, and methodology employed.

Based on the statistical analysis, there was no significant relationship among age, gender, and prevalence of E. gingivalis and T. tenax parasites in children without ID. It has been proven that women display more favorable attitudes towards dental appointments, possess higher levels of oral health knowledge, and exhibit superior oral health practices compared to males (Lipsky et al., 2021). However, our results showed that there was no significant relationship among gender and prevalence of E. gingivalis and T. tenax parasites in non-ID children. Studies also demonstrated that children under 12 years of age are more susceptible to oral and dental diseases due to less knowledge and education, lifestyle habits and more contact with infectious agents (Hazavehei et al., 2015). In the present study, although the prevalence of oral cavity parasites was higher in children less than 10 years old, this difference was not significant. Similarly, in the study conducted by Kooshki et al. (2023) showed that there was no considerable correlation between the gender and the prevalence of E. gingivalis and T. tenax parasites in children with cancer from Lorestan, Iran (Kooshki et al., 2023).

Although, previous investigations have indicated a positive correlation between the level of education attained by parents and the improved oral health outcomes observed in their children. This relationship is believed to stem from the fact that parents with higher educational levels tend to possess greater awareness, financial means, and healthcare opportunities essential for fostering optimal health in their offspring (Minervini et al., 2023). Our study revealed that there was a higher prevalence of oral cavity parasites in children whose parents had lower levels of education; however, no statistically significant difference was noted.

Previous studies showed higher prevalence of oral and dental diseases in lower socioeconomic status may be due to lack of prevention and treatment services as well as poor diet high in sugar (Steele et al., 2015). On the other hand, children from higher income households have more chances to access dental care, including a more specific diagnostic assessment and have one or more filled teeth, explains some of the differences in oral and dental health due to socioeconomic status (Steele et al., 2015). In the present study although no correlation was observed among between head of household’s occupation and frequency of oral cavity parasites in children with ID; however, there a significant association was reported among the monthly family income and frequency of oral cavity parasites in children with ID.

Our results indicated that residing in urban areas and tooth brushing were identified as independent risk factors for oral cavity parasites in children with ID. In line with our results, Azadbakht et al. (2023) reported a significant association between brushing teeth and prevalence of oral protozoa in hemodialysis participants (Azadbakht et al., 2023). Another study conducted by Azadbakht et al. (2022) showed that there was a significant abscission among brushing teeth and the prevalence of oral cavity parasites in pregnant women in Lorestan province, western Iran; whereas no significant correlation was found by age, education, and use of mouthwash (Kooshki et al., 2023). Conversely, Kooshki et al. (2023) have reported that the living in urban regions were considerably linked with the prevalence of oral cavity parasites in children with cancer in Lorestan province, Iran (Kooshki et al., 2023).

Although this study has limitations such as a small sample size, it is noteworthy as it is the first study in the world to demonstrate the significant prevalence of oral cavity parasites in children with mental retardation. Hence, it is imperative for dental professionals and healthcare providers involved in monitoring health to possess knowledge of oral cavity parasites and their risk factors. This knowledge is essential for effectively identifying and addressing oral health concerns in children with intellectual disabilities. This proactive approach is essential for preventing or reducing potential periodontal and other oral complications that may arise in children with intellectual disabilities.

The study identified a notable prevalence of oral cavity parasites in children with intellectual disability in Lorestan province, Western Iran. It is imperative to recognize the primary risk factors and related socio-economic factors associated with these parasites, particularly inadequate teeth brushing, in order to enhance public and oral health strategies for children with intellectual disability. Therefore, pediatric dental professionals should remain vigilant regarding these risk factors to effectively recognize and address oral health issues in this population, thereby mitigating the occurrence of oral diseases and infections.

All data generated or analyzed during this study are included in this published article.

The studies involving humans were approved by The Ethical Committee of Lorestan University of Medical Sciences approved the study protocol under the No. of IR.LUMS.REC.1401.064. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.

BS: Conceptualization, Writing – review & editing. HM: Investigation, Methodology, Writing – review & editing. AK: Validation, Visualization, Writing – review & editing. FF: Investigation, Methodology, Writing – review & editing. FK: Supervision, Validation, Writing – original draft. PB: Data curation, Supervision, Formal analysis, Project administration, Software, Writing – review & editing.