Helminthiases, or infections caused by parasitic worms, are a major global health concern [1]. Communities impacted by poverty and located in tropical regions, such as the Lower Mekong Basin (LMB; a region including Cambodia, Lao People’s Democratic Republic [Lao PDR], and northeast Thailand) are particularly vulnerable to such infections. The most common helminthiases in the LMB are soil-transmitted helminths (STH)—including Ascaris lumbricoides, Trichuris trichiura, and hookworm (Ancylostoma spp. and Necator americanus)—and Opisthorchis viverrini (OV), commonly known as the Southeast Asian liver fluke [2]. Reported prevalence of STH infections have reached 74% (227/308) [3], 83% (134/162) [4], and 28% (24/85) [5], in Cambodia, Lao PDR, and Thailand, respectively. OV is estimated to affect 10 million people in the LMB, the highest reported burden globally [6,7]. Several studies have reported high incidence of helminthiases among preschool- and school-aged children (SAC), often with high infection intensity [2,8-11]. Kaewpitoon et al [2] reported overall STH prevalence of 11.88% (233/1957) among SAC in the LMB in 2015; however, in some areas, prevalence reached 16.08% (152/945). Given the low sensitivity of the Kato-Katz thick smear technique used (particularly for low intensity infections), it is also possible that infection prevalence in the region was underestimated [12]. While there is limited research on OV burden in children, Yoshida et al [13] reported an OV infection rate of 39% (64/164) among children in secondary school in Vientiane, Lao PDR. Helminthiases are associated with stunting, malnutrition, anemia, chronic pain, fatigue, and cognitive deficit [14-17]. In addition, chronic OV infections are causally linked to cholangiocarcinoma, a cancer of the bile duct [18]. Transmission route varies by helminth type: STH is typically transmitted via contact with egg-infected soil, such as consumption of contaminated fruit or vegetables, or playing in contaminated outdoor spaces [19]. OV is transmitted via ingestion of raw or undercooked infected freshwater cyprinid fish [20]. The primary control strategy for STH and OV infection is mass drug administration (MDA); STH infection is typically treated with benzimidazole anthelmintics [19]. Treatment efficacy varies against species: cure rates exceed 90% for Ascaris, 50% for hookworm species [21], and 25% for Trichuris [22]. The recommended treatment for OV is praziquantel [23]. Several studies have found praziquantel to be highly efficacious against OV infection, with cure rates exceeding 90% [24,25]. However, while MDA is effective in treating helminthiases, it does not prevent reinfection. As such, further measures such as education on helminth control and prevention are needed.

Children are an important group for targeted behavioral and educational interventions. Between the ages of 5 and 12 years, children undergo major cognitive growth, including the formation of beliefs and attitudes [26,27]. Health education during this period can inform long-term habits and behaviors [26-28]. SAC are also a well-placed group for intervention delivery, as schools are institutions trusted by children and their families, and can facilitate delivery to a large population, as recognized in World Health Organization’s (WHO) Global School Health Initiative [29].

The “Magic Glasses” is a school-based cartoon health education package that has demonstrated success in improving STH knowledge and attitudes, improving water, sanitation, and hygiene (WASH) practices and reducing disease burden in affected communities [30,31]. The intervention is designed to be relatable and engaging for children, with the cartoon set in the local context, and the protagonists being schoolchildren who learn about STH transmission, symptoms, treatment, and prevention as they explore their community [30,31]. The original “Magic Glasses” in China achieved major improvements in self-reported STH knowledge, attitudes and behaviors, as measured by a knowledge, attitudes, and practices (KAP) questionnaire: the intervention group scored 24.9 percentage points higher than the control after adjusting for baseline scoring (95% CI 23.4-26.4; P<.001) [31]. Overall KAP scores were inversely correlated with STH infection, with uninfected students scoring 9.9 percentage points higher than infected students (95% CI 5.8-14.0; P<.001) [31]. With respect to infection burden, the intervention led to a 50% decrease in STH incidence among intervention schools (odds ratio 0.5, 95% CI 0.35-0.70; P<.001) [31]. From 2016 to 2017, the “Magic Glasses” educational package was adapted for the Philippines, a country with estimated 33% STH prevalence [30]. “Magic Glasses Philippines” led to significant improvements in knowledge and behavior among intervention schools scoring 5.5 percentage points higher than control schools in the knowledge component of the KAP questionnaire (56.8, 95% CI 55.7-57.9 vs 51.5, 95% CI 50.3-53.7; P<.001) and 1.1 percentage points higher in the behavioral component (87.2, 95% CI 86.6-87.9 vs 86.1, 95% CI 85.4-86.8; P=.002) [30]. With respect to disease burden, the intervention achieved a 60% reduction in the odds of any STH infection in intervention schools with a baseline prevalence <15% (adjusted odds ratio 0.4, 95% CI 0.20-0.70; P<.001), although it is important to note that the intervention did not significantly reduce odds of infection when higher prevalence schools were included [30]. Following the success of the “Magic Glasses Philippines” trial, the intervention is now being recommended for roll-out across the Philippines as part of the school curriculum.

The present study is designed to assess the acceptability of 2 new “Magic Glasses” cartoons, developed for the LMB, and their impact on schoolchildren’s self-reported KAP of STH and OV. Several studies have identified acceptability as a key indicator for initial and sustained intervention success [32-36]. However, there remains a lack of consistency among acceptability measures and definitions in public health research. Sekhon et al [37] developed the Theoretical Framework of Acceptability (TFA), and defined acceptability as “a multi-faceted construct that reflects the extent to which people delivering or receiving a healthcare intervention consider it to be appropriate, based on anticipated or experienced cognitive and emotional responses to the intervention” [37]. The TFA outlined 7 domains of acceptability, “affective attitude, burden, perceived effectiveness, ethicality, intervention coherence, opportunity costs, and self-efficacy” [37]. In order to conduct a robust assessment of all the domains of acceptability, the acceptability of the intervention will be assessed using mixed methods. Quantitatively using an adapted version of the TFA questionnaire [38] and qualitatively using focus group discussions (FGDs) with schoolchildren and key informant interviews (KIIs) with teachers. The KAP questionnaire will be administered at baseline and follow-up to assess the impact of the intervention, and the intervention coherence domain of acceptability.

While previous Magic Glasses studies have demonstrated the impact of the cartoon in improving KAP surrounding helminths, a more detailed assessment of acceptability is required. Firstly, this study aims to determine whether the “Magic Glasses” OV and STH video education packages will be acceptable to schoolchildren and their teachers in LMB. Secondly, this study will be the first “Magic Glasses” to target OV, in addition to STH. Finally, this study aims to determine the impact of the “Magic Glasses” cartoons on students’ KAP on OV and STH infection.

The trial is a cluster randomized controlled trial (cRCT) with 2 arms, intervention and control. As the intervention will be delivered through schools, a cRCT design was chosen for practical reasons and to minimize contamination. Each school participating in the trial is a “cluster.” Schools will be randomly allocated to intervention and control. Schools in the intervention arm will receive the “Magic Glasses” education package developed for LMB, consisting of “Magic Glasses Opisthorchiasis” (MGO) and “Magic Glasses Lower Mekong” (MGLM), in addition to the standard health education activities in accordance with local government guidelines. Schools in the control arm of the study will receive the standard health education activities only in accordance with local government guidelines.

The study will be conducted in accordance with the ethical principles of the Australian National Statement on Ethical Conduct in Human Research [39]. Prior to data collection, an information sheet detailing the purpose of the study, potential risks, research contact information, and informed consent form in the local language will be distributed to parents and caregivers. Only schoolchildren who have provided informed assent and parental consent will be included in the study. Participants will not receive compensation for their involvement in the study but will be able to withdraw at any time. In the case that a participant does withdraw from the study, their responses will not be used in analyses. All quantitative data will be collected on paper questionnaires. Qualitative data (KIIs, FGDs) will be recorded using audiotapes and transcribed. To protect participant privacy, all responses will be deidentified prior to data analyses.

The study protocol was submitted to and received ethical approval from the Australian National University Human Ethics Committee (approval number 2022/507), the Cambodia Ministry of Health National Ethics Committee for Health Research (N197NECHR dated June 27, 2023), the Lao PDR Ministry of Health National Ethics Committee for Health Research, and Khon Kaen University Ethics Committee for Human Research (HE651147, record number 4.2.03:16/2565). The study is registered at Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12623000271606.

The trial will be conducted in rural primary schools in Preah Vihear Province, Cambodia; Savannakhet Province, Lao PDR, and Khon Kaen Province, Thailand. To maximize homogeneity within each country, schools will be recruited from the same district where possible. To minimize the risk of contamination, all control and intervention schools will be at least 3 km apart.

A total of 684 schoolchildren in Grades 3-6 from randomly selected schools in Cambodia, Lao PDR, and Thailand will be recruited into the study cohort and followed up approximately 9 months after baseline. During the follow-up period, 1 teacher and 3-5 parents will be recruited from each intervention school.

Among the recruited schools, children across Grades 3-6 who provided consent and assent will be eligible for this study.

Based on local expertise on school student numbers in each country, approximately 6 schools will be selected in each country to achieve a total sample size of 228 per country. Prospective schools will be selected in consultation with the local departments of education. Once schools are identified, permission to conduct the study will be sought from the principal of each selected school. Teachers and parents or legal guardians of prospective participants will then receive an information sheet outlining the procedure and purpose of the study and contact information, and a consent form. On receiving the written parental or guardian consent, the aims, process, and outcome of study will be explained to prospective student participants and their written assent will be sought. Only schoolchildren who have provided informed assent and parental consent will be included in the study. Teachers and parents will be recruited a month before follow-up. As part of the recruitment process, an information sheet will be provided and informed consent will be sought. Once written consent is obtained, teachers and parents will be recruited into the study.

Schools within each country will be randomly allocated to control or intervention arm using Microsoft excel (Microsoft 365) RAND function. Allocation will remain for the duration of the project.

Blinding will not be possible in this cRCT. Due to the nature of the intervention, participants will be aware of whether they are in the intervention or control arm.

The “Magic Glasses” education package will be comprised of two animated cartoon packages developed specifically for the Lower Mekong setting: (1) MGO, an educational cartoon addressing OV infection, including transmission, symptoms, treatment, and prevention, and (2) MGLM, an educational cartoon addressing STH infection, including transmission, symptoms, treatment, and prevention. Each package includes an educational cartoon, an accompanying comic pamphlet with key messages and images from the cartoon, and engaging reinforcement activities for students (drawing competition and essay competition).

Study commencement will be staggered across Thailand, Cambodia, and Lao PDR, based on the school periods in each country. Prior to study commencement and intervention delivery, all study materials will be translated into the local language by the local research team in each country. For anticipated study dates in each country, see Multimedia Appendix 1.

The sample size was calculated to achieve 80% power, assuming baseline knowledge of 30 percentage points (as reported in the original “Magic Glasses” intervention by Bieri et al [31]) and a design effect of 2 to account for cluster sampling. Accounting for 10% attrition, it was estimated that a total of 227 participants would be needed to detect a difference of 5 percentage points in knowledge between intervention and control groups. As such, we will aim to enroll a total of 228 schoolchildren in years 3-5 (114 in intervention arm, 114 in control arm) in each country.