The goal of this clinical trial is to assess whether providing hand and respiratory hygiene interventions in primary school children reduces the incidence rate of absence episodes due to illness in children during an academic year.

The main questions it aims to answer are:

This study aims to assess whether providing hand and respiratory hygiene interventions in primary school children reduces the incidence rate of absence episodes due to illness in children during an academic year.

1. Describe socio-demographic characteristics of participants (school children).
2. Assess the impact of hand and respiratory hygiene intervention on the incidence rate of respiratory illnesses.
3. Assess the impact of hand and respiratory hygiene intervention on the incidence rate of gastrointestinal illnesses.
4. Assess the impact of hand and respiratory hygiene intervention on the length of illness absence episodes.
5. Determine the factors associated with the increased or reduced impact of hand and respiratory hygiene intervention on school absenteeism.

Parallel-group cluster randomized trials take place in primary schools, where schools are allocated using restricted randomization to the intervention or control group. All children (aged 9-13 years) in attendance at participating intervention schools will receive an in-class hand and respiratory hygiene education session and will be provided with soap, shampoo, and shampoo dispensers in school at the beginning of the starting trial (around November). The in-class hand and respiratory hygiene education sessions will be repeated on a monthly basis in the intervention schools.

Control schools will not receive these specific interventions but will continue to receive any hygiene aspects included in the study program. The primary outcome is the number and length of absence episodes due to illness among follow-up children and the reasons for absence, including any respiratory and gastrointestinal infections during the academic year (November to May the following year). The incidence of respiratory and gastrointestinal illnesses will be recorded, even if they do not cause school absences.

Intervention Children in intervention schools will receive an approximately 30-minute in-class hand hygiene education session at the beginning of the study. They will be instructed in the use of hand hygiene and asked to use it after coughing/sneezing and on the way out of the classroom for morning break and lunch. The in-class hand and respiratory hygiene education sessions will be repeated on a monthly basis. In addition, educational posters about hand hygiene and when and how to wash hands will be installed in each school (classrooms and/or corridors) as a reminder for schoolchildren. Caregivers of children at intervention schools will be sent a letter home with the school newsletter explaining the study and asking them to let their child's teacher know Control Children in the control schools will not receive specific hygiene education, and hand soap will not be provided in the school.

Follow up The researcher will visit each school in both the intervention and control groups on a weekly basis to record any absenteeism of schoolchildren and follow up on the reasons with the school and the parents. The occurrence of any illnesses, even without absenteeism, will be recorded.

Inclusion Criteria:

• The study population comprised 802 students from twelve randomly selected public primary schools in Erbil, Iraq. Eligible participants were children enrolled in grades four to six (aged 9-13 years) attending public schools within Erbil city center. All students in the selected schools were invited to participate. Written informed consent was obtained from parents or guardians, and verbal agreement was provided by the children prior to enrollment.

Exclusion Criteria:

• Exclusion criteria included students attending private, evening, or special schools (e.g., for children with disabilities), as well as those with chronic medical conditions likely to influence school attendance. Bilingual schools (English-Arabic) were excluded to maintain comparability in the educational environment.

The study population comprised 802 students from twelve randomly selected public primary schools in Erbil, Iraq. Eligible participants were children enrolled in grades four to six (aged 9-13 years) attending public schools within Erbil city center. All students in the selected schools were invited to participate. Written informed consent was obtained from parents or guardians, and verbal agreement was provided by the children prior to enrollment.

Single (Outcomes Assessor)