Prevalence and Factors Associated with Trachoma among Primary School Children in Harari Region , Eastern Ethiopia

Introduction: Trachoma is the leading infectious cause of blindness worldwide. It is more common in areas where people are socio-economically deprived. Although trachoma is endemic in 571 districts in Ethiopia, its prevalence has not been studied among school children in Harari Region. Objective: To assess the prevalence of trachoma eye infection and factors associated with it among Grades 1-8 schoolchildren in Harari Region, from November 30, 2015 to April 29, 2016. Methodology: A cross-sectional study was done on 1722 students selected from four primary schools. Data were collected using WHO simplified trachoma grading scheme and analysed by SPSS Version 16. The factors influencing the outcome variable were identified via Logistic Regression, and predictors through Odds Ratio and the corresponding confidence intervals. Results: The overall prevalence of trachoma was 1.3% (22/1722) in which 14 had Trachoma Follicular and 8 had both Trachoma Follicular and Trachoma Intense. Unclean face (AOR 3.4, Original Research Article Assefa et al.; OR, 7(3): 1-9, 2017; Article no.OR.37212 2 CI 1.01-11.42), no maternal education (AOR 4.324, CI 1.189 to 15.729), family size of >5 (AOR 7.069, CI 2.248 to 22.228), families monthly income of less than 1000 Ethiopian Birr (AOR 5.71, CI 1.643 to 19.823), and solid waste collected by municipality (AOR 12.672, CI 1.289 to 124.57) were associated with trachoma eye infection. Conclusion: Both Trachoma Follicular and Trachoma Intense are less prevalent among Grades 18 school children in Harari Regional State.


INTRODUCTION
Trachoma is an eye disease caused by bacterium, Chlamydia trachomatis.It is the leading infectious cause of blindness worldwide [1].Nearly 182 million people live in trachoma endemic areas and are at risk of trachoma blindness.The disease is a public health problem in 42 countries, and responsible for the blindness or visual impairment of about 1.9 million people [2].
Ethiopia is one of the most trachoma endemic countries in the world: more than 75 million Ethiopians, the largest number in the world, live in trachoma-endemic areas [2].Its 571 districts were projected to be endemic above the treatment threshold for trachoma by 2016 [3].
The World Health Organization's simplified trachoma grading scheme defines active trachoma as TF and/or TI.TF (trachomatous inflammation follicular) is the presence of five or more follicles in the central part of the upper tarsal conjunctiva, each at least 0.5 mm in diameter, and TI (trachomatous inflammationintense) is pronounced inflammatory thickening of the upper tarsal conjunctiva that obscures more than half of the normal deep vessels [4].Active trachoma is associated with young age, poor access to water and sanitation, and close contact between people.Discharge from the eyes and nose may facilitate the transmission of ocular C trachomatis infection [5].
Studies show that school surveys are important to determine the prevalence of neglected tropical diseases like trachoma in a community [6].But several studies conducted in different parts of Ethiopia [7][8][9][10] were community based, in children 1-9 years, and in adults; they excluded age group of 9-18 years who are attending primary schools and who may be equally infectious.Therefore, the objective of this study was to assess the prevalence of trachoma eye infection and the factors associated with it among primary (Grades 1-8) school children in Harari Region, eastern Ethiopia, from November 30, 2015 to April 29, 2016.

Study Setting and Period
A school based cross-sectional study was conducted in Harari region, Eastern Ethiopia.Harar, the capital of Harari peoples Region, is found in eastern Ethiopia, 515 Kilometres away from Addis Ababa.The region had a projected total population of 210,438 (M: F=102, 369:101,069) in 2010 [11].The net education attendance ratio in the region was 79.8% for male and 77.6% for female, whereas the health service coverage was estimated to be above 100% [12].More than half of the population live in urban areas.In the year 2015/16, there were 84 primary schools (Grades 1-8), of which 62 were government schools (39 rural, 23 urban), 17 were private schools, and 5 were inside religious organizations (1 inside mosque and 4 inside church).In same academic year, there were 41,336 students (35,733 in government schools and 5,603 in private/NGO schools [13].The study was conducted from November 30, 2015 to April 29, 2016.
All the primary school children in Harari Region were included as a source population.And, the primary school children in the randomly selected 4 schools and who were below 18 years of age were the study population.

Sample Size
The sample size was calculated manually by single population proportion formula at a precision of 2%, 95% confidence interval and p value of 0.15 [14] and design effect of 1.5.This gives a sample size of 1836.

Sampling Technique
First, schools were stratified by geographical location of urban and rural.Second, these schools were further stratified as government, private, and inside religious institutions.One school from each stratum was selected using a lottery method, and this was done after thorough observations that the four schools represent all the primary schools.The randomly selected schools were Deker primary school (Government rural), Ras Mekonin primary school (government urban), SOS primary school (private urban) and Mekane Silassie primary school (inside religious institution).All students in these 4 schools that fulfilled inclusion criteria were included in the study.

Data Collection Instrument and Procedure
Data were collected by 4 BSc nurses on a-faceto-face interview using a pre-tested questionnaire.Two-days training was given to the data collectors by an ophthalmologist and investigators on trachoma grading and data collection.Clinical evaluation for trachoma eye infection was done according to the simplified WHO trachoma grading scheme with adequate light in the respective class rooms of students.All the students were subjected for eye examination of TF, TI, corneal opacity (CO), and trichiasis of both right and left eyes.The children were also assessed for facial uncleanness, which was defined by the presence of ocular discharge, nasal discharge and/or flies on the face.

Environmental Variables
Schools were visited three times to cover maximum number of enrolled students.Both positive and negative results were documented in the questionnaire and confusing cases were confirmed by senior ophthalmologist.All the children with active trachoma eye infection were treated with two tube of tetracycline eye ointment in their respective schools and community according to WHO recommendations.

Data Quality Control
The data collection tool was prepared in English and translated into Afan Oromo and Amharic (the local languages of the students).Two days training was given to data collectors and supervisors.Before the actual data collection, inter-observer agreement exercise involving a reference grader of proven accuracy was conducted in one school other than the selected urban schools, according to WHO criteria [15,16].Trained data collectors and ophthalmologist with experience on trachoma assessment have examined the upper tarsal conjunctiva for clinical signs of trachoma according to simplified WHO criteria [15].The presence or absence of TF and TI was documented.The inter-observer agreement between the ophthalmologist and data collectors was good, with weighted Kappa value of 0.64 (95% CI 0.57-0.79)for TF and 0.57 (95% CI 0.47-0.62)for TI.Close supervision was undertaken during data collection by supervisors (Paediatrics nurse and ophthalmologist) and investigators daily until the end of data collection.Every evening the questionnaires were checked by supervisors and investigators for completeness of the data to back trace if any missing variables were detected.Double entry was made on Epi Data Version 3.1 to minimize data entry errors.

Data Processing and Analysis
Data were coded, cross-checked and entered to EPI Data Version 3.1 and then exported to SPSS Version 16 for analysis.Both descriptive and analytical statistical analyses were performed.Multiple logistic regressions (Bivariate and multivariate analyses) was done to control for confounders, and odds ratios and corresponding confidence intervals were used to report the association between dependent and independent variables.By bi-variate analyses, a p-value of ≤0.05 was considered for multivariate analyses.By multi-variate analyses, the variables which had independent association with active trachoma were identified on the basis of Odds Ratio, with 95 % CI and p value less than 0.05.Frequencies, percentages and mean were used to describe the results.

Ethical Considerations
Ethical clearance was obtained from Haramaya University College of Health and Medical Sciences Institutional Health Research Ethics Review Committee (IHRERC) and submitted to Harari Region Educational Bureau, and the selected schools (school principals were consented).Letters of cooperation were written from Harari Region Education Bureau to the respective schools.Parents, students, and their class room teachers were informed about the objectives, risks, and benefits of the study and after participants' information sheet had been read in their respective schools, written and signed consents were obtained from parents.
Confidentiality of students' personal information and privacy were strictly maintained throughout the study.After the data collection, information on the causes, clinical features, complications, treatments, and prevention of eye trachoma was given to all the students and teachers.

Household Environment
Most of the households, 1537 (89.26%), got water from pipe to their yard, but 689 (40%) of the households said that the quantity of the supply was not enough.Most of them, 1534 (88.2%), collected solid waste in temporary storage bins and disposed it in nearby receptacles which was emptied by city municipality.See Table 2.
During the survey, 1589 (92.3%) of the students were with clean face, no discharge and flies on their eyes.

Prevalence of Active Trachoma Eye Infection
The overall prevalence of active trachoma among the primary school children in Harari Region was 1.3% (22/1722).From the 22 cases, 14 had Trachoma Follicular (TF) and 8 had both Trachoma Follicular (TF) and Trachoma Intense (TI), and 13(59.1%)were in age group of 10-18 years.The disease was more in SOS (11/22) and Deker (8/22) schools.

Factors Associated with Trachoma
The factors which were associated with trachoma eye infection were unclean face (AOR 3.

DISCUSSION
The prevalence of active trachoma eye infection in this study (1.3%) was lower than the one found by a longitudinal study conducted in rural Ethiopian schools, in which 15% of the students had the disease before intervention and 6.7% after intervention (p<0.001)[14].This finding is comparable with 0.2% to 2.2% prevalence in Lao People's Democratic Republic [17].It was lower than the prevalence of 22.16% in Shandong Province in China [18], 5% prevalence in Brazil and Australian studies [19,20].This difference might be due to the fact that most of our study subjects were from urban areas.
In this study, like the ones in Ankober and Enemor districts [8,9,26] in Ethiopia, Tanzania and Gambia, no or only primary school maternal education was associated with trachoma eye infection.Moreover, small monthly income was associated with active trachoma infection in this study.This is similar with study findings in Baso Liben District, Ethiopia [5] and Sao Polo, Brazil [27].This may be due to children's wellbeing is highly associated with maternal education and wealth status.As the mother is better off, the possibility of getting good nutrition, proper hygiene and health care seeking for trachoma eye infection would be high.

CONCLUSIONS AND RECOMMENDA-TION
The study found that the overall prevalence of trachoma eye infection among primary school children in

CONSENT
As per international standard or university standard, patient's written consent has been collected and preserved by the authors.

Table 3 . Factors associated with active trachoma eye infection among grade 1-8 students, Harari regional state, Ethiopia, 2015/16
Harari Regional State was 1.3% (22/1722).Both Trachoma Follicular and Trachoma Intense are less prevalent.But, further investigation is needed at community level especially in the rural areas to classify Harari region according to WHO criteria.
As per international standard or university standard, written approval of Ethics committee has been collected and preserved by the authors.and environmental risk factors for active trachoma in children in Yobe state, northeastern Nigeria.Tropical medicine & international health: TM & IH.2010; 15(2):168-172.23.Quicke E, Sillah A, Harding-Esch EM, Last A, Joof H, Makalo P, Bailey RL, Burr SE: