Prevalence and Risk Factors of Active Trachoma among Rural Preschool Children in Wadla District, Northern Ethiopia: A Community Based Cross-Sectional Study

Background Trachoma is a neglected eye problem and primary cause of preventable corneal blindness. In endemic areas, initial infection occurs in early childhood, and recurrent infection progress to scarring and blindness. In the past four decades, GET2020 initiative eliminated Trachoma from developed countries through enhancements of hygiene and sanitation but still a problem of developing countries. Studies and reports also indicated the presence of high prevalence of Trachoma in Ethiopia and in the study area. Thus, the purpose of this study is to assess the prevalence and risk factors of active trachoma among rural preschool children in Wadla district, Ethiopia. Methods: A community based cross-sectional study design was considered to gather data from 583 children using sample size determination, but 596 children were screened for signs of active trachoma because of the sampling procedure nature, cluster sampling technique. Wadla district has 150 rural villages, which are similar in topography and socio-demographic status. Based on rule of thumb 30 villages (clusters) were included for the data collection. An interview on socio-demographic data were collected by health informatics professionals using structured interview questioners, which were prepared through reviewing previous literatures and pretested in Meket Woreda. Eye examination was performed by Integrated Eye Care Workers who trained for one month for the purpose of trachoma screening by Carter center-Ethiopia. Results - The prevalence of active trachoma among rural pre-school children in Wadla district was 130 (21.8%). Regarding risk factors, poor economic status (AOR (95% CI), (3.8 (1.3-11.4), being 37- 48 months old (AOR (95% CI), (4.2 (1.5-12.0), thatched house roof (AOR (95%CI), (4.4 (1.4-13.6), presence of fly in nearby home (AOR (95% CI), 4.6 (2.1-9.9), once weekly face washing frequency (AOR (95% CI), 8.6 (2.5-29.3), unwashed face for longer than a week (AOR (95% CI), 10.6 (2.9-37.7), not using soap (AOR

(AOR (95% CI), 5.1 (2.0-12.9) have association with active trachoma. Conclusion: Environmental factors weigh other factors and this could capture the intention of policy makers to emphasize on the environmental components like sanitation including face cleanness to decrease the prevalence of trachoma Background Trachoma is a neglected eye problem and primary cause of preventable corneal blindness [1,2]. It is categorized as active trachoma (AT) and inactive types of trachoma [2][3][4]. In endemic areas, initial infection occurs in early childhood, and recurrent infection progresses to scarring and blindness [5,6]. Usually, trachoma is a disease of poverty, and poor hygiene [7][8][9], which mainly infect children [5], and adult women because of close and long-time contact with small children, who are the main pool of trachoma infection [10].
Globally, 60 to 80 million peoples were had been active trachoma with annual deaths of 500 and 2.3 million disability adjusted life years [11].
A study in Nigeria [12] disclosed the presence of flies on the face and absence of toilet in the compound as independent factors of active trachoma. A survey in 4 African countries revealed the prevalence of Trachomatous follicular was highest among children aged [2][3][4][5] years in Ethiopia and Niger [13].
Studies in Ethiopia reported that being female, having unclean face, not using soap, poor face washing habit, and absence of latrine as risk factors of active trachoma [14,15]. A study in Gonder indicated being 1-5 years old had association with active trachoma [16]. Consequently, in the past four decades, using GET2020 initiative as weapon trachoma had been eliminated from developed countries particularly with enhancements of hygiene and sanitation but still a problem of developing countries [19].

Sampling Procedure
Wadla district has 20 Kebeles with a total of 247 villages. Of these 150 were rural villages.
While selecting study participants two stage sampling techniques were used. The first stage was selecting 30 of 150 rural clusters or villages as study population. The second phase was choosing 583 children within those 30 villages or cluster. The study includes all children aged 1 to 5 years from 499 households based on cluster sampling assumption ( Figure 1).

Sample size determination
The sample size estimated using single population proportional formula and got 583. The assumptions used was proportion of 35.7% [12], 95% CI, 5% margin of error, 1.5 design effect and 10% non-response rate. It is calculated as identify the active stages using 2.5 times loupe magnifiers [4].

Data Analysis
Data were checked for normality using hosmer-lemeshow-goodness-of-fit, and then coded and entered into Epi-info version 7 and transferred to statistical package for social science version 23 for data analysis. Both bi-variable and multi -variable analysis was carried out.
Potential co-linearity was considered and tested. Variables with P-value less than 0.05 in multivariable analysis were considered as statistically significant.

Results
Socio -demographic characteristics of care-givers Although, the sample size was 583, a total of 596 preschool children from 499 households were screened for signs of active trachoma using cluster sampling technique. All the children aged 1 to 5 years from a single household were examined for trachoma. This causes to have 100% response rate. All 499 households' children aged 1-5 years were included in the study. All 499 households were Amhara in ethnicity and were a follower of Ethiopian orthodox Christianity (Table 1).

Environmental characteristics
Households, which consume less than 20 litter of water per day were 180 (36.1%) and 459 (92%) households were walking 1/2hr to fetch water. Seventy-four percent (371) of the respondents were had private latrine in their nearby house whereas 243 (48.7%) household's surrounding were had feces (Table S1).
Nearly, twenty nine percent of houses were had clean grass house roof, 26.7% had thatched corrugated iron roof, 27.5% had thatched grass roof and 16% were had a clean corrugated iron house roof

Characteristics of children
Off the total screened children for active trachoma 301 (50.5%) were males and 295 (49.5%) were females ( Table 2).

Environmental factors
The multi variable analysis indicated thatched grass house roof (AOR (95%CI), (4.402 (1.425-13.597), and presence of fly near to home increase the odds of active trachoma (Table 3).

Discussion
The prevalence of Active  [29]. There are also studies [14,15,25,28] that reported the prevalence of Active Trachoma above 20%. It displays that trachoma is still a public health problem. The finding also agreed with previous reports and researches [15,30] [15].
The finding of this study was lower than that of the studies done in southern Sudan was 64.5% [31], in Egypt was 49% [32], and in Nigeria was 35.7% [12]. This variation might be the result of different study period and difference in health care service. Because this study conducted after 8 years in relative to these comparing studies. In addition, intensive SAFE strategy implementation in all endemic countries were reached peak in the past seven years. Similarly, the finding is lower than many studies 59.2% [33], 32.4%, 42.4%, 5 6 .9 % [28], 62.6% [14], 40.1% [23] conducted before 2015. Therefore, the current reduction of active trachoma in the study area and in other endemic areas across the c o n t i n e n t [16] Africa, is mainly the result of SAFE strategy and improved sociodemographic characteristics. But, the finding of this study was higher than a study conducted in 2016 in Gonder, Ethiopia (12.1%) [16]. The difference might be because of different study population, level of urbanization and difference in infrastructure. This study done only in rural children aged 6 moths to 5 years but the comparative one is in urban children aged 1 -9 years old [16].
The prevalence of TI in this study area was 3.4% agreed with the study conducted in South Wollo zone was 4.3% [34], and lower than the study in South Gonder zone was 7.0% [34].
This discrepancy might be the result of different study subjects and this discrepancy agreed with the statement that the progress of trachoma from one stage to other stage is gradual and increases as age increases [2].
The study showed washing face once weekly (AOR (95%CI), 8 Written permission was also obtained from Woldia zonal health department and send to Wadla district health office. The Woreda health office was also approved the permission got from North Wollo zone health department. Finally, written consent was taken from children's parents or care givers for interview and eye screening after explaining the purpose of the study to the care givers of children. Confidentiality was also maintained by omitting the name and personal identification of respondents (both children and care givers) because it was not compelled to the study. A v a i l a b i l i t y o f d a t a a n d m a t e r i a l s The raw material supporting the conclusions of this research will be available to researchers needing the data to use for non-commercial purposes.