High prevalence of active trachoma and associated factors among school-aged children in Southwest Ethiopia

Abstract

Background

Active trachoma is a highly contagious ongoing stage of trachoma that predominantly occurs during childhood in an endemic area. This study assessed the prevalence and factors associated with active trachoma among school-aged children.

Methodology/Principal findings

A community-based analytical cross-sectional study was done from March 1st to June 30th, 2021, in Southwest Ethiopia’s people’s regional state. A total of 1292 school-aged children were surveyed. The quantitative data were collected using a pre-tested, structured interview-based questionnaire and observation check list. The World health organization (WHO) simplified trachoma grading system was used to assess stages of trachoma. In this study, the prevalence of active trachoma was 570(44.1%), 95% CI (41.4, 46.9). Also, age group 6–10; being female; flies at household (HH), flies on child’s face, improved water source, improved sanitation, presence of ocular discharge, presence of nasal discharge, and unclean faces of the child were significantly associated with active trachoma.

Conclusions/Significance

The very high prevalence of active trachoma in the study area is significantly associated with; age group 6–10, female gender, presence of flies in household and on child’s face, presence of ocular and nasal discharge, unclean faces, improved water source, improved sanitation in the household. Thus, environmental sanitation and facial cleans trachoma elimination strategy should be intensified in the study area.

Author summary

Trachoma is the leading cause of preventable blindness, due to repeated bacterial infection of the eye. The early and contagious stage of the disease, known as active trachoma, predominantly affects children. The impact of the disease includes permanent visual impairment, dependency and stigma.

The WHO targeted to eliminate trachoma by 2030 as a public health concern in each endemic country. Through the implementation of the SAFE strategy (surgery to treat the blinding stage; antibiotics to clear infection; environmental improvement; improving access to water and sanitation).

In Ethiopia majority of the districts are still trachoma endemic. Thus, this study assessed the prevalence and factors associated with active trachoma among school-aged children in Southwest Ethiopian Peoples Regional State. The region is highly endemic for several neglected tropical diseases including trachoma.

In this study 44.1% of the participant had active trachoma. Also, age groups 6–10, being female, improved water sources, and sanitation, presence of flies in the house and on the child’s face, ocular and nasal discharge, unclean faces were factors associated with the occurrence of active trachoma.

Intensive scaling up of the facial cleanness and environmental improvement components of the SAFE strategy helps reduce the high prevalence of active trachoma.

Introduction

Trachoma is a neglected tropical disease caused by the bacterium Chlamydia trachomatis [1]. The disease is transmitted by direct personal contact and by flies that have come into contact with discharge from an infected person’s eyes or nose [2]. Trachoma limits the education and economic empowerment of infected individuals, which results in dependency and stigma [3]. Communities who lack access to water, sanitation, and hygiene (WASH) were primarily affected by trachoma [4,5].

Trachoma has five clinical stages: trachoma follicular, trachoma intense, trachoma scarring, trachomatous trichiasis, and corneal opacity [1,6]. Active trachoma, an early stage of trachoma, is conjunctival inflammation, which can lead to, scarring, and blindness if untreated [3,6–10]. Globally, from 166.6 million people lived in trachoma-endemic areas in 2019, 87% were from African and 46% from Ethiopia [11–15].

A multitude of factors were associated with active trachoma, including age of the child and the number of children [16–18]; as access WASH at HH [2,12,17–19]; presence of ocular and nasal discharge, habit of face washing, not using soap while washing the face, and sharing towels [12,16,18].

The SAFE strategy is being implemented in endemic countries eliminate trachoma as a public health importance [20–23]. But, in Ethiopia 80% of districts were endemic and majority of HH lack access to improved WASH [13,24–26]. However, no research has assessed the prevalence of active trachoma in the study area. This study aimed to assess the prevalence of active trachoma and associated factors among school-aged children in Southwest Ethiopia Peoples Regional State (SWEPRS).

Methods

Ethics statement

The Ethics and Research Committee of Mizan-Tepi University approved and issued the ethical clearance. Also, permission was obtained from the zonal health department. Informed written consent was sought from parents and assent from children aged 7–16 years. All participants were informed the aims, purpose, risks, and benefits of the study. Throughout the study, confidentiality, anonymity, and the freedom to withdraw from the study at any time were respected. The data was kept safe under strict supervision by the principal investigator. Children who have active trachoma were treated by tetracycline eye ointment, and referral linkage was made with a health facility.

Study design and settings

A Community based Analytical cross- sectional study was done in SWEPRS from the 1^st of March to the 30^th of June, 2021, as part of a broader research theme ‘prevalence of selected neglected tropical diseases among school-aged children in SWEPRS.’ The region is divided into six zones: Kaffa, Bench-Sheko, Sheka, West-omo, Dawro, and Konta Zones. In these zones, there are 57 districts (41 rural districts and 16 city administrations). There are also kebeles in the region (kebele is the lowest legal administrative division in Ethiopia). The total population of the region is 3,368,385 [27]. In the region, there are one teaching university hospital, two general hospitals, 10 primary hospitals, 134 health centers, and 836 health posts.

Study population and eligibility criteria

All school-aged children whose age was found in the range of 6–16 year in SWEPRS were the source population. All school-aged children whose age was found in the range of 6–16 year and lived in selected HH during the data collection were the study population. All school-aged children, irrespective of their school enrollment status, paired with HH heads who lived in the selected kebele for at least 6 months were included in the study. Children who were severely ill and unable to respond or participate were excluded from the study.

Sample size determination and sampling technique

The sample size was calculated using Epi info software, For the first objective, with the assumptions: prevalence of active trachoma 17.5% [13], margin of error 5%, Z/2 95% CL = 1.96, and design effect 2. The calculated sample was 444. For the second objective; considering the assumption: Z/2 95% CL = 1.96, the open defecation-free status variable with OR 2.52, percent of outcome in exposed 85.5% [13], the calculated sample size was 1200 and adding 10% for non-response rate makes the final sample size 1320.

A multi-stage sampling technique was used. First, three zones: Bench-Sheko, Kaffa, and West-Omo were selected randomly. The selected zones were stratified in to rural districts and city administrations to select 12 rural districts and 4 city administrations. At least 30% kebeles in each selected strata were selected by using the lottery method. The sample was proportionally allocated to each selected kebele based on their contribution. Finally, a sampling frame was prepared by listing HH that have eligible individual, and participants were selected using a simple random sampling technique. If more than one school-aged child lived in the same HH, one child was selected by lottery method.

Variables of the study

Dependent variable

Presence or absence of active trachoma.

Independent variable

Socio-demographic characteristics include: the sex of the HH head, education status of the HH head, occupation of HH the head, family size and number children aged 1 to 9 years in the HH. Behavioral factors include: frequency of face washing, using soap, discharge from the eye and nose, presence of flies on child face.

Environmental and WASH related factors includes: Prescence of feces around the HH, waste disposal, source of water, distance to water source and availability of latrine.

Operational definitions

Active trachoma: the presence of five or more follicles greater than 0.5 mm in diameter in the central part of upper tarsal conjunctiva or inflammatory thickening of the tarsal conjunctiva that obscures more than half of the normal deep tarsal vessels in either of the child’s eyes [9,28].

Improved water sources: adequately protected from outside contamination, in particular from fecal matter HH connections, public standpipes, boreholes, protected dug wells, protected springs and rainwater collection [29,30].

Improved sanitation; is flush or pour-flush to piped sewer system, septic tank pit latrines, ventilated-improved pit latrines, or pit latrines with slab or composting toilets [29,30].

Unclean face: Any dust and food on the face during clinical examination [16].

Data collection methods and materials

The data were collected using a structured interviewer-administered questionnaire, and observational checklist prepared and adopted after reviewing relevant literature [16,18], and a simplified WHO trachoma grading system [9,28]. The interview questionnaire measures sociodemographic characteristics, and behavioral factors. The interview was conducted by four trained public health professionals in the participants compound where they are comfortable. The observation check list was used to measure the HH and surrounding for WASH status. The observation was done by four trained environmental health professionals immediately after the interview was completed. The clinical trachoma grading was done by four trained BSc nurses to clinically diagnose each eye of the child.

Data quality control

The questionnaire was prepared in English, then translated into Amharic and retranslated back to English to keep consistency. Also, the interview questionnaire was pretested on 5% of the sample in area where the study was not done. In addition, the data collectors and supervisors were trained on the purpose of the study, data collection technique for two days. Supervisors and investigators checked the collected data for completeness, accuracy.

Data processing and analysis

The data were coded, cleaned, and entered into Epi Data Version 4.02, then exported to SPSS version 23 for further analysis. In bivariable logistic regression analysis variables with p-value less than 0.2 were entered in to multiple logistic regression. In multiple logistic regression variables with p-value less than 0.05 were considered as significantly associated with active trachoma. The model fitness was assessed using Hosmer -Lemeshow and Omnibus test. Finally, the adjusted odds ratio (AOR) reported with 95% CI.

Result

Socio-demographic characteristics of the study participants

In this study 1292 school-aged children participated; the response rate was 97.87%. Nearly half of the study participants were female (55%) and in the age group 6–10 (53%). The majority of study participants (86%) were rural. Moreover, 46% and 12% of the study participants were from 1^st cycle and 2^nd cycle primary schools, respectively. Also, 42% of the participants did not enroll in school (Table 1).

Table 1. Socio-demographic characteristics of study participant (n = 1292).

Variables Category		Frequency(n)	Percent (%)
Place of residence	Urban	155	14
	Rural	1087	86
Number children aged 1–9	One	653	51
	Two or more	639	49
Family size	1–2	438	34
	3–5	439	34
	Above 5	415	32
Wealth index	Poor	609	47
	Medium	420	33
	Rich	263	20
Sex of the child	Male	582	45
	Female	710	55
Age of the child	6–10	680	53
	11–16	612	47
Child enrolment status	Enrolled	747	58
	Not enrolled	545	42
Child educational level	Not enrolled	545	42
	First cycle	594	46
	Second cycle	153	12

HH: Household

Environmental characteristics of the households and surrounding

In this study, (55%) and (56%) of the HH have improved water sources and sanitation. Only 17% of the HH get water within premises. The latrine coverage was 572(44%), but 729(56%) of the child defecate in the field. In 819(63%) and 468 (36%) of the compound of the HH and around the HH human feces and animal feces were observed respectively. In 503(39%) of the HH domestic animal were present. In 956(74%) of the HH the waste disposal system was improper, and in 567 (44%) of the HH flies were observed (Table 2).

Table 2. Environmental characteristics of the households and surrounding.

Variables Category		Frequency(n)	Percent (%)
Source water for HH	Unimproved	575	45
	Improved	717	55
Time to fetch water	1–30 minute	214	17
	30–60 min	740	57
	Above 60 min	338	26
Availability of latrine facilities at HH	Yes	568	44
	No	724	56
Latrine type	Improved	572	44
	Not improved	720	56
Utilization of toilet by the child	Latrine	563	44
	Open field	729	56
Feces near the HH	Yes	819	63
	No	473	37
Domestic animal in the HH	Yes	503	39
	No	789	61
Fece of animal around HH	Yes	468	36
	No	824	64
Is there a flies seen at HH	Yes	567	44
	No	725	56
Waste disposal system	Proper	336	26
	Improper	956	74

HH: Household

Behavioral characteristics of the school aged children

In this study only 374(29%) of school aged children wash their hands and face daily. But only 6% of them uses soap to wash their hands and face. Also, nasal and ocular discharge were observed in 203 (16%) and 220 (17%) of school aged children respectively. Half 646 (50%) of school aged children participated in the study lack facial cleans (Table 3).

Table 3. Behavioural characteristics of school-aged child, Southwest Ethiopia, 2021.

Variable’s Category		Frequency(n)	Percent (%)
Face washing habit	Yes	374	29
	No	918	71
Frequency face washing daily	Do not wash	918	71
	Once a day	170	13
	Two or more	204	16
Using soap to wash hands and face	Water only	297	23
	Soap with water	76	6
	Do not wash	919	71
Clean nail	Yes	241	19
	No	1051	81
Nasal discharge	Yes	203	16
	No	1089	84
Ocular discharge	Yes	220	17
	No	1072	83
Flies y on the child face	Yes	203	16
	No	1089	84
child’s face	Clean	646	50
	Unclean	646	50

Prevalence of active trachoma

In this study, the overall prevalence of active trachoma among school aged children in was 44.12 with 95% CI (41.4, 46.9) (Fig 1).

Fig 1. Prevalence of trachoma among school-aged children in Southwest Ethiopia Peoples Regional States, 2021.

Factor associated with active trachoma

In bivariable logistic regression age group, gender, number of children aged 1–9 years, water source, face washing, availability of latrine, sanitation, human and animal feces at HH, flies in the HH, ocular and nasal discharge, flies on the child’s face, and condition of child’s face were variables showed association at p value less than 0.2. In the multiple logistic regression, age group, gender, water source, sanitation status, flies at HH, ocular discharge, nasal discharge, flies on the child’s face, and condition of child’s face were the variables significantly associated with active trachoma at P value less than 0.05.

Accordingly, the odds of active trachoma were 2.15 times higher among study participants in the age group 6–10 years than those in the age group 11–16 year [adjusted OR = 2.15 (95% CI: 1.51–3.06)]. Similarly, the odds of active trachoma were 15.36 times higher among female children than males [adjusted OR = 15.36 (95% CI: 10.79, 21.86)]. Also, the odds of active trachoma were decreased by 53% and 31% among study participants who have access to improved water source and improved sanitation at their HH [adjusted OR = .47 (95% CI: (.33,.67)]and [adjusted OR = .31 (95% CI: (.22,.59)] respectively.

In addition, the odds of trachoma were 16.26 and 7.19 times higher among study participant in whom HH flies were observed at their HH and on their face [adjusted OR = 16.26 (95% CI: (9.93,26.64)] and [adjusted OR = 7.19 (95% CI: (3.87,13.34)] respectively. On top of this, the odds of active trachoma were 10.18 and 1.61 times higher among study participants who have ocular discharge and nasal discharge [adjusted OR = 10.18 (95% CI: (5.84,17.76)] and [adjusted OR = 1.61 (95% CI: (1.06, 2.46)] respectively.

Moreover, the odds of active trachoma were 2.29 times higher among study participants whose faces were unclean [adjusted OR = 2.29 (95% CI: 1.57, 3.34)] (Table 4).

Table 4. Bivariable and Multiple variable analysis of factors associated with trachoma among School aged children in Southwest Ethiopia, 2021.

		Trachoma		COR (95% CI)	AOR (95% CI)
		Yes	No
Age of the child	6–10	253	427	1.81(1.45,2.27) *	2.15(1.51,3.06) **
	11–16	317	295	1	1
Sex of the child	Male	435	147	1	1
	Female	135	575	12.60(9.67,16.4) *	15.36(10.79,21.86) **
Number of Children in HH	One	307	346	1	1
	Two or more	263	376	1.27(1.01,1.58) *	1.10(.79,1.53)
Water source	Unimproved	293	424	1	1
	Improved	277	298	.71 (.59, .92) *	.47(.33,.67) **
Face washing	Yes	87	287	3.66(2.79, 4.81) *	6.56(4.24,10.16)
	No	483	435	1	1
Availability of latrine	Yes	305	263	1	1
	No	265	459	2.01(1.60,2.51) *	2.12(.13,34.09)
Sanitation status	Improved	308	264	.49(.39, .61) *	.31(.02, 4.59) **
	unimproved	262	458	1	1
Feces near the HH	Yes	321	498	1.3(1.37, 2.17) *	2.42(.97,6.06)
	No	249	224	1	1
Fece of animal around HH	Yes	195	273	1.17(.93,1.47) *	.75(.48,1.18)
	No	375	449	1	1
Flies seen at HH	Yes	298	269	1.85(1.47,2.30) *	16.26(9.93,26.64) **
	No	272	453	1	1
Nasal discharge	Yes	114	89	1.77(1.31, 2.40) *	1.61(1.06, 2.46) **
	No	456	633	1	1
Ocular discharge	Yes	36	184	5.07(3.48, 7.39) *	10.18(5.84,17.76) **
	No	534	538	1	1
Flies on child face	Yes	54	149	2.49(1.78, 3.46) *	7.19(3.87,13.34) **
	No	516	573	1	1
Child’s face	Clean	312	334	1	1
	Unclean	258	388	1.41(1.13, 1.75) *	2.29(1.57,3.34) **

* p value < 0.2,

** p value < 0.05

Discussion

In this study the prevalence of active trachoma among school-aged children was very high 44.1%. This result is in line with findings from adjacent regions and national report [12,31,32]. However, the finding is very high when compared with similar studies in Ethiopia and abroad [13,16,17,19,33–37]. The geography, environment, and population variation can be the reason the result difference. The current study assessed children age ranges 6–16 year; while the earlier research assessed pre-school-aged children [19,33], children aged 1–8 year [17], children aged 1–9 year [13,16,35,36] and children aged 5–9 year [37]. Beyond this, the earlier research had been carried out prior to the COVID-19 pandemic; yet, the pandemic had impeded the progress of the 2020 trachoma elimination goal [38].

In this study, the odds of active trachoma were 2.15 times higher among children in the age group 6–10 year as compared to those in the age group 11–16 year. This result is in line with finding from similar research [37,39]. Its due to the fact that younger children do not follow hygiene practice to protect them self from trachoma [2,39,40].

Also, the odds of active trachoma were 15.36 times higher among female school-aged children than male. The finding is supported by similar research findings and other evidence [13,39,41]. The gender disparity in acquiring active trachoma among girls can be associated with the gender role that baby girls play in taking care of younger family members who are potential sources of trachoma infection. This disproportionate risk can persist even in the later age of the girl as a woman because of the raising of children, which increases the recurrent acquisition of the infection, complications, and blindness.

In addition, the odds of active trachoma decreased by 53% and 69% among school-aged children who have access to improved water sources and improved sanitation in their HH. This is in line with the study findings, because lack of access to improved WASH facilities in HH is a barrier to maintain personal and environmental hygiene [16,33,36]. Majority of HH in Ethiopia lacks access to improved WASH, children living in this HH are at increased risk of trachoma [26].

Subsequently, the odds of active trachoma were 16.26 and 7.19 times higher among participants in whom HH and face flies were observed, respectively. The finding was in line with results from similar studies because certain species of flies act as mechanical vectors for trachoma infection by transporting the bacteria from infected children to healthy children [2,16,21,37,42].

Moreover, the odds of active trachoma were 10.18, 1.61, and 2 times higher among school-aged children on whom ocular and nasal discharge were observed and whose faces conditions were unclean, respectively. The result is in line with findings from similar studies [12,13,16,19,33]. This is because an unclean face, nasal discharge, and ocular discharge attract flies, which transmit the bacteria from infected children to healthy children [2].

Strengths and limitations of the study

The limitation of this study was cross-sectional nature of the design, which is difficult to show temporal relation between variables. Social desirability bias was also potential limitation, but using observation check list had minimized it. Moreover, addressing most trachoma impacted population, with relatively large sample size and large geographical coverage is the strength of the study.

Conclusion

This study found that the prevalence of active trachoma among school-aged children was very high when compared with the WHO threshold. Also, age group 6–10, female gender, presence of ocular and nasal discharge, unclean face of the child’s, presence of flies on the child’s face, and at HH have significantly associated with increased odds of active trachoma among school-aged children, while access to improved water sources and improved sanitation lowered the odds of active trachoma among school-aged children. Thus, to reduce the high prevalence of active trachoma in the study area, intensifying and scaling up the facial cleanness and environmental and sanitation components of the SAFE strategy is needed by giving great attention to those in the age group 6–10 and female gender.

Supporting information

S1 File. Questionnaire.

(DOCX)

S2 File. Trachoma data set.

(DOCX)

S3 File. Observation check list.

(CSV)

Data Availability

The data is included with the submission as a supporting file.

Funding Statement

Mizan-Tepi University (https://mtu.mizantepiuniversity.net/) funded this research under the broader research theme ‘prevalence of selected neglected tropical diseases among school-age children in Southwest Ethiopia's regional state’ by the reference number MTU/59/136/44/21 on February 2, 2021. The grant recipients were DG and FW. Mizan-Tepi University announced a call for the proposal, provided the research theme, evaluated the proposal, and supervised the overall research project management. The funders had no role in study design, data collection and analysis, the decision to publish, or the preparation of the manuscript.