Prevalence of ear disease and its associated hearing loss among primary school children in Tonga: urban versus rural

Abstract

Background. Ear disease and hearing loss among children are significant world- wide health problems that potentially cause speech and language development delay, social isolation, and academic failure. The prevalence is highest in low- and middle- income countries including the Pacific island countries where epidemiological data and resources are limited. National programs to raise awareness and detection rarely existed in most Pacific island countries. The purpose of this case study was to determine the prevalence of ear disease and associated hearing loss in primary school children. The data will be used as informed evidence to develop a propose strategies to address ear and hearing problems among primary school children in Tonga. Methods. This was a cross sectional population- based study which used otoscopy, tympanometry and pure tone audiometry to determine the prevalence of ear disease and hearing loss in 10 urban and 12 rural primary schools in Tongatapu. Results were collected on a digitised form from 489 students (88% of total selected population) class 1 to 6 (5 to 14 years of age) and data were analysed using quantitative statistical and mixed model method. Results. Wax was the most common ear problem found in 54.6% (267 students) of the primary school children both partial and occluded wax and more common in urban children (31%) as compare to rural (24%). This was statistically significant for age and school location but not gender. Followed with middle ear diseases in 12% (60 students, rural 8%, urban 4%) including children with suppurative otitis media (1.4%, perforation with ear discharge), suspected cholesteatoma (0.6%) and possible otitis media with effusion (10%, immobile, dull, retracted, atelectatic ear drum and type B tympanogram). Seven percent (37 students) of the students failed hearing test (defined as > 25 dB of best hearing ear) with middle ear disease (15 students, 41%) the most common cause followed by occluded wax (9 students, 24%), wax plus OME (7 students, 19%) and 6 students (16%) under unknown cause. The mean threshold difference between occluded and non-occluded ears among primary school children were 3 dB. The improvement in mean threshold among children with occluded wax after removal was 7 dB. Of the 15% of children with bilateral hearing loss due to occluded wax, there was 5% reduction in number of students post wax removal. Wax removal benefitted 30% and 35% of students with unilateral and bilateral hearing respectively. Dental caries affected 28% of the primary school children. Conclusion. Ear disease causing hearing loss was commonly found among primary school children in Tonga. A national plan for ear and hearing care for primary school children including early detection and management through school screening are very important to assist children to achieve better education.