A close look at trachoma control and the challenges that district programs pose

Abstract

Trachoma, the leading infectious cause of blindness, is caused by repeated episodes of infection with Chlamydia trachomatis, requiring an environment that facilitates transmission [1]. Trachoma affects an estimated 40 million people worldwide, with 7.6 million blind or severely visually impaired [1]. The productivity loss from visual impairment due to trachoma is estimated at US$5.3 billion [2]. The community pool of active trachoma and infection resides in children. Multiple infections are followed by scarring of the conjunctiva, which may progress to cause entropion and trichiasis, or inturned eyelashes that, if not surgically corrected, lead to corneal damage and vision loss in older ages. There is currently no treatment for corneal opacification, nor interventions to halt the scarring process. The WHO recommends a multifaceted ‘SAFE’ strategy for trachoma control: Surgery for trichiasis (S); Antibiotics to treat the community pool of infection (A); Face washing (F); and Environmental change to sustain reduction in transmission (E). The WHO recommends mass drug administration (MDA) with antibiotics, preferably azithromycin, when the prevalence of follicular trachoma is more than 10% in children aged 1–9 years at the district level [3]. The SAFE strategy is implemented on a district-wide basis. The Ultimate Intervention Goal for trichiasis is district prevalence of <1/1000 population, and for active trachoma, a prevalence of follicular trachoma <5% in children aged 1–9 years [3]. WHO guidelines suggest that annual MDA be provided for all communities in a district for at least 3–5 years before any expectation of significant change [3]. The district is the implementation unit of the control strategy, and this poses unique challenges for a disease program because it is largely not based on ‘case finding’ but implementation of an intervention at a population level. While this approach is not unique to trachoma, there are lessons from the experience with trachoma programs for other programs. This editorial describes some challenges and experiences.