An evaluation of a SAFE-style trachoma control program in central Australia

To the Editor: The important article by Ewald et al shows that offering azithromycin treatment to 70% of a remote community may be inadequate to control hyperendemic trachoma, even when combined with a health promotion campaign.1 Yet, significant short-term gains in similar locations have been achieved with as little as 20% of the population receiving azithromycin, where administration to children with trachoma and their household contacts was directly observed by health staff.2

In that study,2 we reported a 6-month follicle resolution rate in schoolchildren of 72%, followed, however, by a return of trachoma prevalence towards baseline levels over 12 months. The critical factors for short-term success with azithromycin appear to be appropriate selection of cases and contacts, plus, where possible, directly observed therapy to minimise reinfection from untreated cases. Sustainability of initial reduction in trachoma prevalence is problematic, and issues of how extensively and how often to screen and/or treat need to be determined in the Australian context. Similar sustainability considerations have arisen in community scabies programs.3

Ewald et al are correct to identify population mobility as a major issue, with trachoma likely to be reintroduced by untreated children entering a community where a treatment program has occurred. Hence the need for a coordinated regional approach. However, a regional approach to trachoma control does not necessarily mean a uniform approach, and it is vital to tailor programs to suit the capacity of communities and their degree of commitment to labour-intensive treatment and health promotion.

Our study suggested that directly observed twice-yearly azithromycin therapy, with a health promotional component, is likely to be preferable to an annual program.2 Mathematical modelling supports this more frequent dosing and, unlike in Africa, the cost of azithromycin should not be a constraining factor in Australia.4

Regardless of the strategy selected, if, after treatment, the prevalence remains hyperendemic (> 20%), then the outcomes from concurrent health promotion are compromised. Appropriately targeted and directly observed azithromycin therapy can help create conditions favourable for health promotion campaigns, which in turn prolong those gains by reducing trachoma transmission.5 Major issues for trachoma control in Australia are (i) who to screen and treat (with directly observed azithromycin therapy); (ii) how often to screen and treat; (iii) how to plan trachoma programs as regional initiatives; and (iv) who will fund, coordinate and implement trachoma programs.