Impact of single dose azithromycin on group A streptococci in the upper respiratory tract and skin of Aboriginal children

Background. Aboriginal children living in remote Australia experience high rates of bacterial infection such as trachoma, otitis media and streptococcal skin infection, which often progress to associated chronic diseases in later life. Methods. In February, 1995, single dose azithromycin was given to 130 Aboriginal children with trachoma and their contacts. The impact of this program on respiratory and skin group A Streptococcus pyogenes carriage and infection was also monitored. Results. Immediately before treatment 90% of children had skin sores, 38% of sores had pus and 74% of sores with pus had group A Streptococcus (GAS). Overall 57% of children had GAS skin infections. At 2 to 3 weeks and 2 and 6 months after treatment, this proportion was 10, 32 and 51%, respectively. For the upper respiratory tract GAS recovery rates were 8% before treatment and 0, 11 and 15% at the 2- to 3-week, 2-month and 6-month posttreatment visits, respectively. Multiple types occurred concurrently in individuals, particularly after treatment. Identical types were sometimes recovered simultaneously from the upper respiratory tract and skin, suggesting that the high rates of acute rheumatic fever in this population in the absence of high rates of detectable throat GAS carriage could be related to high rates of skin GAS infection. Conclusions. There is an urgent need for education, adequate housing, scabies eradication and improved hygiene to reduce skin trauma and subsequent GAS infection in this population. Clinical trials are needed to determine how these measures can best be integrated with the trachoma eradication program to maximize health outcomes.