Background: The clinical signs of active trachoma are often present in the absence of ocular Chlamydiatrachomatis infection, particularly following mass drug administration. Treatment decisions followingimpact surveys and in post-control surveillance for communities are currently based on the prevalence ofclinical signs, which may result in further unnecessary distribution of mass antibiotic treatment and theincreased spread of macrolide resistance alleles in ‘off-target’ bacterial species. We therefore developed asimple, fast, low cost diagnostic assay (DjinniChip) for diagnosis of ocular C. trachomatis for use bytrachoma control programmes.

 Methods: The study was conducted in London, Germany and Tanzania. For clinical testing in Tanzania,specimens from a sample of 350 children between the ages of 7 to15 years, which were part of alongitudinal cohort that began in February 2012 were selected. Two ocular swabs were taken from theright eye. The second swab was collected dry, kept cool in the field.