Blinding trachoma - a public health challenge

Trachoma affects about 500 million people, causing blindness in 2 million of these. I In order to assess the magnitude of trachoma as a public health problem, a distinction must be made between blinding and non-blinding trachoma. In endemic areas blinding trachoma will be recognized by the presence of large numbers of people with visual loss due to corneal opacities and the presence ofentropion and!or trichiasis. Non-blinding trachoma will give rise to a low prevalence of potentially blinding lesions but does not constitute the urgent threat to public health that blinding trachoma does. Jones er al. 2 visualize blinding trachoma as being the overlap between non-blinding trachoma and bacterial conjunctivitis. This concept emphasizes the role of bacteria in the disease. It is often a bacterial superinfection that precipitates visual loss. The presence of blinding trachoma in an area therefore also indicates an overlapping of the epidemiological conditions necessary for non-blinding trachoma and bacterial conjunctivitis to exist. The initial chlamydial infection often occurs in preschool children, causing keratoconjunctivitis followed by spontaneous cure with no residual effects. In endemic areas this is followed by reinfection and, with each cycle of infection, a quota ofdamage. 3