Chlamydial Infections

1 2 Peter Reeve and Lavelle Hanna lSmith Kline & French Laboratories, Research and Development, 709 Swedeland Road, Swedeland, PA 19479, USA 2Department of Microbiology, S-412, University of California, San Francisco, San Francisco, CA 94143, USA Trachoma, an infectious keratoconjunctivitis due to chlamydial infection, was one of the earliest recognized clinical entities. References to it have been noted in Egyp- tian papyri and in Greco-Roman medical treatises. Since those times it has remained a most important eye infection, and indeed trachoma is still a major cause of blindness in rural communities, affecting probably 6 million people (Dawson). The causal agent of trachoma was identified by Halberstaeter and von Provazek in a much-quoted but little-read paper published over 75 years ago. It was after the isolation and demonstration of the growth of the causal agent of trachoma, Chlamy- dia trachomatis, by Tang and his colleagues in China in the late 1950s that there was an enormous increase in our knowledge of these agents. The real explosion of knowledge and interest in Chlamydia, however, has been in the last decade. With the growing awareness of the extraordinary commonness of chlamydial infections, not only in developing countries but also in the highly developed countries, has come a considerable interest from all areas concerned with medical science, from clinicians to molecular biologists.