Isolation of trachoma virus from patients in West Africa

Abstract

1. By inoculating conjunctival scrapings into the chick embryo yolk-sac trachoma virus was isolated from twenty-four of thirty patients, whereas inclusions were demonstrated in only eighteen of them. 2. Bacterial contamination of the chick embryos can be greatly reduced by treating the scrapings with streptomycin 20,000 μg./ml. 3. In twenty-four of twenty-five isolations, virus was first detected in embryos inoculated directly with conjunctival material. 4. The viruses usually kill the chick embryos, which may show haemorrhagic lesions, but it is not unusual for embryos to survive a large inoculum. 5. The viruses isolated all appear in the chick embryo yolk sac as elementary bodies similar to other members of the psittacosis-lymphogranuloma group. Of the twenty-four strains, two also induced the formation of compact aggregates of elementary bodies containing a carbohydrate, probably glycogen. 6. It is anticipated that this method of isolation will be useful in studying the virology and epidemiology of trachoma, in assessing the influence of treatment, and as a test of cure. We are deeply indebted to Dr I. A. McGregor for all the facilities made available to us at the M.R.C. Laboratories in the Gambia. Our thanks are also due to the medical officers and sisters at the research ward for their kindness and unfailing co-operation in the care of those trachomatous patients who had to be hospitalized. The excellent technical assistance of Miss A. M. Fischer is gratefully acknowledged.