By the early 1950's, it was clear from numerous independent reports that certain of the broad-spectrum
antibiotics were effective against the agent of
trachoma. It seemed, however, that treatment had to be continued over long periods to effect a cure of the average case. With the assistance of WHO, comparative trials on a scale hitherto unprecedented in the disease-involving more than 9000 schoolchildren with active
trachoma-have been conducted in Morocco since 1953 in order to assess the value of local treatment of
trachoma with
chlortetracycline and to develop simple and economic methods of treatment, for which there was a pressing need. Local application of 1%
chlortetracycline ointment two or three times daily for 60 days gave almost 80% cures under reasonably favourable conditions and nearly 100% cures after re-treatment of cases not cured by the first course. Equally good results followed intermittent short-term treatment over longer periods. Relapse and
reinfection rates were low.Collective mass treatment with
antibiotics is clearly a valuable method of
trachoma control. The use of intermittent treatment allows for a great economy both in
antibiotics and in staff and other campaign expenses and makes possible the wide expansion of mass treatment programmes.