Trachoma is the world's leading cause of preventable blindness. This disease, caused by
Chlamydia trachomatis, is endemic in many parts of the developing world. In 1990s we
evaluated the use of community-wide treatment with oral azithromycin in a project called
Azithromycin in Control of Trachoma (ACT). This approach resulted in clinical improvement and
dramatic reduction in prevalence of chlamydial infection through a 1-year follow-up. We
enrolled the ACT villages, as well as an additional village that had not had any prior
treatments, in our ACT II (2005) study and performed clinical surveys to assess trachoma
activity testing conjunctival swabs for the presence of C. trachomatis by nucleic acid
amplification tests (NAATs). Thus, we hoped to determine the long-term (10 year) effects of
azithromycin treatment.
We have completed the census and clinical survey of the initial three villages. Mass
treatment with azithromycin would not be justified with such low rates (1.8 - 4%) of ocular
chlamydial infection. We have treated only those living in households with one or more cases
of chlamydial infection and we will not follow up on these individually treated families.
In order to achieve the goals of our study, we now propose to identify other more remote
villages with trachoma infection rates of 20% or more to evaluate the effect of
community-wide treatment with single dose of oral azithromycin. If one or more of these
villages (dependent upon population) has trachoma rates of 20% or more they will be invited
to participate in the azithromycin treatment. In one set of subjects (1 or 2 villages,
dependent upon population and infection rate) we will perform treatment, and follow them up
at 2-, 12-, and 24-months post-treatment to ascertain infection rates. In a second set of
subjects (1 or 2 villages, dependent upon population and infection rate) we will perform
treatment, then perform re-treatment at 30-days post initial treatment, and follow them up at
2-, 12-, and 24-months post-treatment to ascertain infection rates. This should help us
determine the need for/and the best time for re-treatment to eliminate blinding trachoma, as
some recent studies suggest there is a 2-4% failure rate in the initial treatment. In sum,
this study should provide a rational approach to use of community-wide azithromycin treatment
to eliminate blinding trachoma as a public health problem
Phase:
Phase 4
Details
Lead Sponsor:
University of California, San Francisco
Collaborator:
National Institute of Allergy and Infectious Diseases (NIAID)