Conditions: Trachoma
Keywords: Trachoma Azithromycin Mass treatment
Allocation: RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 128
Healthy volunteers: yes

Brief summary:
Trachoma, an ocular infection caused by C. trachomatis, is the second leading infectious cause of blindness worldwide. Years of repeated infection with C. trachomatis cause the eyelid to scar and contract and ultimately to rotate inward such that the eyelashes rub against the eyeball and abrade the cornea (trichiasis). The World Health Organization (WHO) has endorsed a multi-faceted strategy to combat trachoma, which includes the use of antibiotic treatment to reduce the community pool of infection with C. trachomatis. The objective of this study is to conduct a randomized, community-based trial in three countries (Niger, Tanzania and The Gambia), representing different baseline endemicities, of alternative coverages and frequencies of administration of mass antibiotic treatment as well as to determine the cost-effectiveness of these different strategies from a program perspective.

Detailed description:
A randomized, 2x2 factorial designed trial will be implemented in each of the three countries. Communities will be randomized to two different coverage targets (80%-89% versus ≥90%) for three years of mass treatment.

In The Gambia and Tanzania, communities will be further randomized to yearly mass treatment versus mass treatment at baseline followed by yearly mass treatment only if trachoma prevalence in sentinel children is greater than 5%. The communities will continue to be followed and treatment will resume if trachoma prevalence is found to be 20% or greater at the 12 or 18 month surveys.

In Niger, communities will be randomized to the different coverage levels for annual mass azithromycin distribution and further randomized to biannual treatment at the two coverage targets for children ages twelve or younger.

Cross-sectional rates of trachoma and infection will be determined by examining sentinel children, age five years or younger, randomly selected from each community based on a community census. The census will be updated each year, and villages will be monitored at baseline, 6, 12, 18, 24, 30, and 36 months for infection and clinical disease.

The three-year study is in accord with the WHO guidelines which recommend three years of annual mass treatment followed by a re-survey to determine need for further treatment. The investigators will evaluate the efficacy of guiding further mass treatment according to a laboratory test for Chlamydia or WHO guidelines. Where investigators estimate communities have infection rates less than 5% in sentinel children, or trachomatous inflammation (TF) ( rates less than 5%, the community will be "graduated" from further mass treatment and followed for up to three years to look for evidence of re-emergent infection and disease. If rates of infection are found to be 20% or more return at the 12 or 18 month survey, mass treatment will be re-initiated.

Arms:
arm 1: Selected communities will receive mass treatment annually for three years. arm 2: Selected communities will receive mass treatment annually for three years. arm 3: Treatment to be administered at baseline then continued yearly if trachoma prevalence is greater than 5%

In Niger, treatment will be every 6-months for children ages twelve and under. arm 4: Treatment to be administered at baseline then continued yearly if trachoma prevalence is greater than 5%

In Niger, treatment will be every 6-months for children ages twelve and under.

Interventions: intervention 1: Azithromycin intervention 2: Azithromycin
Intervention descriptions: intervention 1: Comparison of community coverage rate intervention 2: Comparison of coverage levels at baseline treatment followed by annual treatment if prevalence of trachoma is \>5%. In Niger, there will be a comparison of coverage levels in everyone versus in children ages twelve and under who are treated every 6-months.

Protocol document: