In study communities randomized to the Azithromycin Continuation arm, all individuals aged 1 month and older will receive a single mass distribution of azithromycin several weeks after the baseline and 36-month monitoring visits. Oral azithromycin, 20 mg/kg for children and 1 g for adults, will be offered to all households identified on the preceding census in the communities randomized to continuing treatment. Study drug will be distributed by health extension workers and organized by PNSO. Individuals with a known macrolide allergy will be offered a two-week course of daily ophthalmic tetracycline ointment (two tubes).

In study communities randomized to the Azithromycin Discontinuation arm, individuals will receive no treatment.

In study communities randomized to the Azithromycin Continuation arm, all individuals aged 1 month and older will receive a single mass distribution of azithromycin several weeks after the baseline and 36-month monitoring visits. In study communities randomized to Azithromycin Discontinuation, participants will receive no treatment.

Assessed by PCR.

Assessed by PCR.

Assessed from conjunctival photography. Clinical photographs of the conjunctiva will be assessed by masked graders according to the grading scale described by the WHO Simplified Grading System.

The system includes five signs, each of which can be present or absent:

Trachomatous inflammation - follicular Trachomatous inflammation-intense Trachomatous scarring Trachomatous trichiasis Corneal opacity