Inclusion Criteria:  Ages 1 to 11 months Resident in targeted community  Exclusion Criteria:  Children below 3.0 kg (3rd centile for healthy 1-month old infants in the WHO growth charts) Appears seriously ill at the time of the MDA (per the CDD's assessment) Unable to swallow liquid delivered through a needle-less syringe because of physical limitations Known allergy to macrolides, including azithromycin, based on the primary caregiver's report of prior adverse reaction to medication likely to be a macrolide prior allergic reaction to medication likely to be a macrolide