Clinical Research Directory

Inclusion Criteria: Pregnant women: 1. Participant is attending an ANC visit between 13 and 37 weeks gestation, with gestational age estimated using fundal height measurements and/or maternal report of quickening, at a participating health facility. 2. Participant is able to understand and comply with planned study procedures. 3. Participant has provided informed consent prior to initiation of any study procedures. 4. Participant intends to reside in the study area until her newborn infant is at least 12 months old. Infants: Enrollment of pregnant women and their unborn infants will happen simultaneously. Infants attending routine immunization visits at eligible health facilities whose mothers were not enrolled in the study will be eligible for enrollment in the supplemental infant cohort within the rural study cohort with the following inclusion criteria: 1. Infant is \<12 mo attending a DTP-1 routine vaccination visit at a participating health facility. 2. Parent or guardian is able to understand and comply with planned study procedures. 3. Parent or guardian has provided informed consent prior to initiation of any study procedures. 4. Parent or guardian intends to reside in the study area until participant is at least 12 months old. Exclusion Criteria: 1. Allergy to macrolides or azalides. 2. Any condition that, in the opinion of the investigator, might compromise the well-being of the participant or compliance with study procedures. 3. Medical treatment that requires administration of azithromycin (this can be a temporary exclusion if the drug is later discontinued).