Kathryn M. Edwards, United States of America
Vanderbilt University Medical Center PediatricsAuthor Of 1 Presentation
PNEUMOCOCCAL COLONIZATION DENSITY PATTERNS OVER TIME IN YOUNG CHILDREN IN THE PERUVIAN ANDES (ID 246)
- Leigh Howard, United States of America
- Kathryn M. Edwards, United States of America
- Marie R. Griffin, United States of America
- Yuwei Zhu, United States of America
- Jorge E. Vidal, United States of America
- Keith P. Klugman, United States of America
- Ana I. Gil, Peru
- Nicole R. Soper, United States of America
- Isaac P. Thomsen, United States of America
- Claudio F. Lanata, Peru
- Carlos Grijalva, United States of America
Abstract
Background
Factors associated with nasopharyngeal pneumococcal colonization density have not been comprehensively characterized. Age, immunization status, geographical location, population density, season, and/or acute respiratory illness (ARI) may play a role. We assessed longitudinal colonization density patterns in young rural Peruvian children.
Methods
Nasopharyngeal samples were collected monthly from children aged <3 years followed prospectively each week for ARI from May 2009-September 2011. PCV7 was introduced in the region in 2009. Longitudinally-collected samples from a convenience sample of children with >=1 pneumococcus-positive sample underwent density assessment by lytA qPCR. Density values were log10-transformed to reduce skewness. Assessments were stratified by enrollment age.
Results
Pneumococcus was detected in 471/625 (75%) samples from 30 children; 20/30 (67%) were enrolled before age 1. Variability was observed in colonization densities by calendar quarter and enrollment age, with substantial overlap in density levels and trajectories over time among age groups (Figure). Median densities during ARI episodes (n=62) were 5.60 (IQR 4.36-6.24) compared to non-ARI periods (5.00 [3.98-5.93], n=409, p=0.023).
Conclusions
Among these children, density varied by ARI status but did not clearly decrease with age. Future trajectory analyses will assess serotype-specific density colonization patterns and the association of serotype co-colonization, vaccination, and ARI status with pneumococcal density over time.