Trend change of nasopharyngeal colonization with Streptococcus pneumoniae and non-typeable Haemophilus influenzae in children attending daycare centres: nationwide population-based study, South Korea 2014 and 2019

• DOI: 10.1016/j.ijid.2021.08.065
• Publication Date: 2021-09-08T22:25:00Z
• Authors: Young June Choe; Mi Seon Han; Youn Young Choi; Young Joo Sohn; Ye Kyung Kim; Kyung Min Kim; Ji Young Park; Hyun Mi Kang; In Ae Yoon; Jae Hong Choi; Chi Eun Oh; Eun Young Cho; Hyunju Lee; Eun Hwa Choi
• Keywords: Carriage; Pneumococcal infections; Pneumococcal Conjugate Vaccine

BackgroundNasopharyngeal (NP) colonization with Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) is common in children, may evolve as the source of invasive infections. In Korea, pneumococcal conjugate vaccines (PCVs) were introduced >10 years ago, enabling authors to study effect vaccine preventing carriage.MethodsNP swabs taken a household survey was conducted at daycare centres located different regions Korea 2014 2019. Pneumococcal serotypes identified using Quellung method sequencing. NTHi based on pilA bexA genes.ResultsIn total, 1460 NP obtained carriage rates 36.4–42.1% 36.5–26.7%. Among children carrying pneumococci, significant increase seen serotype 23A between 2019 (from 12.6% 22.0%; P=0.005). Children who had received PCV lower risk vaccine-type (2.9% vs 0.8%; P=0.005).ConclusionsBetween 2019, proportion increased significantly, while rate decreased. Continuous surveillance needed assess long-term effects PCVs dynamics pneumococcus NTHi.