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. (October 2021)

• Record Type: Journal Article
• Authors: Choe, Young June; Han, Mi Seon; Choi, Youn Young; Sohn, Young Joo; Kim, Ye Kyung; Kim, Kyung Min; Park, Ji Young; Kang, Hyun Mi; Yoon, In Ae; Choi, Jae Hong; Oh, Chi Eun; Cho, Eun Young; Lee, Hyunju; Choi, Eun Hwa
• Is Part Of: International journal of infectious diseases. Volume 111(2021)
• Page Start: 328
• Page End: 332
• Publication Date: 2021-10
• Subjects: Streptococcus pneumoniae -- Pneumococcus -- Haemophilus influenzae -- NTHi -- Carriage -- Children -- Vaccine; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2021.08.065
• Languages: English
• ISSNs: 1201-9712

Abstract

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