Serotypes and Vaccine Coverage of Streptococcus Pneumoniae Colonization in the Nasopharynx of Thai Children in Congested Areas in Chiang Mai

Abstract

Streptococcus pneumoniae causes around 10% of all deaths in children younger than five years of age. This study aimed to examine the serogroups/serotypes of S. pneumoniae colonization and vaccine serotype coverage of this organism among Thai children. Nasopharyngeal swabs of children less than or equal to 15 years of age were obtained in congested areas in Chiang Mai from 1 February 2013 to 1 August 2013. The serotyping of S. pneumoniae isolates was performed using the ImmuLex™ kit and the vaccine serotype coverage for this organism was evaluated. A total of 292 children were enrolled. One hundred and thirty children (44.5%) had nasopharyngeal colonization with Streptococcus pneumoniae. Eighty-seven (66.9%) isolates were from children younger than five years of age, seventeen (13.1%) were from children aged 6–10 years, and twenty-six (20%) were from children aged 11–15 years. The five most common serogroups/serotypes isolated were 6 (6A, 6B, 6C) (46.1%), 23 (23F, 23A, 23B) (14.6%), 19 (19F, 19A, 19B, 19C) (8.5%), 15 (15F, 15A, 15B, 15C) (6.9%), and 14 (6.1%). Vaccine serotype coverages in pneumococcal conjugate vaccines (PCV):PCV7, PCV10, and PCV13 were 79.1%, 83.6%, and 85.9%, respectively. There were significant increases in coverage between PCV7 and PCV10 (from 79.1% to 83.6%, p < 0.001), PCV7 and PCV13 (from 79.1% to 85.9%, p < 0.001), and PCV10 and PCV13 (from 83.6% to 85.9%, p < 0.001). The majority of pneumococcal serogroup/serotype colonization in the nasopharynx of Thai children in the studied areas was included in the current licensed pneumococcal conjugated vaccines (PCVs). PCV vaccination should be considered for high-risk children to reduce the incidence of invasive pneumococcal disease among Thai children.

Molecular Characterization of Predominant Serotypes, Drug Resistance, and Virulence Genes of Streptococcus pneumoniae Isolates From East China

“…In this study, the PNC non-susceptible rate among the 309 S. pneumoniae isolates was as high as 81.6% (63.2% intermediate and 18.4% resistant), but the CTX non-susceptible rate was only 14.2% (11.6% intermediate and 2.6% resistant). The ETM and AZM resistance rates among the 309 S. pneumoniae isolates were 95.8 and 96.1%, which are similar to those from Western China (94.3%), North China (95–98.2%), and Southwest China (99.1%) ( Zhao et al, 2020 ; Liang et al, 2021 ; Yan et al, 2021 ; Zhou et al, 2022 ) but significantly higher than those from Southeast Asia (38.5–42.0%), India (37.0%), United States (37.1%), and Latin America (43.2%) ( Mendes et al, 2016 ; Singh et al, 2017 ; Moreno et al, 2020 ; Wangirapan et al, 2020 ; Dzaraly et al, 2021 ). In addition, 96.1% of the 309 S. pneumoniae isolates in this study showed different multidrug resistance patterns, which is also similar to those from Western China (93.8%) ( Liang et al, 2021 ), but significantly higher than those from South Korea (46.2%), Malaysia (18.0%), and Latin America (44.3%) ( Park et al, 2019 ; Moreno et al, 2020 ; Dzaraly et al, 2021 ).…”

“…In addition, serotypes 12F, 3, 23A, 19A, 10A, 6C, and 22F and serotypes 3, 19A, and 11A were the commonly found among the S. pneumoniae isolates from Japan and South Korea, respectively ( Park et al, 2019 ; Heo et al, 2020 ; Yanagihara et al, 2021 ). Furthermore, 23F, 19F, 19A, and 14 were the predominant pneumococcal serotypes found in Thailand and Malaysia ( Wangirapan et al, 2020 ; Dzaraly et al, 2021 ). In India, 14, 1, and 19F acted as the predominant serotypes of S. pneumoniae ( Singh et al, 2017 ).…”

“…However, β-lactam antibiotic resistance rates of S. pneumoniae isolates from different areas and countries have a large diversity. For example, PNC and CTX resistance rates among the S. pneumoniae isolates from Western China, North China, and Southwest China were 1.2–79.9% and 0.5–28.6% ( Shen et al, 2017 ; Zhao et al, 2020 ; Liang et al, 2021 ; Yan et al, 2021 ; Zhou et al, 2022 ), while the PNC resistance rates among the S. pneumoniae isolates from East Asia (Japan and South Korea), Southeast Asia (Thailand and Malaysia), India, United States, Europe, and Latin America were 1.7–22.8%, 4–83.1%, 10%, 10.8%, 19.4%, and 68.6%, respectively ( Mendes et al, 2016 ; Yahiaoui et al, 2016 ; Singh et al, 2017 ; Park et al, 2019 ; Moreno et al, 2020 ; Wangirapan et al, 2020 ; Dzaraly et al, 2021 ; Yanagihara et al, 2021 ). In this study, the PNC non-susceptible rate among the 309 S. pneumoniae isolates was as high as 81.6% (63.2% intermediate and 18.4% resistant), but the CTX non-susceptible rate was only 14.2% (11.6% intermediate and 2.6% resistant).…”