Serotype distribution and clinical characteristics associated with streptococcus pneumoniae among Chinese children and adults with invasive pneumococcal disease: a multicenter observational study

Abstract

Few studies in China focused on serotypes of Streptococcus pneumoniae in patients with invasive pneumococcal disease (IPD). We aimed at investigating the serotype distribution for IPD-causing S. pneumoniae and vaccine coverage among Chinese children and adults. This was a multicenter, observational study to collect S. pneumoniae isolates from normal sterile sites and IPD-related clinical information among children and adults. Serotyping was performed by a Capsule-Quellung reaction test using type-specific antisera. The study collected a total of 300 eligible isolates (pediatric = 148, adult = 152) were serotyped in a central laboratory. The most prevalent serotypes were 19A (20.9%) and 23 F (20.3%) in the pediatric group; 3 (21.7%) and 19 F (11.8%) in the adult group. PCV10 had low-to-moderate serotype coverage rates for children (60.8%) and adults (34.2%). PCV13 and PPV23 had high coverage rates for children (89.9%, 93.2%) and adults (70.4%, 82.9%), respectively, Investigational PCVs including PCV15 and PCV20 had high estimated coverage rates in children (89.9%, 93.9%). The study identified 269 subjects with IPD reported as the primary diagnosis in the medical records. Sepsis (48/136, 35.3%) and pneumonia (48/133, 36.1%) had the highest occurrence in the pediatric and adult groups, respectively. Study findings showed that non-PCV7 S. pneumoniae 19A and 3 were the most prevalent serotypes in Chinese children and adults, respectively. High-valent vaccines had similar coverage rates and may have a greater potential in preventing IPD.

Keywords: Streptococcus pneumoniae; in vitro susceptibility; invasive pneumococcal disease; pneumococcal conjugate vaccine; serotype.

Figure 1a.

Study flowchart for enrollment.S. pneumoniae isolates were collected by both prospective and retrospective phases; 300 isolates were eligible [children: 148 (49.3%), adults: 152 (50.7%)] and included for analysis. In the pediatric group, 102 (68.9%) isolates were collected via retrospective phase and 46 (31.1%) via prospective phase; in the adult group, 93 (61.2%) were collected via retrospective phase and 59 (38.8%) via prospective phase;Laboratory issues included isolate death or loss in the central laboratory.Geographic distribution of study sites in China.The study collected S. pneumonia isolates from 27 sites located in 13 provinces in China. A total of 149 isolates were from the North region and 151 isolates were from the South region. Provinces in the North region: Beijing, Gansu, Hebei, Jiangsu (north), Liaoning, Shandong, Shanxi, and Tianjin; provinces in the South region: Anhui, Hainan, Hubei, Jiangsu (south), Shanghai, and Zhejiang

Figure 2.

Serotype distribution of S. pneumoniae isolates in children and adults

Figure 3.

Vaccine coverage rates by age subgroups