Nasopharyngeal carriage of Streptococcus pneumoniae among children <5 years of age in Indonesia prior to pneumococcal conjugate vaccine introduction.

Pneumococcal conjugate vaccines (PCVs) prevent nasopharyngeal colonization with vaccine serotypes of Streptococcus pneumoniae, leading to reduced transmission of pneumococci and stronger population-level impact of PCVs. In 2017 we conducted a cross-sectional pneumococcal carriage study in Indonesia among children aged <5 years before 13-valent PCV (PCV13) introduction. Nasopharyngeal swabs were collected during visits to community integrated health service posts at one peri-urban and one rural study site. Specimens were analyzed by culture, and isolates were serotyped using sequential multiplex polymerase chain and Quellung reaction. Antibiotic susceptibility was performed by broth microdilution method. We enrolled 1,007 children in Gunungkidul District, Yogyakarta (peri-urban) and 815 in Southwest Sumba, East Nusa Tenggara (rural). Pneumococcal carriage prevalence was 30.9% in Gunungkidul and 87.6% in Southwest Sumba (combined: 56.3%). PCV13 serotypes (VT) carriage was 15.0% in Gunungkidul and 52.6% in Southwest Sumba (combined: 31.8%). Among pneumococcal isolates identified, the most common VT were 6B (16.4%), 19F (15.8%), and 3 (4.6%) in Gunungkidul (N = 323) and 6B (17.6%), 19F (11.0%), and 23F (9.3%) in Southwest Sumba (N = 784). Factors associated with pneumococcal carriage were age (1-2 years adjusted odds ratio (aOR) 1.9, 95% CI 1.4-2.5; 3-4 years aOR 1.5, 95% CI 1.1-2.1; reference <1 year), other children <5 years old in the household (aOR 1.5, 95% CI 1.1-2.0), and presence of ≥1 respiratory illness symptom (aOR 1.8, 95% CI 1.4-2.2). Overall, 61.5% of the pneumococcal isolates were non-susceptible to ≥1 antibiotic class and 13.2% were multi-drug non-susceptible (MDNS) (non-susceptible to ≥3 classes of antibiotics). Among 602 VT isolates, 73.9% were non-susceptible and 19.9% were MDNS. These findings are critical to establish a pre-PCV13 carriage prevalence and demonstrate the complexity in evaluating the impact of PCV13 introduction in Indonesia given the wide variability in the carriage prevalence as shown by the two study sites.

Pneumococcal vaccination for splenectomized patients with thalassemia major in Indonesia.

INTRODUCTION: Streptococcus pneumoniae is a capsulated bacterium that can cause severe infection in patients with thalassemia major, particularly those who have undergone splenectomy. The absence of the spleen as well as zinc deficiency in splenectomized patients with thalassemia major increases the possibility of developing invasive pneumococcal infection. The aims of this study are to evaluate pneumococcal IgG levels following PCV and PPV immunizations and the effect of zinc supplementation on qualitative specific immune responses in splenectomized patients with thalassemia. METHODS: Splenectomized patients with thalassemia major were administered a PCV pneumococcal vaccine (Prevenar 13®) at the start of the trial, after which they were randomly assigned to 2 groups (zinc and placebo group). After 8weeks, the patients received a PPV pneumococcal vaccine (Pneumovax®). Zinc syrup was provided to the zinc group at a dose of 1.5mg/kg/day (maximum of 50mg/day). Pneumococcal IgG examinations were conducted at the start of the trial and after 12weeks. RESULTS: In the group without PPV, the median initial pneumococcal IgG value was 315 (ranging from 65 to 1419) mU/mL for the zinc group and 338.5 (ranging from 82 to 1648) mU/mL for the placebo group. The median final pneumococcal IgG value was 1812.5 (ranging from 834 to 2444) mU/mL for the zinc group and 2857.5 (ranging from 834 to 2624) for the placebo group. The increase in the pneumococcal IgG value between the two groups was comparable (p=0.642). In the group with previous PPV, the median initial pneumococcal IgG value was 1333 (ranging from 793 to 2031) mU/mL for the zinc group and 880 (ranging from 74 to 1686) mU/mL for the placebo group. The median final pneumococcal IgG value was 1487 (ranging from 635 to 1757) mU/mL for the zinc group and 1012 (ranging from 292 to 1732) mU/mL for the placebo group. The increase in the pneumococcal IgG value between the two groups was comparable (p=0.528). CONCLUSION: There is no difference in the increase in pneumococcal IgG level in splenectomized patients with thalassemia major prior to and after receiving PPV. There were no differences observed in the development of pneumococcal IgG following zinc supplementation.