Surveillance of invasive Streptococcus pneumoniae in Taiwan, 2002-2003

Area of Science:

• Microbiology
• Epidemiology
• Vaccinology

Background:

• Streptococcus pneumoniae causes invasive diseases globally.
• Understanding serotype distribution and antimicrobial resistance is crucial for effective prevention strategies.
• Taiwanese data on invasive pneumococcal isolates is essential for public health planning.

Purpose of the Study:

• To determine the serotype distribution of invasive Streptococcus pneumoniae isolates in Taiwan.
• To assess antimicrobial resistance patterns, particularly penicillin non-susceptibility.
• To evaluate the potential coverage of existing and upcoming pneumococcal vaccines.

Main Methods:

• Collection and analysis of 522 invasive Streptococcus pneumoniae isolates from Taiwan between January 2002 and December 2003.
• Serotyping of isolates to identify prevalent types.
• Antimicrobial susceptibility testing, focusing on penicillin resistance.
• Assessment of vaccine coverage for different serotype-specific vaccines.

Main Results:

• The most frequent serotypes were 14 (18.4%), 23F (15.1%), 3 (13.8%), 19F (13.4%), and 6B (8.2%).
• Penicillin non-susceptible strains constituted 67.7% of isolates, predominantly among serotypes 23F, 19F, 6B, and 14.
• A 23-valent vaccine demonstrated 87.2% serotype coverage and 100% coverage of penicillin-non-susceptible serotypes.
• Protein conjugate vaccines showed 78.8% (7-valent) and 86.5% (11-valent) coverage for serotypes in children under 2 years.

Conclusions:

• Serotype distribution in Taiwan is characterized by specific prevalent types, with significant penicillin resistance.
• The 23-valent vaccine offers broad coverage, including all penicillin-non-susceptible strains identified.
• Vaccine formulations need careful consideration to ensure adequate protection against prevalent and resistant pneumococcal serotypes in Taiwan.