Serotype distribution and penicillin-non-susceptibility of Streptococcus pneumoniae causing invasive diseases in Kuwait: A 10-year study of impact of pneumococcal conjugate vaccines

ABSTRACT

Objectives: The impact of PCV7 and PCV13 on pneumococcal infections in Kuwait is not known. Therefore we evaluated the impact on pneumococcal serotype distribution and penicillin-non-susceptibility in invasive infections in Kuwait.

Methods: Children < 2 y were given PCV7 from Aug 2006 to Jul 2010 (period I), and PCV13 from Aug 2010 to Jul 2013 (period II) with a pre-vaccination period from Aug 2003 to Jul 2006. Serotype and penicillin-non-susceptibility of blood and cerebrospinal fluid isolates from all ages were determined.

Results: In <2 y old children, even with a small number of infections, a drop in PCV7 serotypes was evident after vaccination. For all age groups combined, in the pre-vaccination period, PCV7, PCV13, PCV13 non-PCV7 serotypes and penicillin-non-susceptibility constituted 53.2%, 72.6%, 19.4% and 6.5% of the isolates respectively. PCV7, PCV13 non-PCV7 serotypes and penicillin-non-susceptibility changed to 32.7%, 28.2% and 7.3% (period I) and 6.6%, 22.2% and 8.9% (period II).

Conclusions: Vaccines reduced invasive infections due to PCV7 serotypes.

KEYWORDS:

• Streptococcus pneumoniae
• invasive pneumococcal disease
• pneumococcal conjugate vaccines
• pneumococcal serotypes
• antibiotic resistance
• Kuwait

Acknowledgments

We thank Mary Divia, Shabeera Syed, Anwar Al Haway and Al Anoud Al Aryan for the laboratory work. We also thank Dr. William P. Hausdorff, Glaxo SmithKline Vaccines, Belgium, for critical comments on the manuscript.