Profile of Streptococcus pneumoniae Serotypes of Children with Invasive Disease in Tehran, Iran. An Implication for Vaccine Coverage

Objectives: This study aims to define S. pneumoniae serotypes in children hospitalized with an invasive pneumococcal disease from March 20, 2012 to March 10, 2013 by polymerase chain reaction (PCR) method. Methods: Specimens from cerebrospinal fluid and blood were collected from children aged one month-18 years with suspected invasive pneumococcal infection admitted to Mofid Children's Hospital and other regional hospitals. Multiplex PCR with 13 groups of primers were used to detect 33 serotypes of S. pneumoniae in positive blood and cerebrospinal fluid cultures. Out of 563 samples, 83 S. pneumoniae isolates were identified. Sixty-seven samples were typeable. Results: The results showed that serotypes 3 (21.7%), 23F (13.2%), and 19F (10.8%) were the most prevalent serotypes. Sixteen samples (19.3%) were non-typeable by Multiplex PCR method. The 13-valent pneumococcal vaccine provides the highest coverage (66.23%), followed by the 10-valent vaccine (34.9%) and, lastly, the 7-valent vaccine (33.71%). Conclusions: We found that serotypes 3, 23F, and 19F accounted for almost 46% of invasive pneumococcal isolates. As per relatively high coverage of prevalent serotypes, PCV13 should be considered for routine childhood vaccination programs.