The current status of invasive pneumococcal disease in Poland.

The objectives of this study were to assess the incidence of invasive pneumococcal disease (IPD) in Poland (2006-2009), where mass vaccination had not been implemented, and to determine the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae isolates. The IPD incidence rates were highest among children under 2 years of age (3.39/100,000 in 2009) and children 2-5 years old (2.44/100,000). The most common serotypes were 14, 3, 1, 4, 19F, 23F, 6B, and 12F (61.7% of all isolates). In children aged less than 5 years, isolates of serotypes 14, 6B, and 19F were most prevalent (52.7% of the IPD cases). The PCV7, PCV10, and PCV13 covered 43.3%, 54.8%, and 68.8% of all IPD cases, and 68.7%, 76.3%, and 86.3% of cases involving children under 5 years of age. Penicillin resistance was found in 21.3% of the isolates responsible for meningitis and in 1.2% of isolates responsible for other invasive infections. Introduction of antipneumococcal conjugated vaccines into the national immunisation programme would likely lead to a significant reduction of IPD-associated morbidity among Polish children in particular, as well as in the population as a whole, especially in cases involving pneumococci with a decreased susceptibility to antibiotics.