External quality assurance scheme for Streptococcus pneumoniae, 2012 : as part of the IBD-labnet surveillance network

External quality assurance (EQA) is part of quality management systems (QMS) and evaluates performance of laboratories, by an outside agency, on material that is supplied specifically for the purpose. ECDC's disease specific networks organise a series of EQA activities for EU/EEA countries. In some specific networks, non-EU/EEA countries are also involved in the EQA activities organised by ECDC, although at their own costs. The aim of the EQA is to identify needs for improvement in laboratory diagnostic capacities relevant to surveillance of disease listed in Decision No 2119/98/EC and to ensure comparability of results in laboratories from all EU/EEA countries. Streptococcus pneumoniae (pneumococcus) is a common commensal of the upper respiratory tract and is a cause of local and invasive infections. Local infections of the respiratory tract include otitis media, sinusitis and pneumonia. Invasive pneumococcal disease (IPD) may present as a pneumonia, meningitis, septic arthritis or a bacteraemia without obvious focus. Young children, immunocompromised individuals and the elderly are at major risk of developing IPD. The World Health Organization estimates that more than 1.6 million people die of pneumococcal infection every year and half of these deaths are in children aged less than five years of age. Of the 93 different serotypes of pneumococcus that have to date been identified, only 20 to 30 are responsible for the majority of pneumococcal infections worldwide. There is some evidence of an association between serotype and severity of disease. Serotype prevalence varies between geographic regions and may change over time in response to selective vaccine pressure or clonal spread. Furthermore, capsular switching may occur, allowing the survival of specific clones and evasion of vaccine-induced immunity. A number of pneumococcal vaccines are now available. The first to be introduced was the 23-valent plain pneumococcal polysaccharide vaccine (PPV23). This vaccine is indicated for use in children over the age of two years within risk groups and for the elderly. The first pneumococcal conjugate vaccine (PCV7) was licensed in the United States in 2000 and in Europe in 2001.This vaccine contains purified capsular polysaccharide of seven pneumococcal serotypes. The introduction of PCV7 led to a dramatic fall in the incidence of IPD in young children caused by these seven serotypes. In addition, the vaccination of infants with PCV7 reduced the nasopharyngeal carriage of these serotypes, resulting in a decline in the incidence of IPD due to these serotypes in older age groups through a 'herd effect'. However, the use of PCV7 was associated with an increase in other serotypes, not included in the vaccine (serotype replacement), notably 19A and 7F. More recently, a 10-valent (PCV10) and a 13- valent (PCV13) vaccine have been introduced. Laboratory diagnostics and molecular epidemiology of S. pneumoniae are extremely important for the effective surveillance of this organism. Since the introduction of PCV10 and PCV13 in European countries, surveillance should monitor the impact of these vaccines in order to compare the different vaccine schedules adopted by Member States and to detect and study changes in serotype distribution and any possible serotype replacement due to vaccine pressure. The specific objectives of this EQA exercise are: Further harmonisation of molecular typing of S. pneumoniae; Further harmonisation of methods for antimicrobial susceptibility testing of S. pneumoniae; Training and dissemination of methods for the laboratory surveillance of invasive bacterial infections; Assisting the countries in capacity building, when required; Supporting ECDC in linking laboratory surveillance data and epidemiological data.