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Comparative incidence dynamics and serotypes of meningitis, bacteremic pneumonia and other-IPD in young children in the PCV era: Insights from Israeli surveillance studies

Author:
Ben-Shimol, Shalom, Givon-Lavi, Noga, Grisaru-Soen, Galia, Megged, Orli, Greenberg, David, Dagan, Ron
Source:
Vaccine 2018 v.36 no.36 pp. 5477-5484
ISSN:
0264-410X
Subject:
blood, children, meningitis, monitoring, pathogenesis, pneumonia, serotypes, vaccines
Abstract:
Widespread introduction of pneumococcal conjugated vaccines (PCVs) impacted on invasive pneumococcal disease (IPD). However, IPD reduction may not be similar in all outcomes within IPD.We assessed PCV7/PCV13 impact on pneumococcal meningitis, bacteremic pneumonia (BP) and other (non-meningitis, non-pneumonia) IPD episodes in children <5years in Israel.A prospective, population-based, active nationwide surveillance.All pneumococcal invasive episodes with positive blood/CSF cultures, July 2000 through June 2016, were included. Three sub-periods were defined: pre-PCV (2000–2008), PCV7 (2009–2011) and PCV13 (2014–2016). Incidence rate ratios (IRRs) were calculated.Overall, 4321 episodes were recorded; 456 (10.6%) meningitis, 1478 (34.2%) pneumonia and 2387 (55.2%) other-IPD.In the pre-PCV period, proportion of serotypes in PCV13, but not in PCV7 (mainly serotypes 1, 5 and 19A) was higher in BP (43.3%) compared with other-IPD episodes (32.8%, p<0.001) and similar to that of meningitis (37.6%, p=0.1). The proportion of episodes in children <12months was higher in meningitis (52.1%) compared with pneumonia (23.2%) and other-IPD episodes (39.5%; p<0.001 for both).The declines of the 3 entities were not similar; Meningitis rate non-significantly declined by 24% (IRR=0.76; 95% CI 0.57–1.01), while BP and other-IPD rates significantly declined by 57% and 70%, respectively. In contrast to other entities, BP did not decline significantly after PCV7 introduction but started to decline only after PCV13 introduction.Rates of meningitis, pneumonia and other-IPD caused by PCV13-serotypes (VT13) substantially declined by 88%, 95% and 97%, respectively, comparing PCV13 and the pre-PCV periods. However, diseases caused by non-VT13 increased by 256%, 302% in meningitis and pneumonia, respectively, but only 116% in other-IPD.Following PCV7/PCV13 introduction, rates of episodes caused by VT13 were substantially reduced in all 3 groups. However, differences in age distribution, serotype replacement and specific serotype decrease suggest different pathogenesis and host susceptibility between the 3 entities.
Agid:
6102315