A Laboratory-Based Surveillance Study of Invasive Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae Diseases in a Serbian Pediatric Population-Implications for Vaccination.

Snezana Delic,Metka Paragi,Marina Siljic,Boris Jegorovic,Vera Mijac,Maja Stanojevic,Lazar Ranin,Ina Gajic,Davor Culic,Dusan Kekic,Milos Markovic,Natasa Opavski,Valentina Cirkovic

doi:10.3390/diagnostics11061059

Abstract

The aim of this study was to present the epidemiology of invasive diseases caused by Neisseria meningitidis and Streptococcus pneumoniae in the pre-vaccine period, and Haemophilus influenzae in the post-vaccine period in a pediatric population from Serbia. Among the meningococci, serogroup B dominated (83%), followed by serogroup C (11.3%). High antigenic diversity was found, with fine type P1.5-1,10-4 being the most frequent. Moderate susceptibility to penicillin was common (55%). Within pneumococci, serotypes 19F, 14, 6B, 6A, 18C, 23F, 3, and 7F prevailed, while 19A was rare (3.6%). The coverages of PCV10 and PCV13 were 68% and 84%, respectively. Major sequence types were ST320, ST15, ST273, ST271, and ST81. Non-susceptibility to penicillin (66.7%), cefotaxime (37%), and macrolides (55%) was predominantly detected in vaccine-related serotypes. Among the 11 invasive H. influenzae isolates collected, there were six Hib, three non-type b, and two non-typeable strains (ntHi) that were antibiotic susceptible. These results imply a potential benefit of future Men-B vaccine implementations. For pneumococci, as PCV10 was recently introduced, a significant reduction of morbidity and antibiotic resistance might be expected. The efficiency of Hib vaccination is evident, but a shift towards non-type b and ntHi strains may be anticipated.

Highlights

Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae are important human pathogens causing invasive life-threatening infections that are a major cause of morbidity and mortality in childhood
Many countries have introduced some of these vaccines into their immunization programs, which resulted in a marked reduction in the incidence of invasive diseases caused by vaccine-related serotypes/serogroups (e.g., >90% for Hib) [3,4,5]
Epidemiological survey of invasive meningococcal diseases (IMD) in EU countries from 2004 to 2014 revealed that the majority of cases in all age groups were caused by serogroup B (74% in total), with decreasing trends of serogroup C-related IMDs in countries with meningococcal C conjugate (MCC) vaccine introduced into immunization programs [4]

Summary

Introduction

Streptococcus pneumoniae, and Haemophilus influenzae are important human pathogens causing invasive life-threatening infections that are a major cause of morbidity and mortality in childhood. More than 90 capsular serotypes have been described and serogroups 1, 6, 14, 19, and 23 were among the most common causes of bacteriaemia, sepsis, meningitis, and other invasive pneumococcal diseases (IPD) in children [1]. Regarding H. influenzae, significant invasive potential is related primarily to capsular type b (Hib). Many countries have introduced some of these vaccines into their immunization programs, which resulted in a marked reduction in the incidence of invasive diseases caused by vaccine-related serotypes/serogroups (e.g., >90% for Hib) [3,4,5]. A significant change in serotypes/serogroups of meningococcus, pneumococcus, and H. influenzae causing invasive diseases, a phenomenon referred to as “serotype replacement”, has been observed after the use of conjugate vaccines in many populations [9,10,11]

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