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

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.

Serotype distribution, antimicrobial susceptibility and molecular epidemiology of invasive Streptococcus pneumoniae in the nine-year period in Serbia

“…As the consumption of antibiotics in Serbia is still very high, especially broad-spectrum macrolides, quinolones, and thirdgeneration cephalosporins (Tomas et al, 2021), bacterial resistance is on the rise. Results on antimicrobial resistance of invasive S. pneumoniae are in line with previous findings that reported high levels of pneumococcal non-susceptibility to penicillin (47.6%) and macrolides (40.4%) in Serbia (Gajic et al, 2013;Delic et al, 2021). Particularly worrying is the non-susceptibility to the third-generation cephalosporins (16.6%) and high levels of MDR (20%) and XDR (16.9%) isolates, which mainly express simultaneous non-susceptibility to first-line anti-pneumococcal antibiotics.…”

“…So far, no population-based study on IPD has been performed in Serbia. However, National Reference Laboratory (NRL) for Streptococci performs voluntary-based laboratory surveillance on IPD and serotype distribution ( Gajic et al, 2013 ; Delic et al, 2021 ).…”