Pneumococcal Vaccine May Reduce Resistant Streptococcus Pneumoniae Carriage

The implementation of the pneumococcal conjugate vaccine (PCV) and its effect on antibiotic-nonsusceptible Streptococcus pneumoniae carriage “is a dynamic, multi-component process, highly dependent on antibiotic consumption in the community, which may result in continuous increase in antibiotic resistance in the replacing serotypes,” according to study findings published in Clinical Infectious Diseases.

A number of factors can influence the overall PCV impact on antibiotic-nonsusceptible S pneumoniae,  including crowded living conditions, the extent and nature of antibiotic use in the community, pre-PCV implementation nasopharyngeal carriage rates, and pre-PCV antibiotic-nonsusceptible S pneumoniae prevalence in PCV and non-PCV serotypes. In this study, researchers sought to document antibiotic-nonsusceptible S pneumoniae nasopharyngeal carriage in Jewish and Bedouin children living in southern Israel and compared the post-PCV7/PCV13 dynamics between these 2 distinct ethnic groups.

During a 6-year period, nasopharyngeal cultures for S pneumoniae were obtained daily from children younger than 5 years. A total of 8446 nasopharyngeal samples were obtained; 48.3% were positive (42.0% and 52.8% for Jewish and Bedouin children, respectively; P <.001). The researchers observed that nonsusceptibility was significantly more frequent in PCV serotypes vs non-PCV serotypes and more frequent in Bedouin vs Jewish children. PCV serotype carriage was reduced by 80%, but non-PCV serotypes increased by 140%. In all serotypes overall, pneumococcal carriage significantly declined (33% and 11% in Bedouin and Jewish children, respectively).

“While the resulting impact so far is an overall reduction in antibiotic-nonsusceptible S pneumoniae carriage prevalence, it is plausible that the process is dynamic and despite markedly reducing antibiotic consumption in our community,” concluded the researchers. “[Antibiotic-nonsusceptible S pneumoniae] rates may increase in the following years, highlighting the need for careful continuous vigilance, combined with efforts to reduce antibiotic consumption by judicious use of antibiotics in pediatrics.”

Reference

Danino D, Givon-Lavi N, Ben-Shimol S, Greenberg D, Dagan R. Understanding the evolution of antibiotic-nonsusceptible pneumococcal nasopharyngeal colonization following pneumococcal conjugate vaccines implementation in young children [published online October 29, 2018] Clin Infect Dis. doi:10.1093/cid/ciy926