Pneumococcal Colonization in the Familial Context and Implications for Anti-Pneumococcal Immunization in Adults: Results from the BINOCOLO Project in Sicily

Abstract

The spread of Streptococcus pneumoniae within families has been scarcely investigated so far. This feasibility study aimed to estimate the prevalence of pneumococcal carriage in school-aged children and co-habiting relatives and to explore the potential link between the family environment and the sharing of pneumococcal serotypes covered by the vaccine. Oropharyngeal samples of 146 subjects belonging to 36 different family groups were molecularly tested for pneumococcal detection and serotyping. The overall prevalence of pneumococcal carriage was 65.8% (n = 96/146), whereas it was higher among schoolchildren (77.8%, n = 28/36); subjects of seven years of age had the highest odds of being colonized (odds ratio, OR = 5.176; p = 0.145). Pneumococcal serotypes included in the 13-valent conjugate vaccine formulation were largely detected in the study population and multiple serotypes colonization was considerable. Factors relating to a close proximity among people at the family level were statistically associated with pneumococcal carriage (OR = 2.121; p = 0.049), as well as active smoking habit with a clear dose-response effect (ORs = 1.017–3.326). About half of family clusters evidenced similar patterns of carried pneumococcal serotypes and the odds of sustaining a high level of intrafamilial sharing increased with household size (ORs = 1.083–5.000). This study highlighted the potential role played by the family environment in sustaining both the circulation and horizontal transmission of pneumococcus.

Changes in the incidence of invasive disease due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis during the COVID-19 pandemic in 26 countries and territories in the Invasive Respiratory Infection Surveillance Initiative: a prospective analysis of surveillance data

“…It is also possible that shielding of older adults, regardless of school closures, could have reduced bacterial transmission. [20][21][22] Globally, morbidity and mortality rates associated with S pneumoniae, H influenzae, and N meningitidis are high. Safe and effective vaccines are available, and although these vaccines do not protect against all serotypes of each pathogen, they have been successfully implemented in childhood immunisation programmes in many countries.…”

“…It is also possible that shielding of older adults, regardless of school closures, could have reduced bacterial transmission. 20 , 21 , 22 …”

The epidemiology of invasive pneumococcal disease in older adults in the post-PCV era. Has there been a herd effect?

“…Factors such as poor diet, smoking and poor awareness of lung disease may also contribute to increased risk of infection in the adult population [40]. Interestingly, increased interaction with children, such as the provision of childcare, may also contribute to carriage of pneumococcal serotypes in the older adult population [41].…”

The Invasive Respiratory Infection Surveillance (IRIS) Initiative reveals significant reductions in invasive bacterial infections during the COVID-19 pandemic

“…Therefore, whilst school closures would have contributed to the observed reductions in movement of people and reduced transmission of S pneumoniae, in addition to physical distancing and other measures, closing schools did not produce a detectable additional reduction in invasive pneumococcal disease in these data. It is also possible that shielding older adults regardless of school closures may have limited bacterial transmission (19)(20)(21).…”