Pneumococcal colonization in older adults

Abstract

BackgroundLittle is known about pneumococcal carrier states in older adults. The main aim of this study was to evaluate pneumococcal colonization patterns among older adults in two centres in Milan, Italy, before the widespread use of the 13-valent pneumococcal vaccine (PCV13) in this age group, to investigate demographic and clinical features that are associated with pneumococcal colonization and to estimate the potential coverage offered by PCV13.ResultsAmong 417 adults ≥65 years old (171, 41.1 %, ≥75 years), 41 (9.8 %) were pneumococcal carriers. Univariate and multivariate analyses revealed that pneumococcal colonization was significantly less common among individuals with underlying co-morbidities than among those without (odds ratio [OR] 0.453, 95 % confidence interval [CI] 0.235–0.875, p = 0.018; adjusted OR 0.503, 95 % CI 0.255–0.992, p = 0.047). Moreover, among these patients, those with cardiac disease had a significantly lower risk of colonization (OR 0.308, 95 % CI 0.119–0.795, p = 0.015; adjusted OR 0.341, 95 % CI 0.13–0.894, p = 0.029). Only one vaccinated subject who received 23-valent polysaccharide pneumococcal vaccine (PPV23) was colonized. Twenty-five (89.3 %) of the subjects who were <75 years old and 9 (75.0 %) of those who were ≥75 years old were colonized by at least one of the serotypes that is included in PCV13, with serotype 19 F being the most common. Respiratory allergies as well as overall co-morbidities were more common in subjects who were positive for only non-PCV13 serotypes compared with negative subjects and those who were carriers of only PCV13 serotypes.ConclusionsAlthough this study included a relatively small number of subjects and has been performed in a limited geographic setting, results showed that pneumococcal colonization in older people is common, and the monitoring of carriers can offer useful information about the circulation of this pathogen among older people and the potential protective effect of pneumococcal vaccines. Because the colonization in most cases involves the strains that are included in PCV13, this vaccine could be useful in the prevention of pneumococcal infections in the overall population of older people. In subjects with respiratory allergies and in those with co-morbidities, the addition of the PPV23 to PCV13 should be recommended. Due to the low vaccination coverage, urgent educational programmes are required to inform older adults and their medical doctors of the risks of pneumococcal infection and the efficacy and safety of the available pneumococcal vaccines.

Colonisation of Irish patients with chronic obstructive pulmonary disease byStreptococcus pneumoniaeand analysis of the pneumococcal vaccine coverage: a non-interventional, observational, prospective cohort study

“…A very recent study describing S. pneumoniae colonisation in adults >65 years of age used molecular methods of detection and reported a predominance of PCV-13 serotypes within the cohort whereas this study revealed a predominance of NVT serotypes within the cohort. 24 The different findings between this study and that of Esposito et al (2016) could be due to regional variation and the lack of molecular detection methods used in this study. A factor that may be negatively impacting on the recovery of S. pneumoniae from the study volunteers could be the high rate of antibiotic use in this patient group; patients reported high antibiotic use between visits with the median number of courses of antibiotics prescribed in the period between visits ranging from one in the spring to two in the autumn.…”

Pneumococcal Capsular Polysaccharide Immunity in the Elderly

“…Table 2 lists examples of studies that attempted to define the rate of pneumococcal colonization in elderly persons (defined as either Ͼ60 or Ͼ65 years old in different studies) (15)(16)(17)(18)(19)(20)(21). Much of the variation between these studies can be explained by the different sampling sites-nasopharyngeal, oropharyngeal, or saliva-and detection methods-classical culture, PCR, or some combination of the two.…”

Assessing the diagnostic accuracy of PCR-based detection ofStreptococcus pneumoniaefrom nasopharyngeal swabs collected for viral studies in Canadian adults hospitalised with community-acquired pneumonia: a Serious Outcomes Surveillance (SOS) Network of the Canadian Immunization Research (CIRN) study

“…[24][25][26][27] While this study evaluated the performance for S. pneumoniae detection by PCR in NP swab collected for viral studies, it was recognised that other specimen types, such as oral and oropharyngeal swabs, were previously shown to perform better than sampling from the nasopharynx to assess pneumococcal colonisation. [28][29][30] Since the performance of NP swab PCR is affected by the results of its comparator, a future studies would benefit from a direct comparison between PCR-based detection of pneumococcal DNA in NP swabs and concurrent quantitative S. pneumoniae from culture swabs collected from the nasopharynx. 31 Other studies have also suggested broth enrichment prior to lytA real-time PCR can enhance the detection of S. pneumoniae, particularly for low density colonisation.…”