Prospective, population-based surveillance of the burden of Streptococcus pneumoniae in community-acquired pneumonia in older adults, Chrzanów County, Poland, 2010 to 2012.

INTRODUCTION: Community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae is a substantial cause of morbidity and mortality among older adults. This study estimated incidences of CAP, chest x-ray-confirmed CAP (CXR+CAP), S pneumonia- positive CAP, S pneumonia-positive CXR+CAP, and S. pneumoniae serotype distribution among 46,000 at-risk adults aged ≥ 50 years residing in Chrzanów County, Poland. MATERIAL AND METHODS: From January 2010 to January 2012, all facilities providing ambulatory and inpatient care enrolled all consenting resident patients with suspicion of CAP. Chest x-rays, urine, blood, and sputum samples were analyzed. Annualized incidence rates were determined. Presence of S pneumonia-positive CAP and/or S. pneumoniae serotype distribution was determined using the urine antigen detection assay (capable of detecting the serotypes in the 13-valent pneumococcal conjugate vaccine [PCV13]), BinaxNOW®, and/or microbiology cultures. RESULTS: Among 5055 enrolled patients, 1195 (23.7%) were diagnosed with CAP and 1166 (23.4%) had CXR+CAP. S. pneumoniae was detected in 144 (12.1%) and 131 (11.2%) patients from the CAP and CXR+CAP cohorts, respectively. Annualized incidence rates of CAP, CXR+CAP, S pneumonia-positive CAP, and S. pneumonia-positive CXR+CAP were 12.8, 12.5, 1.6, and 1.4 per 1000 residents, respectively. Among CXR+CAP patients, 39.7% were aged 50 to 64 years and 60.3% were aged ≥ 65 years. Incidence rates generally increased with age. The most common serotypes in S. pneumoniae-positive CXR+CAP patients were 3 (n = 15), 23F (n = 10), 18C (n = 9), and 9V (n = 6). CONCLUSIONS: CAP due to PCV13 serotypes is a source of morbidity among adults >50 years and may be reduced by greater access to pneumococcal vaccines.

Distribution of 13-valent pneumococcal conjugate vaccine Streptococcus pneumoniae serotypes in US adults aged ≥50 years with community-acquired pneumonia.

BACKGROUND: Streptococcus pneumoniae causes a substantial proportion of community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP) in the United States. Limited data are available regarding the pneumococcal serotypes causing CAP and HCAP. METHODS: Adults aged ≥ 50 years presenting to participating US hospitals with radiographically confirmed pneumonia between February 2010 and September 2011 were screened for inclusion. S. pneumoniae was identified using microbiological cultures, BinaxNOW® S. pneumoniae assay, or urine antigen detection (UAD) assay capable of detecting 13-valent pneumococcal conjugate vaccine (PCV13)-associated serotypes. RESULTS: Among 710 subjects enrolled, the median age was 65.4 years; 54.2% of subjects were male, 22.4% of radiographically confirmed pneumonia cases were considered HCAP, and 96.6% of subjects were hospitalized. S. pneumoniae was detected in 98 subjects (13.8%) by any test, and PCV13-associated serotype(s) were identified by UAD in 78 (11.0%). Serotype 19A was most prevalent, followed by 7F/A, 3, and 5. Serotypes associated with 7-valent pneumococcal conjugate vaccine (PCV7) accounted for 25% of UAD-positive isolates. CONCLUSIONS: Pneumococcal serotypes causing noninvasive pneumonia in adults may differ significantly from those causing invasive disease, with PCV7-associated serotypes overrepresented. Serotype 5, rarely seen in contemporary surveillance of invasive disease in the United States, substantially contributed to the observed cases of S. pneumoniae-positive CAP or HCAP.

Pneumococcal epidemiology among us adults hospitalized for community-acquired pneumonia.

BACKGROUND: Few studies have measured the burden of adult pneumococcal disease after the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) into the US infant vaccination schedule. Further, most data regarding pneumococcal serotypes are derived from invasive pneumococcal disease (IPD), which represents only a fraction of all adult pneumococcal disease burden. Understanding which pneumococcal serotypes cause pneumonia in adults is critical for informing current immunization policy. The objective of this study was to measure the proportion of radiographically-confirmed (CXR+) community-acquired pneumonia (CAP) caused by PCV13 serotypes in hospitalized US adults. METHODS: This observational, prospective surveillance study recruited hospitalized adults aged ≥18 years from 21 acute care hospitals across 10 geographically-dispersed cities in the United States between October 2013 and September 2016. Clinical and demographic data were collected during hospitalization. Vital status was ascertained 30 days after enrollment. Pneumococcal serotypes were detected via culture from the respiratory tract and normally-sterile sites (including blood and pleural fluid). Additionally, a novel, Luminex-based serotype-specific urinary antigen detection (UAD) assay was used to detect serotypes included in PCV13. RESULTS: Of 15,572 enrolled participants, 12,055 eligible patients with CXR+CAP were included in the final analysis population. Mean age was 64.1 years and 52.7% were aged ≥65 years. Common comorbidities included chronic obstructive pulmonary disease (43.0%) and diabetes mellitus (28.6%). PCV13 serotypes were detected in 552/12,055 (4.6%) of all patients and 265/6347 (4.2%) of those aged ≥65 years. Among patients aged 18-64 years PCV13 serotypes were detected in 3.8-5.3% of patients depending on their risk status. CONCLUSIONS: After implementation of a pneumococcal conjugate vaccination program in US children, and despite the herd protection observed in US adults, a persistent burden of PCV13-type CAP remains in this population.