Etiological analysis and epidemiological comparison among adult CAP and NHCAP patients in Okinawa, Japan

Alterations in the prevalence and serotypes of Streptococcus pneumoniae in elderly patients with community-acquired pneumonia: a meta-analysis and systematic review

BACKGROUND

Pneumococcal pneumonia is a common disease with a significant impact on morbidity and mortality among the elderly population. The main purpose of this meta-analysis was to estimate the prevalence of community-acquired pneumonia (CAP) in elderly individuals caused by Streptococcus pneumoniae (S. pneumoniae).

METHODS

A systematic search of the PubMed, Web of Science, and Scopus databases was conducted for relevant studies published between January 2013 and December 2023. Subgroup analysis and meta-regression were used to identify the sources of heterogeneity affecting the 87,430 patient studies obtained from 47 papers that met the inclusion and exclusion criteria.

RESULTS

The combined prevalence rate for S. pneumoniae among all CAP patients included in the study was 14.8% (95% confidence interval [CI]: 12.3-17.8%). The 5-year pooled prevalence decreased from 16.5% (95% CI: 15.0-18.2%) in 1996-2000 to 8.4% (95% CI: 6.3-11.0%) in 2016-2020 for bacterial culture alone and from 17.4% (95% CI: 16.3-18.7%) to 13.5% (95% CI: 10.7-16.8%) for bacterial culture and urinary antigen testing (UAT) combined (P < 0.001). The most prevalent serotype was serotype 3, followed by serotypes 8, 19 A, 22 F, 11 A, 5, 9 N, 12 F, 6 A, and 10 A. The vaccine-serotype coverage was 53.5% for PCV 13, 60.5% for PCV 15, 85.2% for PCV 20 and 88.6% for PPSV 23.

CONCLUSION

These findings indicate a decrease in the overall burden of pneumococcal CAP among elderly individuals over the decade, which lends support to the proposition that the delivery of immunization should be expanded across the life course.

Epidemiology of community-acquired pneumonia caused by S treptococcus pneumoniae in older adults: a narrative review

PURPOSE OF REVIEW

This review covers updated perspectives on different aspects of pneumococcal community-acquired pneumonia (pCAP), including the epidemiology, clinical presentation, risk factors, antibiotic treatment, and existing preventive strategies in older adults.

RECENT FINDINGS

pCAP remains the most prevalent condition among lower respiratory tract infections in the older adults according to Global Burden of Diseases 2019. Older adults can display atypical symptoms such as confusion, general clinical deterioration, new onset of and exacerbation of underlying illness that might trigger clinical suspicion of pCAP. Older adults with pCAP often experience increased disease severity and a higher risk of pulmonary complications compared with younger individuals, owing to age-related changes in immunity and a higher prevalence of comorbidities. Vaccination stands fundamental for prevention, emphasizing the need for effective immunization strategies, specifically tailored for older adults. There is a pressing need to reinforce efforts aimed at boosting pneumococcal vaccination rates.

SUMMARY

Despite a high morbidity and mortality, the burden of pCAP, in particular hospital admission and occurrence of invasive infections, among the elderly population is not sufficiently documented. This review findings emphasize the substantial burden of pCAP in this vulnerable population, driven by factors such as advancing age and underlying comorbidities. The emergence of antibiotic-resistant pneumococcal strains further complicates treatment decisions and highlights the importance of tailored approaches for managing pCAP in older adults.

Is the JRS atypical pneumonia prediction score useful in detecting COVID-19 pneumonia under nursing or healthcare settings?

BACKGROUND

SARS-CoV-2 causes frequent outbreaks in elderly care facilities that meet the criteria for nursing and healthcare-associated pneumonia (NHCAP). We evaluated whether the Japanese Respiratory Society (JRS) atypical pneumonia prediction score could be adapted to the diagnosis of nursing and healthcare acquired COVID-19 (NHA-COVID-19) with pneumonia.

METHODS

We analyzed 516 pneumonia patients with NHA-COVID-19 and compared them with 1505 pneumonia patients with community-associated COVID-19 (CA-COVID-19). NHA-COVID-19 patients were divided into six groups; 80 cases had the ancestral strain, 76 cases had the Alfa variant, 30 cases had the Delta variant, 120 cases had the Omicron subvariant BA.1, 53 cases had the Omicron subvariant BA.2, and 157 cases had the Omicron subvariant BA.5.

RESULTS

The sensitivities of the diagnosis of atypical pneumonia in patients with NHA-COVID-19 based on four or more predictors were 22.8 % in the ancestral strain group, 32.0 % in the Alfa variant group, 34.5 % in the Delta variant group, 23.1 % in the BA.1 subvariant group, 32.7 % in the BA.2 subvariant group, and 30.4 % in the BA.5 subvariant group. The diagnostic sensitivity for the presumptive diagnosis of atypical pneumonia was significantly lower for NHA-COVID-19 than for CA-COVID-19 (28.2 % vs 64.1 %, p < 0.0001).

CONCLUSIONS

Our present study demonstrated that the JRS atypical pneumonia prediction score is not a useful tool in elderly patients even if there is a lot of atypical pneumonia in the NHCAP group. The caution is necessary that JRS atypical pneumonia prediction score was not fully applied to prediction for NHA-COVID-19 pneumonia.

Aetiological agents of adult community-acquired pneumonia in Japan: systematic review and meta-analysis of published data

OBJECTIVE

Epidemiological information is essential in providing appropriate empiric antimicrobial therapy for pneumonia. This study aimed to clarify the epidemiology of community-acquired pneumonia (CAP) by conducting a systematic review of published studies in Japan.

DESIGN

Systematic review.

DATA SOURCE

PubMed and Ichushi web database (January 1970 to October 2022).

ELIGIBILITY CRITERIA

Clinical studies describing pathogenic micro-organisms in CAP written in English or Japanese, excluding studies on pneumonia other than adult CAP, investigations limited to specific pathogens and case reports.

DATA EXTRACTION AND SYNTHESIS

Patient setting (inpatient vs outpatient), number of patients, concordance with the CAP guidelines, diagnostic criteria and methods for diagnosing pneumonia pathogens as well as the numbers of each isolate. A meta-analysis of various situations was performed to measure the frequency of each aetiological agent.

RESULTS

Fifty-six studies were included and 17 095 cases of CAP were identified. Pathogens were undetectable in 44.1% (95% CI 39.7% to 48.5%). Streptococcus pneumoniae was the most common cause of CAP requiring hospitalisation or outpatient care (20.0% (95% CI 17.2% to 22.8%)), followed by Haemophilus influenzae (10.8% (95% CI 7.3% to 14.3%)) and Mycoplasma pneumoniae (7.5% (95% CI 4.6% to 10.4%)). However, when limited to CAP requiring hospitalisation, Staphylococcus aureus was the third most common at 4.9% (95% CI 3.9% to 5.8%). Pseudomonas aeruginosa was more frequent in hospitalised cases, while atypical pathogens were less common. Methicillin-resistant S. aureus accounted for 40.7% (95% CI 29.0% to 52.4%) of S. aureus cases. In studies that used PCR testing for pan-respiratory viral pathogens, human enterovirus/human rhinovirus (9.4% (95% CI 0% to 20.5%)) and several other respiratory pathogenic viruses were detected. The epidemiology varied depending on the methodology and situation.

CONCLUSION

The epidemiology of CAP varies depending on the situation, such as in the hospital versus outpatient setting. Viruses are more frequently detected by exhaustive genetic searches, resulting in a significant variation in epidemiology.

A Retrospective Study on Amoxicillin Susceptibility in Severe Haemophilus influenzae Pneumonia

Introduction

Treatment of Haemophilus influenzae (Hi) pneumonia is on concern because resistance to amoxicillin is largely diffused. This study describes the evolution of resistance to amoxicillin and amoxicillin/clavulanic acid (AMC) in Hi isolates and characteristics of patients with Hi severe pneumonia.

Methods

A monocentric retrospective observational study including patients from 2008 to 2017 with severe pneumonia hospitalized in ICU. Evolution of amoxicillin and AMC susceptibility was showed. Characteristics of patients with Hi pneumonia were compared to characteristics of patients with Streptococcus pneumoniae (Sp) pneumonia, as reference. Risk factors for amoxicillin resistance in Hi were investigated.

Results

Overall, 113 patients with Hi and 132 with Sp pneumonia were included. The percentages of AMC resistance among Hi strains decreased over the years (from 10% in 2008-2009 to 0% in 2016-2017) while resistance to amoxicillin remained stable at 20%. Also, percentages of Sp resistant strains for amoxicillin decreased over years (from 25% to 3%). Patients with Hi pneumonia experienced higher prevalence of bronchitis (18% vs. 8%, p=0.02, chronic obstructive pulmonary disease (43% vs. 30% p=0.03), HAP (18% vs. 7%, p=0.01, ventilator-associated pneumonia (27% vs. 17%, p=0.04, and longer duration of mechanical ventilation (8 days vs. 6 days, p=0.04) than patients with Sp pneumonia. Patients with Sp pneumonia had more frequently local complications than patients with Hi pneumonia (17% vs. 7%, p=0.03). De-escalation of antibiotics was more frequent in patients with Sp than in patients with Hi (67% vs. 53%, p=0.03). No risk factors were associated with amoxicillin resistance among patients with Hi pneumonia.

Conclusions

Amoxicillin resistance was stable over time, but no risk factors were detected. AMC resistance was extremely low, suggesting that AMC could be used for empiric treatment of Hi pneumonia, as well as other molecules, namely, cephalosporins. Patients with Hi pneumonia had more pulmonary comorbidities and severe diseases than patients with Sp pneumonia.

Hospitalizations for Community-Acquired and Non-Ventilator-Associated Hospital-Acquired Pneumonia in Spain: Influence of the Presence of Bronchiectasis. A Retrospective Database Study

To examine and compare in-hospital mortality (IHM) of community-acquired pneumonia (CAP) and non-ventilator hospital-acquired pneumonia (NV-HAP) among patients with or without bronchiectasis (BQ) using propensity score matching. A retrospective observational epidemiological study using the Spanish Hospital Discharge Records, 2016–17. We identified 257,455 admissions with CAP (3.97% with BQ) and 17,069 with NV-HAP (2.07% with BQ). Patients with CAP and BQ had less comorbidity, lower IHM, and a longer mean length of hospital stay (p < 0.001) than non-BQ patients. They had a higher number of isolated microorganisms, including Pseudomonas aeruginosa. In patients with BQ and NV-HAP, no differences were observed with respect to comorbidity, in-hospital mortality (IHM), or mean length of stay. P. aeruginosa was more frequent (p = 0.028). IHM for CAP and NV-HAP with BQ was 7.89% and 20.06%, respectively. The factors associated with IHM in CAP with BQ were age, comorbidity, pressure ulcers, surgery, dialysis, and invasive ventilation, whereas in NV-HAP with BQ, the determinants were age, metastatic cancer, need for dialysis, and invasive ventilation. Patients with CAP and BQ have less comorbidity, lower IHM and a longer mean length of hospital stay than non-BQ patients. However, they had a higher number of isolated microorganisms, including Pseudomonas aeruginosa. In patients with BQ and NV-HAP, no differences were observed with respect to comorbidity, in-hospital mortality, or mean length of stay, but they had a greater frequency of infection by P. aeruginosa than non-BQ patients. Predictors of IHM for both types of pneumonia among BQ patients included dialysis and invasive ventilation.

Where is Chlamydophila pneumoniae pneumonia?

BACKGROUND

Molecular diagnostic methods have recently gained widespread use, and consequently, the importance of viral pathogens in community-acquired pneumonia (CAP) has undergone re-evaluation. Under these circumstances, the role of Chlamydophila pneumoniae as a pathogen that causes CAP also needs to be reviewed.

METHODS

We reviewed articles that contained data on the frequency of identification of C. pneumoniae pneumonia as a causative pathogen for CAP. The articles were identified by performing a search in PubMed with the keywords "community-acquired pneumonia" and "pathogen".

RESULTS

Sixty-three articles were identified. The reviewed articles demonstrated that the rates of identification of C. pneumoniae as the causative pathogen for CAP were significantly lower in assessments based on polymerase chain reaction (PCR) methods than in those based on serological methods. In some studies, it was possible to compare both serological and PCR methods directly using the same set of samples.

CONCLUSIONS

The use of PCR methods, including multiplex PCR assays, has revealed that C. pneumoniae may play a limited role as a pathogen for CAP.

Disease Burden and Etiologic Distribution of Community-Acquired Pneumonia in Adults: Evolving Epidemiology in the Era of Pneumococcal Conjugate Vaccines

Pneumonia is the leading cause of morbidity and mortality, particularly in old adults. The incidence and etiologic distribution of community-acquired pneumonia is variable both geographically and temporally, and epidemiology might evolve with the change of population characteristics and vaccine uptake rates. With the increasing prevalence of chronic medical conditions, a wide spectrum of healthcare-associated pneumonia could also affect the epidemiology of community-acquired pneumonia. Here, we provide an overview of the epidemiological changes associated with community-acquired pneumonia over the decades since pneumococcal conjugate vaccine introduction.