Severe community-acquired pneumonia in Reunion Island: Epidemiological, clinical, and microbiological characteristics, 2016-2018

Lianhua Qingke Tablet in severe pneumonia: Clinical efficacy and immunoregulatory mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Lianhua Qingke (LHQK), a traditional Chinese medicine, has shown efficacy in treating acute and chronic bronchitis and bronchiolitis. However, the specific mechanism underlying the therapeutic effects of LHQK on severe pneumonia is not clear.

AIM OF THE STUDY

Severe pneumonia remains a critical health challenge, particularly in cases progressing to sepsis and septic shock, where host immune responses become dysregulated or dysfunctional. This study aims to evaluate the immunomodulatory effects of LHQK in severe pneumonia.

MATERIALS AND METHODS

This research examined LHQK's therapeutic and immunomodulatory mechanisms in patients with severe pneumonia and a lipopolysaccharide (LPS)-induced mouse model of severe pneumonia. Patients with severe pneumonia were randomized into three groups: basal treatment, LHQK-Low dose (12 tablets/day), and LHQK-High dose (24 tablets/day). BALB/c mice were categorized into four groups: control, model, LHQK-Low dose (3.7 mg/kg), and LHQK-High dose (7.4 mg/kg). Clinical efficacy was evaluated by assessing parameters including the value and rate of change in APACHE II score, improvement in chest X-ray or CT, partial pressure of oxygen (PO2), oxygen saturation in arterial blood (SaO2), oxygenation index (OI), and the length of hospitalization after 7 days of treatment. The viscosity of sputum was measured by viscosimeter. Moreover, lung histopathology, airway barrier integrity, and immune cells in BALF, were assessed using hematoxylin and eosin staining, immunostaining, and Wright-Giemsa staining. Cytokine levels were measured using Luminex assay and Olink, while pulmonary immune cell patterns were analyzed using multiplex fluorescence and Cytometry by Time-Of-Flight (CyTOF).

RESULTS

In comparison to the basal treatment group of patients, LHQK treatment exhibited a reduction in the severity of severe pneumonia and inflammatory status, as evidenced by observations on Chest X-ray or CT scans. Additionally, LHQK treatment led to an elevation in OI, PO2, and SaO2 levels, and notably, a decreased duration of hospitalization. Further analysis revealed that LHQK enhanced the integrity of the airway epithelial barrier, reduced the viscosity of sputum, and significantly decreased inflammatory cells infiltration. The application of Luminex and Olink assay further confirmed the inhibitory impact of LHQK on the cytokine storm in mice. Moreover, multiplex fluorescence and CyTOF analysis demonstrated that LHQK effectively suppressed the activation of monocyte derived macrophages, neutrophils, and Treg cells, while preserved the levels of alveolar macrophages, B cells, and CD4+ and CD8+ T lymphocytes, therefore restoring immune homeostasis within the lung of severe pneumonia. These findings significantly substantiate the potential clinical application of LHQK in severe pneumonia treatment.

CONCLUSION

LHQK demonstrates therapeutic efficacy in severe pneumonia by maintaining structural integrity, suppressing cytokine storms, enhancing intrinsic immunity, reversing T cell exhaustion, and correcting lung immune disorders. These findings significantly substantiate LHQK's potential clinical application in severe pneumonia treatment.

Severe community-acquired pneumonia compared to severe community-acquired Acinetobacter baumannii pneumonia in Reunion Island: A retrospective study

Acinetobacter baumannii (Ab) has emerged in the last decades as a cause of community-acquired pneumonia (CAP) in tropical and subtropical regions. We previously conducted the first investigation on this topic in France with a case series of severe CAP-Ab in Reunion Island over an eight-year period. In the present work, we aim to highlight the specific aspects of CAP-Ab by comparing our case series with an historical cohort (PAC_RUN), obtained by retrospective chart review (2016-2021) of severe community-acquired pneumonia cases on Reunion Island, in which CAP-Ab was ruled out. During the study period, eight CAP-Ab cases were identified, giving an incidence of 0.1 cases per 100,000 people/year, and an incidence of 16.5 cases per 100,000 people/year for non-Ab-related CAP (n = 761). By comparing with non-Ab-related CAP, patients had more excessive alcohol use (75% vs. 25.6%, p = 0.005) and lower body mass index (21 vs. 24 kg/m2, p = 0.004). Six cases (75%) of CAP-Ab occurred during the rainy season (p = 0.06). Mortality was higher (62.5% vs. 24.3%, p = 0.02) and time to death was shorter (median 2 days vs. 7, p = 0.009) in the CAP-Ab group. Bacteraemic pneumonia was strongly associated with CAP-Ab (62.5% vs. 15.7%, p = 0.004). Significant differences were found in the need for renal replacement therapy (75% vs. 17.2%, p < 0.001), catecholamine use (100% vs. 54.5%, p = 0.01) and use of invasive mechanical ventilation (100% vs. 62.7%, p = 0.03). Also, in the proportion of severe acute respiratory distress syndrome (62.5% vs. 23.2%, p = 0.02), septic shock (100% vs. 40.6%, p < 0.001), and cardiogenic shock (87.5% vs. 15.9%, p < 0.001). Compared to severe non-Ab-related CAP, severe CAP-Ab is characterised by higher mortality, associated with a high frequency of multiple organ failure. Excessive alcohol consumption and malnutrition seem to be risk factors. To improve outcomes, broader spectrum antibiotic therapy must be immediately proposed when CAP-Ab is suspected.

Case Report: Severe Community-Acquired Pneumonia in Réunion Island due to Acinetobacter baumannii

Acinetobacter baumannii (Ab) is a well-known nosocomial pathogen that has emerged as a cause of community-acquired pneumonia (CAP) in tropical regions. Few global epidemiological studies of CAP-Ab have been published to date, and no data are available on this disease in France. We conducted a retrospective chart review of severe cases of CAP-Ab admitted to intensive care units in Réunion University Hospital between October 2014 and October 2022. Eight severe CAP-Ab cases were reviewed. Median patient age was 56.5 years. Sex ratio (male-to-female) was 3:1. Six cases (75.0%) occurred during the rainy season. Chronic alcohol use and smoking were found in 75.0% and 87.5% of cases, respectively. All patients presented in septic shock and with severe acute respiratory distress syndrome. Seven patients (87.5%) presented in cardiogenic shock, and renal replacement therapy was required for six patients (75.0%). Five cases (62.5%) presented with bacteremic pneumonia. The mortality rate was 62.5%. The median time from hospital admission to death was 3 days. All patients received inappropriate initial antibiotic therapy. Acinetobacter baumannii isolates were all susceptible to ceftazidime, cefepime, piperacillin-tazobactam, ciprofloxacin, gentamicin, and imipenem. Six isolates (75%) were also susceptible to ticarcillin, piperacillin, and cotrimoxazole. Severe CAP-Ab has a fulminant course and high mortality. A typical case is a middle-aged man with smoking and chronic alcohol use living in a tropical region and developing severe CAP during the rainy season. This clinical presentation should prompt administration of antibiotic therapy targeting Ab.

Identification and Clinical Characteristics of Community-Acquired Acinetobacter baumannii in Patients Hospitalized for Moderate or Severe COVID-19 in Peru

Acinetobacter baumannii has been described as a cause of serious community-acquired infections in tropical countries. Currently, its implications when simultaneously identified with other pathogens are not yet adequately understood. A descriptive study was conducted on hospitalized patients with a diagnosis of moderate/severe SARS-CoV-2-induced pneumonia confirmed via real-time RT-PCR. Patients aged > 18 years who were admitted to a specialized COVID-19 treatment center in Peru were selected for enrollment. A. baumannii was detected via the PCR amplification of the blaOXA-51 gene obtained from nasopharyngeal swabs within 48 h of hospitalization. A total of 295 patients with COVID-19 who met the study inclusion criteria were enrolled. A. baumannii was simultaneously identified in 40/295 (13.5%) of COVID-19-hospitalized patients. Demographic data and comorbidities were comparable in both Acinetobacter-positive and -negative subgroups. However, patients identified as being infected with Acinetobacter were more likely to have received outpatient antibiotics prior to hospitalization, had a higher requirement for high-flow nasal cannula and a higher subjective incidence of fatigue, and were more likely to develop Acinetobacter-induced pneumonia during hospitalization. Conclusions: The group in which SARS-CoV-2 and A. baumannii were simultaneously identified had a higher proportion of fatigue, a higher frequency of requiring a high-flow cannula, and a higher proportion of superinfection with the same microorganism during hospitalization.

Impact of the COVID-19 pandemic on severe non-SARS-CoV-2 community-acquired pneumonia in Reunion Island: a multicenter retrospective observational study, 2016-2021

The Coronavirus 2019 (COVID-19) pandemic has had a considerable impact on the incidence of severe community-acquired pneumonia (CAP) worldwide. The aim of this study was to assess the early impact of the COVID-19 pandemic in the Reunion Island. This multicenter retrospective observational study was conducted from 2016 to 2021 in the hospitals of Reunion Island. The incidence of severe non-SARS-CoV-2 CAP, microorganisms, characteristics and outcomes of patients hospitalized in intensive care unit were compared between the pre-COVID-19 period (January 1, 2016 to February 29, 2020) and the early COVID-19 period (March 1, 2020 to October 31, 2021). Over the study period, 389 patients developed severe non-SARS-CoV-2 CAP. The incidence of severe non-SARS-CoV-2 CAP significantly decreased between the two periods (9.16 vs. 4.13 cases per 100,000 person-years). The influenza virus was isolated in 43.5% patients with severe non-SARS-CoV-2 CAP in the pre-COVID-19 period and in none of the 60 patients in the early COVID-19 period (P < 0.0001). The only virus that did not decrease was rhinovirus. Streptococcus pneumoniae was the most frequently isolated bacterial microorganism, with no significant difference between the two periods. In Reunion Island, the COVID-19 pandemic led to a significant decrease in the incidence of influenza, which likely explains the observed decrease in the incidence of severe non-SARS-CoV-2 CAP. The pandemic had no impact on the incidence of other viral and bacterial severe non-SARS-CoV-2 CAP. Monitoring influenza incidence is crucial now that COVID-19 control measures have been removed.

Prevalence of atypical pathogens in patients with severe pneumonia: a systematic review and meta-analysis

OBJECTIVES

We aimed to summarise the prevalence of atypical pathogens in patients with severe pneumonia to understand the prevalence of severe pneumonia caused by atypical pathogens, improve clinical decision-making and guide antibiotic use.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Web of Science and Cochrane Library were searched through November 2022.

ELIGIBILITY CRITERIA

English language studies enrolled consecutive cases of patients diagnosed with severe pneumonia, with complete aetiological analysis.

DATA EXTRACTION AND SYNTHESIS

We conducted literature retrieval on PubMed, Embase, Web of Science and The Cochrane Library to estimate the prevalence of Chlamydia, Mycoplasma and Legionella in patients with severe pneumonia. After double arcsine transformation of the data, a random-effects model was used for meta-analyses to calculate the pooled prevalence of each pathogen. Meta-regression analysis was also used to explore whether the region, different diagnostic method, study population, pneumonia categories or sample size were potential sources of heterogeneity.

RESULTS

We included 75 eligible studies with 18 379 cases of severe pneumonia. The overall prevalence of atypical pneumonia is 8.1% (95% CI 6.3% to 10.1%) In patients with severe pneumonia, the pooled estimated prevalence of Chlamydia, Mycoplasma and Legionella was 1.8% (95% CI 1.0% to 2.9%), 2.8% (95% CI 1.7% to 4.3%) and 4.0% (95% CI 2.8% to 5.3%), respectively. We noted significant heterogeneity in all pooled assessments. Meta-regression showed that the pneumonia category potentially influenced the prevalence rate of Chlamydia. The mean age and the diagnostic method of pathogens were likely moderators for the prevalence of Mycoplasma and Legionella, and contribute to the heterogeneity of their prevalence.

CONCLUSIONS

In severe pneumonia, atypical pathogens are notable causes, especially Legionella. The diagnostic method, regional difference, sample size and other factors contribute to the heterogeneity of prevalence. The estimated prevalence and relative heterogeneity factors can help with microbiological screening, clinical treatment and future research planning.

PROSPERO REGISTRATION NUMBER

CRD42022373950.

Analysis of Neutrophil/Lymphocyte Ratio and Culture Results on Clinical Severity of Patients with CAP

Community-Acquired Pneumonia (CAP) is an acute infection with high morbidity and mortality, especially among toddlers and elders in Indonesia. Culture is the gold standard for infectious diseases, which requires a long time. Therefore, a rapid, inexpensive, easy-to-use marker such as NLR is needed. To analyze the relationship of NLR and culture results with the clinical severity of CAP. A retrospective study with a cross-sectional design was performed using secondary data from CAP patients at Dr. Wahidin Sudirohusodo Hospital from January 1st, 2018 to July 31st, 2021. The study conducted on 113 samples showed no significant differences between NLR and clinical severity of CAP (p-value of 0.071). However, the mean value of NLR in severe CAP was higher (6±4.74) than in moderate CAP (2.58±1.8) with no significant correlation (p-value 0.071). There was a significant difference in culture on the clinical severity of CAP (p-value 0.005). A positive correlation was found between culture and clinical severity of CAP (p-value 0.004) with weak correlation strength (r=0.266). NLR is an early detection marker of infection. Stimulation of growth hormone causes an increase in neutrophil count, apoptosis acceleration, and lymphocyte redistribution; therefore, increased neutrophils are common in severe clinical conditions. The insignificant relationship between NLR and clinical severity might be caused by the therapeutic intervention given. The ATS/IDSA guidelines stated that culture results were positive in 4-15%. The mean NLR value in severe CAP was slightly higher than that of moderate CAP, but no significant difference was found. There was a weak correlation between culture results and the clinical severity of CAP patients.