[Managing lower respiratory tract infections in immunocompetent patients. Definitions, epidemiology, and diagnostic features]

CRP under 130 mg/L rules out the diagnosis of Legionella pneumophila serogroup 1 (URINELLA Study)

INTRODUCTION

In case of pneumonia, some biological findings are suggestive for Legionnaire's disease (LD) including C-reactive protein (CRP). A low level of CRP is predictive for negative Legionella Urinary-Antigen-Test (L-UAT).

METHOD

Observational retrospective study in Nord-Franche-Comté Hospital with external validation in Besançon University Hospital, France which included all adults with L-UAT performed during January 2018 to December 2022. The objective was to determine CRP optimal threshold to predict a L-UAT negative result.

RESULTS

URINELLA included 5051 patients (83 with positive L-UAT). CRP optimal threshold was 131.9 mg/L, with a negative predictive value (NPV) at 100%, sensitivity at 100% and specificity at 58.0%. The AUC of the ROC-Curve was at 88.7% (95% CI, 86.3-91.1). External validation in Besançon Hospital patients showed an AUC at 89.8% (95% CI, 85.5-94.1) and NPV, sensitivity and specificity was respectively 99.9%, 97.6% and 59.1% for a CRP threshold at 131.9 mg/L; after exclusion of immunosuppressed patients, index sensitivity and NPV reached also 100%.

CONCLUSION

In case of pneumonia suspicion with a CRP level under 130 mg/L (independently of the severity) L-UAT is useless in immunocompetent patients with a NPV at 100%. We must remain cautious in patients with symptoms onset less than 48 h before CRP dosage.

Non-steroidal Anti-inflammatory Drugs may Worsen the Course of Community-Acquired Pneumonia: A Cohort Study

PURPOSE

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed or used as self-medication in cases of community-acquired pneumonia (CAP). Nevertheless, the consequences of such medication on the risk of pleuroparenchymal complications are not well known. The aim was to investigate whether exposure to NSAIDs prior to hospital admission among patients suffering from CAP is associated with the development of pleural complications or a lung abscess.

METHODS

All consecutive non-immunocompromised patients with CAP and admitted to a university hospital were prospectively included (2-year period). The risk of pleuropulmonary complications was analyzed according to previous exposure to NSAIDs.

RESULTS

Of the 221 included patients, 40 (18.1%) had developed a pleuropulmonary complication. NSAIDs intake prior to admission was reported for 24 patients (10.9%) who were younger (50.6 ± 18.5 vs. 66.5 ± 16.4 years; p = 0.001), had less comorbidities (60 vs. 25.1%; p = 0.001), had a longer duration between the first symptoms of CAP and the start of an antibiotic therapy (6.1 ± 7.6 vs. 2.8 ± 3.8 days; p = 0.001), and who had a higher incidence of pleuropulmonary complications (33.3 vs. 16.2%; p = 0.048). In multivariate analyses, two factors were independently associated with the development of pleuroparenchymal complications: NSAIDs intake [Odds Ratio (OR) = 2.57 [1.02-6.64]; p = 0.049] and alcohol abuse (OR = 2.68 [1.27-5.69]; p = 0.01).

CONCLUSIONS

Our findings suggest that NSAIDs, often taken by young and healthy patients, may worsen the course of CAP with delayed therapy and a higher rate of pleuropulmonary complications.

[First epidemiologic data on pneumonia in Cambodia]

About 15% of deaths in adults are related to lung infections in Cambodia. Some knowledge on microbial epidemiology is crucial for deciding first-line antibiotic treatment. However, to date, these data are not available in Cambodia. Consequently, antibiotic prescription relies on French or neighborhood's countries guidelines, which are possibly not suitable. This cases-series aimed to provide data on microbial ecology in pneumonia. Medical charts of patients newly admitted for lung infection in the pulmonology unit of Preah Kossamak Hospital were retrospectively reviewed. Ninety-four patients were included and 29% had a complete microbiological diagnosis. Main germs isolated were: Gram-negative bacilli (n=20; 70.4%) and M. tuberculosis infections (n=7; 25.9%). There was one case of myeloïdosis. No S. pneumonia was isolated, possibly due to sample shipping tropical conditions. Antibiograms showed high resistance profiles. Although this study bring new data in the field, it also showed that European guidelines for antibiotic are not relevant in such countries and stress the need for further dedicated and prospective studies.