Impact of Streptococcus pneumoniae Urinary Antigen Testing in Patients With Community-Acquired Pneumonia Admitted Within a Large Academic Health System

A review of the value of point-of-care testing for community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is an infectious disease associated with high mortality worldwide. Although Streptococcus pneumoniae remains the most frequent pathogen in CAP, data from recent studies using molecular tests have shown that respiratory viruses play a key role in adults with pneumonia. The impact of difficult-to-treat pathogens on the outcomes of pneumonia is also important even though they represent only a small proportion of overall cases. Despite improvements in the microbiological diagnosis of CAP in recent decades, the identification of the causative pathogen is often delayed because of difficulties in obtaining good-quality sputum samples, issues in transporting samples, and slow laboratory processes. Therefore, the initial treatment of CAP is usually empirical. Point-of-care testing (POCT) was introduced to avoid treatment delays and reduce reliance on empirical antibiotics.

AREAS COVERED

This review summarizes the main scientific evidence on the role of POCT in the diagnosis and management of patients with CAP. The authors searched for articles on POCT in pneumonia on PubMed from inception to 20 January 2024. The references in the identified articles were also searched.

EXPERT OPINION

POCT involves rapid diagnostic assays that can be performed at the bedside especially in cases of severe CAP and immunocompromised patients. These tests can produce results that could help guide initial therapy and management.

Utility of incorporation of beta-D-glucan and T2Candida testing for diagnosis and treatment of candidemia

The additive role of non-culture-based methods for the diagnosis of candidemia remains unknown. We evaluated 2 clinical practices followed in our hospitals for the diagnosis of candidemia, namely practice#1 including a combination of blood cultures and T2Candida, and practice#2 that also included Beta-D-glucan (BDG). Three out of 96 patients testing positive with practice#1 received a complete antifungal course. Of the 120 patients evaluated with practice#2, 29 were positive. Only 55.2% of those received a complete course. We observed significant differences in antifungal utilization, with 268.5 antifungal days/1000 patient-days for practice#1, as opposed to 371.9 days for practice#2, a nearly 40% difference. However, we found similar rates of antifungal discontinuation among negative patients at 3 days of testing (36.8% and 37.0% respectively). No differences were detected in death and/or subsequent diagnosis of candidemia. In summary, addition of BDG was interpreted variably by clinicians, was associated with an increase in antifungal utilization, and did not correlate with measurable clinical benefits for patients.