Physicians' prediction for the assessment of atypical pathogens in respiratory tract infections

Patients with acute respiratory tract infections are frequently prescribed antimicrobials despite high rates of virus detection. Physicians may overprescribe antimicrobials owing to the concern of bacterial infections, including those because of atypical pathogens. We investigated the accuracy of clinical predictions concerning atypical pathogen infections.

We prospectively enrolled adult patients who presented with a fever and cough in outpatient clinics between December 2016 and August 2018. After taking a history and performing physical examinations, physicians predicted the possibility of respiratory infections because of atypical pathogens. Disease probabilities were categorized into 3 grades (high: ≥50%, intermediate: 20% ≥ and <50%, and low: <20%) and were judged by physicians who were taking care of the patients. Confirmation of atypical pathogens was performed by comprehensive molecular analyses of respiratory samples.

Atypical pathogens were detected in 21 of 210 patients. A close contact history (odds ratio [OR]: 11.4, 95% confidence interval [CI]: 2.4-53.5) and the presence of pneumonia (OR: 12.9, CI: 4.3-39.2) were associated with the detections. Atypical pathogens were detected in 32.3% of high-probability cases (10/31), while atypical pathogens were only detected in 8.8% of intermediate-probability cases (8/91) and 3.4% of low-probability cases (3/88) (P < .001).

The current study indicates that physicians' predictions were associated with the detection of atypical pathogens; however, overestimation was observed.