Abstract
Mycoplasmapneumoniae is one of the major causative pathogens of community-acquired pneumonia (CAP). M. pneumoniae CAP is clinically and radiologically distinct from bacterial CAPs. One feature of the Japanese Respiratory Society (JRS) guidelines is a trial to be carried out to differentiate between M. pneumoniae pneumonia and bacterial pneumonia for the selection of antibiotics. The purpose of the present study was to clarify the clinical and radiological differences of the M. pneumoniae CAP and coronavirus disease 2019 (COVID-19) CAP. This study was conducted at 5 institutions and assessed a total of 210 patients with M. pneumoniae CAP and 956 patients with COVID-19 CAP. The median age was significantly younger in patients with M. pneumoniae CAP than COVID-19 CAP. Among the clinical symptoms, cough and sputum were observed more frequently in patients with M. pneumoniae CAP than those with COVID-19 CAP. However, the diagnostic specificity of these findings was low. In contrast, loss of taste and anosmia were observed in patients with COVID-19 CAP but not observed in those with M. pneumoniae CAP. Bronchial wall thickening and nodules (tree-in-bud and centrilobular), which are chest computed tomography (CT) features of M. pneumoniae CAP, were rarely observed in patients with COVID-19 CAP. Our results demonstrated that there were two specific differences between M. pneumoniae CAP and COVID-19 CAP: (1) the presence of loss of taste and/or anosmia and (2) chest CT findings.
Highlights
Mycoplasma pneumoniae is one of the major causative pathogens of community-acquired pneumonia (CAP) and the most frequent pathogen in atypical pneumonia [1]
Underlying conditions, clinical symptoms, laboratory data, and radiologic findings of M. pneumoniae pneumonia are different from other bacterial pneumonia [5,6]
The most common pathogens were Streptococcus pneumoniae, found in 281 cases, followed by Haemophilus influenzae in 93 cases, Moraxella catarrhalis in 21 cases and Staphylococcus aureus in 16 cases
Summary
Mycoplasma pneumoniae is one of the major causative pathogens of community-acquired pneumonia (CAP) and the most frequent pathogen in atypical pneumonia [1]. Epidemiological studies in Japan have demonstrated that the incidence of M. pneumoniae pneumonia is the second-to-third leading pathogen of CAP, accounting for as many as 10–30% of all cases of CAP [2,3,4]. Pneumonia due to M. pneumoniae is usually of mild-to-moderate severity, some cases are known to develop into severe, life-threatening pneumonia [1,2,3,4]. Underlying conditions, clinical symptoms, laboratory data, and radiologic findings of M. pneumoniae pneumonia are different from other bacterial pneumonia [5,6]. The Japanese Respiratory Society (JRS) pneumonia guidelines proposed a differential diagnosis between other bacterial and M. pneumoniae pneumonia for the selection of an appropriate antibiotic for the management of CAP [2]. Clinical findings of M. pneumoniae pneumonia are clearly different from Legionella CAP [7]
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