# Epidemiology, Characteristics, and Treatment Outcomes of Mycoplasma pneumoniae Pneumonia in Hospitalized Adults: A 5-Year Retrospective Cohort Study

## TL;DR

This study analyzed 747 hospitalized adults with Mycoplasma pneumoniae pneumonia in Sweden, finding tetracyclines were linked to better outcomes than other antibiotics.

## Contribution

The study identifies tetracyclines as a potentially superior treatment for Mycoplasma pneumoniae pneumonia compared to macrolides and fluoroquinolones.

## Key findings

- The incidence rate of Mycoplasma pneumoniae pneumonia was 8.5 cases per 100,000 person-years.
- Tetracycline-treated patients had shorter hospital stays and fever duration compared to those treated with macrolides or fluoroquinolones.
- Severe disease was associated with longer symptom duration at admission.

## Abstract

This study aimed to describe the incidence rate, patient characteristics, treatments, and outcomes of adults hospitalized with Mycoplasma pneumoniae pneumonia.

This retrospective cohort study included adults diagnosed with M pneumoniae pneumonia and admitted to emergency care hospitals in Stockholm County, Sweden, from 2013 to 2017. Patients were identified through positive M pneumoniae polymerase chain reaction and ICD-10 code J15.7 (M pneumoniae pneumonia). Medical records were reviewed manually, and population data were extracted from statistical databases. Incidence rates were calculated, and treatment outcomes were analyzed using regression models.

A total of 747 adults with a median age of 42 (interquartile range [IQR], 33–55) years, of whom 55% (385/747) were male, were hospitalized with M pneumoniae pneumonia. The incidence rate was 8.5 cases per 100 000 person-years, peaking at 14.1 in 2016. Cough (95%) and fever (92%) were the most common symptoms, and 71% were hypoxemic at admission. Patients with severe disease had longer symptom duration at admission. In-hospital mortality was 0.4%, and 6% required intensive care unit admission. Median length of stay (4 [IQR, 2–6] days) was longer in patients treated with macrolides (+1.0 [IQR, 0.9–1.2] days; P < .001) and fluoroquinolones (+0.8 [IQR, 0.1–1.4] days; P = .03) compared to those treated with tetracyclines. The median fever duration was significantly longer (+0.3 [IQR, 0.1–0.6] days; P = .02) in patients treated with fluoroquinolones compared to those treated with tetracyclines.

The study highlights the importance of timely and accurate treatment of M pneumoniae pneumonia. Tetracycline treatment was associated with better outcomes, suggesting they may be an effective first-line treatment option.

The study analyzed 747 adults hospitalized with Mycoplasma pneumoniae pneumonia, finding an incidence rate of 8.5 per 100 000 person-years. Patients with severe disease had longer symptom duration at admission. Tetracycline treatment was associated with better outcomes compared to macrolides and fluoroquinolones.