Severe Staphylococcus aureus infection: associated factors and outcomes

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Epidemiology

Background:

• Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), causes severe, life-threatening infections with limited treatment options.
• This study investigates serious S. aureus infections in hospitalized patients in Rio de Janeiro, Brazil, from 2016 to 2021.

Purpose of the Study:

• To describe serious S. aureus infections in a Brazilian hospital setting.
• To compare clinical and demographic characteristics and outcomes between Patients Living with HIV (PLHIV) and non-HIV patients.
• To analyze the prevalence and characteristics of MRSA infections in this cohort.

Main Methods:

• Retrospective study utilizing data from microbiology laboratory diagnoses and medical record reviews.
• Comparison of clinical-demographic variables and outcomes between PLHIV and non-HIV patients.
• Statistical analysis performed using Jamovi 1.6 and R 4.0.1 software.

Main Results:

• 67 patients with severe S. aureus infections were identified; 46.3% were PLHIV, who were significantly younger (median 36 vs. 60 years).
• 29.9% of infections were MRSA, with a higher proportion (38.8%) occurring in community-acquired infections. Over a third of PLHIV had MRSA, all sensitive to cotrimoxazole.
• No significant difference in mortality was observed between PLHIV and non-HIV patients, or between MRSA and MSSA groups. However, MRSA bacteremia had higher 30-day mortality (44.4%) compared to MSSA bacteremia (10%).

Conclusions:

• HIV is a frequent comorbidity in severe S. aureus infections, with a notable prevalence of MRSA among PLHIV.
• PLHIV were younger and did not experience higher mortality, but showed increased rates of infection relapses and new staphylococcal infections.