COVID-19 Survivors Face Hidden Risk: Why MRSA Infections Spiked in Hospitals After 2020

Patients recovering from COVID-19 played a major role in a troubling surge of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections in hospitals between 2020 and 2022. New surveillance data from the Centers for Disease Control and Prevention (CDC) shows that COVID-19 survivors contributed substantially to rising rates of hospital-onset MRSA bacteremia—a serious bloodstream infection caused by antibiotic-resistant bacteria—during this critical period.

What Happened to MRSA Rates During the Pandemic?

The CDC's Invasive Staphylococcus aureus Infection Surveillance Program, which monitors seven sites across the United States, tracked three distinct types of MRSA infections: hospital-onset (HO), healthcare-associated community-onset (HACO), and community-associated (CA) infections. Between 2021 and 2022, healthcare-associated community-onset MRSA infections became more common, but hospital-onset and community-associated infections showed little change overall.

However, the story becomes more complex when examining the 2020-2022 period specifically. The data reveals that patients with recent COVID-19 infections were a significant driver of increased hospital-onset MRSA bacteremia during these years. This connection highlights an unexpected consequence of the pandemic: severely ill COVID-19 patients hospitalized for extended periods faced elevated risks of acquiring secondary bacterial infections.

Why Are COVID-19 Patients More Vulnerable to MRSA?

When patients are hospitalized with severe COVID-19, they often require prolonged stays in intensive care units, mechanical ventilation, and multiple invasive medical procedures. These factors create ideal conditions for MRSA to take hold. The virus itself can damage the respiratory tract and immune system, making patients more susceptible to bacterial superinfections. Additionally, hospitalized patients are exposed to healthcare environments where antibiotic-resistant bacteria circulate more readily, and they may receive broad-spectrum antibiotics that disrupt their protective gut bacteria.

MRSA is particularly dangerous because it resists methicillin and related antibiotics, limiting treatment options. When MRSA enters the bloodstream—a condition called bacteremia—it can spread throughout the body and cause sepsis, organ failure, and death if not treated promptly with alternative antibiotics like vancomycin or daptomycin.

How Is the CDC Monitoring This Threat?

The CDC's surveillance program uses active, population-based and laboratory-based monitoring across multiple U.S. regions to identify and track invasive S. aureus infections. Trained professionals regularly query clinical laboratories to identify cases among people living in defined geographic areas. The surveillance sites include regions in California, Connecticut, Georgia, Maryland, Minnesota, New York, and Tennessee.

This comprehensive approach allows public health professionals and healthcare providers to:

• Track Infection Trends: Monitor changes in the incidence of hospital-onset, healthcare-associated community-onset, and community-associated invasive MRSA and methicillin-sensitive S. aureus (MSSA) infections over time.
• Identify Vulnerable Populations: Pinpoint which groups of patients would benefit most from improved prevention and treatment strategies, such as those with recent COVID-19 or those requiring hemodialysis.
• Evaluate Prevention Strategies: Assess the effectiveness of established infection control measures and identify where new interventions are needed.
• Analyze Bacterial Characteristics: Study the molecular and microbiologic features of strains causing invasive infections to understand resistance patterns and transmission routes.

The CDC and its partners clean, analyze, and disseminate this data through annual reports and peer-reviewed publications, making it available to healthcare systems nationwide.

What Does This Mean for Hospital Safety Going Forward?

The connection between COVID-19 and increased MRSA bacteremia underscores the importance of rigorous infection prevention in hospitals, especially during respiratory disease outbreaks. Healthcare facilities must balance the urgent need to treat severely ill patients with strict protocols to prevent secondary bacterial infections. This includes careful hand hygiene, appropriate use of invasive devices, judicious antibiotic stewardship, and rapid identification and isolation of patients with MRSA.

The data also highlights why surveillance systems matter. By continuously monitoring these infections, public health agencies can detect emerging threats early and help hospitals implement targeted prevention strategies. For patients and families, understanding that secondary infections like MRSA are a known risk of severe COVID-19 hospitalization can inform conversations with healthcare providers about infection prevention measures and monitoring during recovery.

As the pandemic continues to evolve and COVID-19 becomes endemic, healthcare systems will need to remain vigilant about MRSA and other antibiotic-resistant bacteria that may exploit weakened immune systems and prolonged hospitalizations.