Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in respiratory cultures and diagnostic performance of the MRSA nasal polymerase chain reaction (PCR) in patients hospitalized with coronavirus disease 2019 (COVID-19) pneumonia

Abstract

To the Editor-The need for studies on coronavirus disease 2019 (COVID-19) superinfections that can inform rational antimicrobial treatment and stewardship strategies has been recognized. 1 In a recent review from our institution, 2 we found that up to 71% of patients admitted with COVID-19 received antibiotics. Anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) agents, particularly vancomycin, are important stewardship targets, and they are included in the 2019 World Health Organization (WHO) Watch List of Antibiotics. Recently, guidance was published on the treatment of possible concomitant community-acquired bacterial pneumonia (CAP) for patients admitted with COVID-19. 3 The authors recommend selective use of anti-MRSA therapy, as for any other patient with CAP, and the utility of the MRSA nares PCR is not addressed. However, the empiric use of these agents for admitted COVID-19 patients remains prevalent, driven by several factors. For one, staphylococcal superinfection is a common complication of other viral pneumonias, such as influenza, 4 and the 2018 Infectious Diseases Society of America (IDSA) guidelines on influenza treatment state that "agents with activity against MRSA should be included in the empiric regimen for critically ill patients." 5 Additionally, the real-world treatment of patients with COVID-19 is complicated by recurrent fevers, fluctuating oxygen requirements, prolonged hospitalization and/or ventilation, blurring the line between community-acquired versus hospital-acquired pneumonia. Therefore, we sought to determine the prevalence of MRSA in respiratory cultures of patients admitted with COVID-19, and we evaluated the diagnostic performance of the MRSA nares PCR test, a valuable stewardship tool for ruling out MRSA pneumonia in low-prevalence settings, 6 in this cohort.

Impact of SARS-CoV-2 Epidemic on Antimicrobial Resistance: A Literature Review

“…In any case, it should be considered that the presence of MRSA pulmonary coinfections reflects the usual epidemiology of different countries and was less influenced by the COVID-19 pandemic itself. For instance, in a large case series conducted in the US, a low prevalence of MRSA nasal colonization was found, in accordance with the decreasing local incidence [27] even during an important pandemic wave. In contrast, data from a large meta-analysis showed a significant influence of MRSA co-infection on COVID-19 mortality, especially in the case of co-infections, causing a significant number of ICU admissions [28].…”

The interface between COVID-19 and bacterial healthcare-associated infections

“…In 4,221 adult patients admitted with COVID-19 pneumonia in New York, USA, 472 patients (11.1%) produced a positive respiratory culture. ( 22 ) In these patients, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in respiratory cultures rose from a low of 0.6% on day 3 to 5.7% at day 28 post admission. The authors deduced that the MRSA in severe COVID-19 cases was “more likely to be a hospital-acquired or ventilator-associated complication than a community-acquired coinfection”.…”

“…The authors deduced that the MRSA in severe COVID-19 cases was “more likely to be a hospital-acquired or ventilator-associated complication than a community-acquired coinfection”. ( 22 ) S. aureus has been reported as a frequently-isolated organism from deep respiratory specimens taken from critically-ill COVID-19 patients with VAP. ( 23 ).…”

Antimicrobial resistance and COVID-19: Intersections and implications

“…Moreover, patients with COVID-19 may require multiple courses of broad-spectrum antibiotics, mechanical ventilation, other organ support, and/or other invasive devices. This increases exposure to, and risk of, infections with hospital-associated pathogens that are often highly resistant such as methicillin-resistant Staphylococcus aureus (MRSA), P. aeruginosa, Candida auris, and Acinetobacter baumannii ( Chowdhary et al, 2020 ; Perez et al, 2020 ; Punjabi et al, 2020 ). Early anecdotal evidence from two acute care facilities in New York and Missouri reported three- to fourfold increases in central line-associated bloodstream infection rates, likely related to a shift towards a higher risk case-mix ( McMullen et al, 2020 ).…”