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Additional Infections Rare in Hospitalized COVID Patients

— Most were secondary infections, U.K. researchers found

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Bacterial co-infections from COVID-19 were rare, few were of clinical importance and most were secondary infections, researchers found in a prospective cohort study in the U.K..

Out of over 8,600 patients with microbiologic culture results, 1,107 had coinfection results deemed "clinically significant," as confirmed by bloodstream culture or respiratory secondary infection from COVID-19, reported Antonia Ho, PhD, and colleagues from the University of Glasgow Centre for Virus Research in Scotland.

Among 1,080 microbiologically confirmed COVID-19 related infections with known timing, 71% were secondary, meaning they happened more than 2 days after hospital admission, researchers wrote in .

Gram-negative organisms and Staphylococcus aureus (S. aureus) were the most common pathogens identified in blood and respiratory cultures, they added.

"These findings have implications for empirical therapy, indicating a need to treat Gram-negative bacteria and S aureus empirically until culture results are available," the authors wrote.

Without clear evidence of bacterial infection, the U.K.'s COVID-19 guidelines do not advise the use of empirical therapy for lower respiratory tract infections due to COVID-19. with small sample sizes have lacked species-specific data of clinical significance on COVID-19 co-infections in patients.

Ho and colleagues stated, "there is an urgent need to characterize the causes of bacterial infections in patients admitted to hospital with COVID-19 to determine optimal empirical antimicrobial management strategies and identify targets for antimicrobial stewardship interventions."

They examined data from the ongoing (ISARIC) of the World Health Organization (WHO) protocol (CCP-UK), which includes patients from 260 U.K. hospitals with confirmed or likely COVID-19.

Patients were excluded if they had a negative COVID-19 test result, lacked a recorded outcome after 28 days of hospitalization, or were infected with organisms deemed "clinically insignificant." Outcomes were assessed at 28 days or more of hospitalization.

From February 6, 2020 to June 8, 2020, there were 48,902 patients. About 57% of patients were men and the median age was 74. Chronic cardiac disease, hypertension, immunosuppression, diabetes, and chronic pulmonary disease (excluding asthma) were the most common comorbidities. The average length of hospital stay was 9 days.

Over a third (37%) of patients received antibiotics for this illness prior to admission. Almost 70% received supplemental oxygen while hospitalized, while 9% required invasive mechanical ventilation and 32% of patients died.

For just over 17% of patients, microbiological investigations were conducted. Patients admitted to the ICU were more likely to have a respiratory or blood culture versus other hospitalized patients.

There was no association between respiratory or bloodstream infections and inpatient mortality among ICU patients, the authors said.

The most commonly confirmed secondary infections arising from COVID-19 came from S. aureus (31% of 45 organisms) and Gram-negative such as E. coli (4.5% of 642 tested organisms) bacteria.

During hospitalization, 85% of over 46,000 patients were prescribed at least one or more antimicrobial drugs, and almost half of all prescriptions involved antibiotics on (meaning they should only be used for specific indications), they said.

Limitations of this study include an underestimation of reported bacterial infections, since less than 20% of patients underwent microbiological analysis. Also, since clinical findings were not collected during microbiological sampling, the quantity of true infections reported may not be definitive. This study was also unable to identify Mycoplasma pneumoniae co-infections or respiratory viral infections.

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    Zaina Hamza is a staff writer for 51˶, covering Gastroenterology and Infectious disease. She is based in Chicago.

Disclosures

This study was funded by the UK Medical Research Council (MRC), National Institute for Health Research (NIHR), Wellcome Trust, NIHR Health Protection Research Unit (HPRU) in Emerging Zoonotic Infections at the University of Liverpool, NIHR HPRU in Respiratory Infections at Imperial College London, UK Department for International Development, EU Platform for European Preparedness Against (Re-)emerging Epidemics, and the Bill & Melinda Gates Foundation. Funding was also received from the Biomedical Research Center at the Imperial College London (NIHR). Coauthors also reported receiving grants from the UK Department of Health and Social Care, Wellcome Trust, and the NIHR UK outside of this research.

One coauthor receives personal consultancy fees from Janssen, Pfizer, GlaxoSmithKline, Cepheid, Bavarian Nordic, MRC Global Challenge Research fund, European Respiratory Society, the EU, MRC-GlaxoSmithKline, NIHR BRC and declares being a senior investigator for the NIHR outside of this research.

Also outside of this research, another coauthor reports serving as chair of the scientific advisory board in addition to being a minority shareholder for Integrum Scientific.

Another coauthor reports serving as President of the British Society for Immunology.

Primary Source

The Lancet Microbe

Russell CD, et al "Co-infections, secondary infections, and antimicrobial use in patients hospitalised with COVID-19 during the first pandemic wave from the ISARIC WHO CCP-UK study: A multicentre, prospective cohort study" Lancet Microbe 2021: DOI:10.1016/S2666-5247(21)00090-2.