Re: predictors and microbiology of respiratory and bloodstream infection in patients with COVID-19

Abstract

We read the latest systematic review and meta-analysis by Langford et al. with great interest [[1]Langford B.J. So M. Leung V. Raybardhan S. Lo J. Kan T. et al.Predictors and microbiology of respiratory and bloodstream bacterial infection in patients with COVID-19: living rapid review update and meta-regression.Clin Microbiol Infect. 2022; 28: 888-889Abstract Full Text Full Text PDF Scopus (2) Google Scholar]. The authors provide a high-quality review concerning the incidence and microbiological predictors of respiratory and bloodstream bacterial infections in COVID-19 patients. Among other exclusion criteria, they chose to exclude editorials and letters, studies in which bacterial infection was only presumed or suspected, and studies in which serology was used as a bacterial infection diagnostic approach. Based on those criteria, it is unclear why certain references were included in their final analysis. First, two studies were, in our opinion, inappropriately included in the category of ‘bacterial co-infection’. The first study by Di Nisio et al. exclusively describes viral co-infection rates and rates of Mycoplasma spp. co-infection [[2]Di Nisio M. Potere N. Candeloro M. Spacone A. Pieramati L. Ferrandu G. et al.Interleukin-6 receptor blockade with subcutaneous tocilizumab improves coagulation activity in patients with COVID-19.Eur J Intern Med. 2021; 83: 34e8Abstract Full Text Full Text PDF Scopus (13) Google Scholar]. Because it is unclear if the diagnosis of Mycoplasma spp. infections was based on serological testing, we would exclude this study. The second study by Ferguson et al. did not microbiologically define the diagnosis of ventilator-associated pneumonia. Because viral and fungal co-infections might have been included in Langford's analysis of bacterial co-infection rates, we would also exclude this study [[3]Ferguson J. Rosser J.I. Quintero O. Scott J. Subramanian A. Gumma M. et al.Characteristics and outcomes of coronavirus disease patients under nonsurge conditions, Northern California, USA, March-April 2020.Emerg Infect Dis. 2020; 26: 1679e85Crossref Scopus (56) Google Scholar]. Second, an observational study by Karaba et al., including 1016 patients, accurately described bacterial co-infection rates. However, Langford et al. categorized those infections as ‘co-infection’ instead of ‘bacterial co-infection’, possibly leading to an underestimation of bacterial co-infections [[4]Karaba S.M. Jones G. Helsel T. Smith L.L. Avery R. Dzintars K. et al.Prevalence of co-infection at the time of hospital admission in COVID-19 patients, a multicenter study.Open Forum Infect Dis. 2021; 8: ofaa578Crossref PubMed Scopus (32) Google Scholar]. Third, a letter to the editor was included in the meta-analysis, despite the exclusion criteria [[5]Lee S.-I. Koh J.S. Kim Y.J. Kang D.H. Park D. Park H.S. et al.Secondary infection among hospitalized COVID-19 patients: a retrospective cohort study in a tertiary care setting.Respirol Carlton Vic. 2021; 26: 277e8Google Scholar]. To guarantee the reproducibility of this meta-analysis, we also think that including the final search strategy in the Supplementary Material section would be of added value. Moreover, the forest plots that were used to determine the bacterial co-/superinfection rates should display every included study, separately for co-infections and secondary infections. Johan Van Laethem and Sabine D. Allard have no conflicts of interest to declare. No funding was received. Predictors and microbiology of respiratory and bloodstream bacterial infection in patients with COVID-19: living rapid review update and meta-regressionClinical Microbiology and InfectionVol. 28Issue 4PreviewThe prevalence of bacterial infection in patients with COVID-19 is low, however, empiric antibiotic use is high. Risk stratification may be needed to minimize unnecessary empiric antibiotic use. Full-Text PDF Predictors and microbiology of respiratory and bloodstream bacterial infection in patients with COVID-1: author's responseClinical Microbiology and InfectionVol. 28Issue 6PreviewWe thank the authors for their interest and comments regarding our publication [1]. Given the vast amount of literature published on the topic of coinfections and secondary infections with coronavirus disease 2019, as well as the heterogeneity in publication quality, methodological approach, and data reporting strategies, it was necessary to make some assumptions regarding whether studies met the inclusion criteria. We agree there are certainly limitations that may affect the precision of our estimate and have highlighted some of these concerns in our discussion. Full-Text PDF