Risk factors, outcomes, and epidemiological and etiological study of hospitalized COVID-19 patients with bacterial co-infection and secondary infections

Eur J Clin Microbiol Infect Dis. 2024 Mar;43(3):577-586. doi: 10.1007/s10096-024-04755-5. Epub 2024 Jan 22.

Abstract

Background: As a common complication of viral respiratory tract infection, bacterial infection was associated with higher mortality and morbidity. Determining the prevalence, culprit pathogens, outcomes, and risk factors of co-infection and secondary infection occurring in hospitalized patients with coronavirus disease 2019 (COVID-19) will be beneficial for better antibiotic management.

Methods: In this retrospective cohort research, we assessed clinical characteristics, laboratory parameters, microbiologic results, and outcomes of laboratory-confirmed COVID-19 patients with bacterial co-infection and secondary infection in West China Hospital from 2022 December 2nd to 2023 March 15th.

Results: The incidence of bacterial co-infection and secondary infection, as defined by positive culture results of clinical specimens, was 16.3% (178/1091) and 10.1% (110/1091) respectively among 1091 patients. Acinetobacter, Klebsiella, and Pseudomonas were the most commonly identified bacteria in respiratory tract samples of COVID-19 patients. In-hospital mortality of COVID-19 patients with co-infection (17.4% vs 9.5%, p = 0.003) and secondary infection (28.2% vs 9.5%, p < 0.001) greatly exceeded that of COVID-19 patients without bacterial infection. Cardiovascular disease (1.847 (1.202-2.837), p = 0.005), severe COVID-19 (1.694 (1.033-2.778), p = 0.037), and critical COVID-19 (2.220 (1.196-4.121), p = 0.012) were proved to be risk factors for bacterial co-infection, while only critical COVID-19 (1.847 (1.202-2.837), p = 0.005) was closely related to secondary infection.

Conclusions: Bacterial co-infection and secondary infection could aggravate the disease severity and worsen clinical outcomes of COVID-19 patients. Notably, only critical COVID-19 subtype was proved to be an independent risk factor for both co-infection and secondary infection. Therefore, standard empirical antibiotics was recommended for critically ill COVID-19 rather than all the inpatients according to our research.

Keywords: COVID-19; Outcomes; Risk factors.

MeSH terms

  • Bacteria
  • Bacterial Infections* / complications
  • Bacterial Infections* / epidemiology
  • Bacterial Infections* / microbiology
  • COVID-19* / complications
  • COVID-19* / epidemiology
  • COVID-19* / microbiology
  • Coinfection* / microbiology
  • Humans
  • Respiratory Tract Infections* / epidemiology
  • Retrospective Studies
  • Risk Factors
  • SARS-CoV-2