Fungal and bacterial coinfections increase mortality of severely ill COVID-19 patients

Abstract

Background: SARS-CoV-2 predisposes patients to secondary infections; however, a better understanding of the impact of coinfections on the outcome of hospitalized COVID-19 patients is still necessary.

Aim: To analyse death risk due to coinfections in COVID-19 patients.

Methods: The odds of death of 212 severely ill COVID-19 patients were evaluated, with detailed focus on the risks for each pathogen, site of infection, comorbidities and length of hospitalization.

Findings: The mortality rate was 50.47%. Fungal and/or bacterial isolation occurred in 89 patients, of whom 83.14% died. Coinfected patients stayed hospitalized longer and had an increased odds of dying (odds ratio (OR): 13.45; R² = 0.31). The risk of death was increased by bacterial (OR: 11.28) and fungal (OR: 5.97) coinfections, with increased levels of creatinine, leucocytes, urea and C-reactive protein. Coinfections increased the risk of death if patients suffered from cardiovascular disease (OR: 11.53), diabetes (OR: 6.00) or obesity (OR: 5.60) in comparison with patients with these comorbidities but without pathogen isolation. The increased risk of death was detected for coagulase-negative Staphylococcus (OR: 25.39), Candida non-albicans (OR: 11.12), S. aureus (OR: 10.72), Acinetobacter spp. (OR: 6.88), Pseudomonas spp. (OR: 4.77), and C. albicans (OR: 3.97). The high-risk sites of infection were blood, tracheal aspirate, and urine. Patients with coinfection undergoing invasive mechanical ventilation were 3.8 times more likely to die than those without positive cultures.

Conclusion: Severe COVID-19 patients with secondary coinfections required longer hospitalization and had higher risk of death. The early diagnosis of coinfections is essential to identify high-risk patients and to determine the right interventions to reduce mortality.

Keywords: Bacterial; COVID-19; Coinfections; Fungal; Mortality.

Figure 1

Demographics and clinical characteristics of hospitalized COVID-19 patients. Comparative analyses of COVID-19 case fatality rates by sex (A), age range (B), comorbidities and lifestyle (C), symptoms (D), invasive ventilation (E), and presence or absence of fungal and/or bacterial coinfections (F). The values in parentheses indicate the number of occurrences in the respective category. All relative frequency values are expressed as a percentage of the study cohort (N = 212). ∗P < 0.05 according to the logistic regression analysis. COPD, chronic obstructive pulmonary disease; HIV, human immunodeficiency virus.

Figure 2

Length of hospitalization period. Hospitalization (days) for patients who were discharged or who died (A) and for the presence or absence of fungal and/or bacterial coinfections (B). P-values calculated by Mann–Whitney U-test.