High rate of infections during ICU admission of patients with severe SARS-CoV-2 pneumonia: A matter of time?

Prevalence, risk factors, and outcomes of secondary infections among hospitalized patients with COVID-19 or post-COVID-19 conditions in Victoria, 2020-2023

OBJECTIVES

Estimates of secondary infections are variedly reported, with few studies done in Australia. We investigated the occurrence and impact of secondary infections complicating COVID-19 and post-COVID-19 admissions in Victoria, Australia, 2020-2023.

METHODS

We used linked population-wide data sets and specific International Classification of Disease, 10th Revision codes to identify and estimate the occurrence of secondary infections. Using hospital/intensive care unit length of stay in negative binomial regression and mortality, we examined the impact of secondary infections.

RESULTS

Secondary infections were identified in 6.9% (13,467 of 194,660) of COVID-19 and post-COVID-19 admissions: 6.0% (11,651 of 194,660) bacterial, 0.9% (1691 of 194,660) viral, and 0.2% (385 of 194,660) fungal. Prevalence was highest during the pre-Delta (10.4%) and Omicron-BA2 (8.1%) periods. Sepsis and pneumonia were the most reported syndromes; the occurrence of sepsis declined gradually over time. The odds of secondary infections were higher among the ≥70-year-olds (adjusted odds ratio (aOR) 3.76, 95% confidence interval [CI] 3.43-4.14, vs 20-29-year-olds), individuals with chronic conditions (aOR 3.15, 95% CI 2.88-3.45, vs those without), the unvaccinated (aOR 1.59, 95% CI 1.45-1.75), and the lowest socioeconomic group (aOR 1.12, 95% CI 1.05-1.19). Patients with secondary infections had 2.43 times longer hospital length of stay and 9.60 times longer intensive care unit length of stay than those without secondary infections. The mortality risk was 2.17 times higher in those with secondary infections.

CONCLUSIONS

Secondary infections occurred in 69 per 1000 COVID-19-associated hospital admissions in Victoria, mostly in high-risk groups, and were associated with severe outcomes.

Bacterial Community- and Hospital-Acquired Pneumonia in Patients with Critical COVID-19-A Prospective Monocentric Cohort Study

The impact of bacterial pneumonia on patients with COVID-19 infection remains unclear. This prospective observational monocentric cohort study aims to determine the incidence of bacterial community- and hospital-acquired pneumonia (CAP and HAP) and its effect on mortality in critically ill COVID-19 patients admitted to the intensive care unit (ICU) at University Hospital Olomouc between 1 November 2020 and 31 December 2022. The secondary objectives of this study include identifying the bacterial etiology of CAP and HAP and exploring the capabilities of diagnostic tools, with a focus on inflammatory biomarkers. Data were collected from the electronic information hospital system, encompassing biomarkers, microbiological findings, and daily visit records, and subsequently evaluated by ICU physicians and clinical microbiologists. Out of 171 patients suffering from critical COVID-19, 46 (27%) had CAP, while 78 (46%) developed HAP. Critically ill COVID-19 patients who experienced bacterial CAP and HAP exhibited higher mortality compared to COVID-19 patients without any bacterial infection, with rates of 38% and 56% versus 11%, respectively. In CAP, the most frequent causative agents were chlamydophila and mycoplasma; Enterobacterales, which were multidrug-resistant in 71% of cases; Gram-negative non-fermenting rods; and Staphylococcus aureus. Notably, no strains of Streptococcus pneumoniae were detected, and only a single strain each of Haemophilus influenzae and Moraxella catarrhalis was isolated. The most frequent etiologic agents causing HAP were Enterobacterales and Gram-negative non-fermenting rods. Based on the presented results, commonly used biochemical markers demonstrated poor predictive and diagnostic accuracy. To confirm the diagnosis of bacterial CAP in our patient cohort, it was necessary to assess the initial values of inflammatory markers (particularly procalcitonin), consider clinical signs indicative of bacterial infection, and/or rely on positive microbiological findings. For HAP diagnostics, it was appropriate to conduct regular detailed clinical examinations (with a focus on evaluating respiratory functions) and closely monitor the dynamics of inflammatory markers (preferably Interleukin-6).

Healthcare-associated infections in critical COVID-19 patients in Tunis: epidemiology, risk factors, and outcomes

BACKGROUND

Coronavirus disease 2019 (COVID-19) pandemic disrupted adherences to healthcare-associated infection (HAI) prevention protocols. Herein, we studied the characteristics of all HAIs occurring in critically ill COVID-19 patients.

METHODS

A retrospective, single-center cohort of critical COVID-19 patients during 2021. Microbiological samples were collected if HAI was suspected. We analyzed all factors that could potentially induce HAI, using septic shock and mortality as endpoints.

RESULTS

Sixty-four among 161 included patients (39.7%) presented a total of 117 HAIs with an incidence density of 69.2 per 1,000 hospitalization days. Compared to the prior COVID-19 period (2013-2019), the identification of HAI increased in 2021. HAIs were classified into ventilator-associated pneumonia (VAP; n=38), bloodstream infection (n=32), urinary tract infection (n=24), catheter-related infection (n=12), and fungal infection (n=11). All HAIs occurred significantly earlier in the post-COVID-19 period (VAP: 6 vs. 10 days, P=0.045, in 2017 and 2021). Acinetobacter baumannii (39.5%) and Klebsiella pneumoniae (27%) were the most commonly isolated pathogens that exhibited a multidrug-resistant (MDR) profile, observed in 89% and 64.5%, respectively. The HAI factors were laboratory abnormalities (odds ratio [OR], 6.4; 95% confidence interval [CI], 2.3-26.0), cumulative steroid dose (OR, 1.9; 95% CI, 1.3-4.0), and invasive procedures (OR, 20.7; 95% CI, 5.3-64.0). HAI was an independent factor of mortality (OR, 8.5; P=0.004).

CONCLUSIONS

During the COVID-19 era, the incidence of HAIs increased and MDR isolates remained frequent. A severe biological inflammatory syndrome, invasive devices, and elevated cumulative steroid dosages were related to HAIs. HAI was a significant death factor.

A Systematic Review of Antimicrobial Resistance During the COVID-19 Pandemic

Antimicrobial-resistant pathogens, or "superbugs," cause more than 35 000 deaths and more than 2.8 million antibiotic-resistant infections in the US each year. Worldwide, antimicrobial resistance (AMR) has claimed at least 700 000 lives per year, including 230 000 from multi-drug resistant (MDR) tuberculosis. AMR-related deaths are projected to increase to 10 million by the year 2050. The use of biocides, improper prescribing of antibiotics for viral infections, prolonged hospital stays, and other issues contribute to AMR. The purpose of this study was to determine whether the COVID-19 pandemic has had an impact on the rates of AMR globally. While it is still early for the results of research studies, 4 articles indicated an increase, 2 found a decrease, and 2 had mixed results. It is possible that this pandemic may be contributing to an increase of medication-resistant infections.

Value of syndromic panels in the management of severe community-acquired pneumonia

Community-acquired pneumonia requiring hospital admission is a prevalent and potentially serious infection, especially in high-risk patients (e.g., those requiring ICU admission or immunocompromised). International guidelines recommend early aetiological diagnosis to improve prognosis and reduce mortality. Syndromic panels that detect causative pathogens by molecular methods are here to stay. They are highly sensitive and specific for detecting the targets included in the test. A growing number of studies measuring their clinical impact have observed increased treatment appropriateness and decreased turnaround time to aetiological diagnosis, need for admission, length of hospital stay, days of isolation, adverse effects of medication and hospital costs. Its use is recommended a) per a pre-established protocol on making the diagnosis and managing the patient, b) together with an antimicrobial stewardship programme involving both the Microbiology Service and the clinicians responsible for the patient, and c) the final evaluation of the whole process. However, we recall that microbiological diagnosis with traditional methods remains mandatory due to the possibility that the aetiological agent is not included among the molecular targets and to determine the antimicrobial susceptibility of the pathogens detected.

High Rates of Bacterial Pulmonary Co-Infections and Superinfections Identified by Multiplex PCR among Critically Ill COVID-19 Patients

BACKGROUND

The role of bacterial co-infection and superinfection among critically ill COVID-19 patients remains unclear. The aim of this study was to assess the rates and characteristics of pulmonary infections, and associated outcomes of ventilated patients in our facility.

METHODS

This was a retrospective study of ventilated COVID-19 patients between March 2020 and March 2021 that underwent BioFire^®, FilmArray^® Pneumonia Panel, testing. Community-acquired pneumonia (CAP) was defined when identified during the first 72 h of hospitalization, and ventilator-associated pneumonia (VAP) when later.

RESULTS

148 FilmArray tests were obtained from 93 patients. With FilmArray, 17% of patients had CAP (16/93) and 68% had VAP (64/93). Patients with VAP were older than those with CAP or those with no infection (68.5 vs. 57-59 years), had longer length of stay and higher mortality (51% vs. 10%). The most commonly identified FilmArray target organisms were H. influenzae, S. pneumoniae, M. catarrhalis and E. cloacae for CAP and P. aeruginosa and S. aureus for VAP. FilmArray tests had high negative predictive values (99.6%) and lower positive predictive values (~60%).

CONCLUSIONS

We found high rates of both CAP and VAP among the critically ill, caused by the typical and expected organisms for both conditions. VAP diagnosis was associated with poor patient outcomes.

Secondary infections in mechanically ventilated patients with COVID-19: An overlooked matter?

OBJECTIVE

The susceptibility to infection probably increases in COVID-19 patients due to a combination of virusand drug-induced immunosuppression. The reported rate of secondary infections was quite low in previous studies. The objectives of our study were to investigate the rate of secondary infections, risk factors for secondary infections and risk factors for mortality in COVID-19 critically ill patients.

METHODS

We performed a single-center retrospective study in mechanically ventilated critically ill COVID-19 patients admitted to our Critical Care Unit (CCU). We recorded the patients' demographic data; clinical data; microbiology data and incidence of secondary infection during CCU stay, including ventilator-associated pneumonia (VAP) and nosocomial bacteremia (primary and secondary).

RESULTS

A total of 107 patients with a mean age 62.2 ± 10.6 years were included. Incidence of secondary infection during CCU stay was 43.0% (46 patients), including nosocomial bacteremia (34 patients) and VAP (35 patients). Age was related to development of secondary infection (65.2 ± 7.3 vs. 59.9 ± 12.2 years, p=0.007). Age ≥ 65 years and secondary infection were independent predictors of mortality (OR=2.692, 95% CI 1.068-6.782, p<0.036; and OR=3.658, 95% CI 1.385- 9.660, p=0.009, respectively). The hazard ratio for death within 90 days in the ≥ 65 years group and in patients infected by antimicrobial resistant pathogens was 1.901 (95% CI 1.198- 3.018; p= 0.005 by log-rank test) and 1.787 (95% CI 1.023-3.122; p= 0.036 by log-rank test), respectively.

CONCLUSIONS

Our data suggest that the incidence of secondary infection and infection by antimicrobial resistant pathogens is very high in critically ill patients with COVID-19 with a significant impact on prognosis.

The role of co-infections and secondary infections in patients with COVID-19

BACKGROUND

It has been recognised for a considerable time-period, that viral respiratory infections predispose patients to bacterial infections, and that these co-infections have a worse outcome than either infection on its own. However, it is still unclear what exact roles co-infections and/or superinfections play in patients with COVID-19 infection.

MAIN BODY

This was an extensive review of the current literature regarding co-infections and superinfections in patients with SARS-CoV-2 infection. The definitions used were those of the Centers for Disease Control and Prevention (US), which defines coinfection as one occurring concurrently with the initial infection, while superinfections are those infections that follow on a previous infection, especially when caused by microorganisms that are resistant, or have become resistant, to the antibiotics used earlier. Some researchers have envisioned three potential scenarios of bacterial/SARS-CoV-2 co-infection; namely, secondary SARS-CoV-2 infection following bacterial infection or colonisation, combined viral/bacterial pneumonia, or secondary bacterial superinfection following SARS-CoV-2. There are a myriad of published articles ranging from letters to the editor to systematic reviews and meta-analyses describing varying ranges of co-infection and/or superinfection in patients with COVID-19. The concomitant infections described included other respiratory viruses, bacteria, including mycobacteria, fungi, as well as other, more unusual, pathogens. However, as will be seen in this review, there is often not a clear distinction made in the literature as to what the authors are referring to, whether true concomitant/co-infections or superinfections. In addition, possible mechanisms of the interactions between viral infections, including SARS-CoV-2, and other infections, particularly bacterial infections are discussed further. Lastly, the impact of these co-infections and superinfections in the severity of COVID-19 infections and their outcome is also described.

CONCLUSION

The current review describes varying rates of co-infections and/or superinfections in patients with COVID-19 infections, although often a clear distinction between the two is not clear in the literature. When they occur, these infections appear to be associated with both severity of COVID-19 as well as poorer outcomes.