Co-infections in people with COVID-19: a systematic review and meta-analysis

Metagenomic profiling of raw wastewater in Portugal highlights microbiota and resistome signatures of public health interest beyond the usual suspects

In response to the rapid emergence and dissemination of antimicrobial resistant bacteria (ARB) and genes (ARGs), integrated surveillance systems are needed to address antimicrobial resistance (AMR) within the One Health Era. Wastewater analyses enable biomarker monitoring at the sewershed level, offering timely insights into pathogen circulation and ARB/ARGs trends originating from different compartments. During two consecutive epidemic waves of the COVID-19 pandemic in Portugal, taxonomic and functional composition of raw urban wastewater from two wastewater treatment plants (WWTPs) representing one million in equivalent population, located in the main urban areas of the country, were profiled by shotgun metagenomics. Hospital wastewater from two central hospitals located in the WWTPs catchment areas were also sequenced. The resistome and virulome were profiled using metagenomic assemblies without taxonomic constraint, and then specifically characterized for ESKAPE pathogens. Urban and hospital wastewater exhibited specific microbiota signatures, Pseudomonadota dominated in the first and Bacteroidota in the latter. Correlation network analyses highlighted 85 (out of top 100) genera co-occurring across samples. The most frequent ARGs were classified in the multidrug, tetracyclines, and Macrolides, Lincosamides, Streptogramins (MLS) classes. Links established between AMR determinants and bacterial hosts evidenced that the diversity and abundance of ARGs is not restricted to ESKAPE, being also highly predominant among emergent enteropathogens, like Aeromonas and Aliarcobacter, or in the iron (II) oxidizer Acidovorax. The Aliarcobacter genus accumulated high abundance of sulphonamides and polymyxins ARGs, while Acinetobacter and Aeromonas hosted the highest abundance of ARGs against beta-lactams. Other bacteria (e.g. Clostridioides, Francisella, Vibrio cholerae) and genes (e.g. vanA-type vancomycin resistance) of public health interest were detected, with targeted monitoring efforts being needed to establish informative baseline data. Altogether, results highlight that wastewater monitoring is a valuable component of pathogen and AMR surveillance in healthy populations, providing a community-representative snapshot of public health trends beyond priority pathogens.

Association of antibiotics with the outcomes in COVID-19 pneumonia patients with elevated PCT levels

OBJECTIVE

To assess antibiotics impact on outcomes in COVID-19 pneumonia patients with varying procalcitonin (PCT) levels.

METHODS

This retrospective cohort study included 3665 COVID-19 pneumonia patients hospitalized at five Mayo Clinic sites (March 2020 to June 2022). PCT levels were measured at admission. Patients' antibiotics use and outcomes were collected via the Society of Critical Care Medicine (SCCM) Viral Infection and Respiratory Illness Universal Study (VIRUS) registry. Patients were stratified into high and low PCT groups based on the first available PCT result. The distinction between high and low PCT was demarcated at both 0.25 ng/ml and 0.50 ng/ml.

RESULTS

Our cohort consisted of 3665 patients admitted with COVID-19 pneumonia. The population was predominantly male, Caucasian and non-Hispanic. With the PCT cut-off of 0.25 ng/ml, 2375 (64.8 %) patients had a PCT level <0.25 ng/mL, and 1290 (35.2 %) had PCT ≥0.25 ng/ml. While when the PCT cut off of 0.50 ng/ml was used we observed 2934 (80.05 %) patients with a PCT <0.50 ng/ml while 731(19.94 %) patients had a PCT ≥0.50 ng/ml. Patients with higher PCT levels exhibited significantly higher rates of bacterial infections (0.25 ng/ml cut-off: 4.2 % vs 7.9 %; 0.50 ng/ml cut-off: 4.6 % vs 9.2 %). Antibiotics were used in 66.0 % of the cohort. Regardless of the PCT cutoffs, the antibiotics group showed increased hospital length of stay (LOS), intensive care unit (ICU) admission rate, and mortality. However, early de-escalation (<24 h) of antibiotics correlated with reduced hospital LOS, ICU LOS, and mortality. These results were consistent even after adjusting for confounders.

CONCLUSION

Our study shows a substantial number of COVID-19 pneumonia patients received antibiotics despite a low incidence of bacterial infections. Therefore, antibiotics use in COVID pneumonia patients with PCT <0.5 in the absence of clinical evidence of bacterial infection has no beneficial effect.

A fulminant presentation of post-COVID-19 necrotizing pneumonia and ischemic stroke in an 8-year-old girl: A case report and literature review

Necrotizing pneumonia (NP) is the destruction of the interstitial part of the lung due to severe infection. One cause of this rare and fatal condition in pediatrics is Acinetobacter. Severe infections, especially pneumonia, can prone pediatric patients to ischemic stroke. This study reports an 8-year-old girl presented to the emergency department complaining of shortness of breath, fever, and fatigue. She was admitted to the intensive care unit due to respiratory distress and pericardial effusion. Swab and respiratory secretion tests for COVID-19 and Acinetobacter were positive. In her admission course, her condition deteriorated, and on the fifth day, she underwent a craniotomy due to the signs of increased intracranial pressure (ICP). The computed tomography (CT) scan showed an ischemic stroke. Despite all efforts and medical efforts, the patient's clinical condition got worse, and she died 10 days after the surgery. COVID-19 can lead to vulnerability to severe bacterial infections such as NP in pediatrics. Severe infections are a significant risk factor for ischemic stroke. The presentation might be different in intubated unconscious patients, such as detecting increased ICP signs. In severe and extensive cases of NP and ischemia, the destruction of the lungs and brain tissue might be irreversible and even lethal. Doctors and parents should consider neurologic complaints in children with infectious diseases as a serious issue since infections make children vulnerable to complications such as stroke.

Changes in seasonal respiratory viral infections among pediatric population around the COVID-19 pandemic; 2019-2023

PURPOSE

This study aims to describe the prevalence and the fluctuations of respiratory viral infections among the pediatric population in a tertiary care center during 2019-2023, parallel with the COVID-19 pandemic, and the specific preventative measures applied in the region during this time.

METHODS

In this observational study, we extracted all respiratory virus PCR tests collected from pediatric patients (< 15 years old) between January 2019 and March 2023. Data on the positivity rate and prevalence of 18 respiratory viruses were presented over the study period.

RESULTS

The lowest rate for the studied respiratory viruses was observed in 2020/2021 (during the COVID-19 pandemic), followed by a gradual increase in positive cases in the 2021/2022 season. Timing (seasonality) was altered during 2022/2023 with an early circulation of respiratory viruses in May-June followed by an early start of the usual respiratory viruses' season in September, leading to prolonged respiratory virus activity. Most respiratory viruses were circulating at unprecedented levels during the 2022/2023 season, with rhinovirus/enterovirus being the most commonly detected virus in all seasons. Other viruses that had atypical activity after the COVID-19 pandemic were influenza A(H3) virus, adenovirus, and parainfluenza 3 virus.

CONCLUSION

Our study demonstrates the extended influence of the COVID-19 pandemic and its associated community restriction measures on the timing and distribution of other respiratory viruses. Continuous monitoring of changes in the circulation of respiratory viruses is crucial for the success of related public health measures such as vaccination distributions and epidemic preparedness.

Candida Isolation During COVID-19: Microbiological Findings of a Prospective Study in a Regional Hospital

BACKGROUND

Prolonged hospitalization due to the COVID-19 pandemic gathered risk factors for developing invasive candidiasis.

AIM

To describe Candida spp. isolated from patients with clinical suspicion of COVID treated in a public hospital specialized in COVID-19 during the pandemic, considering the susceptibility profiles and the risk factors related to the species detected in a positive yeast culture.

METHODS

From different samples of 33 patients with comorbidities, 42 clinical isolates were identified by VITEKⓇ MS Plus. Antifungal susceptibility testing was performed using VITEKⓇ 2 Compact with the AST-YS08 card.

RESULTS

The most frequently identified species were C. albicans and C. glabrata, which were also the most common co-infections, Saprochaete capitata, an uncommon yeast was isolated in one patient. 85% of the co-infections were COVID positive and 100% of patients with a co-infection required mechanical ventilation (MV) which has been described as one of the major predisposing factors to candidiasis. Candida species vary in their response to treatment. In this study, 44% of isolates identified as C. glabrata were fluconazole-resistant, which were also immediately susceptible to caspofungin; this profile limits therapeutic options and emphasizes the importance of evaluating the susceptibility profile.

CONCLUSIONS

This work highlights the increase in isolation of different Candida species during COVID-19 and the importance of establishing criteria to declare Candida colonization or infection and the correct etiological identification to establish an agent-based antifungal treatment, to reduce the spreading risk of Candida spp. in the hospital environment, mortality, time, and cost of hospitalization.

Are Mycoplasma pneumoniae coinfections frequent in COVID-19 patients? A systematic review

Understanding the proportion of SARS-CoV-2 patients with Mycoplasmapneumoniae coinfection is crucial for treating patients suffering from coronavirus disease (COVID-19), help to ensure responsible use of antibiotics and minimize the negative consequences of overuse. In addition, this knowledge could have an impact on empirical antibiotic management guidelines for patients with COVID-19. This systematic review aimed to identify the prevalence of M. pneumoniae in patients with coronavirus disease 2019 (COVID-19). A bibliographic search of studies published in Spanish or English was conducted using the PubMed search engine. Fourteen articles from different continents (America, Asia and Europe) were included, involving a total of 5855 patients in these studies. The mean age of COVID-19 patients with M. pneumoniae was 48 years old (range 1-107), most of whom were male. The detection of laboratory-confirmed M. pneumoniae infection varied between 0 and 33.3%. Most of patients referred fever, cough, and dyspnea, and received empirical antibiotic treatment. Bacterial coinfection was not associated with increased ICU admission and mortality. The prevalence of coinfection showed extremely dissimilar figures according to the population studied and diagnostic criteria. However, it is important to develop Latin American studies, given the heterogeneity observed in the studies conducted in different countries. Standardized definitions should be developed in order to be able to assess the impact of coinfections in patients with a diagnosis of COVID-19.

Hospitalized COVID-19 Patients with Urinary Tract Infection in Iran: Candida Species Distribution and Antifungal Susceptibility Patterns

Candida species, typically part of the human skin and mucous membrane flora, can cause opportunistic fungal infections, notably urinary tract infections (UTIs), which are on the rise among hospitalized COVID-19 patients. The lack of understanding of UTIs in this population, coupled with the emergence of multidrug-resistant strains, poses significant challenges for effective treatment and further investigations. In this study, urine samples were collected from 70 COVID-19 patients with UTIs in sterile containers for microbiology examination. After microscopic observation, the isolates were identified both by phenotypic and molecular techniques such as multiplex PCR. Antifungal susceptibility testing (AFST) against fluconazole (Flu), itraconazole (Itr), and amphotericin B (AMB) was performed according to CLSI M27/S4 standard methods, with the frequency of isolates including Candida albicans (n = 20, 51.3%), Candida tropicalis (n = 15, 38.4%), Nakaseomyces glabrata (previously Candida glabrata) (n = 2, 5.1%), Pichia kudriavzevii (previously Candida krusei), and Candida parapsilosis (n = 1, 2.5%). All isolates of C. albicans, C. tropicalis, C. glabrata, and C. parapsilosis were sensitive to amphotericin B, while C. kruzei was resistant to AMB. Around 70% of C. albicans isolates were sensitive to Flu; 20% of C. tropicalis were resistant to itraconazole, while 33% were resistant to fluconazole. C. albicans and C. tropicalis were the main causes of candiduria in infected cases and both Flu and AMB showed good results in AFST in these species. Performing drug susceptibility testing for clinical isolates of Candida spp. provided guidance for appropriate management and control, and timely antifungal treatment.

Interaction and antiviral treatment of coinfection between SARS-CoV-2 and influenza in vitro

BACKGROUND

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has lasted for three years. Coinfection with seasonal influenza may occur resulting in more severe diseases. The interaction between these two viruses for infection and the effect of antiviral treatment remains unclear.

METHODS

A SARS-CoV-2 and influenza H1N1 coinfection model on Calu-3 cell line was established, upon which the simultaneous and sequential coinfection was evaluated by comparing the viral load. The efficacy of molnupiravir and baloxavir against individual virus and coinfection were also studied.

RESULTS

The replication of SARS-CoV-2 was significantly interfered when the influenza virus was infected simultaneously or in advance (p < 0.05). On the contrary, the replication of the influenza virus was not affected by the SARS-CoV-2. Molnupiravir monotherapy had significant inhibitory effect on SARS-CoV-2 when the concentration reached to 6.25 μM but did not show any significant anti-influenza activity. Baloxavir was effective against influenza within the dosage range and showed significant effect of anti-SARS-CoV-2 at 16 μM. In the treatment of coinfection, molnupiravir had significant effect for SARS-CoV-2 from 6.25 μM to 100 μM and inhibited H1N1 at 100 μM (p < 0.05). The tested dosage range of baloxavir can inhibit H1N1 significantly (p < 0.05), while at the highest concentration of baloxavir did not further inhibit SARS-CoV-2, and the replication of SARS-CoV-2 significantly increased in lower concentrations. Combination treatment can effectively inhibit influenza H1N1 and SARS-CoV-2 replication during coinfection. Compared with molnupiravir or baloxavir monotherapy, combination therapy was more effective in less dosage to inhibit the replication of both viruses.

CONCLUSIONS

In coinfection, the replication of SARS-CoV-2 would be interfered by influenza H1N1. Compared with molnupiravir or baloxavir monotherapy, treatment with a combination of molnupiravir and baloxavir should be considered for early treatment in patients with SARS-CoV-2 and influenza coinfection.

Tolerance to Haemophilus influenzae infection in human epithelial cells: Insights from a primary cell-based model

Haemophilus influenzae is a human respiratory pathogen and inhabits the human respiratory tract as its only niche. Despite this, the molecular mechanisms that allow H. influenzae to establish persistent infections of human epithelia are not well understood. Here, we have investigated how H. influenzae adapts to the host environment and triggers the host immune response using a human primary cell-based infection model that closely resembles human nasal epithelia (NHNE). Physiological assays combined with dualRNAseq revealed that NHNE from five healthy donors all responded to H. influenzae infection with an initial, 'unproductive' inflammatory response that included a strong hypoxia signature but did not produce pro-inflammatory cytokines. Subsequently, an apparent tolerance to large extracellular and intraepithelial burdens of H. influenzae developed, with NHNE transcriptional profiles resembling the pre-infection state. This occurred in parallel with the development of intraepithelial bacterial populations, and appears to involve interruption of NFκB signalling. This is the first time that large-scale, persistence-promoting immunomodulatory effects of H. influenzae during infection have been observed, and we were able to demonstrate that only infections with live, but not heat-killed H. influenzae led to immunomodulation and reduced expression of NFκB-controlled cytokines such as IL-1β, IL-36γ and TNFα. Interestingly, NHNE were able to re-activate pro-inflammatory responses towards the end of the 14-day infection, resulting in release of IL-8 and TNFα. In addition to providing first molecular insights into mechanisms enabling persistence of H. influenzae in the host, our data further indicate the presence of infection stage-specific gene expression modules, highlighting fundamental similarities between immune responses in NHNE and canonical immune cells, which merit further investigation.

Alterations of pathogen transmission patterns and attenuated immune stimulation might be the cause of increased adult respiratory infections cases in 2023, results from a multi-center study in mainland China

Background

Several respiratory infections outbreaks have been observed in mainland China after reduction of non-pharmaceutical interventions. Other countries have seen increases in respiratory infections outside typical seasons post-COVID-19, warranting investigation into underlying causes.

Methods

We established monitoring networks for suspected respiratory infection in 14 tertiary hospitals nationwide. PCR for SARS-CoV-2, influenza A and B were performed on 3708 respiratory specimens and deep sequencing were conducted to identify co-infections or newly emerging microbes in 2023. Viral evolutionary analysis was completed. We retrospectively detected serum antibody level for various respiratory pathogens from 4324 adults without respiratory infections over 7 years to observe its dynamic curves.

Findings

SARS-CoV-2 and influenza A were the main pathogens during outbreaks in 2023, bacterial-virus and bacterial-bacterial co-infections were most detected, but community co-infections didn't significantly increase pneumonia incidence. Different SARS-CoV-2 and influenza variants were present in different outbreaks, and no novel pathogens were found. The epidemiological patterns of influenza A, COVID-19 and etc. were altered, exhibiting characteristics of being "staggered" compared to most global regions, and potentially led to "overlapping prevalence". Binding antibody testing showed regular fluctuation, without significant decrease against common respiratory pathogens in adults. Influenza A antibody stimulation was attenuated during the 2023 outbreak.

Conclusions

"Misaligned" alteration in seasonal respiratory disease patterns possibly caused combined epidemics, leading to cases spike in China, 2023. In adults, antibody levels didn't show significant decline, but reduced immune response to influenza during 2020-2023 emphasizes the need for consistent vaccination during pandemics.

Incidence of Carbapenem-Resistant Gram-Negative Bacterial Infections in Critically Ill Patients with COVID-19 as Compared to Non-COVID-19 Patients: A Prospective Case-Control Study

Introduction

Critically ill COVID-19 patients hospitalized in intensive care units (ICU) are immunosuppressed due to SARSCoV-2-related immunological effects and are administered immunomodulatory drugs. This study aimed to determine whether these patients carry an increased risk of multi-drug resistant (MDR) and especially carbapenem-resistant Gram-negative (CRGN) bacterial infections compared to other critically ill patients without COVID-19.

Materials and Methods

A prospective case-control study was conducted between January 2022 and August 2023. The ICU patients were divided into two groups (COVID-19 and non-COVID-19). Differences in the incidence of CRGN infections from Klebsiella pneumoniae, Acinetobacter spp., and Pseudomonas aeruginosa were investigated. In addition, an indicator of the infection rate of the patients during their ICU stay was calculated. Factors independently related to mortality risk were studied.

Results

Forty-two COVID-19 and 36 non-COVID-19 patients were analyzed. There was no statistically significant difference in the incidence of CRGN between COVID-19 and non-COVID-19 patients. The infection rate was similar in the two groups. Regarding the aetiological agents of CRGN infections, Pseudomonas aeruginosa was significantly more common in non-COVID-19 patients (p=0.007). COVID-19 patients had longer hospitalisation before ICU admission (p=0.003) and shorter ICU length of stay (LOS) (p=0.005). ICU COVID-19 patients had significantly higher mortality (p < 0.001) and sequential organ failure assessment (SOFA) score (p < 0.001) compared to non-COVID-19 patients. Μortality secondary to CRGN infections was also higher in COVID-19 patients compared to non-COVID-19 patients (p=0.033). Male gender, age, ICU LOS, and hospital LOS before ICU admission were independent risk factors for developing CRGN infections. Independent risk factors for patients' mortality were COVID-19 infection, obesity, SOFA score, total number of comorbidities, WBC count, and CRP, but not infection from CRGN pathogens.

Conclusions

The incidence of CRGN infections in critically ill COVID-19 patients is not different from that of non-COVID-19 ICU patients. The higher mortality of COVID-19 patients in the ICU is associated with higher disease severity scores, a higher incidence of obesity, and multiple underlying comorbidities, but not with CRGN infections.

Exploring Prior Antibiotic Exposure Characteristics for COVID-19 Hospital Admission Patients: OpenSAFELY

Previous studies have demonstrated the association between antibiotic use and severe COVID-19 outcomes. This study aimed to explore detailed antibiotic exposure characteristics among COVID-19 patients. Using the OpenSAFELY platform, which integrates extensive health data and covers 40% of the population in England, the study analysed 3.16 million COVID-19 patients with at least two prior antibiotic prescriptions. These patients were compared to up to six matched controls without hospitalisation records. A machine learning model categorised patients into ten groups based on their antibiotic exposure history over the three years before their COVID-19 diagnosis. The study found that for COVID-19 patients, the total number of prior antibiotic prescriptions, diversity of antibiotic types, broad-spectrum antibiotic prescriptions, time between first and last antibiotics, and recent antibiotic use were associated with an increased risk of severe COVID-19 outcomes. Patients in the highest decile of antibiotic exposure had an adjusted odds ratio of 4.8 for severe outcomes compared to those in the lowest decile. These findings suggest a potential link between extensive antibiotic use and the risk of severe COVID-19. This highlights the need for more judicious antibiotic prescribing in primary care, primarily for patients with higher risks of infection-related complications, which may better offset the potential adverse effects of repeated antibiotic use.

Epidemiological and Genetic Characteristics of Respiratory Viral Coinfections with Different Variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

This study aimed to determine the incidence and etiological, seasonal, and genetic characteristics of respiratory viral coinfections involving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Between October 2020 and January 2024, nasopharyngeal samples were collected from 2277 SARS-CoV-2-positive patients. Two multiplex approaches were used to detect and sequence SARS-CoV-2, influenza A/B viruses, and other seasonal respiratory viruses: multiplex real-time polymerase chain reaction (PCR) and multiplex next-generation sequencing. Coinfections of SARS-CoV-2 with other respiratory viruses were detected in 164 (7.2%) patients. The most common co-infecting virus was respiratory syncytial virus (RSV) (38 cases, 1.7%), followed by bocavirus (BoV) (1.2%) and rhinovirus (RV) (1.1%). Patients ≤ 16 years of age had the highest rate (15%) of mixed infections. Whole-genome sequencing produced 19 complete genomes of seasonal respiratory viral co-pathogens, which were subjected to phylogenetic and amino acid analyses. The detected influenza viruses were classified into the genetic groups 6B.1A.5a.2a and 6B.1A.5a.2a.1 for A(H1N1)pdm09, 3C.2a1b.2a.2a.1 and 3C.2a.2b for A(H3N2), and V1A.3a.2 for the B/Victoria lineage. The RSV-B sequences belonged to the genetic group GB5.0.5a, with HAdV-C belonging to type 1, BoV to genotype VP1, and PIV3 to lineage 1a(i). Multiple amino acid substitutions were identified, including at the antibody-binding sites. This study provides insights into respiratory viral coinfections involving SARS-CoV-2 and reinforces the importance of genetic characterization of co-pathogens in the development of therapeutic and preventive strategies.

Influenza A, Influenza B, human respiratory syncytial virus and SARSCoV-2 molecular diagnostics and epidemiology in the post COVID-19 era

BACKGROUND

The concurrent circulation of SARS-CoV-2 with other respiratory viruses is unstoppable and represents a new diagnostic reality for clinicians and clinical microbiology laboratories. Multiplexed molecular testing on automated platforms that focus on the simultaneous detection of multiple respiratory viruses in a single tube is a useful approach for current and future diagnosis of respiratory infections in the clinical setting.

METHODS

Two time periods were included in the study: from February to April 2022, an early 2022 period, during the gradual lifting of COVID-19 prevention measures in the country, and from October 2022 to April 2023, the 2022/23 respiratory infections season. We analysed a total of 1,918 samples in the first period and 18,131 respiratory samples in the second period using a multiplex molecular assay for the simultaneous detection of Influenza A (Flu-A), Influenza B (Flu-B), Human Respiratory Syncytial Virus (HRSV) and SARS-CoV-2.

RESULTS

The results from early 2022 showed a strong dominance of SARS-CoV-2 infections with 1,267/1,918 (66.1%) cases. Flu-A was detected in 30/1,918 (1.6%) samples, HRSV in 14/1,918 (0.7%) samples, and Flu-B in 2/1,918 (0.1%) samples. Flu-A/SARS-CoV-2 co-detections were observed in 11/1,267 (0.9%) samples, and HRSV/SARS-CoV-2 co-detection in 5/1,267 (0.4%) samples. During the 2022/23 winter respiratory season, SARS-CoV-2 was detected in 1,738/18,131 (9.6%), Flu-A in 628/18,131 (3.5%), Flu-B in 106/18,131 (0.6%), and HRSV in 505/18,131 (2.8%) samples. Interestingly, co-detections were present to a similar extent as in early 2022.

CONCLUSION

The results show that the multiplex molecular approach is a valuable tool for the simultaneous laboratory diagnosis of SARS-CoV-2, Flu-A/B, and HRSV in hospitalized and outpatients. Infections with Flu-A/B, and HRSV occurred shortly after the COVID-19 control measures were lifted, so a strong reoccurrence of various respiratory infections and co-detections in the post COVID-19 period was to be expected.

The Trend of Antibiotic Consumption After the COVID-19 Pandemic: Approach to Future Outbreaks

Background

Earlier reports suggested high rates of antibiotic utilization among COVID-19 patients despite the lack of direct evidence of their activity against viral pathogens. Different trends in antibiotic consumption during 2020 compared to 2019 have been reported.

Purpose

The objective of this study is to assess the impact of COVID-19 pandemic on antibiotic consumption in the presence of active Antibiotic Stewardship Program.

Methods

This study represented a five years assessment of the consumption of the commonly prescribed antibiotics measured as DDDs/100-Bed Days. We analyzed the data by using nonparametric Friedman and Friedman tests to compare the antibiotic consumption before and during the three subsequent waves of COVID-19.

Results

Antibiotic consumption through the DDDs/100-BD has shown reduction in the median of antibiotics consumption of most antibiotics during the period of COVID-19 as compared to the pre-COVID-19 period, which was significant for meropenem and ciprofloxacin, except colomycin that slightly increased. Significant reduction in the consumption of imipenem and meropenem during the second and third waves as compared to the pre-COVID period. Throughout the years, significant reductions were observed between 2018 and 2019 (p=<.001), 2018 and 2020 (p=0.008), and 2018 and 2022 (p=0.002).

Conclusion

The reduction in antibiotic consumption is attributed to the strong influence if the ASP and the reluctance of people to visit hospitals during the COVID-19 pandemic. Other related COVID-19 precautions such as physical distance, good hand hygiene, facemasks, that resulted in the prevention of secondary bacterial infections have contributed to the reduction in antibiotic utilization during the pandemic.

Coxsackievirus A7 and Enterovirus A71 Significantly Reduce SARS-CoV-2 Infection in Cell and Animal Models

In this study, we investigated the features of co-infection with SARS-CoV-2 and the enterovirus vaccine strain LEV8 of coxsackievirus A7 or enterovirus A71 for Vero E6 cells and Syrian hamsters. The investigation of co-infection with SARS-CoV-2 and LEV-8 or EV-A71 in the cell model showed that a competitive inhibitory effect for these viruses was especially significant against SARS-CoV-2. Pre-infection with enteroviruses in the animals caused more than a 100-fold decrease in the levels of SARS-CoV-2 virus replication in the respiratory tract and more rapid clearance of infectious SARS-CoV-2 from the lower respiratory tract. Co-infection with SARS-CoV-2 and LEV-8 or EV-A71 also reduced the severity of clinical manifestations of the SARS-CoV-2 infection in the animals. Additionally, the histological data illustrated that co-infection with strain LEV8 of coxsackievirus A7 decreased the level of pathological changes induced by SARS-CoV-2 in the lungs. Research into the chemokine/cytokine profile demonstrated that the studied enteroviruses efficiently triggered this part of the antiviral immune response, which is associated with the significant inhibition of SARS-CoV-2 infection. These results demonstrate that there is significant viral interference between the studied strain LEV-8 of coxsackievirus A7 or enterovirus A71 and SARS-CoV-2 in vitro and in vivo.

Secondary bacterial infections in post-COVID-19 mucormycosis cases: a retrospective study at Imam Khomeini Hospital Complex, March 2020-April 2021

Background and Objectives

To explore the prevalence and characteristics of secondary bacterial infections among patients suffering from mucormycosis following COVID-19 infection.

Materials and Methods

We conducted a cross-sectional, retrospective analysis from March 2020 to April 2022 at Imam Khomeini Hospital Complex in Tehran. The study included patients with histopathologically confirmed mucormycosis and documented secondary bacterial infections. We extracted and analyzed data from hospital records using SPSS software, version 26.

Results

The study comprised 27 patients, with a predominance of females (70.4%) and an average age of 56 years. The majority of these patients (63%) had pre-existing diabetes mellitus. The severity of their COVID-19 infections varied. Treatment regimens included immunosuppressive drugs and antibiotics. Rhinocerebral mucormycosis was the most common form observed. The predominant secondary infections involved the urinary tract, respiratory system, bloodstream (bacteremia), and soft tissues, with resistant strains of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae being the most frequently identified microorganisms. Notably, cases of bacteremia and pneumonia exhibited a higher mortality rate. Ultimately, 55.6% of patients were discharged, while 44.4% succumbed to their infections.

Conclusion

Patients recovering from COVID-19 with mucormycosis are significantly susceptible to secondary bacterial infections, particularly those with diabetes mellitus or those undergoing immunosuppressive therapy. Such infections compound the morbidity and mortality risks in this vulnerable patient cohort.

Two Cases of Lung Abscess and Pleuritis in Severe COVID-19 Patients

We report two patients who were treated with remdesivir, steroids, and tocilizumab for severe coronavirus disease 2019 (COVID-19) and developed lung abscesses and pleuritis. Although complications due to bacterial infections are often reported in COVID-19 patients, these severe infections are rare. Patients receiving tocilizumab are at a high risk of developing serious bacterial infections, and the diagnosis is often delayed because symptoms such as fever and elevated C-reactive protein levels are often minimal. The possibility of complications owing to severe bacterial infections should be considered when treating patients with severe COVID-19.

Co-Infection of SARS-CoV-2 and Klebsiella pneumoniae: A Systematic Review and Meta-Analysis

The study aimed to assess the prevalence of COVID-19 and Klebsiella spp. coinfection across continents. Conducted following PRISMA guidelines, a systematic review utilized PubMed, Embase, SCOPUS, ScienceDirect, and Web of Science databases, searching for literature in English published from December 2019 to December 2022, using specific Health Sciences descriptors. A total of 408 records were identified, but only 50 were eligible, and of these, only 33 were included. Thirty-three references were analyzed to evaluate the correlation between COVID-19 and Klebsiella spp. infections. The tabulated data represented a sample group of 8741 coinfected patients. The findings revealed notable disparities in co-infection rates across continents. In Asia, 23% of individuals were infected with Klebsiella pneumoniae, while in Europe, the proportion of co-infected patients stood at 15%. Strikingly, on the African continent, 43% were found to be infected with Klebsiella pneumoniae, highlighting significant regional variations. Overall, the proportion of Klebsiella pneumoniae co-infections among COVID-positive individuals were determined to be 19%. Particularly concerning was the observation that 1 in 6 ICU coinfections was attributed to Klebsiella pneumoniae, indicating its substantial impact on patient outcomes and healthcare burden. The study underscores the alarming prevalence of co-infection between COVID-19 and Klebsiella pneumoniae, potentially exacerbating the clinical severity of patients and posing challenges to treatment strategies. These findings emphasize the importance of vigilant surveillance and targeted interventions to mitigate the adverse effects of bacterial coinfections in the context of the COVID-19 pandemic.

Evaluation of the Efficacy and Safety of Intravenous Immunoglobulin (IVIG) in Moderate-to-Severe Hospitalized COVID-19 Patients: A Randomized, Open-Label Parallel-Group Study

Purpose

Since February 2020, the world has been overwhelmed by the SARS-CoV-2 outbreak, and several patients suffered interstitial pneumonia and respiratory failure requiring mechanical ventilation, threatening the capability of healthcare systems to handle this amount of critical cases. Intravenous immunoglobulins (IVIG) possess potential immunomodulatory properties beneficial for COVID-19 patients, yet evidence supporting IVIG as adjunctive therapy remains sparse. This study evaluated the outcomes of adjunctive IVIG with the standard of care (SoC) in moderate-to-severe COVID-19 patients.

Methods

This randomized study included 59 moderate-to-severe COVID-19 patients with known comorbidities. One arm (n = 33) received high-dose IVIG (400 mg/kg/day) within 48 hours for five days alongside SoC, while the other arm (n = 26) received SoC, comprising steroids, enoxaparin, and remdesivir. The primary endpoint was clinical improvement, as measured by the National Early Warning Score 2 (NEWS2) and discharged/death proportions. Secondary outcomes included IVIG safety, hospitalization duration, changes in oxygen saturation, inflammatory markers, IgG titer, CTSS (CT severity score), and radiological findings.

Results

There was an improvement in the NEWS2 at the end of treatment in the IVIG arm (5.67 vs. 5.96). A significant absolute effect improvement (Day 1 vs. Day 9) was seen in serum LDH, D-dimer, hs-CRP, IL-6, CTSS, procalcitonin, respiratory rate, and chest radiographic findings. SARS-CoV-2 IgG titer increased significantly in the IVIG arm. There was a statistically significant reduction in mortality in the IVIG group (5 vs. 10).

Conclusion

IVIG was a safe and effective adjunctive therapy to SoC treatment in moderate-to-severe COVID-19 patients needing ventilatory support. Furthermore, studies are required to validate our findings. This trial is registered with CTRI/2021/05/033622.

Outbreak of influenza and SARS-CoV-2 at the Armed Forces of the Philippines Health Service Education and Training Center, September 25-October 10, 2023

In the last week of September 2023, a surge of influenza-like illness was observed among students of the Armed Forces of the Philippines (AFP) Health Service Education and Training Center, where 48 (27 males and 21 females; age in years: mean 33, range 27-41) of 247 military students at the Center presented with respiratory symptoms. Between September 25 and October 10, 2023, all 48 symptomatic students were evaluated with real-time reverse transcription polymerase chain reaction and sequencing for both influenza and SARS-CoV-2. Thirteen (27%) students were found positive for influenza A/H3 only, 6 (13%) for SARS-CoV-2 only, and 4 (8%) were co-infected with influenza A/H3 and SARS-CoV-2. Seventeen influenza A/ H3N2 viruses belonged to the same clade, 3C.2a1b.2a.2a.3a, and 4 SARSCoV-2 sequences belonged to the JE1.1 lineage, indicating a common source outbreak for both. The influenza A/H3N2 circulating virus belonged to a different clade than the vaccine strain for 2023 (3C.2a1b.2a.2a). Only 4 students had received the influenza vaccine for 2023. In response, the AFP Surgeon General issued a memorandum to all military health institutions on October 19, 2023 that mandated influenza vaccination as a prerequisite for enrollment of students at all education and training centers, along with implementation of non-pharmaceutical interventions and early notification and testing of students exhibiting influenza-like-illness.

Comparison of clinical outcomes in hospitalized patients with COVID-19 or non-COVID-19 community-acquired pneumonia in a prospective observational cohort study

PURPOSE

Coronavirus disease 2019 (COVID-19) and non-COVID-19 community-acquired pneumonia (NC-CAP) often result in hospitalization with considerable risks of mortality, ICU treatment, and long-term morbidity. A comparative analysis of clinical outcomes in COVID-19 CAP (C-CAP) and NC-CAP may improve clinical management.

METHODS

Using prospectively collected CAPNETZ study data (January 2017 to June 2021, 35 study centers), we conducted a comprehensive analysis of clinical outcomes including in-hospital death, ICU treatment, length of hospital stay (LOHS), 180-day survival, and post-discharge re-hospitalization rate. Logistic regression models were used to examine group differences between C-CAP and NC-CAP patients and associations with patient demography, recruitment period, comorbidity, and treatment.

RESULTS

Among 1368 patients (C-CAP: n = 344; NC-CAP: n = 1024), C-CAP showed elevated adjusted probabilities for in-hospital death (aOR 4.48 [95% CI 2.38-8.53]) and ICU treatment (aOR 8.08 [95% CI 5.31-12.52]) compared to NC-CAP. C-CAP patients were at increased risk of LOHS over seven days (aOR 1.88 [95% CI 1.47-2.42]). Although ICU patients had similar in-hospital mortality risk, C-CAP was associated with length of ICU stay over seven days (aOR 3.59 [95% CI 1.65-8.38]). Recruitment period influenced outcomes in C-CAP but not in NC-CAP. During follow-up, C-CAP was linked to a reduced risk of re-hospitalization and mortality post-discharge (aOR 0.43 [95% CI 0.27-0.70]).

CONCLUSION

Distinct clinical trajectories of C-CAP and NC-CAP underscore the need for adapted management to avoid acute and long-term morbidity and mortality amid the evolving landscape of CAP pathogens.

Healthcare-associated infections in Iranian pediatric and adult intensive care units: A comprehensive review of risk factors, etiology, molecular epidemiology, antimicrobial sensitivity, and prevention strategies during the COVID-19 pandemic

The current review article provides a comprehensive analysis of nosocomial infections in pediatric and adult intensive care units (ICUs) in Iran. We examine the risk factors and etiology of nosocomial infections, with a particular focus on molecular epidemiology and antimicrobial sensitivity. In this article, we explore a range of prevention strategies, including hand hygiene, personal protective equipment, environmental cleaning, antibiotic stewardship, education, and training. Moreover, we discuss the impact of the COVID-19 pandemic on infection control measures in ICUs and provide valuable insights for healthcare professionals and policymakers seeking to address this critical public health issue. In conclusion, this review article can serve as a valuable resource for those interested in understanding and improving infection control in ICUs and beyond.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

Diagnostic testing and antibiotic utilization among inpatients evaluated for coronavirus disease 2019 (COVID-19) pneumonia

We evaluated diagnostic test and antibiotic utilization among 252 patients from 11 US hospitals who were evaluated for coronavirus disease 2019 (COVID-19) pneumonia during the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) omicron variant pandemic wave. In our cohort, antibiotic use remained high (62%) among SARS-CoV-2-positive patients and even higher among those who underwent procalcitonin testing (68%).

Predictors and patterns of empirical antibiotic therapy and associated outcomes in COVID-19 patients: a retrospective study in a tertiary care facility in South India

BACKGROUND

The coronavirus disease (COVID-19) led to a global health crisis. Inappropriate use of antibiotics in COVID-19 patients has been a concern, leading to antimicrobial resistance. This study evaluated the patterns and predictors of empirical antibiotic therapy in COVID-19 patients and associated outcomes.

METHODS

A hospital-based retrospective study was conducted with 525 patients admitted to Kasturba Hospital, Manipal, India, with moderate and severe COVID-19 from 1 March to 1 August 2021. They were divided based on empirical therapy, and predictors of antibiotic usage were assessed by logistic regression.

RESULTS

Four hundred and eighty (91.4%) COVID-19 patients received at least one course of antibiotics, with 440 (83.8%) initiating empirical therapy. Patients with severe COVID-19 manifestations were more likely to be prescribed empirical antibiotics. Multivariable analysis showed that patients initiated on empirical antibiotics had significantly elevated levels of procalcitonin [OR: 3.91 (95% CI: 1.66-9.16) (p = 0.001)], invasive ventilation [OR: 3.93 (95% CI: 1.70-9.09) (p = 0.001)], shortness of breath [OR: 2.25 (95% CI: 1.30-3.89) (p = 0.003)] and higher CRP levels [OR: 1.01 (95% CI: 1.00-1.01) (p = 0.005)]. Most antibiotics (65.9%) were prescribed from the 'Watch' group, the highest being ceftriaxone. Only 23.8% of the patients had microbiologically confirmed infections.

CONCLUSION

The study identified predictors for initiating empirical antibacterial therapy in our setting.

Meropenem population pharmacokinetics and model-based dosing optimisation in patients with serious bacterial infection

OBJECTIVES

The objective of this study was to develop a population pharmacokinetic model of meropenem in a heterogeneous population of patients with a serious bacterial infection in order to propose dosing optimisation leading to improved achievement of the pharmacokinetic/pharmacodynamic (PK/PD) target.

METHODS

A total of 174 meropenem serum levels obtained from 144 patients during therapeutic drug monitoring were analysed using a non-linear mixed-effects modelling approach and Monte Carlo simulation was then used to compare various dosing regimens in order to optimise PK/PD target attainment.

RESULTS

The meropenem volume of distribution of the patient population was 54.95 L, while clearance started at 3.27 L/hour and increased by 0.91 L/hour with each 1 mL/s/1.73 m2 of estimated glomerular filtration rate. Meropenem clearance was also 0.31 L/hour higher in postoperative patients with central nervous system infection. Meropenem administration by continuous infusion showed a significantly higher probability of attaining the PK/PD target than a standard 30 min infusion (95.3% vs 49.5%).

CONCLUSIONS

A daily meropenem dose of 3 g, 6 g and 10.5 g administered by continuous infusion was shown to be accurate for patients with moderate to severe renal impairment, normal renal function to mild renal impairment and augmented renal clearance, respectively.

Community antibiotic prescribing in patients with COVID-19 across three pandemic waves: a population-based study in Scotland, UK

OBJECTIVES

This study aims to examine community antibiotic prescribing across a complete geographical area for people with a positive COVID-19 test across three pandemic waves, and to examine health and demographic factors associated with antibiotic prescribing.

DESIGN

A population-based study using administrative data.

SETTING

A complete geographical region within Scotland, UK.

PARTICIPANTS

Residents of two National Health Service Scotland health boards with SARS-CoV-2 virus test results from 1 February 2020 to 31 March 2022 (n=184 954). Individuals with a positive test result (n=16 025) had data linked to prescription and hospital admission data ±28 days of the test, general practice data for high-risk comorbidities and demographic data.

OUTCOME MEASURES

The associations between patient factors and the odds of antibiotic prescription in COVID-19 episodes across three pandemic waves from multivariate binary logistic regression.

RESULTS

Data included 768 206 tests for 184 954 individuals, identifying 16 240 COVID-19 episodes involving 16 025 individuals. There were 3263 antibiotic prescriptions ±28 days for 2395 episodes. 35.6% of episodes had a prescription only before the test date, 52.3% of episodes after and 12.1% before and after. Antibiotic prescribing reduced over time: 20.4% of episodes in wave 1, 17.7% in wave 2 and 12.0% in wave 3. In multivariate logistic regression, being female (OR 1.31, 95% CI 1.19 to 1.45), older (OR 3.02, 95% CI 2.50 to 3.68 75+ vs <25 years), having a high-risk comorbidity (OR 1.45, 95% CI 1.31 to 1.61), a hospital admission ±28 days of an episode (OR 1.58, 95% CI 1.42 to 1.77) and health board region (OR 1.14, 95% CI 1.03 to 1.25, board B vs A) increased the odds of receiving an antibiotic.

CONCLUSION

Community antibiotic prescriptions in COVID-19 episodes were uncommon in this population and likelihood was associated with patient factors. The reduction over pandemic waves may represent increased knowledge regarding COVID-19 treatment and/or evolving symptomatology.

SARS-CoV-2 co-detection with influenza and human respiratory syncytial virus in Ethiopia: Findings from the severe acute respiratory illness (SARI) and influenza-like illness (ILI) sentinel surveillance, January 01, 2021, to June 30, 2022

SARS-CoV-2 co-infection with the influenza virus or human respiratory syncytial virus (RSV) may complicate its progress and clinical outcomes. However, data on the co-detection of SARS-CoV-2 with other respiratory viruses are limited in Ethiopia and other parts of Africa to inform evidence-based response and decision-making. We analyzed 4,989 patients' data captured from the national severe acute respiratory illness (SARI) and influenza-like illness (ILI) sentinel surveillance sites over 18 months period from January 01, 2021, to June 30, 2022. Laboratory specimens were collected from the patients and tested for viral respiratory pathogens by real-time, reverse transcription polymerase chain reaction (RT-PCR) at the national influenza center. The median age of the patients was 14 years (IQR: 1-35 years), with a slight preponderance of them being at the age of 15 to less than 50 years. SARS-CoV-2 was detected among 459 (9.2%, 95% CI: 8.4-10.0) patients, and 64 (1.3%, 95% CI: 1.0-1.6) of SARS-CoV-2 were co-detected either with Influenza virus (54.7%) or RSV (32.8%) and 12.5% were detected with both of the viruses. A substantial proportion (54.7%) of SARS-CoV-2 co-detection with other respiratory viruses was identified among patients in the age group from 15 to less than 50 years. The multivariable analysis found that the odds of SARS-CoV-2 co-detection was higher among individuals with the age category of 20 to 39 years as compared to those less than 20 years old (AOR: 1.98, 95%CI:1.15-3.42) while the odds of SARS-CoV-2 co-detection was lower among cases from other regions of the country as compared to those from Addis Ababa (AOR:0.16 95%CI:0.07-0.34). Although the SARS-CoV-2 co-detection with other respiratory viral pathogens was minimal, the findings of this study underscore that it is critical to continuously monitor the co-infections to reduce transmission and improve patient outcomes, particularly among the youth and patients with ILI.

Development and validation of machine learning-based models for predicting healthcare-associated bacterial/fungal infections among COVID-19 inpatients: a retrospective cohort study

BACKGROUND

COVID-19 and bacterial/fungal coinfections have posed significant challenges to human health. However, there is a lack of good tools for predicting coinfection risk to aid clinical work.

OBJECTIVE

We aimed to investigate the risk factors for bacterial/fungal coinfection among COVID-19 patients and to develop machine learning models to estimate the risk of coinfection.

METHODS

In this retrospective cohort study, we enrolled adult inpatients confirmed with COVID-19 in a tertiary hospital between January 1 and July 31, 2023, in China and collected baseline information at admission. All the data were randomly divided into a training set and a testing set at a ratio of 7:3. We developed the generalized linear and random forest models for coinfections in the training set and assessed the performance of the models in the testing set. Decision curve analysis was performed to evaluate the clinical applicability.

RESULTS

A total of 1244 patients were included in the training cohort with 62 healthcare-associated bacterial/fungal infections, while 534 were included in the testing cohort with 22 infections. We found that patients with comorbidities (diabetes, neurological disease) were at greater risk for coinfections than were those without comorbidities (OR = 2.78, 95%CI = 1.61-4.86; OR = 1.93, 95%CI = 1.11-3.35). An indwelling central venous catheter or urinary catheter was also associated with an increased risk (OR = 2.53, 95%CI = 1.39-4.64; OR = 2.28, 95%CI = 1.24-4.27) of coinfections. Patients with PCT > 0.5 ng/ml were 2.03 times (95%CI = 1.41-3.82) more likely to be infected. Interestingly, the risk of coinfection was also greater in patients with an IL-6 concentration < 10 pg/ml (OR = 1.69, 95%CI = 0.97-2.94). Patients with low baseline creatinine levels had a decreased risk of bacterial/fungal coinfections(OR = 0.40, 95%CI = 0.22-0.71). The generalized linear and random forest models demonstrated favorable receiver operating characteristic curves (ROC = 0.87, 95%CI = 0.80-0.94; ROC = 0.88, 95%CI = 0.82-0.93) with high accuracy, sensitivity and specificity of 0.86vs0.75, 0.82vs0.86, 0.87vs0.74, respectively. The corresponding calibration evaluation P statistics were 0.883 and 0.769.

CONCLUSIONS

Our machine learning models achieved strong predictive ability and may be effective clinical decision-support tools for identifying COVID-19 patients at risk for bacterial/fungal coinfection and guiding antibiotic administration. The levels of cytokines, such as IL-6, may affect the status of bacterial/fungal coinfection.

Specific and Non-specific Aspects and Future Challenges of ICU Care Among COVID-19 Patients with Obesity: A Narrative Review

PURPOSE OF REVIEW

Since the end of 2019, the coronavirus disease 2019 (COVID-19) pandemic has infected nearly 800 million people and caused almost seven million deaths. Obesity was quickly identified as a risk factor for severe COVID-19, ICU admission, acute respiratory distress syndrome, organ support including mechanical ventilation and prolonged length of stay. The relationship among obesity; COVID-19; and respiratory, thrombotic, and renal complications upon admission to the ICU is unclear.

RECENT FINDINGS

The predominant effect of a hyperinflammatory status or a cytokine storm has been suggested in patients with obesity, but more recent studies have challenged this hypothesis. Numerous studies have also shown increased mortality among critically ill patients with obesity and COVID-19, casting doubt on the obesity paradox, with survival advantages with overweight and mild obesity being reported in other ICU syndromes. Finally, it is now clear that the increase in the global prevalence of overweight and obesity is a major public health issue that must be accompanied by a transformation of our ICUs, both in terms of equipment and human resources. Research must also focus more on these patients to improve their care. In this review, we focused on the central role of obesity in critically ill patients during this pandemic, highlighting its specificities during their stay in the ICU, identifying the lessons we have learned, and identifying areas for future research as well as the future challenges for ICU activity.

The DmsABC S-oxide reductase is an essential component of a novel, hypochlorite-inducible system of extracellular stress defense in Haemophilus influenzae

Defenses against oxidative damage to cell components are essential for survival of bacterial pathogens during infection, and here we have uncovered that the DmsABC S-/N-oxide reductase is essential for virulence and in-host survival of the human-adapted pathogen, Haemophilus influenzae. In several different infection models, H. influenzae ΔdmsA strains showed reduced immunogenicity as well as lower levels of survival in contact with host cells. Expression of DmsABC was induced in the presence of hypochlorite and paraquat, closely linking this enzyme to defense against host-produced antimicrobials. In addition to methionine sulfoxide, DmsABC converted nicotinamide- and pyrimidine-N-oxide, precursors of NAD and pyrimidine for which H. influenzae is an auxotroph, at physiologically relevant concentrations, suggesting that these compounds could be natural substrates for DmsABC. Our data show that DmsABC forms part of a novel, periplasmic system for defense against host-induced S- and N-oxide stress that also comprises the functionally related MtsZ S-oxide reductase and the MsrAB peptide methionine sulfoxide reductase. All three enzymes are induced following exposure of the bacteria to hypochlorite. MsrAB is required for physical resistance to HOCl and protein repair. In contrast, DmsABC was required for intracellular colonization of host cells and, together with MtsZ, contributed to resistance to N-Chlorotaurine. Our work expands and redefines the physiological role of DmsABC and highlights the importance of different types of S-oxide reductases for bacterial virulence.

Incidence of secondary bacterial infections and risk factors for in-hospital mortality among coronavirus disease 2019 subjects admitted to secondary care hospital: A single-center cross-sectional retrospective study

Background

This study aims to determine the prevalence of secondary bacterial infections (SBIs) in hospitalized coronavirus disease 2019 (COVID-19) subjects and evaluate their antibiotic susceptibility. The study also sought to identify risk factors for the outcome of SBIs in COVID-19 subjects.

Methods

This single-center cross-sectional retrospective study was carried out at Sohar Hospital in Oman. The study examined hospitalized COVID-19 subjects diagnosed with SBIs during March 2020-December 2022. The relevant subjects' data were extracted from hospital electronic health records and analyzed using STATA version 14. The Chi-square test or Fisher's exact test was employed for analyzing categorical variables, and P < 0.05 was deemed statistically significant.

Results

The research encompassed a total of 817 bacteria recovered from various clinical samples of 421 subjects. The older individuals (39.4%) and men (65.6%) experienced bacterial infections more frequently, with bloodstream and respiratory infections being the most common. Gram-negative bacilli (GNB) were responsible for a higher proportion (85.6%) of infections, with Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae being the most common pathogens. Subjects who underwent mechanical ventilation, received corticosteroid therapy, and who had underlying comorbidities, such as diabetes and chronic renal disease, were found to have higher mortality rates. Neutrophilia, elevated C-reactive protein, lymphocytopenia, decreased serum albumin level, sepsis, and pneumonia were found to be independent contributors to mortality.

Conclusions

SBI is common among COVID-19-hospitalized subjects. GNB were primarily linked to SBI. The severity and the likelihood of SBI increased in subjects undergoing medical interventions and immunosuppressive therapy.

Changes in clinical parameters and inflammatory markers after blood culture collection facilitate early identification of positive culture in adult patients with COVID-19 and clinically suspected bloodstream infection

OBJECTIVE

We explored whether changes in clinical parameters and inflammatory markers can facilitate early identification of positive blood culture in adult patients with COVID-19 and clinically suspected bloodstream infection (BSI).

METHODS

This single-center retrospective study enrolled 20 adult patients with COVID-19 admitted to the intensive care unit who underwent blood culture for clinically suspected BSI (February 2020-November 2021). We divided patients into positive (Pos) and negative blood culture groups. Clinical parameters and inflammatory markers were obtained from medical records between blood culture collection and the first positive or negative result and compared between groups on different days.

RESULTS

Patients in the positive culture group had significantly older age and higher D-dimer, immunoglobulin 6 (IL-6), and Sequential Organ Failure Assessment score as well as lower albumin (ALB). The area under the receiver operating characteristic curve (AUC) was 0.865 for IL-6, D-dimer and ALB on the first day after blood culture collection; the AUC was 0.979 for IL-6, IL-10, D-dimer, and C-reactive protein on the second day after blood culture collection.

CONCLUSION

Changes in clinical parameters and inflammatory markers after blood culture collection may facilitate early identification of positive culture in adult patients with COVID-19 and clinically suspected BSI.

Prevalence of Respiratory Viral Infections in Deceased Persons during the COVID-19 Pandemic Season 2021-2022: A Population-Based Observational Study

Although the omicron variant of SARS-CoV-2 circulated intensely during the 2021-2022 season, many patients with severe acute respiratory disease tested negative for COVID-19. The aim of this study was to assess the presence of different respiratory viruses in deceased persons. The proportion of deceased persons with respiratory viral infections in the 2021-2022 season in Navarre, Spain, was estimated considering all deaths caused by confirmed COVID-19 according to the epidemiological surveillance and the results of multiplex PCR tests for respiratory viruses performed in a sample of deceased persons with a cause of death other than COVID-19. Of 3578 deaths, 324 (9.1%) were initially reported as caused by pre-mortem confirmed COVID-19. A sample of 242 persons who died by causes other than COVID-19 were tested post-mortem; 64 (26.4%) of them were positive for any respiratory virus: 11.2% for SARS-CoV-2, 5.8% for rhinovirus, 3.7% for human coronavirus, 2.5% for metapneumovirus, 1.7% for respiratory syncytial virus, 1.7% for parainfluenza, 1.2% for influenza, and less than 1% each for adenovirus and bocavirus. Combining both approaches, we estimated that 34.4% of all deceased persons during the study period had a respiratory viral infection and 19.2% had SARS-CoV-2. Only 33.3% (9/27) of SARS-CoV-2 and 5.0% (2/40) of other viruses detected post-mortem had previously been confirmed pre-mortem. In a period with very intense circulation of SARS-CoV-2 during the pandemic, other respiratory viruses were also frequently present in deceased persons. Some SARS-CoV-2 infections and most other viral infections were not diagnosed pre-mortem. Several respiratory viruses may contribute to excess mortality in winter.

Adapted methods for monitoring influenza virus and respiratory syncytial virus in sludge and wastewater

Wastewater-based surveillance constitutes a valuable methodology for the continuous monitoring of viral circulation, with the capacity to function as an early warning system. It holds particular significance in scenarios where respiratory viruses exhibit overlapping clinical presentations, as occurs with SARS-CoV-2, influenza virus (IV), and respiratory syncytial virus (RSV), and allows seasonal virus outbreaks to be distinguished from COVID-19 peaks. Furthermore, sewage sludge, given it harbors concentrated human waste from a large population, serves as a substantial reservoir for pathogen detection. To effectively integrate wastewater-based epidemiology into infectious disease surveillance, the detection methods employed in wastewater samples must be adapted to the distinct characteristics of sludge matrices. In this study, we adapted and applied protocols for the detection of IV and RSV in sewage sludge, comparing their performance with the results obtained in wastewater. To assess the efficiency of these protocols, sludge and wastewater samples were spiked with IV and RSV RNA, either free or incorporated in lentiviral particles. Samples were concentrated using the aluminum hydroxide adsorption-precipitation method before viral RNA extraction. Absolute virus quantification was carried out by RT-qPCR, including an internal control to monitor potential inhibitory factors. Recovery efficiencies for both free IV and RSV RNA were 60 % in sludge, and 75 % and 71 % respectively in wastewater, whereas the values for IV and RSV RNA in lentiviral particles were 16 % and 10 % in sludge and 21 % and 17 % in wastewater respectively. Additionally, the protocol enabled the quantification of naturally occurring IV and RSV in wastewater and sludge samples collected from two wastewater treatment plants during the winter months, thus affirming the efficacy of the employed methodologies.

Device-Associated Infections in COVID-19 Patients: Frequency of Resistant Bacteria, Predictors and Mortality in Medellín, Colombia

INTRODUCTION

Increased antimicrobial use during the COVID-19 pandemic has raised concerns about the spread of resistant bacteria. This study analyzed the frequency of device-associated infections (DAI) caused by resistant bacteria, the predictors of these infections, and 30-day all-cause mortality in patients with and without COVID-19.

METHODS

A retrospective cohort study was conducted on DAI patients admitted to the ICU (intensive care unit) in 20 hospitals in Medellin, Colombia (2020-2021). The exposure assessed was the COVID-19 diagnosis, and outcomes analyzed were resistant bacterial infections and 30-day mortality. Clinical and microbiological information was collected from surveillance databases. Statistical analysis included generalized linear mixed-effects models.

RESULTS

Of the 1521 patients included, 1033 (67.9%) were COVID-19-positive and 1665 DAI were presented. Carbapenem-resistant Enterobacteriaceae (CRE) infections predominated during the study (n = 98; 9.9%). The patients with COVID-19 had a higher frequency of metallo-beta-lactamase-producing CRE infections (n = 15; 33.3%) compared to patients without the disease (n = 3; 13.0%). Long-stay in the ICU (RR: 2.09; 95% CI: 1.39-3.16), diabetes (RR: 1.73; 95% CI: 1.21-2.49), and mechanical ventilation (RR: 2.13; 95% CI: 1.01-4.51) were CRE infection predictors in COVID-19 patients, with a mortality rate of 60.3%.

CONCLUSION

CRE infections were predominant in COVID-19 patients. In pandemic situations, the strategies to control DAI should be maintained to avoid infections caused by resistant bacteria, such as length of stay in the ICU and duration of mechanical ventilation.

Coinfection and Nonrandom Recombination Drive the Evolution of Swine Enteric Coronaviruses

Coinfection with multiple viruses is a common phenomenon in clinical settings and is a crucial driver of viral evolution. Although numerous studies have demonstrated viral recombination arising from coinfections of different strains of a specific species, the role of coinfections of different species or genera during viral evolution is rarely investigated. Here, we analyzed coinfections of and recombination events between four different swine enteric coronaviruses that infect the jejunum and ileum in pigs, including porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and swine acute diarrhea syndrome coronavirus (SADS-CoV), and a deltacoronavirus, porcine deltacoronavirus (PDCoV). Various coinfection patterns were observed in 4,468 fecal and intestinal tissue samples collected from pigs in a 4-year survey. PEDV/PDCoV was the most frequent coinfection. However, recombination analyses have only detected events involving PEDV/TGEV and SADS-CoV/TGEV, indicating that inter-species recombination among coronaviruses is most likely to occur within the same genus. We also analyzed recombination events within the newly identified genus Deltacoronavirus and found that sparrows have played a unique host role in the recombination history of the deltacoronaviruses. The emerging virus PDCoV, which can infect humans, has a different recombination history. In summary, our study demonstrates that swine enteric coronaviruses are a valuable model for investigating the relationship between viral coinfection and recombination, which provide new insights into both inter- and intraspecies recombination events among swine enteric coronaviruses, and extend our understanding of the relationship between coronavirus coinfection and recombination.

Changes in Spectrum of Respiratory Pathogen Infections and Disease Severity Among Children in Hohhot, China: Impact of COVID-19 Prevention Measures

BACKGROUND This retrospective study evaluated the effects of specific COVID-19 preventive measures, including the use of medical masks, nucleic acid testing, and patient isolation, on respiratory infections, disease severity, and seasonal patterns among children in Hohhot, located in northern China. Understanding these alterations is pivotal in developing effective strategies to handle pediatric respiratory infections within the context of continuous public health initiatives. MATERIAL AND METHODS At the First Hospital of Hohhot, throat swabs were collected from 605 children with community-acquired respiratory between January 2022 and March 2023 for pathogen infection spectrum detection using microarray testing. RESULTS Among the patients, 56.03% were male, and their average age was 3.45 years. SARS-CoV-2 infections were highest between October 2022 and January 2023. Influenza A peaked in March 2023, and other pathogens such as respiratory syncytial virus and influenza B virus disappeared after December 2022. The proportion of mixed infections was 41.94% among SARS-CoV-2 patients, while other pathogens had mixed infection rates exceeding 57.14%. Before December 2022, the mean WBC count for Streptococcus pneumoniae and Haemophilus influenzae was 8.83×10⁹/L, CRP was 18.36 mg/L, and PCT was 1.11 ng/ml. After December 2022, these values decreased significantly. Coughing, difficulty breathing, running nose, and lower respiratory tract infection diagnoses decreased in December 2022, except for SARS-CoV-2 infections. CONCLUSIONS SARS-CoV-2 peaked around November 2022, influenza A peaked in March 2023, and other pathogens like respiratory syncytial virus and influenza B virus were greatly reduced after December 2022. Inflammatory markers and respiratory symptoms decreased after December 2022, except for SARS-CoV-2.

Epidemiology of fungal infection in COVID 19 in Spain during 2020 and 2021: a nationwide study

We realize a nationwide population-based retrospective study to analyze the characteristics and risk factors of fungal co-infections in COVID-19 hospitalized patients as well as describe their causative agents in the Spanish population in 2020 and 2021. Data were obtained from records in the Minimum Basic Data Set of the National Surveillance System for Hospital Data in Spain, provided by the Ministry of Health, and annually published with two years lag. The assessment of the risk associated with the development of healthcare-associated fungal co-infections was assessed using an adjusted logistic regression model. The incidence of fungal co-infection in COVID-19 hospitalized patients was 1.41%. The main risk factors associated were surgery, sepsis, age, male gender, obesity, and COPD. Co-infection was associated with worse outcomes including higher in-hospital and in ICU mortality, and higher length of stay. Candida spp. and Aspergillus spp. were the microorganisms more frequent. This is the first study analyzing fungal coinfection at a national level in hospitalized patients with COVID-19 in Spanish population and one of the few studies available that demonstrate that surgery was an independent risk factor of Aspergillosis coinfection in COVID-19 patients.

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

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.

More attention should be paid to Omicron-associated sepsis: a multicenter retrospective study in south China

Background

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly transmissible but causes less severe disease compared to other variants. However, its association with sepsis incidence and outcomes is unclear. This study aimed to investigate the incidence of Omicron-associated sepsis, as per the Sepsis 3.0 definition, in hospitalized patients, and to explore its relationship with clinical characteristics and prognosis.

Methods

This multicenter retrospective study included adults hospitalized with confirmed SARS-CoV-2 infection across six tertiary hospitals in Guangzhou, China from November 2022 to January 2023. The Sequential Organ Failure Assessment (SOFA) score and its components were calculated at hospital admission to identify sepsis. Outcomes assessed were need for intensive care unit (ICU) transfer and mortality. Receiver operating characteristic curves evaluated the predictive value of sepsis versus other biomarkers for outcomes.

Results

A total of 299 patients (mean age: 70.1±14.4 years, 42.14% female) with SOFA score were enrolled. Among them, 152 were categorized as non-serious cases while the others were assigned as the serious group. The proportion of male patients, unvaccinated patients, patients with comorbidity such as diabetes, chronic cardiovascular disease, and chronic lung disease was significantly higher in the serious than non-serious group. The median SOFA score of all enrolled patients was 1 (interquartile range, 0-18). In our study, 147 patients (64.19%) were identified as having sepsis upon hospital admission, with the majority of these septic patients (113, representing 76.87%) being in the serious group, the respiratory, coagulation, cardiovascular, central nervous, and renal organ SOFA scores were all significantly higher in the serious compared to the non-serious group. Among septic patients, 20 out of 49 (40.81%) had septic shock as indicated by lactate measurement within 24 hours of admission, and the majority of septic patients were in the serious group (17/20, 76.87%). Sepsis was present in 118 out of 269 (43.9%) patients in the general ward, and among those with sepsis, 34 out of 118 (28.8%) later required ICU care during hospitalization. By contrast, none of the patients without sepsis required ICU care. Moreover, the mortality rate was significantly higher in patients with than without sepsis.

Conclusions

A considerable proportion of patients infected with Omicron present with sepsis upon hospital admission, which is associated with a poorer prognosis. Therefore, early recognition of viral sepsis by evaluation of the SOFA score in hospitalized coronavirus disease 2019 patients is crucial.

Recurring SARS-CoV-2 variants: an update on post-pandemic, co-infections and immune response

The post-pandemic era following the global spread of the SARS-CoV-2 virus has brought about persistent concerns regarding recurring coinfections. While significant strides in genome mapping, diagnostics, and vaccine development have controlled the pandemic and reduced fatalities, ongoing virus mutations necessitate a deeper exploration of the interplay between SARS-CoV-2 mutations and the host's immune response. Various vaccines, including RNA-based ones like Pfizer and Moderna, viral vector vaccines like Johnson & Johnson and AstraZeneca, and protein subunit vaccines like Novavax, have played critical roles in mitigating the impact of COVID-19. Understanding their strengths and limitations is crucial for tailoring future vaccines to specific variants and individual needs. The intricate relationship between SARS-CoV-2 mutations and the immune response remains a focus of intense research, providing insights into personalized treatment strategies and long-term effects like long-COVID. This article offers an overview of the post-pandemic landscape, highlighting emerging variants, summarizing vaccine platforms, and delving into immunological responses and the phenomenon of long-COVID. By presenting clinical findings, it aims to contribute to the ongoing understanding of COVID-19's progression in the aftermath of the pandemic.

Serotype Distribution and Antimicrobial Susceptibility Pattern of Streptococcus pneumoniae in COVID-19 Pandemic Era in Brazil

Despite the introduction of the pneumococcal vaccine, Streptococcus pneumoniae remains a cause of invasive diseases in Brazil. This study provides the distribution of serotypes and antimicrobial susceptibility patterns for pneumococcal isolates before and during the years of the COVID-19 pandemic in two age groups, <5 and ≥50 years. This is a national laboratory-based surveillance study that uses data from the Brazilian national laboratory for invasive S. pneumoniae from the pre-COVID-19 (January 2016 to January 2020) and COVID-19 (February 2020 to May 2022) periods. Antimicrobial resistance was evaluated by disk diffusion and minimum inhibitory concentration. The year 2020 was marked by a 44.6% reduction in isolates received and was followed by an upward trend from 2021 onwards, which became evident in 2022. No differences were observed in serotypes distribution between the studied periods. The COVID-19 period was marked by the high prevalence of serotypes 19A, 3, and 6C in both age groups. Serotypes 19A and 6C were related to non-antimicrobial susceptibility. We observed a reduction in S. pneumoniae, without changes in serotypes distribution and epidemiological capsular switch during the COVID-19 period. We observed elevated resistance rates, mainly to penicillin and ceftriaxone for non-meningitis cases in children under 5 years of age.

Description of Cryptococcosis Following SARS-CoV-2 Infection: A Disease Survey Through the Mycosis Study Group Education and Research Consortium (MSG-19)

BACKGROUND

Invasive fungal infections have been described throughout the COVID-19 pandemic. Cryptococcal disease after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported in several isolated case reports and 1 larger case series. We sought to describe cryptococcal infections following SARS-CoV-2 through establishing a database to investigate underlying risk factors, disease manifestations, and outcomes.

METHODS

We created a crowdsourced call for cases solicited through the Mycoses Study Group Education and Research Consortium, the Centers for Disease Control and Prevention Emerging Infectious Diseases Network, and infectious diseases Twitter groups. Data were collected in a web-based and secure REDCap survey without personal identifiers.

RESULTS

Sixty-nine cases were identified and submitted by 29 separate institutional sites. Cryptococcosis was diagnosed a median of 22 days (interquartile range, 9-42 days) after SARS-CoV-2 infection. Mortality among those with available follow-up was 72% (26/36) for the immunocompetent group and 48% (15/31) for the immunocompromised group (likelihood ratio, 4.01; P = .045). We observed a correlation between disease manifestation (central nervous system infection, proven/probable disseminated disease, and respiratory) and mortality (P = .002).

CONCLUSIONS

The mortality rate of 59% for patients with cryptococcosis following SARS-CoV-2 is higher than that of modern Cryptococcus cohorts. There was an association between immunocompromised status and cryptococcal disease manifestations as well as mortality. Moreover, our series emphasizes the need for clinical and laboratory assessment of opportunistic infections beyond 30 days when concerning symptoms develop.

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).

Acute neutrophilic vasculitis (leukocytoclasia) in 36 COVID-19 autopsy brains

BACKGROUND

Hypercytokinemia, the renin-angiotensin system, hypoxia, immune dysregulation, and vasculopathy with evidence of immune-related damage are implicated in brain morbidity in COVID-19 along with a wide variety of genomic and environmental influences. There is relatively little evidence of direct SARS-CoV-2 brain infection in COVID-19 patients.

METHODS

Brain histopathology of 36 consecutive autopsies of patients who were RT-PCR positive for SARS-CoV-2 was studied along with findings from contemporary and pre-pandemic historical control groups. Immunostaining for serum and blood cell proteins and for complement components was employed. Microcirculatory wall complement deposition in the COVID-19 cohort was compared to historical control cases. Comparisons also included other relevant clinicopathological and microcirculatory findings in the COVID-19 cohort and control groups.

RESULTS

The COVID-19 cohort and both the contemporary and historical control groups had the same rate of hypertension, diabetes mellitus, and obesity. The COVID-19 cohort had varying amounts of acute neutrophilic vasculitis with leukocytoclasia in the microcirculation of the brain in all cases. Prominent vascular neutrophilic transmural migration was found in several cases and 25 cases had acute perivasculitis. Paravascular microhemorrhages and petechial hemorrhages (small brain parenchymal hemorrhages) had a slight tendency to be more numerous in cohort cases that displayed less acute neutrophilic vasculitis. Tissue burden of acute neutrophilic vasculitis with leukocytoclasia was the same in control cases as a group, while it was significantly higher in COVID-19 cases. Both the tissue burden of acute neutrophilic vasculitis and the activation of complement components, including membrane attack complex, were significantly higher in microcirculatory channels in COVID-19 cohort brains than in historical controls.

CONCLUSIONS

Acute neutrophilic vasculitis with leukocytoclasia, acute perivasculitis, and associated paravascular blood extravasation into brain parenchyma constitute the first phase of an immune-related, acute small-vessel inflammatory condition often termed type 3 hypersensitivity vasculitis or leukocytoclastic vasculitis. There is a higher tissue burden of acute neutrophilic vasculitis and an increased level of activated complement components in microcirculatory walls in COVID-19 cases than in pre-pandemic control cases. These findings are consistent with a more extensive small-vessel immune-related vasculitis in COVID-19 cases than in control cases. The pathway(s) and mechanism for these findings are speculative.

Hfe Permease and Haemophilus influenzae Manganese Homeostasis

Haemophilus influenzae is a commensal of the human upper respiratory tract that can infect diverse host niches due, at least in part, to its ability to withstand both endogenous and host-mediated oxidative stresses. Here, we show that hfeA, a gene previously linked to iron import, is essential for H. influenzae manganese recruitment via the HfeBCD transporter. Structural analyses show that metal binding in HfeA uses a unique mechanism that involves substantial rotation of the C-terminal lobe of the protein. Disruption of hfeA reduced H. influenzae manganese acquisition and was associated with decreased growth under aerobic conditions, impaired manganese-superoxide dismutase activity, reduced survival in macrophages, and changes in biofilm production in the presence of superoxide. Collectively, this work shows that HfeA contributes to H. influenzae manganese acquisition and virulence attributes. High conservation of the hfeABCD permease in Haemophilus species suggests that it may serve similar roles in other pathogenic Pasteurellaceae.