COVID-19 Autopsies Reveal Underreporting of SARS-CoV-2 Infection and Scarcity of Co-infections

[Clinical courses and costs for hospitalizations of potentially immunocompromised COVID-19 patients in Germany]

BACKGROUND

 Patients at increased risk of inadequate immune response to COVID-19 vaccinations due to their underlying disease or therapy are potentially vulnerable to severe COVID-19 courses. The aim is to assess the population size, clinical courses and hospitalization costs of these patients in Germany.

METHODS

 This retrospective cohort study is based on extrapolations of a representative sample of statutory health insurance (SHI) claims data from 2020. Clinical COVID-19 courses, hospitalization costs and durations are compared between the insured group at increased risk for inadequate immune response to COVID-19 vaccinations (risk group) and the insured group without this risk.

RESULTS

 There are approximately 1.82 million SHI-insured individuals in the risk group, of whom an estimated 240 000 insured individuals do not develop a humoral immune response after 3 COVID-19 vaccinations. The risk group shows higher proportions with COVID-19 (relative risk [RR] 1.21; 95 % confidence interval [95 % CI] 1.20-1.23), hospitalizations for COVID-19 (RR 3.40; 95 % CI 3.33-3.48), hospitalizations for COVID-19 with intensive care treatment (RR 1.36; 95 % CI 1.30-1.42), and mortality (RR 5.14; 95 % CI 4.97-5.33) compared with the group without risk. In addition, hospitalizations in the risk group are on average 18 % longer (15.36 days vs. 13.00 days) and 19 % more expensive (12 371 € vs. 10 410 €). Expected hospitalization costs in the risk group are four times greater than in the group without risk (4115 € vs. 1017 €).

CONCLUSIONS

 The risk group is vulnerable to COVID-19 and requires additional resources in the German hospital sector. This results in a need for further protective measures. Further studies are needed to evaluate the impact of different viral variants, active and passive immunizations, and therapies on clinical COVID-19 courses and their costs.

Minimally invasive autopsies for the investigation of pulmonary pathology of COVID-19-experiences of a longitudinal series of 92 patients

Minimally invasive autopsies (MIAs) allow the collection of tissue samples for diagnostic and research purposes in special situations, e.g., when there is a high risk of infection which is the case in the context of COVID-19 or restrictions due to legal or personal reasons. We performed MIA to analyze lung tissue from 92 COVID-19 patients (mean age 78 years; range 48-98; 35 women, 57 men), representing 44% of all patients who died from the disease between October 2020 and April 2021. An intercostal approach was used with removal of a 5-cm rib section followed by manual collection of four lung tissue samples (5-8 cm in size). Diffuse alveolar damage (DAD) was found in 89 (97%) patients at various stages. Exudative DAD (eDAD) predominated in 18 (20%) patients, proliferative DAD (pDAD) in 43 (47%) patients, and mixed DAD (mDAD) in 31 (34%) patients. There were no significant differences in the predominant DAD pattern between tissue samples from the same patient. Additional purulent components were present in 46 (50%) cases. Fungi were detected in 11 (12%) patients. The pDAD pattern was associated with longer hospital stay including intensive care unit (p=0.026 and p<0.001) and younger age (p=0.019). Positive bronchoalveolar lavage and blood cultures were observed more frequently in pDAD patterns (p<0.001; p=0.018). In contrast, there was no significant association between intravital positive microbiological results and superimposed bronchopneumonia or fungal infection at autopsy. Having demonstrated the characteristic lung changes in a large longitudinal autopsy series, we conclude that the presented MIA approach can be considered a reliable and safe method for performing post mortem lung diagnostics in COVID-19 and other high-risk situations. The lack of correlation between histological changes indicative of bacterial or fungal superinfection and microbiology could have clinical implications for disease and treatment surveillance.

The use of smart environments and robots for infection prevention control: A systematic literature review

BACKGROUND

Infection prevention and control (IPC) is essential to prevent nosocomial infections. This manuscript aims at investigating the current use and role of robots and smart environments on IPC systems in nosocomial settings METHODS: The systematic literature review was performed following the PRISMA statement. Literature was searched for articles published in the period January 2016 to October 2022. Two authors determined the eligibility of the papers, with conflicting decisions being mitigated by a third. Relevant data was then extracted using an ad-hoc extraction table to facilitate the analysis and narrative synthesis.

RESULTS

The search strategy returned 1520 citations and 17 papers were included. This review identified 3 main areas of interest: hand hygiene and personal protective equipment compliance, automatic infection cluster detection and environments cleaning (ie, air quality control, sterilization). This review demonstrates that IPC practices within hospitals mostly do not rely on automation and robotic technology, and few advancements have been made in this field.

CONCLUSIONS

Increasing the awareness of healthcare workers on these technologies, through training and involving them in the design process, is essential to accomplish the Health 4.0 transformation. Research priorities should also be considering how to implement similar or more contextualized alternatives for low-income countries.

NEDD4 Regulated Pyroptosis Occurred from Co-infection between Influenza A Virus and Streptococcus pneumoniae

Co-infection of respiratory tract viruses and bacteria often result in excess mortality, especially pneumonia caused by influenza viruses and Streptococcus pneumoniae. However, the synergistic mechanisms remain poorly understood. Therefore, it is necessary to develop a clearer understanding of the molecular basis of the interaction between influenza virus and Streptococcus pneumonia. Here, we developed the BALB/c mouse model and the A549 cell model to investigate inflammation and pyroptotic cell death during co-infection. Co-infection significantly activated the NLRP3 inflammasome and induced pyroptotic cell death, correlated with excess mortality. The E3 ubiquitin ligase NEDD4 interacted with both NLRP3 and GSDMD, the executor of pyroptosis. NEDD4 negatively regulated NLRP3 while positively regulating GSDMD, thereby modulating inflammation and pyroptotic cell death. Our findings suggest that NEDD4 may play a crucial role in regulating the GSDMD-mediated pyroptosis signaling pathway. Targeting NEDD4 represents a promising approach to mitigate excess mortality during influenza pandemics by suppressing synergistic inflammation during co-infection of influenza A virus and Streptococcus pneumoniae.

Excess mortality in 22 European countries in 2020 and 2021: relationship with socioeconomic indicators

AIMS

For better understanding of the impact of COVID-19 pandemic on mortality in different countries, we studied the excess mortality from any cause during 2020 and 2021 in 22 European countries, and its relationship with three socioeconomic variables: life expectancy at birth in 2019, per capita income, and low education level.

METHODS

Using an ecological design, we analyzed excess mortality data between January 2020 and December 2021 in 22 European countries, obtained from the EuroMOMO surveillance system. Using weekly Z-score data for each country, we estimated the annual average deviation in mortality during 2020 and 2021 for each country. We analyzed possible relationships between the excess mortality and three independent variables: gross domestic product per capita (GDPpc) in 2020, life expectancy at birth in 2019, and proportion of the population over age 18 years with a lower than secondary education level in 2018.

RESULTS

In the 22 European countries analyzed, the total number of excess deaths in 2020 and 2021 was 800,011 (11%) more than expected, with deaths among those aged 65 years and over accounting for 87.66% of these. Excess mortality was higher in 2020, especially in Spain, UK, Italy, and France. In 2021, excess mortality was highest in Hungary, the Netherlands, France, and Germany. Excess mortality during 2021 was inversely correlated with life expectancy (r =-.489, p = .021) and income level (r =-.550, p = .008).

CONCLUSION

Reducing socioeconomic inequalities among countries not only improves conditions of most disadvantages but also will help to reduce excess of mortality from future pandemics.

Pharmacological approaches to pulmonary fibrosis following COVID-19

Background: In the past few years, COVID-19 became the leading cause of morbidity and mortality worldwide. Although the World Health Organization has declared an end to COVID-19 as a public health emergency, it can be expected, that the emerging new cases at the top of previous ones will result in an increasing number of patients with post-COVID-19 sequelae. Despite the fact that the majority of patients recover, severe acute lung tissue injury can in susceptible individuals progress to interstitial pulmonary involvement. Our goal is to provide an overview of various aspects associated with the Post-COVID-19 pulmonary fibrosis with a focus on its potential pharmacological treatment options. Areas covered: We discuss epidemiology, underlying pathobiological mechanisms, and possible risk and predictive factors that were found to be associated with the development of fibrotic lung tissue remodelling. Several pharmacotherapeutic approaches are currently being applied and include anti-fibrotic drugs, prolonged use or pulses of systemic corticosteroids and non-steroidal anti-inflammatory and immunosuppressive drugs. In addition, several repurposed or novel compounds are being investigated. Fortunately, clinical trials focused on pharmacological treatment regimens for post-COVID-19 pulmonary fibrosis have been either designed, completed or are already in progress. However, the results are contrasting so far. High quality randomised clinical trials are urgently needed with respect to the heterogeneity of disease behaviour, patient characteristics and treatable traits. Conclusion: The Post-COVID-19 pulmonary fibrosis contributes to the burden of chronic respiratory consequences among survivors. Currently available pharmacotherapeutic approaches mostly comprise repurposed drugs with a proven efficacy and safety profile, namely, corticosteroids, immunosuppressants and antifibrotics. The role of nintedanib and pirfenidone is promising in this area. However, we still need to verify conditions under which the potential to prevent, slow or stop progression of lung damage will be fulfilled.

A Systematic Review of Lung Autopsy Findings in Elderly Patients after SARS-CoV-2 Infection

Although COVID-19 may cause various and multiorgan diseases, few research studies have examined the postmortem pathological findings of SARS-CoV-2-infected individuals who died. Active autopsy results may be crucial for understanding how COVID-19 infection operates and preventing severe effects. In contrast to younger persons, however, the patient's age, lifestyle, and concomitant comorbidities might alter the morpho-pathological aspects of the damaged lungs. Through a systematic analysis of the available literature until December 2022, we aimed to provide a thorough picture of the histopathological characteristics of the lungs in patients older than 70 years who died of COVID-19. A thorough search was conducted on three electronic databases (PubMed, Scopus, and Web of Science), including 18 studies and a total of 478 autopsies performed. It was observed that the average age of patients was 75.6 years, of which 65.4% were men. COPD was identified in an average of 16.7% of all patients. Autopsy findings indicated significantly heavier lungs, with an average weight of the right lung of 1103 g, while the left lung mass had an average weight of 848 g. Diffuse alveolar damage was a main finding in 67.2% of all autopsies, while pulmonary edema had a prevalence of between 50% and 70%. Thrombosis was also a significant finding, while some studies described focal and extensive pulmonary infarctions in 72.7% of elderly patients. Pneumonia and bronchopneumonia were observed, with a prevalence ranging from 47.6% to 89.5%. Other important findings described in less detail comprise hyaline membranes, the proliferation of pneumocytes and fibroblasts, extensive suppurative bronchopneumonic infiltrates, intra-alveolar edema, thickened alveolar septa, desquamation of pneumocytes, alveolar infiltrates, multinucleated giant cells, and intranuclear inclusion bodies. These findings should be corroborated with children's and adults' autopsies. Postmortem examination as a technique for studying the microscopic and macroscopic features of the lungs might lead to a better knowledge of COVID-19 pathogenesis, diagnosis, and treatment, hence enhancing elderly patient care.

Postmortem lung and heart examination of COVID-19 patients in a case series from Jordan

BACKGROUND

Coronavirus disease 2019 (COVID-19) has emerged as a pandemic for more than 2 years. Autopsy examination is an invaluable tool to understand the pathogenesis of emerging infections and their consequent mortalities. The aim of the current study was to present the lung and heart pathological findings of COVID-19-positive autopsies performed in Jordan.

METHODS

The study involved medicolegal cases, where the cause of death was unclear and autopsy examination was mandated by law. We included the clinical and pathologic findings of routine gross and microscopic examination of cases that were positive for COVID-19 at time of death. Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed through molecular detection by real-time polymerase chain reaction, serologic testing for IgM and electron microscope examination of lung samples.

RESULTS

Seventeen autopsies were included, with male predominance (76.5%), Jordanians (70.6%), and 50 years as the mean age at time of death. Nine out of 16 cases (56.3%) had co-morbidities, with one case lacking such data. Histologic examination of lung tissue revealed diffuse alveolar damage in 13/17 cases (76.5%), and pulmonary microthrombi in 8/17 cases (47.1%). Microscopic cardiac findings were scarcely detected. Two patients died as a direct result of acute cardiac disease with limited pulmonary findings.

CONCLUSIONS

The detection of SARS-CoV-2 in postmortem examination can be an incidental or contributory finding which highlights the value of autopsy examination to determine the exact cause of death in controversial cases.

Microbial diversity and antimicrobial susceptibility in endotracheal tube biofilms recovered from mechanically ventilated COVID-19 patients

In patients with acute respiratory failure, mechanical ventilation through an endotracheal tube (ET) may be required to correct hypoxemia and hypercarbia. However, biofilm formation on these ETs is a risk factor for infections in intubated patients, as the ET can act as a reservoir of microorganisms that can cause infections in the lungs. As severely ill COVID-19 patients often need to be intubated, a better knowledge of the composition of ET biofilms in this population is important. In Spring 2020, during the first wave of the COVID-19 pandemic in Europe, 31 ETs were obtained from COVID-19 patients at Ghent University Hospital (Ghent, Belgium). Biofilms were collected from the ET and the biofilm composition was determined using culture-dependent (MALDI-TOF mass spectrometry and biochemical tests) and culture-independent (16S and ITS1 rRNA amplicon sequencing) approaches. In addition, antimicrobial resistance was assessed for isolates collected via the culture-dependent approach using disc diffusion for 11 antimicrobials commonly used to treat lower respiratory tract infections. The most common microorganisms identified by the culture-dependent approach were those typically found during lung infections and included both presumed commensal and potentially pathogenic microorganisms like Staphylococcus epidermidis, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans. More unusual organisms, such as Paracoccus yeei, were also identified, but each only in a few patients. The culture-independent approach revealed a wide variety of microbes present in the ET biofilms and showed large variation in biofilm composition between patients. Some biofilms contained a diverse set of bacteria of which many are generally considered as non-pathogenic commensals, whereas others were dominated by a single or a few pathogens. Antimicrobial resistance was widespread in the isolates, e.g. 68% and 53% of all isolates tested were resistant against meropenem and gentamicin, respectively. Different isolates from the same species recovered from the same ET biofilm often showed differences in antibiotic susceptibility. Our data suggest that ET biofilms are a potential risk factor for secondary infections in intubated COVID-19 patients, as is the case in mechanically-ventilated non-COVID-19 patients.

Unbiased screen for pathogens in human paraffin-embedded tissue samples by whole genome sequencing and metagenomics

Identification of bacterial pathogens in formalin fixed, paraffin embedded (FFPE) tissue samples is limited to targeted and resource-intensive methods such as sequential PCR analyses. To enable unbiased screening for pathogens in FFPE tissue samples, we established a whole genome sequencing (WGS) method that combines shotgun sequencing and metagenomics for taxonomic identification of bacterial pathogens after subtraction of human genomic reads. To validate the assay, we analyzed more than 100 samples of known composition as well as FFPE lung autopsy tissues with and without histological signs of infections. Metagenomics analysis confirmed the pathogenic species that were previously identified by species-specific PCR in 62% of samples, showing that metagenomics is less sensitive than species-specific PCR. On the other hand, metagenomics analysis identified pathogens in samples, which had been tested negative for multiple common microorganisms and showed histological signs of infection. This highlights the ability of this assay to screen for unknown pathogens and detect multi-microbial infections which is not possible by histomorphology and species-specific PCR alone.