Clinical-Pathological Correlation of the Pathophysiology and Mechanism of Action of COVID-19 - a Primer for Clinicians

Pathophysiology of SARS-CoV-2 Infection of Nasal Respiratory and Olfactory Epithelia and Its Clinical Impact

PURPOSE OF REVIEW

While the predominant cause for morbidity and mortality with SARS-CoV-2 infection is the lower respiratory tract manifestations of the disease, the effects of SARS-CoV-2 infection on the sinonasal tract have also come to the forefront especially with the increased recognition of olfactory symptom. This review presents a comprehensive summary of the mechanisms of action of the SARS-CoV-2 virus, sinonasal pathophysiology of COVID-19, and the correlation with the clinical and epidemiological impact on olfactory dysfunction.

RECENT FINDINGS

ACE2 and TMPRSS2 receptors are key players in the mechanism of infection of SARS-CoV-2. They are present within both the nasal respiratory as well as olfactory epithelia. There are however differences in susceptibility between different groups of individuals, as well as between the different SARS-CoV-2 variants. The sinonasal cavity is an important route for SARS-CoV-2 infection. While the mechanism of infection of SARS-CoV-2 in nasal respiratory and olfactory epithelia is similar, there exist small but significant differences in the susceptibility of these epithelia and consequently clinical manifestations of the disease. Understanding the differences and nuances in sinonasal pathophysiology in COVID-19 would allow the clinician to predict and counsel patients suffering from COVID-19. Future research into molecular pathways and cytokine responses at different stages of infection and different variants of SARS-CoV-2 would evaluate the individual clinical phenotype, prognosis, and possibly response to vaccines and therapeutics.

Prevalence and risk factors of work-related contact dermatitis symptoms among healthcare cleaners during the COVID-19 pandemic in Northwest Ethiopia: a multicentre cross-sectional survey

OBJECTIVE

This study was aimed to explore the prevalence and risk factors of work-related contact dermatitis (WRCD) symptoms among cleaners working in healthcare institutions in Gondar city, Northwest Ethiopia, during the COVID-19 pandemic.

DESIGN

A multicentre cross-sectional study was conducted from September to October 2021. An interviewer-administered standardised Nordic Occupational Skin Questionnaire, V.2002 (NOSQ-2002) was used to assess WRCD. The collected data were entered into EpiData V.4.6 and analysed using Stata V.14 software. The association between dependent and independent variables was computed with a binary logistic regression. The association was determined using an adjusted OR (AOR) with a 95% CI at a p value of <0.05.

SETTING

The study was conducted in Gondar city healthcare institutions, Northwestern Ethiopia.

PARTICIPANTS

A total of 409 cleaners participated in this study.

OUTCOME MEASURES

The primary outcome is the prevalence of WRCD symptoms, which was measured using the NOSQ-2002.

RESULTS

The response rate was 95.6%. The majority, 302 (73.8%), of the study participants were female. The mean age (±SD) was 31 (±7.87) years old. The overall prevalence of self-reported WRCD during the last 12 months was 213 (52.1%) (95% CI (47.1% to 57.0%)). The highest symptoms reported were skin redness, 51.6% (n=110), and the most affected skin body sites were hands (hand dermatitis), 74.2% (n=158). Hand washing frequency more than 20 times per day (AOR=1.73, 95% CI (1.03 to 2.92)), personal history of eczema (AOR=1.46, 95% CI (1.01 to 2.42)) and lack of training on skin hazards (AOR=2.06, 95% CI (1.16 to 3.63)) were factors influencing the occurrence of WRCD.

CONCLUSIONS

This study revealed the prevalence of WRCD is common during the COVID-19 pandemic. Adjusting hand washing frequency per day, educating people with atopy about the avoidance of exposure to skin irritants and providing training on skin hazards were recommended to minimise the condition.

Two years of COVID-19 pandemic: Framework of health interventions in a Brazilian city

The COVID-19 pandemic and its effects on public health have urgently demanded effective health policies to avoid the spread of COVID-19. Thus, public administrators have implemented non-pharmacological and pharmacological interventions to mitigate the pandemic's impacts and strengthen health services. The aim of this ecological study is to describe the scenario of COVID-19 pandemic in a Brazilian city, during 2 years. This ecological study was carried out in Nova Friburgo, a Brazilian city, for 105 weeks (two years), from March 29, 2020 (week 1) to April 02, 2022 (week 105). Data on COVID-19 cases and COVID-19 deaths, occupation of COVID-19 exclusive beds in hospitals, community mobility, vaccination, government regulation on the opening of city establishments and city risk assessment were collected from public datasets. Four waves of COVID-19 cases and deaths were observed during this period. The first case occurred in week 1 and first death in week 3 of this study. The highest peaks of cases and deaths were observed during the third wave with 1,131 cases (week 54) and 47 deaths (week 55) and where the highest occupation of COVID-19 exclusive beds in local hospitals occurred. Interventions from more restrictive to more flexible, were implemented throughout this study, including lockdown and gradual return in economic and social strata levels. Vaccination began on week 43 and at the end of this study 89.91% of the total population was vaccinated with at least one dose, being 83.22% fully vaccinated. A deep description of several interventions used to avoid COVID-19 spread in a Brazilian city during 2 years of this pandemic can help promote better decision-making in the future while it exposes the challenges of conducting public health policies in a pandemic scenario.

Ambulation capacity, age, immunosuppression, and mechanical ventilation are risk factors of in-hospital death in severe COVID-19: a cohort study

IMPORTANCE

Despite ambulation capacity being associated with a decreased level of physical activity and survival may be influenced by the functional capacity, studies have not addressed the association between ambulation capacity and death in patients hospitalized by COVID-19.

OBJECTIVE

To verify the functional, clinical, and sociodemographic risk factors associated with in-hospital death in individuals with severe COVID-19.

METHODS

It is a cohort retrospective study performed at a large tertiary hospital. Patients 18 years of age or more, of both sexes, hospitalized due to severe COVID-19 were included. Cases with dubious medical records and/or missing essential data were excluded. Patients were classified according to their ambulation capacity before the COVID-19 infection. Information regarding sociodemographic characteristics, in-hospital death, total hospital stays, Intensive Care Unit (ICU) stays, and the necessity of Mechanical Ventilation (MV) were collected from medical records and registered in a RedCap database. Multiple logistic regression analysis was used to identify possible factors associated with the in-hospital death rate.

RESULTS

Data from 1110 participants were included in the statistical analysis. The median age of the patients was 57 (46‒66) years, 58.42% (n = 590) were male, and 61.73% (n = 602) were brown or black. The case fatality rate during hospitalization was 36.0% (n = 363). In-hospital death was associated with ambulation capacity; dependent ambulators (OR = 2.3; CI 95% = 1.2-4.4) and non-functional ambulation (OR = 1.9; CI 95% = 1.1-3.3), age [older adults (OR = 3.0; CI 95% = 1.9‒4.), ICU stays (OR = 1.4; CI 95% = 1.2‒1.4), immunosuppression (OR = 5.5 CI 95% = 2.3‒13.5) and mechanical ventilation (OR = 27.5; CI 95% = 12.0-62.9).

CONCLUSION AND RELEVANCE

Decreased ambulation capacity, age, length of ICU stay, immunosuppression, and mechanical ventilation was associated with a high risk of in-hospital death due to COVID-19.

Adoptive T-cell therapies to overcome T cell-dependent immune dysregulations in COVID-19

Coronavirus disease 2019 (COVID-19) pandemic has been an important global interest that affected millions of people, and it requires a deep investigation of the disease immunology for developing further therapeutic applications. Adoptive T cell therapy promises to address T cell-dependent immune dysregulation in COVID-19 patients by the generation of specific T cell clones against virus-specific antigens. Additionally, targeting B cell-dependent protection through COVID-19 vaccines, which have been developed in the recent year, possessed sufficient prevention for spreading the virus, since the cases and deaths related to COVID-19 tend to decrease after the vaccination. However, adoptive cell therapies are now encouraging scientists to deal with pathological challenges like inadequate T cell-dependent immune response or lymphopenia, since they are the most frequent outcome of severe infection, especially in immunocompromized patients. In this review, the current knowledge of immunopathology of COVID-19 was aimed to be highlighted along with the T cell responses against SARS-CoV-2 to comprise a basis for therapeutics. Moreover, current therapeutics and treatment strategies for COVID-19 were discussed to evaluate possible agents. Furthermore, the use of adoptive T cell therapy representing an emerging therapeutic approach was purposed to be presented comprehensively against SARS-CoV-2 infection. Even though further studies are needed to fully understand T cell response against SARS-CoV-2 in order to develop therapies to provide long term and efficient protection, adoptive cell therapies now meet the demand for a large population of people who suffer immunocompromization, considering the previous usage of the technique for different infectious diseases.

Frequency and Clinical Utility of Olfactory Dysfunction in COVID-19: a Systematic Review and Meta-analysis

Background

Olfactory dysfunction (OD) has been gaining recognition as a symptom of COVID-19, but its clinical utility has not been well defined.

Objectives

To quantify the clinical utility of identifying OD in the diagnosis of COVID-19 and determine an estimate of the frequency of OD amongst these patients.

Methods

PubMed was searched up to 1 August 2020. Meta-analysis A included studies if they compared the frequency of OD in COVID-19 positive patients (proven by reverse transcription polymerase chain reaction) to COVID-19 negative controls. Meta-analysis B included studies if they described the frequency of OD in COVID-19 positive patients and if OD symptoms were explicitly asked in questionnaires or interviews or if smell tests were performed.

Results

The pooled frequency of OD in COVID-19 positive patients (17,401 patients, 60 studies) was 0.56 (0.47–0.64) but differs between detection via smell testing (0.76 [0.51–0.91]) and survey/questionnaire report (0.53 [0.45–0.62]), although not reaching statistical significance (p = 0.089). Patients with reported OD were more likely to test positive for COVID-19 (diagnostic odds ratio 11.5 [8.01–16.5], sensitivity 0.48 (0.40 to 0.56), specificity 0.93 (0.90 to 0.96), positive likelihood ratio 6.10 (4.47–8.32) and negative likelihood ratio 0.58 (0.52–0.64)). There was significant heterogeneity amongst studies with possible publication bias.

Conclusion

Frequency of OD in COVID-19 differs greatly across studies. Nevertheless, patients with reported OD were significantly more likely to test positive for COVID-19. Patient-reported OD is a highly specific symptom of COVID-19 which should be included as part of the pre-test screening of suspect patients.