Asthma and clinical outcomes of COVID-19 in a community setting

Association between underlying health conditions and long COVID among non-hospitalized and hospitalized individuals as modified by health literacy: A multi-center study

OBJECTIVES

We investigated the effect modification of health literacy (HL) in ameliorating the negative impact of underlying health conditions (UHC) on long COVID among non-hospitalized and hospitalized survivors.

STUDY DESIGN

An online cross-sectional study was conducted in Vietnam from December 2021 to October 2022.

METHODS

A sample of 4507 participants recruited from 18 hospitals and health centers were those aged 18 or older, had contracted COVID-19 for at least 28 days, and were not in the acute phase of reinfection. Participants reported their long COVID symptoms, UHC, health literacy, socio-demographics, clinical parameters, the COVID-19 impact battery disability scale, and health-related behaviors. The logistic regression models were used to examine the associations and interactions.

RESULTS

Underlying health conditions were associated with a higher likelihood of long COVID in non-hospitalized participants (adjusted odds ratio, aOR = 2.10 [1.61, 2.61]; p < 0.001), and hospitalized ones (aOR = 2.26 [1.87, 2.73]; p < 0.001). In non-hospitalized participants, higher HL scores were significantly linked to a reduced likelihood of experiencing long COVID (aOR = 0.96 [0.95, 0.97]; p < 0.001). Furthermore, HL moderated the adverse effect of underlying health conditions (UHC) on long COVID in this group (aOR = 0.97 [0.94-0.99]; p = 0.042). In hospitalized participants, although higher HL scores were also associated with a lower risk of long COVID (aOR = 0.99 [0.98-0.99]; p = 0.036), HL did not significantly mitigate the negative impact of UHC on long COVID (aOR = 1.01 [0.99-1.03]; p = 0.332).

CONCLUSIONS

In non-hospitalized individuals, high health literacy ameliorated the negative impact of UHC on long COVID. Such effects of health literacy were not observed in hospitalized COVID-19 survivors.

The inflammatory microenvironment of the lung at the time of infection governs innate control of SARS-CoV-2 replication

Severity of COVID-19 is affected by multiple factors; however, it is not understood how the inflammatory milieu of the lung at the time of SARS-CoV-2 exposure affects the control of viral replication. Here, we demonstrate that immune events in the mouse lung closely preceding SARS-CoV-2 infection affect viral control and identify innate immune pathways that limit viral replication. Pulmonary inflammatory stimuli including resolved, antecedent respiratory infections with Staphylococcus aureus or influenza, ongoing pulmonary Mycobacterium tuberculosis infection, ovalbumin/alum-induced asthma, or airway administration of TLR ligands and recombinant cytokines all establish an antiviral state in the lung that restricts SARS-CoV-2 replication. In addition to antiviral type I interferons, TNFα and IL-1 potently precondition the lung for enhanced viral control. Our work shows that SARS-CoV-2 may benefit from an immunologically quiescent lung microenvironment and suggests that heterogeneity in pulmonary inflammation preceding SARS-CoV-2 exposure may contribute to variability in disease outcomes.

Asthma as a risk factor and allergic rhinitis as a protective factor for COVID-19 severity: a case-control study

PURPOSE

The COVID-19 pandemic has resulted in significant global morbidity and mortality. The disease presents a broad clinical spectrum, significantly influenced by underlying comorbidities. While certain conditions are known to exacerbate COVID-19 outcomes, the role of chronic inflammatory airway diseases such as asthma and rhinitis in influencing disease severity remains controversial. This study investigates the association between asthma and allergic rhinitis and the severity of COVID-19 outcomes in a specific geographical region prior to widespread vaccine deployment.

METHODS

We conducted a case-control study with unvaccinated adult patients who had laboratory-confirmed COVID-19 by polymerase chain reaction (PCR). Cases were defined as severe or critical COVID-19 patients requiring intensive care unit (ICU) admission, and controls were non-severe patients without signs of viral pneumonia or hypoxia. We utilized the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire to assess the presence of asthma and allergic rhinitis. The association between these chronic inflammatory airway diseases and the severity of COVID-19 was evaluated using multivariate logistic regression analysis.

RESULTS

A total of 122 patients were analyzed, with 61 in each group. The presence of asthma (9 patients) was associated with an increased likelihood of severe COVID-19 (OR = 13.0; 95% CI 1.27-133.74), while rhinitis (39 patients) was associated with a protective effect against severe outcomes (OR = 0.36; 95% CI 0.13-0.99). No significant association was found between the frequency of asthmatic episodes or the severity of rhinitis and the severity of COVID-19 outcomes.

CONCLUSION

This study underscores the divergent effects of chronic inflammatory airway diseases on COVID-19 severity, with asthma associated with a higher likelihood of severe outcomes and rhinitis potentially offering protective effects. These findings enhance our understanding of the complex interactions between respiratory allergies and COVID-19, emphasizing the importance of targeted clinical management and public health strategies.

The inflammatory microenvironment of the lung at the time of infection governs innate control of SARS-CoV-2 replication

SARS-CoV-2 infection leads to vastly divergent clinical outcomes ranging from asymptomatic infection to fatal disease. Co-morbidities, sex, age, host genetics and vaccine status are known to affect disease severity. Yet, how the inflammatory milieu of the lung at the time of SARS-CoV-2 exposure impacts the control of viral replication remains poorly understood. We demonstrate here that immune events in the mouse lung closely preceding SARS-CoV-2 infection significantly impact viral control and we identify key innate immune pathways required to limit viral replication. A diverse set of pulmonary inflammatory stimuli, including resolved antecedent respiratory infections with S. aureus or influenza, ongoing pulmonary M. tuberculosis infection, ovalbumin/alum-induced asthma or airway administration of defined TLR ligands and recombinant cytokines, all establish an antiviral state in the lung that restricts SARS-CoV-2 replication upon infection. In addition to antiviral type I interferons, the broadly inducible inflammatory cytokines TNFα and IL-1 precondition the lung for enhanced viral control. Collectively, our work shows that SARS-CoV-2 may benefit from an immunologically quiescent lung microenvironment and suggests that heterogeneity in pulmonary inflammation that precedes or accompanies SARS-CoV-2 exposure may be a significant factor contributing to the population-wide variability in COVID-19 disease outcomes.