People with asthma are at less risk of COVID-19, but why?

People with asthma are not at increased risk for acquiring COVID-19 compared to those without asthma and have similar clinical outcomes, a review concludes.

The systematic review of 57 studies by the George Institute for Global Health and funded by Asthma Australia found that people with asthma had a 14 percent lower risk of acquiring COVID-19, an absolute reduction of 50 cases per 1,000 people.

People with asthma were also significantly less likely to be hospitalised with the virus and there was no apparent difference in the risk of death from COVID-19 in people with asthma compared to those without.

According to the authors the findings could be explained by lower interferon levels in asthma which are hypothesised to be protective against cytokine storm, differences in behaviours around shielding and the beneficial treatment effects of corticosteroids.

Trial sheds light on how azithromycin reduces asthma exacerbations

Azithromycin’s ability to suppress dysregulated TNF signalling could explain why it helps reduce exacerbations in people with poorly controlled asthma, researchers say.

In a sub-analysis of the AMAZES trial the research team found that neutrophilic asthma was associated with significantly increased levels of sputum TNFR1 and TNFR2, with sputum marker levels positively correlated with sputum neutrophils.

Increased levels of TNF receptors, sputum TNFR2 in particular, were increased in severe asthma and correlated with poorer lung function, worse asthma control and increasing age.

Treatment with low-dose azithromycin reduced sputum and serum TNFR2 and sputum TNF, an effect that was most marked in participants with non-eosinophilic airway inflammation.

“Our study demonstrates dysregulation of key TNF pathway components in clinically important phenotypes of asthma, namely neutrophilic and severe asthma, and demonstrates an anti-inflammatory effect of azithromycin involving modulation of the TNF pathway,” they concluded in their paper published in European Journal of Allergy and Clinical Immunology.

Huge spike in RSV in kids sends a public health message 

An unprecedented resurgence of respiratory syncytial virus (RSV) in kids in Western Australian signals an important public health message for both the southern and northern hemispheres, infectious disease specialists say.

Latest figures show that with the relaxing of physical distancing measures, RSV case numbers in the state markedly increased, way exceeding the median seasonal peak seen in previous years.

The authors observed a change in the age of children contracting the virus, with the median patient age at 18.4 months, significantly higher than the range of 7.3 to 12.5 months seen prior to the pandemic.

According to the researchers the data demonstrate the fragility of RSV control and the critical impact of physical distancing and respiratory hygiene practices.

Their findings also raised concerns for RSV control in the Northern Hemisphere, who experienced a shortened season last winter.

Bushfires had an acute impact on people with asthma: survey

During last summer’s bushfires a staggering proportion of people with asthma reported having respiratory symptoms requiring medical attention, despite making a concerted effort to minimise their smoke exposure.

The survey completed by over 12,000 people found that 94 percent of respondents with asthma had respiratory symptoms compared to 70% of those without asthma.

People with asthma were significantly more likely to report seeking medical assistance compared to those without asthma (23.3% vs 13.3%) and were more likely to attend emergency (5.9% vs 1.4%), require hospitalisation (2.4% vs 0.6%) and require corticosteroids (16.3% vs 2.4%).