Upper respiratory viruses associated with racial, ethnic disparities in ED asthma visits

Respiratory viruses contributed to the excess burden of asthma-related visits to the ED for children in racial and ethnic minority groups outside of the COVID-19 lockdown, according to study results.

Based on these findings, these children may be more vulnerable to upper respiratory viral infections, Darlene Bhavnani, PhD, MPH, assistant professor in the department of population health, Dell Medical School, University of Texas at Austin, and colleagues wrote in Journal of Allergy and Clinical Immunology.

To better understand how respiratory viruses contribute to racial and ethnic disparities in ED visit rates, researchers examined data from electronic medical records at Dell Children’s Medical Center in Travis County, Texas, estimating incidence rate ratios (IRRs) for ED visits by year and by season from 2019 to 2021.

The researchers classified patient race and ethnicity into three groups: Latinx, excluding Black; Black, excluding Latinx; and white.

In 2019, white children had an annual incidence rate for asthma-related ED visits of 59.1 (95% CI, 52.9-65.8). Rates were 1.6 times higher for Latinx children at 96.2 (95% CI, 89.9-103) and approximately five times higher for Black children at 312 (95% CI, 287-338).

Compared with white children, the IRRs for spring 2019 included 6.67 (95% CI, 4.92-9.05) for Black children and 2.1 (95% CI, 1.57-2.8) for Latinx children. In spring 2020, when schools and other public facilities had closed in response to the COVID-19 pandemic, the IRRs fell 74% to 1.73 (95% CI, 0.9-3.32) for Black children and 68% to 0.68 (95% CI, 0.38-1.23) for Latinx children.

Also, the incidence rate among Black, Latinx and white children together in spring 2020 was 15% of the incidence rate of spring 2019.

This reduction persisted when researchers only looked at ED visits that resulted in patient observation or hospitalization (n = 280). Specifically, spring IRRs for hospitalization for Black compared with white children with asthma included 4.7 (95% CI, 1.82-12.1) in 2019, dropping to 1.54 (95% CI, 0.22-10.9) in 2020 and rebounding to 5.63 (95% CI, 2.39-13.2) in 2021.

By summer 2020, IRRs compared with white children increased to 8.44 (95% CI, 4.23-16.9) for Black children and 1.43 (95% CI, 0.7-2.95) for Latinx children.

Through fall 2020 and summer 2021, IRRs fell to levels consistent with those seen in 2019. The researchers attributed these changes to the phased reopening of commercial and recreational facilities in Texas between May 1 and June 3 and the return of in-person instruction in public schools in September 2020.

Noting that rhinovirus infections are the most common asthma exacerbation triggers among children, the researchers found that rhinovirus test positivity rates fell from 29.8% (95% CI, 25.7-34.3) in spring 2019 to 6.45% (95% CI, 3.71-10.8) in spring 2020. Similarly, influenza test positivity rates fell from 3.07% (95% CI, 1.76-5.22) to 0% (95% CI, 0-2.17), whereas respiratory syncytial virus test positivity rates remained level from 1.1% (95% CI, 0.4-2.69) to 1.38% (95% CI, 0.36-4.31).

In fall 2020, the test positivity rates of all three viruses returned to levels consistent with those that were seen in fall 2019.

Based on these findings, the researchers wrote that respiratory viruses may contribute substantially to the excess burden of ED visits related to asthma experienced by Black and Latinx children during non-pandemic periods. Previous studies have indicated that Black and Latinx children may be more exposed to, be more susceptible to or have more severe upper respiratory infections than white children, the researchers noted.

Overcrowding in home and at school may increase exposure to these viruses compared with white children, the researchers continued, whereas psychosocial stress, indoor allergens and air pollution may be factors in these higher rates as well.

The researchers called for additional studies to examine whether upper respiratory viral infections underlie these disparities between Black, Latinx and white children, adding that the insights gained during the pandemic could inform this research.