Odds for respiratory infections, wheeze reduced in children born during COVID-19 pandemic

Key takeaways:

• Children born during vs. before the pandemic faced lower odds for respiratory outcomes.
• Smaller/identical proportions of these children had been prescribed antibiotics vs. children born before the pandemic.

The likelihood for upper respiratory tract infections and wheeze in children was impacted by when the child was born in relation to the COVID-19 pandemic, according to findings published in The Journal of Allergy and Clinical Immunology.

Fanny Kelderer

“Respiratory infections and wheeze have a significant impact on the quality of life for affected children and their families, increase the use of health resources, irrespective of the cause, and result in a high economic and social cost, especially recurrent episodes,” Fanny Kelderer, MD, PhD student at Umeå University, told Healio. “Our results suggest that improved strategies for reducing respiratory tract infections during infancy may prevent early wheeze and respiratory infections and possibly reduce the risk of developing asthma.”

Using the Swedish NorthPop Birth Cohort Study, Kelderer and colleagues evaluated 1,661 children (48.5% female) born during the COVID-19 pandemic (March 2020 to April 2021) to determine if the prevalence and confounding factor-adjusted odds for respiratory morbidity in the first 18 months of life differ between these children and 1,676 children (47.9% female) born before the pandemic (May 2016 to August 2018).

Among those born during the COVID-19 pandemic, 7% had been diagnosed with acute upper respiratory tract infection in the first 18 months, whereas this proportion was significantly higher among those born before the pandemic at 18.3% (P < .001), according to the study.

This pattern continued to be found when researchers looked at the prevalence of croup diagnoses (during pandemic, 1.3% vs. before pandemic, 3.5%; P < .001) and bronchitis diagnoses (during, 0.9% vs. before, 1.8%; P = .026).

Switching to antibiotic prescriptions in the first 18 months, researchers observed that a smaller or identical proportion of children born during the pandemic had been prescribed each of the six assessed antibiotics — penicillin V, amoxicillin, amoxicillin/clavulanic acid, flucloxacillin, clindamycin and erythromycin — vs. children born before the pandemic, with three achieving significance. These three included penicillin V (during, 11.3 vs. before, 14.1%; P = .012), amoxicillin (1.9% vs. 3.4%; P = .006) and flucloxacillin (during, 0.9% vs. 1.8%; P = .026).

“Although Sweden took a different approach to the COVID-19 pandemic compared to many other countries by avoiding a full lockdown and keeping preschools open, we observed a clear difference among the COVID-19-exposed children,” Kelderer told Healio. “Children born and brought up during the COVID-19 pandemic showed a significantly decreased prevalence of respiratory tract infections, as well as fewer prescriptions of antibiotics compared to children born before the COVID-19 pandemic.”

Between the two sets of children, those born during the COVID-19 pandemic had significantly lower odds for acute upper respiratory tract infection development (adjusted OR = 0.33; 95% CI, 0.26-0.42), according to the study.

Researchers also found significantly reduced odds among those born during vs. before the COVID-19 pandemic when assessing bronchitis development (aOR = 0.5; 95% CI, 0.27-0.95) and croup development (aOR = 0.59; 95% CI, 0.37-0.94).

Using data from questionnaires taken by parents when their child was aged 9 months and 18 months, the study further highlighted that children born during vs. before the pandemic faced a reduced likelihood for wheeze in the first 9 months (aOR = 0.7; 95% CI, 0.55-0.89).

Additionally, researchers had serum IgE levels to aeroallergens for 1,702 children at age 18 months and found that children born during the COVID-19 pandemic had a comparable prevalence of aeroallergen sensitization when placed against children born before the pandemic.

“The effects of implemented infection prevention measures during the COVID-19 pandemic on allergic diseases may be twofold,” Kelderer told Healio. “While it could have a mitigating effect on asthma development by the observed reduction in respiratory infections and less antibiotic prescriptions, the pandemic control measures may have increased the risk of other allergic diseases, such as eczema and food allergies, where early exposure to microbes is suggested to provide protection.”

Kelderer said this topic will need to be evaluated in future studies, and the NorthPop Birth Cohort will continue to follow these children.

“In this study, we report wheeze and concomitant medication because asthma is inherently difficult to diagnose in young children, mainly because objective testing is not feasible,” Kelderer told Healio. “Whether the reduction in respiratory infections and prescribed antibiotics in children born during the COVID-19 pandemic will impact asthma risk is being followed in the NorthPop Birth Cohort, as the participating children grow older, and follow-up is ongoing.”

For more information:

Fanny Kelderer, MD, can be reached at fanny.kelderer@umu.se.