Indigenous ethnicity raises odds for antibiotic response in pediatric bronchiectasis

Key takeaways:

• Indigenous ethnicity and new abnormal auscultatory signs raised the odds for symptom resolution after antibiotic treatment.
• Resolution was less likely with high cough scores or multiple bronchiectatic lobes.

The odds for symptom resolution after a 14-day antibiotic treatment for nonsevere exacerbation of bronchiectasis increased among Indigenous children and children with low cough scores, according to results published in CHEST.

“This is important clinically because identifying exacerbations that are more likely to respond to oral antibiotics may help to prevent these becoming more severe and leading to hospitalization,” Vikas Goyal, PhD, respiratory and sleep physician at the Queensland Children’s Hospital, and colleagues wrote. “Furthermore, understanding the factors associated with the failure of oral antibiotics can stimulate introducing different strategies for treating exacerbations and addressing modifiable risk factors.”

In this study, Goyal and colleagues assessed 217 children (median age at exacerbation, 6.6 years; 52% boys; 41% Indigenous) with bronchiectasis given a 14-day oral antibiotics course for nonsevere exacerbations to determine if there is a link between certain phenotypic features and symptom resolution in this patient population.

Researchers reported use of two different oral antibiotics: amoxicillin-clavulanate (n = 115) and azithromycin (n = 102).

More than half of the children (n = 130; 60%) achieved symptom resolution/responded to the treatment by day 14, whereas the rest of the cohort (n = 87; 40%) still had symptoms/did not respond to the treatment.

Researchers observed significantly higher odds of responding to the oral antibiotic treatment among Indigenous (Australian First Nations, New Zealand Māori or Pacific Islander) children vs. non-Indigenous children (adjusted OR = 3.59; 95% CI, 1.35-9.54) in the adjusted multivariable logistic regression model.

This analysis also showed increased odds for treatment response when children had new abnormal auscultatory findings (aOR = 3.85; 95% CI, 1.56-9.52).

In contrast, the odds for response to the 14-day oral antibiotics course significantly declined when children had multiple bronchiectatic lobes at diagnosis (aOR = 0.66; 95% CI, 0.46-0.95) or high cough scores at the beginning of treatment (aOR = 0.55; 95% CI, 0.34-0.9), according to researchers.

Notably, researchers did not find a significant link between antibiotic failure and the presence of a respiratory virus or a respiratory bacterial pathogen prior to exacerbation treatment.

When dividing the total cohort according to Indigenous vs. non-Indigenous ethnicity, children with Indigenous ethnicity faced significantly higher odds for respiratory bacterial pathogens (OR = 3.75; 95% CI, 1.72-8.19) but did not differ from non-Indigenous children in terms of the number of bronchiectatic lobes and cough score.

During mediation analysis, researchers reported that the relationship between respiratory bacterial pathogens and antibiotic response was mediated by Indigenous ethnicity, as was the relationship between new abnormal auscultatory findings and antibiotic response (direct and indirect effects).

This effect was not found when researchers evaluated the number of bronchiectatic lobes and cough score.

“Although benefits are associated with treating exacerbations early to avoid treatment failure and subsequent IV antibiotics, future research also needs to identify exacerbations that can be managed without antibiotics,” Goyal and colleagues wrote. “Phenotypic features and developing objective biomarkers that can be undertaken feasibly in children (eg, in blood, urine or saliva) could help to fulfil this role.”