Risk for asthma at age 4 years higher after pneumonia in infancy

Children diagnosed with pneumonia in infancy have an increased risk for prevalent asthma at age 4 years, according to a study published online in the August issue of CHEST.

Samuel Rhedin, Ph.D., from the Karolinska Institutet in Stockholm, and colleagues examined the relationship between pneumonia in infancy and prevalent asthma at four years using data from a nationwide register of Swedish children. Changes in the association were evaluated before and after the introduction of nationwide pneumococcal conjugate vaccine (PCV) immunization.

The researchers observed a strong association between pneumonia diagnosis in infancy and prevalent asthma at age 4 years (adjusted odds ratio, 3.38); this association was also seen in the full sibling analyses (adjusted odds ratio, 2.81). For those born in the PCV period, the risk for asthma following pneumonia diagnosis in infancy was slightly higher compared with those born in the pre-PCV period (adjusted odds ratio, 3.80 versus 3.28). In the PCV period, the proportion of viral pneumonia etiology was also higher (14.5 versus 10.7 percent), and the overall asthma prevalence was lower (5.3 percent versus 6.6 percent).

“The findings might have implications for future pneumonia preventive measures and need to be considered when assessing the morbidity that can be attributed to pneumonia,” the authors write.