Sibling-borne infections can affect infant's adult income and education level, study finds

Infants exposed to respiratory infections brought home by older siblings may face long-term consequences affecting their adult lives, according to a Danish study. The research indicates that these early-life exposures are associated with diminished outcomes in education, earnings, and overall health later in life.

“

Babies exposed to respiratory infections through their older siblings fare worse on average in adulthood in terms of education, earnings, and health.

The study highlights a common scenario in many families: a child starts daycare, and soon the entire household is dealing with illness. Babies, in particular, are identified as being highly vulnerable to viruses introduced by their siblings. N. Meltem Daysal, an associate professor of economics at the University of Copenhagen and a participant in the study, noted that infants have a two to three times greater risk of hospitalization due to respiratory infections compared to their older siblings at the same age.

This disparity is most pronounced in the first six months of life, a period when infants are biologically most susceptible. The research suggests that a respiratory infection contracted during these early months can have lasting effects. Daysal explained that when siblings are compared, early exposure to illness correlates with a reduced probability of completing both secondary and higher education. Furthermore, it can manifest as lower earnings in adulthood.

“

the younger sibling has two or three times higher risk of being hospitalized due to a respiratory infection as an infant than the older sibling had at the same age.

Researchers tracked over 1.2 million Danish children from birth into adulthood. By comparing siblings born in different orders and utilizing data on the prevalence of respiratory infections among young children, they aimed to isolate the impact of infant illness from other factors like family background. The findings suggest that preventing infant illnesses through measures such as vaccination and good hygiene could have far-reaching benefits.

“

early exposure to illness is associated with a lower probability of completing both a secondary school degree and a university degree. In addition, it can also be reflected in lower earnings later in life.