Childhood pneumonia linked with higher death risk from respiratory infection as adult: Lancet study

London: Respiratory infections contracted during early childhood are associated with an increased risk in death from respiratory illness between the ages of 26 and 73 years, according to a study published in The Lancet journal.

The study suggests that, although the overall number of premature deaths from respiratory disease was small, people who had a lower respiratory tract infection (LRTI), such as bronchitis or pneumonia, by the age of two were 93 per cent more likely to die prematurely from respiratory disease as adults, regardless of socioeconomic background or smoking status.

Chronic respiratory diseases pose a major public health problem, with an estimated 3.9 million deaths in 2017, accounting for 7 per cent of all deaths worldwide, the researchers said.

Chronic obstructive pulmonary disease (COPD) caused most of these deaths, they said.

Infant LRTIs have been shown to be linked to the development of adult lung function impairments, asthma, and COPD, but it was previously unclear if there exists a link to premature death in adulthood.

The latest research is the first lifetime-spanning study on this topic, providing the best evidence yet to suggest that early respiratory health has an impact on mortality later in life.

”Current preventative measures for adult respiratory disease mainly focus on adult lifestyle risk factors such as smoking,” said James Allinson, from Imperial College London, UK and lead author of the study.

”Linking one in five of adult respiratory deaths to common infections many decades earlier in childhood shows the need to target risk well before adulthood,” Allinson said.

The study used data from a nationwide British cohort (The National Survey of Health and Development), which recruited individuals at birth in 1946, and looked at health and death records up to the year 2019.

Of the 3,589 study participants, 25 per cent had a LRTI before the age of two. By the end of 2019, 19 per cent of participants had died before the age of 73 years.

Among these 674 premature adult deaths, 8 per cent participants died from respiratory disease, mostly COPD.

Analysis adjusting for socioeconomic background during childhood and smoking status, suggests children who had a LRTI by the age of two were 93 per cent more likely to die prematurely as adults from respiratory disease, than children who had not had a LRTI by age two.

This equates to a 2.1 per cent rate of premature adult death from respiratory disease among those who had a LRTI in early childhood, compared to 1.1 per cent among those who did not report a LRTI before the age of two, the researchers said.

Having a lower respiratory infection before the age of two was only associated with an increased risk of premature death from respiratory diseases, and not other illnesses, such as heart disease or cancers, they said.

”The results of our study suggest that efforts to reduce childhood respiratory infections could have an impact on tackling premature mortality from respiratory disease later in life. We hope that this study will help guide the strategies of international health organisations in tackling this issue,” said Professor Rebecca Hardy, from Loughborough University and University College London, UK.

The authors acknowledge some limitations with the study. Although socioeconomic background and smoking were adjusted for in the analysis, there may have been other factors that were unreported, such as parental smoking and being born premature.

During this life spanning study, societal change may also have driven changes in lung function of subsequent cohorts, altering outcomes.

The study was not able to investigate which bacteria or viruses caused the LRTI in the children.