Ten percent of children in high-burden tuberculosis (TB) settings may develop the disease by the age of ten.
This is according to new study by researchers from UCT’s Department of Paediatrics and Child Health, Boston University School of Public Health (BUSPH), and the University of São Paulo which found there was a high risk of TB infection and disease in children up to ten years old who lived in areas where TB spread was common.
An estimated 1.2 million children develop TB, and 200 000 kids die from TB worldwide every year, but the risk of developing TB infection and disease throughout childhood remains under-studied. Further, the majority of studies on the paediatric burden of TB are informed by data from patients in healthcare settings, rather than people in real-world, community settings.
The study is the first birth cohort study to assess TB infection and active TB disease during children’s first decade of life in high-burden settings, the researchers said.
The results found that there was a consistently high rate of annual TB infection among children in the study group – between 4 and 9% – and that more than 10% of children developed TB disease by the time they were ten years old.
“Despite reasonable nutrition and almost no children living with HIV, there was an extraordinarily high, concerning rate of TB infection and disease in this cohort,” said co-senior author Professor Heather Zar, principal investigator of the Drakenstein Child Health Study and chair of the Department of Paediatrics and Child Health at UCT. She is also the director of SAMRC Unit on Child and Adolescent Health.
“Many children with TB disease were diagnosed when they presented with acute pneumonia, suggesting that in areas of high TB prevalence, children with pneumonia should be investigated for TB.”
For the study, the team observed and followed a birth cohort of 1 137 pregnant women and their 1 143 children enrolled in the Drakenstein Child Health Study and living near Cape Town between 2012 and 2023. They tested the children for TB infection and disease at age six months, 12 months, and then annually for those who produced negative test results, as well as whenever they developed lower respiratory tract infection.
By eight years old, the team estimated that children’s cumulative risk of developing TB infection was a substantial 36%.
New cases of TB disease were highest during the first year of life, and even though this risk decreased as children grew older, one in ten children afflicted by TB disease by age ten was an alarming finding because this population will likely have weakened immune systems that may make them susceptible to future health issues and challenges later, both in young adulthood and in older age, the researchers said.
Dr Leonardo Martinez, assistant professor of epidemiology at BUSPH and study co-senior author, said: “These results are striking and show that children in these communities in South Africa are at extraordinarily high risk.
“Perhaps 1000 to 2000 South African children are at greater risk of TB than their young counterparts in the United States. It’s clearly an urgent health problem with both short and long-term impacts on these children and their families.”
With TB drugs, TB disease is highly treatable, and the researchers found that preventative treatments were broadly effective for infected children who accessed this care – but only a small proportion of the cohort did so.
Most eligible children with TB infection did not receive preventive treatment, and the majority of those who developed TB disease had not received preventive medicine.
“If we are to reduce paediatric TB globally, a multisectoral approach is needed that brings together researchers, policymakers, healthcare workers, funders, and advocates to find comprehensive solutions,” Martinez said.
Cape Times