Researchers at the University of Sheffield, Imperial College London, and TB Alliance have found evidence that a large gap exists between the number of TB cases in children that get notified to authorities and the true underlying incidence.
The gap, detailed in a study published today in the journal Lancet Global Health, shows that TB in children is a major public health problem worldwide.
The investigators estimated the number of children with TB in the 22 countries with the highest burden of TB in the world. The study suggests that in these countries more than 650,000 children developed the disease in 2010, while 7.6 million became infected with the TB bacterium. Overall more than 53 million children were estimated to latently harbor the infection.
Diagnosing TB in children can be challenging and the disease can often be overlooked or mistaken for something else. This can lead to under-reporting, distorting the true scope of the problem and the real demand for pediatric TB treatment. The first estimates of pediatric TB by the World Health Organization (WHO) were published in 2012, and last year the WHO estimated 530,000 pediatric cases worldwide. However, given the acknowledged difficulties in detecting TB in children, there is need for additional study and focus on the burden of disease in children.
Health economics researcher Peter Dodd, from the University of Sheffield’s School of Health and Related Research (ScHARR), said: “Quantifying the burden of TB in children is important because without good numbers, there can be no targets for improvement, no monitoring of trends and there is a lack of evidence to encourage industry to invest in developing medicines or diagnostics that are more appropriate for children than those available today.”
He added: “Historically, TB in children has not received the attention that it might have done. The WHO is now encouraging countries to report the number of TB cases they find in children, but we still have only a poor idea what proportion of cases are recorded in youngsters.”
For the first time, researchers used a mechanistic mathematical model to estimate the number of cases of pediatric TB in the 22 high TB burden countries, which are reported to harbor 80% of the global burden. In addition to providing global estimates, the study also revealed additional findings. Over a quarter of all pediatric TB cases were found in India and 15 million children under the age of 15 were found to be living with somebody with TB. The 53 million children with latent TB represent a huge reservoir for future disease. .
Co-author on the study, Dr. James Seddon from the Department of Medicine, Imperial College London, said: “Although these 53 million infected children may not be currently experiencing any problems they are at a very high risk for developing the disease in the future. It is also interesting to note that only a third of children with TB disease are currently identified, treated and reported. This compares to two thirds in adults.”
The study is part of a larger effort, led by TB Alliance and supported by UNITAID and USAID, to improve TB treatment for children and deliver optimized child-friendly first-line TB drugs. This study adds to the growing body of research examining the true burden of pediatric TB.
Read the study at Lancet Global Health : What’s in a number? Accurate estimates of childhood tuberculosis.
Source: Imperial College London, adapted.