NEW FIGURES ESTIMATE that over 650,000 children develop tuberculosis every year in the 22 countries with a high burden of the disease.

That’s almost 25% higher than the total number of new cases estimated worldwide by the World Health Organisation (WHO) in 2012.

The research, published in The Lancet Global Health, also suggests that about 15 million children are exposed to TB every year, and roughly 53 million are living with latent TB infection, which can progress to infectious active TB at any time.

Lead author Dr Peter Dodd from the University of Sheffield in the UK says:

Our findings highlight an enormous opportunity for preventive antibiotic treatment among the 15 million children younger than 15 years of age who are living in the same household as an adult with infectious TB.

“Wider use of isoniazid therapy for these children as a preventative measure would probably substantially reduce the numbers of children who go on to develop the disease.”

Research 

Standard estimates are reliant on paediatric case reporting – which varies widely between countries.

The researchers for this study used mathematical modelling to estimate rates of infection and disease in children based on country-specific data on household and population structure, and the prevalence of TB in adults.

The model incorporated both social and epidemiological variables including the effects of age, BCG vaccination efficacy, and the effect of the HIV infection.

The findings show that about 7.6 million children under 15 became infected with Mycobacterium tuberculosis in 2010 - in the 22 countries with the highest burden of the disease (HBCs).

Of those- roughly 650,000 developed TB.

India had by far the highest burden of childhood TB, accounting for 27% of the total burden in these countries.

The overall estimated case detection rate was 35%—meaning that 65% of active TB cases in children are missed every year by national TB programmes.

This case detection rate is substantially lower than the WHO estimate of 66% in adults.

Dr Dodd 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.

Commenting on the study, Andrea T Cruz and Jeffrey R Starke from the Baylor College of Medicine, Houston, USA write:

“The crucial role of childhood infection as a reservoir for future disease cases is ignored in many high-burden countries.

Without improved case-detection and prevention strategies for children, it is difficult to envisage the high-burden countries following the same downward trajectory of incidence rates seen by industrialised countries during the past several decades.

The 22 high burden countries are Afghanistan, Bangladesh, Brazil, Cambodia, China, DR Congo, Ethiopia, India, Indonesia, Kenya, Mozambique, Myanmar, Nigeria, Pakistan, Philippines, Russia, South Africa, Thailand, Uganda, Tanzania, Vietnam and Zimbabwe.

Read: As TB re-emerges, a link is found to low vitamin D in children>