TB infection in children may be 25 percent higher than previous estimates
The WHO research suggests approximately 15 million children are exposed to the bacteria every year, and approximately 53 million live with latent TB, which can turn into an active infection at any time, Science Daily reports.
"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," lead study author Peter Dodd from the U.K.'s University of Sheffield said, according to Science Daily. "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."
The researchers used mathematic modeling to estimate infection rates and disease in children based on data from each country and the prevalence of TB in adults. The model incorporated a number of variables, including the effects of age and HIV infection.
According to the findings, approximately 7.6 million children younger than 15 became infected with TB-causing bacteria in the 22 countries in 2010, approximately 650,000 developed TB. India had the most incidences of childhood TB, representing 27 percent of the total disease burden, Science Daily reports.
Overall detection was at 35 percent, meaning 65 percent of active TB cases go undetected every year by national TB programs. The rate, however, is lower than the estimated 66 percent of TB cases in adults that are detected.
"Children are an often ignored but important part of TB control efforts. In high-burden settings, childhood TB makes up a substantial fraction of the total TB burden," Dodd said, according to Science Daily. "The estimated incidence is higher than the number of notifications, with under-reporting more common in younger children. 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."
Andrea Cruz and Jeffrey Starke from Baylor College of Medicine in Houston, Texas, said the findings show that the idea that controlling TB in adults will help control infection in children is "fallacious" as a single strategy.
"Until the gap in case-detection and reporting is closed, children will continue to suffer from insufficient access to appropriate resources," Cruz and Starke said, Science Daily reports. "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 industrialized countries during the past several decades."