NEW DELHI — In 2012, the World Health Organization (WHO) estimated that approximately 530,000 children were infected with tuberculosis that year. Now, research published in the Lancet Global Health has found that the estimated cases of tuberculosis each year have been underestimated by almost 25 percent, with a possible 650,000 worldwide cases in 2010. The WHO now plan to revise their estimates in light of the new research.
Various reasons contribute to the poor quality of information regarding the number of tuberculosis cases around the world. One responsible factor is how reporting of the disease varies across countries.
Tuberculosis, especially in children, presents a number of issues that has resulted in its underreporting throughout the world. Children are often more difficult to obtain samples from, and the disease has fewer detectable bacteria in children. In addition, the inaccurate perception that children are not infectious and that the disease is less pressing continues to affect reporting numbers.
After the WHO called for alternative methods to find a more accurate number of TB cases, a team associated with the University of Sheffield, Imperial College London and the Global Alliance for TB Drug Development created a mathematical prediction model.
Using adult data, the behavior of the bacteria and the rates of the adult TB cases in households and communities in 22 different countries with the highest levels of TB, the team estimated the total number of children with the disease. The model found that approximately 15 million children live in the same household as an adult with infectious TB. The findings also suggest that some 53 million children carry an inactive form of TB, which can become infectious and active at any time.
The 22 countries that were used in the model account for 80 percent of the global TB cases. In addition, a quarter of the pediatric TB cases were in India. In these high-burden countries, children are a substantial fraction of the total TB burden.
If these estimates are accurate, then almost two-thirds of active TB cases in children have not been reported every year. In comparison, approximately a third of adult cases are not reported each year.
The research calls for a change in tuberculosis perceptions. Andrea Cruz and Jeffrey Starke from Baylor College of Medicine stated that the treatment for adult cases, which was expected to control not only adult cases but also children cases, will no longer be held as an effective strategy.
By ignoring the treatment of children, future cases are essentially ignored. And by ignoring the future consequences, it is unlikely these high prevalence countries will ever reduce their incidence rates. The researchers recommend the application of preventative antibiotic treatment for children that share households with infectious TB adults. The study was conducted as a component of a larger effort to improve tuberculosis awareness and treatment for children around the world.
– William Ying