A new study from the Harvard Medical School and affiliated Brigham and Women’s Hospital concludes that the current World Health Organization (WHO) estimate of childhood cases of tuberculosis are likely half of what actual numbers are. Conventional TB tests, already not easily available enough in many of the regions where TB is a real issue, are designed for diagnosing adults, and subsequently are not as good a predictor when used on children. This means that too many children go undiagnosed in countries with real problems with the respiratory illness.
In the study published today, March 23, in the medical journal The Lancet, it is described how researchers used data previously available to the public to implement a novel method correcting for the current under-diagnosis in children, thought to be mainly caused by the lack of testing designed for the younger population. They then came up with two models: one to estimate regional numbers and one to estimate global numbers. What they found is that where the current WHO estimate is around a half million new cases of TB in children each year, the true number is likely double this, at around one million. Also, an estimated 32,000 children each year develop multidrug-resistant tuberculosis (MDR-TB). If what was previously thought by the World Health organization to be a correct estimate of childhood cases is, in fact, half, does this mean that what has been described as a public health crisis is now double?
When TB goes undiagnosed and therefore untreated for too long, and is not subsequently controlled by antibiotics, new, drug-resistant strains take hold. These are then untreatable by any current medications. This means that instead of lowering the number of cases or even attempting to keep them stable, the illness proliferates and can reach epidemic proportions, which, in some regions, it is thought to be approaching. The situation in India, for instance, with regards to MDR-TB among children, is described as “grim.”
Most alive today are too young to remember firsthand when TB was previously a death sentence, even in the developed world. Many, therefore, may not comprehend its seriousness. It is important to note that although it has not been much of an issue in North America and parts of Europe for close to a century, tuberculosis cases have never gone away, and TB is once again considered by the WHO to be at levels if not already a global epidemic, then rapidly approaching. Last year the WHO asked for MDR-TB to be considered a public health crisis. What made this respiratory illness just about disappear from North American thought, as in much of the world, was antibiotic treatment, not initially available when TB was previously a global problem. Now that so many cases of children around the world going undiagnosed and therefore developing drug-resistant strains is a reality, similar situations to historical ones (in terms of gravity) are popping up all over the world.
Countries experiencing new cases of MDR-TB each year include China, India, Russia, Belarus, South Africa and Swaziland (where numbers are alarming). As of December 2011, over three years ago, 77 countries had cases of this fast-spreading and not always treatable illness. The WHO’s previous estimate of the number of people worldwide that will be infected with a drug-resistant form of TB by 2015 is two million. This means that if today’s released study is correct, within less than twelve months that figure will be much higher, and the number of children among those cases would number more than one million.
Across the board, researchers in this field say better and quicker testing is required, and global awareness of this adaptable killer bacteria must be a priority. If no thought is put into the fight against tuberculosis, the repercussions may be double what previously thought.
By Julie Mahfood
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