Over the years, health experts have been faced with the challenge of reducing the incidence of Tuberculosis (TB), a contagious disease caused by a bacterium known as Mycobacterium tuberculosis, which mostly affects the lungs. According to recent statistics, it is estimated that one-third of the world's population is currently infected with the TB bacillus.
It is believed that about 5 to 10 percent of people infected with TB bacilli (but who are not infected with Human Immuno Virus (HIV) ) become sick or infectious at some time during their life even as people with HIV and TB infection are much more likely to develop TB.
Like the common cold, the infection spreads from infectious individuals who cough, sneeze, talk or spit hereby propelling TB germs, known as bacilli, into the air. However, an individual needs only to inhale a small number of these to be infected.
As various countries across the globe continues its quest to reach Millennium Development Goal for TB incidence and the Stop TB Partnership 2015 target for mortality especially in Africa and Eastern Europe, the World Health Organization (WHO) recently endorsed a new and novel rapid test for tuberculosis especially relevant in countries most affected by the disease.
The test is expected to revolutionize TB care and control by providing an accurate diagnosis for many patients in about 100 minutes, compared to current tests that can take up to three months to obtain the results.
WHO's endorsement of the rapid test, which is a fully automated NAAT (nucleic acid amplification test), follows 18 months of rigorous assessment of its field effectiveness in the early diagnosis of TB, as well as multidrug-resistant TB (MDR-TB) and TB complicated by HIV infection, which are more difficult to diagnose.
The health body also released recommendations and guidance for countries to incorporate this test in their programs which includes testing protocols (or algorithms) to optimize the use and benefits of the new technology in those persons where it is needed most.
Evidence to date indicates that implementation of this test could result in a three-fold increase in the diagnosis of patients with drug-resistant TB and a doubling in the number of HIV-associated TB cases diagnosed in areas with high rates of TB and HIV.
In an interview with Folasade Ogunsola, Head, Department of Medical Microbiology, college of medicine, Lagos State University Teaching Hospital (LUTH), Ogunsola disclosed that TB drug resistance is a major public health problem which may threaten the success of directly observed treatment (DOTS), which is the WHO-recommended treatment approach for detection and cure of TB. The medical expert noted that currently, strains of TB resistant to major anti-TB drugs have emerged which is traceable to improper use of antibiotics in chemotherapy of drug-susceptible TB patients.
According to her, “a dangerous form of drug-resistant TB, multidrug-resistant TB (MDR-TB), resists the treatment of at least isoniazid and rifampicin, the two most powerful anti-TB drugs. The emergence of extensively drug-resistant (XDR) TB occurs particularly in settings where many TB patients are also infected with HIV, and this poses serious threat to TB control.
The challenge of detecting the etiological agent M. tuberculosis is that many countries still rely principally on sputum smear microscopy, a diagnostic method that was developed over a century ago. But this new 'while you wait' test incorporates modern DNA technology that can be used outside of conventional laboratories. It also benefits from being fully automated and therefore easy and safe to use.”
For Giwa Temidayo, a health expert, some teaching hospitals as well as medical laboratories though might be aware of the rapid test for TB, medical facilities to conduct such diagnosis is not operational in most laboratories where such TB tests are carried out.
According to Temidayo “few hospitals in the country may possess the equipment to conduct this rapid TB tests. If teaching hospitals where lots of medical personnel are produced don’t have equipment to conduct this kind of test then, latent TB cases may be difficult to ascertain. Though there have been major improvements in TB care and control, there is the need for in improving access to diagnosis and treatment, and also in the scale up of TB/HIV intervention as well as laboratory strengthening.”
Even as the world health body (WHO) is calling for the fully automated NAAT to be rolled out under clearly defined conditions and as part of national plans for TB and MDR-TB care and control, affordability of facilities for NAAT has been a major concern.
Just before the end of 2010, co-developer FIND (the Foundation for Innovative and New Diagnostics) announced that it has negotiated with the manufacturer, Cepheid, a 75 percent reduction in the price for countries most affected by TB, compared to the current market price. Health experts are of the believe that preferential pricing will be granted to 116 low- and middle- income countries where TB is endemic, with additional reduction in price once there is significant volume of demand.
For Giorgio Roscigno, FIND's Chief Executive Officer, “There has been a strong commitment to remove any obstacles, including financial barriers that could prevent the successful roll-out of this new technology. For the first time in TB control, we are enabling access to state-of-the-art technology simultaneously in low, middle and high income countries. The technology also allows testing of other diseases, which should further increase efficiency.”
Alexander Chiejina
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