21 July 2011
By Kounteya Sinha
New Delhi, India
‘Inaccurate Results Lead To Faulty Diagnosis’
Mario Raviglione, director of WHO’s Stop TB department, said blood tests lead to faulty diagnosis and wrong treatment. WHO said: "It is strongly recommended that these commercial tests not be used for the diagnosis of pulmonary and extra–pulmonary TB. Currently available commercial serodiagnostic tests (also referred to as serological tests) provide inconsistent and imprecise findings. There is no evidence that existing commercial serological assays improve patient outcomes."
According to the world body, the high proportions of false–positive and false–negative results may have an adverse impact on the patients’ health. Dr Nevin Kishore, a pulmonologist in Max Hospital, agreed. He said: "A lot many blood tests are being done in India to detect TB. Whenever a new blood test for TB comes into India, doctors latch onto it without even knowing how to interpret their results, resulting in a lot of false positive and false negative results. Some tests like the Eliza commonly used in India have relatively poor sensitivity and specificity."
According to WHO, a blood test can cost up to $30 per patient. More than a million commercial serological tests are carried out every year. Most serological tests available in low and middle–income countries have no published evidence to support their claims of accuracy.
"There are perverse financial incentives that may encourage the blood tests to be used by doctors, laboratories, diagnostic companies and other stakeholders. Compared to appropriate diagnosis of TB through WHO–endorsed tests in a country like India, it is estimated that serological testing would result in 121,000 additional false–positive diagnoses. Research also suggest that for each additional smear–negative TB case found by serology, more than six additional falsepositive cases would be inappropriately diagnosed," WHO added.
It is estimated that around one third of the world’s population is infected with mycobacteria tuberculosis, but only around 5%– 10% of infected people develop the deadly respiratory disease.
Currently, diagnostic methods in the US and other developed countries consist of isolating and culturing the bacterium (known as the acid–fast smear test) as well as a nucleic acid amplification test for the bacterium’s DNA.
"But in developing countries, there is a widespread and unregulated use of serodiagnostic kits, which detect antibodies against M. tuberculosis in the blood, often by organizations with financial motivation. Many of these tests are used in the private–for–profit sector, charging poor people who do not understand the lack of value of the test," Raviglione added.
Global Warning Target ’12 for polio ‘at risk’
New Delhi: So much for the world’s ambitious target to rid itself of polio.
The Independent Monitoring Board (IMB) of the Global Polio Eradication Initiative (GPEI) on Wednesday admitted that the global plan to stop polio transmission by 2012 is "at risk".
Though the progress made by India was termed "exciting", the persistent transmission of polio worldwide is being called a "global health emergency".
The warning from IMB is chilling — the disease will resurge if it is not completely eradicated. According to IMB, the fight against polio is being hampered by a $590–million funding gap coupled with weak political leadership in some countries and persistent problems in the quality of key polio vaccination campaigns.
Though worldwide cases of polio have been brought down by 99% since the GPEI was founded in 1988 (from 350,000 in 1988 to around 1,000 cases in 2010), the target to eradicate it by 2012 might be elusive.
The IMB said: "India is on track to interrupt polio by end of 2011. While the country is now entering the traditional high season of polio transmission, the scale of its response has been immense."
India’s only polio victim this year has been an 18–month–old girl from West Bengal’s Howrah district. She was tested for polio after the onset of paralysis on June 13. Experts say West Bengal is the only state with continuing poliovirus transmission and stopping this transmission holds a key to poliovirus eradication in India.
Last year, Bengal’s Murshidabad district reported seven cases and another one came to light in Birbhum.