The number of visits made all the difference

With population growth, the number of TB cases is progressing in the world, even if the percentage of infections per capita moves. According to the latest figures from the who, approximately 9.2 million new cases were reported in 2007, compared to 8.3 million in 2000 and 6.6 million in 1990. The France is not spared and there is a consensus to see that the number of persons affected increases regularly. Screening, two schools compete. On the one hand, the proponents of classical prick (IDR) tuberculin skin test. On the other, supporters of the blood test that detects the production of interferon gamma (called test Igra). But this product, sold in France mainly by Cellestis, Australian society of biotechnology, under the trade name QuantiFeron - TB Gold In - Tube (QFT), difficulty in drilling, having regard to its price. And it is still not refunded. A new illustration of the difficulty for laboratories to impose their innovations.

Easier to use

The results of the blood test are yet more reliable analysis published the month last in the specialized magazine "Chest". "The study confirms that the blood tests represent a modern developments in the diagnosis of this ancient disease which is as important today as in the 1700s," judge Roland Diel, Faculty of medicine, Hanover.

After one hundred years of use of the tuberculin skin test, blood test brings an innovation in terms of specificity, that positive results indicate true infection. "With the IDR, there is a likelihood of confusion on the interpretation." "If positive reaction, a physician can for example estimate that the patient has a good sensitivity, while another considers that it is infected with TB bacteria," says Elisabeth Bouvet, Bichat hospital. The blood test is also easier to use, since a taking of blood is sufficient, whereas the IDR require a second visit to the doctor, to read the test 72 hours after injection of tuberculin under the skin. "The number of visits made all the difference." "In the case of the IDR, one person in two is not reading", details Philippe - Henri Lagrange, microbiologist at Paris.

But innovation has a high cost. First of all, because a blood test involves to a biologist. There is also a very large difference in price between the two tests. "An IDR amounts to 2.16 euros, then the blood test costs on average 40,50 euros," said Yazdan Yazdanpanah, of the CHU of Tourcoing. But he would be in the end a better cost-effectiveness ratio. "As the blood test is more credible, he reduced the number of unnecessary treatments, knowing that treating tuberculosis isoniazid costs approximately 230 euros per patient", continues Yazdan Yazdanpanah.

Sales growth

Price explains that the majority of the tests in France are of IDR (850,000 tests), while Cellestis, who holds some 95 of Igra testing market, sells kits of reagents with which approximately 50,000 blood tests are performed. "The product there is a growing membership and sales are growing, but the refund is expected." "The folder is on the desktop of the CNAM since 2006," said Jean-François Cessou, commercial Director of Cellestis. In France, the biotech is slightly more than 1 million euros of turnover over 9 million for the whole of the European subsidiary. She won the Department of Paris and most of the CHU, but not the centre of struggle against tuberculosis of the Department of the North. Finally, it has launched in France its second product, testing of Cytomegalovirus intended for monitoring of transplant patients.