October 25th, 2006 09:38 EST
Global Market Exists for Better Tuberculosis Tests, Report Says
Washington -- A large and mainly untapped global market exists for more effective, affordable tests to diagnose tuberculosis (TB) in low- and middle-income countries, where most cases now occur.
This is the major finding of a new report, Diagnostics for Tuberculosis: Global Demand and Market Potential, released October 25 by the World Health Organization (WHO) Special Programme for Tropical Disease Research and Training (TDR) and the Foundation for Innovative New Diagnostics (FIND).
The report was financed by the Bill and Melinda Gates Foundation and involved more than 100 public health and industry experts and several international agencies.
Most people in the world who have TB or live in TB risk areas do not have access to rapid and accurate testing, according to the report, regarded as the most comprehensive review of the TB-diagnostics market.
Better tests could bolster international TB-control efforts and respond to a large market demand, the report added, calling for industry investment in new diagnostic tools targeted at low- and middle-income countries.
A third of the world’s population is infected with latent (nonactive) TB and is at risk of developing the active disease. (See related article.)
HIV is fueling TB epidemics in many countries, and multidrug resistance is a growing threat; 1.7 million people a year die from TB, many because the infection is undiagnosed or diagnosed too late.
"We need simple tests to accurately screen for and identify active tuberculosis,” said TDR Director Dr. Robert Ridley October 25.
New tests also are needed to monitor treatment response, identify bacterial drug resistance and detect latent infection in people at greatest risk for progression to active TB, he added.
Of the estimated 9 million people who develop active TB every year, most do not receive a laboratory-confirmed diagnosis. Only about 2.2 million TB cases annually are diagnosed and reported with sputum-smear (saliva, mucus or phlegm coughed up from the respiratory tract) microscopy, the most widely available test.
Other cases are diagnosed through an inefficient and sometimes wasteful combination of chest X-rays, bacterial cultures and guesswork.
The global market for TB diagnostics is more than twice that of the market for TB drugs. Worldwide, about $1 billion is spent on TB tests and evaluations that screen 100 million people annually; $300 million is spent on drugs.
MORE EFFECTIVE TOOLS
In low- and middle-income countries, where three-quarters of TB tests and screenings are performed, $326 million is spent annually on TB diagnostics. An even larger potential market exists for more effective, affordable tools.
Between 70 percent and 90 percent of the potential market for new TB diagnostics is in 22 countries that have the highest TB burden.
High-tech molecular and rapid-culture diagnostics available in developed countries are too complex and costly for many settings where TB is most prevalent, the report said.
Yet traditional sputum-smear, X-ray and culture tests might not identify active TB accurately, particularly in HIV-positive patients.
In low- and middle-income countries alone, more than 66 million sputum-microscopy examinations, 39 million chest X-rays and 8.5 million cultures are performed each year on suspected TB patients using technologies developed 50 to 100 years ago.
Such diagnostics might miss critical distinctions between latent and active TB, and between drug-sensitive and drug-resistant forms of the disease.
“There is a huge opportunity for diagnostics developers to expand their investments to meet this very real need,” said FIND Chief Executive Dr. Giorgio Roscigno.
RANGE OF TB TESTS
For the report, an international network of researchers and policy experts examined for the first time the full range of tests available for active disease, latent infection, drug resistance and treatment response.
Despite increased global funding for TB control and the emergence of public-private partnerships to support product development, the report said, commercial interest in TB diagnostics is limited by a lack of information on the TB-diagnostics market, especially in the developing world.
Most recently developed tests serve laboratories in industrialized countries, where less than 5 percent of global TB cases are found.
“Despite scientific progress that is rapidly changing other fields,” said Dr. Mario Raviglione, director of WHO's Stop TB Department, “most of the world’s TB patients have access only to conventional microscopy,” which requires repeated testing, may miss half the cases, and works poorly for HIV co-infected patients.
A test that detects latent infection and predicts progression to active disease could have the greatest use, with a potential market of 204 million patient evaluations a year, the report concluded.
"Such a test,” the report stated, “if widely implemented and accompanied by successful treatment, could revolutionize TB control."
Large markets also exist for point-of-care screening (at clinics and health posts), with a potential available market of 79 million patient evaluations a year, and less-revolutionary replacement technologies for smear (49 million patients), culture (20 million patients) and drug-susceptibility testing (23 million patients).
The full text of a press release on the report is available on the WHO Web site.
For information on U.S. policy, see Health.
(Distributed by the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)