Most of the nine million people who fall ill with tuberculosis each year lack access to adequate testing and diagnosis, complicating efforts to stop its spread, the World Health Organization (WHO) said on Wednesday.
The United Nations agency said big investments are needed to develop diagnostics in low- and middle-income countries, where three quarters of screenings are performed for this bacterial disease, which claims 1.7 million lives a year.
"The world urgently needs new, safe and affordable diagnostics to simplify case detection, Mario Raviglione, director of the WHO's Stop TB Department, said in a statement.
"Most of the world's tuberculosis patients have access only to conventional microscopy which requires repeated testing, may miss half the cases, and which works especially poorly for HIV co-infected patients," he added.
Only 2.2 million TB cases are identified each year with sputum smear microscopy, the most widely available test.
The rest are diagnosed through what the WHO said separately is "an often inefficient and sometimes wasteful combination of chest X-rays, bacterial cultures and guesswork."
About $1 billion is spent annually on tuberculosis screenings of some 100 million people worldwide, and another $300 million is spent on drugs treatment.