A new microscope that runs on AA batteries can diagnose tuberculosis just as accurately as professional laboratory models.
The £150 ($240) microscope, described online in the science journal PLoS ONE, weighs just two and a half pounds.
It could transform treatment in the world’s poorest countries that don’t have expensive lab equipment and reliable electricity.
Some 1.3 million people died from tuberculosis in 2008, mostly in Africa, Asia and South America, according to figures from the World Health Organisation.
The microscope, "which is portable, durable and inexpensive, could be used to diagnose tuberculosis in community or rural health centres with limited infrastructure in the developing world, promoting early detection and successful treatment of the disease” said researcher Professor Rebecca Richards-Kortum, at Rice University in Texas.
Rice University bio-engineering student Andy Miller developed the device as part of a school project last year to design a highly functional but portable, low-cost microscope.
Using off-the-shelf parts, Mr Miller invented an AA battery-powered microscope that a new study shows is just as good at diagnosing tuberculosis as hospital machines that cost about £25,500 ($40,000).
"What Andy did, the ingenuity he showed, was remarkable," said Ms Richards-Kortum, his adviser and a professor of bioengineering. "I never thought he'd take the assignment so far," she told The Houston Chronicle.
The device could have a huge impact in the developing world, where people routinely delay or put off treatment because they are too far from facilities that can confirm they have a disease. It would allow health care workers to get people with TB on medication sooner and isolate them so the disease doesn't spread. His invention, called the Global Focus microscope, is also expected to diagnose malaria and parasites. But studies have not yet been carried out with those samples.
The finished product is so neat it can fit inside a lunch box, and its design is so simple that five screws separate the shell from the one-piece body. It magnifies 1,000 times.
And it works, proved a study, out last week in PLoS ONE. Blind testing 63 specimens — controls and TB smear samples from Iran − the team got similar results with the microscope to the most sophisticated instruments 98.4 per cent of the time. “You're not going to miss anything using one of these," said Edward Graviss, director of the Methodist Hospital Research Institute's Molecular Tuberculosis Laboratory which ran the test.