A Diagnostics & Imaging Week

The observance of World TB Day on March 24 will have particular significance for Rapid Biosensor Systems (RBS; Cambridge, UK). After six years of development, the company's TB Breathalyser will be in active use for the first time – delivering what RBS terms "instant, reliable and cost-effective screening for early stage infection with tuberculosis at the point of care."

The Breathalyser is to be launched first in India and South Africa, which are ranked first and fifth, respectively, on the World Health Organization (WHO; Geneva, Switzerland) list of high-burden TB countries.

"The social and humanitarian need for more effective screening is urgent, with TB is at near-pandemic levels in both countries," RBS said.

Concurrent with the launch, RBS will begin the approvals processes that will be required to allow use of the Breathalyser in Europe and the U.S.

The company said the Breathalyser will "revolutionize screening for tuberculosis and other infectious diseases in humans." The device is based on proprietary bio-optical sensor technologies and is both lightweight and portable.

RBS said it also is the "fastest and most reliable method" available for detecting infected subjects capable of transmitting TB to others, providing a result in minutes to a verified accuracy level of 95% or higher.

The company cited WHO statistics indicating that 8.8 million active cases of TB are diagnosed each year and of these, almost 2 million die. "Once thought to be under control or even close to extinction, TB infection levels are rising and the threat is compounded by new, virulent and drug-resistant strains," the company said.

Although most cases occur in the developing world – with 22 countries accounting for 80% of all global cases – RBS said increasing population mobility, combined with facility of transmission, means that "no country is immune from the resurgence of TB."

CEO Dennis Camilleri said he is confident that the advantages of the device over current screening methods will arouse "significant interest" among stakeholder groups in TB care.

"The most prevalent method of screening currently is the Mantoux TB test, which involves a health worker injecting test fluid under the patient's skin, then waiting for up to 72 hours to see if there is a localised reaction that indicates the presence of TB," he said. "There are, however, many factors that can influence the reaction, meaning that expert assessment and with it a degree of subjectivity is involved in interpreting the results. Further, the test is prone to delivering false positives or false negatives, implying that further testing and interpretation may be required.

Camilleri added, "By contrast, the RBS Breathalyser delivers an unequivocal positive or negative result within minutes, with no interpretation required. Significantly, it is highly specific to detecting active TB and is not compromised by the presence of HIV or other co-infections."

He described the unit as "extremely portable and easy to use," noting that it requires no running water or electricity for operation and "can therefore be deployed in remote locations, without the need for subjects to attend a screening clinic."

The performance of the Breathalyser has been validated thus far in a series of clinical trials within a hospital environment in India and in independent trials in Ethiopia supervised by the London School of Hygiene and Tropical Medicine. An additional trial at a WHO-approved hospital in South Africa also is nearing completion.

New terahertz technology reported

A new biochip technology based on terahertz spectroscopy allows the detection of DNA without fluorescent markers. Precise assays with sensitivity in the femtomolar range can be carried out and evaluated in a short period of time.

The inventor of the procedure, Professor Haring Bolivar of the Institute of High Frequency and Quantum Electronics at the University of Siegen (Siegen, Germany), will talk about the technology behind the DNA detection method at a conference for Terahertz Systems and Industrial Applications in London on Wednesday in a presentation on "Small Scale Terahertz – Lab-on-a-chip."

The DNA detector enables the accurate distinction between single- and double-stranded DNA molecules, the identification of their presence and the detection of gene mutations.

Bolivar said this new procedure represents a "substantial improvement" in the detection of genes with the help of so-called gene chips, for the detection of genetic diseases in humans. Unlike the conventional method with fluorescent markers, the new procedure achieves more accurate results and a significantly higher detection limit, he said.