Battling TB from the Badger State
Madison biotech firm Salus Discovery is leading the way globally on improved tuberculosis diagnostics for remote health care settings.
Researchers provide training in Uganda on a new diagnostic test for tuberculosis being developed by Madison-based Salus Discovery that will be similar to home pregnancy tests.
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Tuberculosis my not be the epidemic in the United States that it once was, but it’s still one of the leading causes of death and illness in the world. However, thanks to a project currently underway at Salus Discovery, a Madison-based biotech firm, the disease soon could be easier than ever to diagnose in remote settings, allowing for more rapid treatment of those infected with TB and helping to slow the spread of the disease.
According to the National Institutes of Health, it’s estimated that one-third of the world’s population is infected with the TB bacterium and that 16.2 million people currently have TB. The Centers for Disease Control and Prevention note that in 2016, 10.4 million people around the world became sick with TB, and there were 1.7 million TB-related deaths worldwide. TB is also a leading killer of people who are HIV infected.
The picture in the U.S. is better — a total of 9,272 TB cases (a rate of 2.9 cases per 100,000 persons) were reported in the United States in 2016. This is a decrease from the number of cases reported in 2015 and the lowest case count on record in the United States.
Currently, many cases of TB are diagnosed via nucleic acid amplification tests on collected samples of sputum, which is a mixture of saliva and mucus coughed up from the respiratory tract, typically as a result of infection or other disease and often examined microscopically to aid medical diagnosis.
Unfortunately, sputum can be difficult to collect and the tests can require expert personnel to interpret, something that slows down the diagnostic process in remote locations, such as many parts of Africa, where the greatest number of deaths from TB per capita occurs.
While effective TB diagnostics exist, they are limited to locations with clinical laboratories and may be unaffordable to those most at risk to TB-related mortality, notes John Guckenberger, a senior engineer at Salus Discovery. “Our goal is to develop a low-cost assay that can be deployed to locations otherwise unreachable by existing assays.”
Salus was recently awarded a $2.6 million investment from the Bill & Melinda Gates Foundation to advance development of a non-sputum based point-of-care tuberculosis triage test.
In 2014, the World Health Organization identified this test as a specific global need. Salus Discovery, led by co-founders Dr. David Beebe and Dr. Scott Berry, are overseeing the 30-month project, which also involves eight sub-grantees from six different countries.
Salus Discovery, which was started nearly five years ago by researchers from the University of Wisconsin–Madison, currently has seven employees. Its main technology portfolio is geared toward simplified methods to manipulate and analyze biomarkers, including proteins and nucleic acids.
“We’re excited to lead an exceptionally talented group of international collaborators toward a goal that’s incredibly important to global health,” says Beebe. It is estimated that a diagnostic test for tuberculosis with sufficient sensitivity and specificity that is adaptable in areas with limited infrastructure would be used 100 million times per year and save at least 400,000 lives annually.
“We’re extremely grateful to the Bill & Melinda Gates Foundation for this investment, which is very significant for a company of our size,” adds Guckenberger. “Through our work at both Salus and UW–Madison, we’ve developed a reputation for our ability to leverage technology to reduce the cost and complexity of diagnostic tests, and we plan to continue this trend via the development of the next generation of TB diagnostics.”
The simple, low-cost triage test will be designed for use in remote healthcare settings, bringing the test closer to the patients that need it most. The technology will differ from traditional tuberculosis assays by targeting a biomarker in urine versus relying on a difficult-to-collect sputum sample. It will also feature a straightforward, lateral-flow assay readout, provided by U.K.-based Mologic Ltd., that’s similar to a home pregnancy test and will allow for interpretation without an expert. The test aims to accurately detect tuberculosis in both HIV-positive and HIV-negative adults and children, addressing several limitations of current methods. Most importantly, it will bring tuberculosis tests to those without current access.
Field testing in both South Africa and Ethiopia will validate assay functionality with hundreds of “real-world” samples from patients with either confirmed or suspected tuberculosis. Following successful clinical evaluation, Salus intends to seek approval from regulatory agencies and WHO endorsement.