For nearly 150 years, diagnosing tuberculosis (TB) has relied on a method that is both cumbersome and often inaccurate: examining phlegm under a microscope. This traditional approach, established by Dr. Robert Koch in the late 1800s, faces significant challenges. Phlegm is an unpleasant substance for patients to produce and for health workers to handle, often being viscous and difficult to process in laboratories. Furthermore, not all individuals, particularly children, the elderly, or those severely ill, can easily produce the required sample. The test itself is prone to errors, leading to both false positives and, crucially, false negatives, where the disease is missed in about half of actual cases. This diagnostic delay allows TB, the world's deadliest infectious disease that claims over a million lives annually, to progress unchecked.
This long-standing diagnostic hurdle may finally be overcome with the advent of a new tuberculosis test. Developed by the Chinese company Pluslife, the MiniDock MTB offers a faster, more accurate, and significantly more accessible alternative. This innovative device, announced last year, moves beyond the reliance on phlegm. While it can still process phlegm samples, it also offers the option of using a simple tongue swab, a considerable advantage for patients unable to produce phlegm. The process involves heating and spinning the sample, followed by a machine scan to detect the DNA of the TB bacteria.
"It's cheaper than a microscope," notes Dr. Adithya Cattamanchi, a pulmonologist at UC Irvine, highlighting the economic benefits. The device itself costs approximately $300, with each test running an estimated $3 to $4. This affordability and ease of use make it a more accessible option for a wider range of healthcare settings. "So it's more affordable, it's more accessible," Cattamanchi added. The improved accuracy of this new test has been validated by a recent study co-authored by Cattamanchi and Alfred Andama, a microbiologist at Makerere University College of Health Sciences in Uganda, among other colleagues. Their findings were published in the prestigious New England Journal of Medicine.
The study involved nearly 1,400 patients exhibiting TB symptoms across health centers in seven countries spanning Africa and Asia, including Uganda. The results demonstrated that the MiniDock MTB was not only easy to implement but also met the stringent accuracy targets set by the World Health Organization (WHO), regardless of whether phlegm or a tongue swab was used. The WHO had already recommended the test the previous month, signaling its potential global impact.
"What we hope it means is that many more people will have access to high-quality TB testing," stated Cattamanchi. Early and accurate diagnosis is critical for initiating timely treatment, which can save lives and prevent the further spread of the disease. By reducing transmission, this new test could significantly curb the ongoing global TB epidemic. "To have this low-cost option is, I think, really going to help countries scale up," he further elaborated.
Cattamanchi’s firsthand experience working in health centers in central and eastern Uganda has underscored the profound delays patients often face. The diagnostic journey can be protracted, involving multiple visits to pharmacies for symptomatic relief before eventually reaching a facility equipped for TB testing. "Many people are making three, four, five visits before they finally come to a health center where there is TB testing available," he explained. This lengthy process allows the disease to advance, leading to more severe illness for the patient and increased risk of transmission to others.
"The patient would probably have become even sicker," observed Andama. "And they keep transmitting the disease as they move between these different facilities," he added, emphasizing the public health implications of delayed diagnosis. The ability to diagnose TB quickly and efficiently is therefore paramount to controlling its spread and improving patient outcomes. The MiniDock MTB test emerges as a significant advancement in this critical area.
The development of the MiniDock MTB is partly a result of the rapid innovation spurred by the COVID-19 pandemic. The widespread adoption and improvement of swab-based testing for COVID-19 created a fertile ground for companies, including Pluslife, to adapt and apply similar technologies to other pressing global health challenges like tuberculosis.
Andama expressed optimism about the broad implications of this new technology. "Most of the patients who are suspected to have TB could have access to TB testing," he said. "Detecting patients early, starting them on treatment early and following up to make sure they adhere to treatments makes a lot of improvement in their lives." This comprehensive approach, enabled by accessible diagnostics, promises to transform patient care and disease management.
Lucica Ditiu, executive director of the U.N. organization Stop TB Partnership, who was not involved in the research, acknowledged the global excitement surrounding the test. "There is a lot of excitement in the world," she stated. However, she also pointed out two important caveats. First, while the test appears effective for patients with established TB, its sensitivity in detecting the disease in its very early stages, when bacterial loads are low, may need further improvement. "For that type of work, we don't think this is the tool yet," she commented. "Maybe it needs some improvement."
Second, Ditiu noted that the MiniDock MTB, like the conventional microscope test, cannot differentiate between standard TB and drug-resistant strains. Identifying drug-resistant TB requires additional, specialized testing to determine the appropriate treatment regimen. However, she also emphasized that early detection and treatment of TB can, in itself, reduce the likelihood of drug resistance developing in the first place, a crucial point in combating evolving pathogens.
Cattamanchi acknowledged that challenges remain but views the MiniDock MTB as a significant stride forward. "My hope honestly is that after more than 150 years, we finally get rid of using a microscope," he expressed. "And everyone who has TB symptoms is getting a high quality molecular test." He concluded with a hopeful outlook, stating, "And I think we're closer to that today than we've ever been before."
