Bombardier Beetle Inspires Design for Portable TB Test

When most people hear the words “tuberculosis” and “HIV,” they don’t think of beetles. And yet, it’s this very insect—specifically, the bombardier beetle and its explosive chemical defense—that inspired a diagnostic test that might finally crack one of infectious disease’s most frustrating blind spots.

Tuberculosis remains the world’s deadliest infectious disease, and for people living with HIV, it’s particularly insidious. Because HIV suppresses the immune system, standard TB tests that rely on interferon-gamma production by CD4+ cells are notoriously unreliable. That makes diagnosis harder, treatment slower, and survival less likely in communities where co-infection rates are high. Enter ASTRA: a self-powered, credit card-sized test that requires just a single drop of blood and no electricity. ASTRA doesn’t just work in low-resource settings—it thrives in them.

Developed at Tulane University, ASTRA gets around the CD4+ cell problem by targeting two other immune markers—OX-40 and 4-1BB—that are found on both CD4+ and CD8+ T cells. These markers light up when exposed to TB antigens, regardless of HIV status, allowing for a much more accurate read. In field trials in Eswatini, a country with the highest HIV infection rate on the planet, ASTRA delivered 87% sensitivity in HIV-positive individuals, compared to 60% from the standard IGRA test. That’s not an incremental improvement—it’s a leap.

And about that beetle: when threatened, bombardier beetles ignite a two-part chemical reaction in their abdomen, shooting a hot, pressurized spray at their attackers. ASTRA uses a similar two-reagent system to push the blood sample through its microfluidic channels—no batteries or pump required. The device basically powers itself through biochemistry, which makes it a brilliant match for field use in rural clinics or mobile testing units.

The test completes in about four hours and includes an optional colorimetric readout, offering a low-friction way for healthcare workers to get results fast. There’s no need for specialized training, complex lab equipment, or internet access. It’s plug-and-play biology in a plastic shell.

Beyond TB, the platform is modular and could be adapted to detect other diseases where rapid, decentralized diagnosis is needed—think dengue, Zika, or even vaccine response testing. For now, the focus is on TB, and rightfully so: delays in diagnosis are a major barrier to care, especially for people already living with compromised immune systems.

In many ways, ASTRA represents the kind of medtech that matters most: not flash-forwards into some speculative biotech future, but practical solutions that work in the gritty, real-world present. It’s elegant science doing unglamorous but vital work. And if all goes well, it just might help rewrite the story of TB and HIV co-infection in some of the world’s most underserved communities.