Marburg Virus Discovery at Uganda’s Python Cave

Marburg virus disease (MVD) poses a significant health threat, often leading to fatal outcomes in humans. The Egyptian fruit bat is the main carrier of this virus, which can be transmitted to humans through contact in caves or mines where these bats reside. Researchers monitoring Python Cave in Uganda—a well-known reservoir for the Marburg virus—were taken aback by their observations. They discovered that numerous individuals were entering the cave, most without any protective gear and disregarding safety protocols, thereby increasing the risk of virus transmission from bats to people.

The findings were published in a correspondence in the journal Current Biology. Alongside the human visitors, the research team’s cameras recorded over 14 animal species in the cave, including leopards and monkeys interacting with bats. These visuals provide rare evidence of how various species, including humans, might come into proximity with a lethal virus in a natural setting.

The researchers, primarily associated with the Volcanoes Safaris Partnership Trust, had initially set up six solar-powered camera traps to observe African leopards and spotted hyenas. In total, the cameras captured nearly 9,000 hours of footage during 368 monitoring nights from February to June 2025.

Caught on Camera

Upon reviewing the footage, the team observed not only a diverse array of animals preying on bats but also noted 214 visits to the cave, including by tourists and school groups. Astonishingly, only one visitor was wearing a mask.

The team noted, “Our findings reflect landscape-level risk: not only the presence of reservoir hosts, but the behaviors, interactions, and human-access patterns shaping exposure.”

Given that part of the cave’s ceiling had collapsed, bats were frequently found at lower levels, making them easily accessible. It wasn’t that people were oblivious to the risks involved—numerous warning signs around the cave highlight the presence of the virus, which currently lacks an approved vaccine or effective treatment. Past incidents include two tourists contracting the virus after visits in 2007 and 2008, with one later succumbing to the illness.

While the researchers did not test for virus transmission during their study, their footage showcases how animal and human behavior can create ideal conditions for an outbreak. “Visual confirmation of a predator guild engaging with a Marburg-virus bat reservoir represents a watershed moment for field-based zoonotic surveillance,” they emphasized.

Protective Measures Suggested

Due to the inherent risks, the researchers advocate for blood testing of predators frequently visiting the cave, along with park rangers. They also recommend mandatory protective clothing for tourists accessing the cave to minimize health risks.