Ebola, which is currently spreading in the Democratic Republic of the Congo (DRC), is a nightmare disease. The virus floods the immune system, eventually shredding our vasculature. There’s a roughly 50-50 shot at survival, and the unlucky half will die in agony, bleeding profusely as their organs begin to fail.

I’ve seen this story before. For nearly a decade, I worked for the U.S. Centers for Disease Control and Prevention, fighting epidemics around the world. In 2014, I deployed to Liberia for the largest-ever outbreak of Ebola, then five years later to DRC for the second-largest Ebola outbreak ever. In these resource-limited settings, infection control is tough. The virus spreads through bodily fluids, yet I witnessed local health workers forced to reuse their disposable masks and gloves because of limited supply. Faced with such inequities, it’s no wonder that thousands of people died between those two outbreaks.

This latest Ebola outbreak is unfolding alongside a frightening hantavirus outbreak that erupted on a cruise ship. To be sure, Ebola and hantavirus are different viruses spreading under different circumstances, but both come from animals. This is a public health pattern we keep re-learning and failing to act on. Infectious disease professionals like myself predict that until we break this cycle of inaction, such outbreaks will arise with growing frequency.

Ebola, for example, is a disease tied to deforestation. The 2014 outbreak in West Africa likely began with an axe. In rural Guinea, starving communities cleared forests to make way for new farms. Those forests were previously home to bats, a natural reservoir for all kinds of nasty viruses. The bats, in turn, found new homes among local villagers. Some researchers believe patient zero was a two-year-old boy who acquired the virus from bats living inside a hollowed-out tree where he played.

In my field, we........

© Time