Here’s some light, uplifting weekend reading.

The Congo is one of the most biodiverse countries in the world. It was here that HIV bubbled into a pandemic, eventually detected half a world away, in California. It was here that monkeypox was first documented in people. The country has seen outbreaks of Marburg virus, Crimean-Congo hemorrhagic fever, chikungunya virus, yellow fever. These are all zoonotic diseases, which originate in animals and spill over into humans. Wherever people push into wildlife-rich habitats, the potential for such spillover is high. Sub-Saharan Africa’s population will more than double during the next three decades, and urban centers will extend farther into wilderness, bringing large groups of immunologically naive people into contact with the pathogens that skulk in animal reservoirs—Lassa fever from rats, monkeypox from primates and rodents, Ebola from God-knows-what in who-knows-where.