Pathogen

A pervasive fungus, passed along by pigeon droppings, can kill HIV patients by using a Trojan Horse strategy to invade their brains.

• By John Upton

The good news: Antibiotics didn't create antibiotic-resistant bacteria. The bad news: Antibiotic-resistant bacteria is everywhere.

• By Michael White

Human disease is littered with examples of fractious, sometimes furious rows over what emerging pathogens are called.

• By Kate Kelland

You've eaten boogers before—admit it. You might even do it now. Either way, one biochemist thinks you're onto something.

• By Ryan O'Hanlon