Epidemics start in mundane ways. A child might play with a pet. An air-conditioning unit might break down. A pool of water might collect in an empty flowerpot. Any one of those actions is all it takes for a virus to find a host and infect its first case. From there, the virus can spread exponentially — across cities, regions, countries. Millions of people might be exposed from that single event, and thousands might die. This year, the Western Hemisphere is reeling from an outbreak of the mosquito-borne Zika virus, which has been linked to unusually small heads and brain damage in newborns. But Zika is just the latest of many. Which will be next?
This year, it’s the Zika virus. But what about next year?
