Tens of millions of Chinese now identify as Christians, and the number has grown rapidly, posing challenges for a government that is officially atheist and wary of threats to its power.

As more people in China practice religion, the government continues to toughen oversight, increase religious persecution, and attempt to co-opt state-sanctioned religious organizations.

The Zika virus, which has been found to cause severe birth defects, has spread across the Americas, prompting the World Health Organization to declare a global health emergency.