LONDON (AP) — Chinese authorities have taken measures this week to try to curb the spread of chikungunya , a virus that often causes fever and joint pain. As of Wednesday, the government reported there had been more than 7,000 cases, mostly in the southern manufacturing hub of Foshan. Here’s what to know about chikungunya: What is chikungunya? Chikungunya is a disease caused by a virus of the same name. The chikungunya virus was first identified in people sickened during an outbreak in Tanzania