According to Bloomberg, all English tests for IELTS, TOEFL and the GRE and GMAT graduate entry exams next month are canceled to contain the spread of coronavirus at all public venues, including test centers. 
Later on, ACT.org and CollegeBoard also announced test cancellation in areas affected by the coronavirus. Students with canceled registrations will receive a full refund. 

For more info, please check the official websites of GMAC, GRE, TOEFL, ILETS, SAT, and ACT.