Thousands of cases of the chikungunya virus, which sickens people bitten by an infected mosquito, have broken out in China during the past week. The virus causes extremely severe joint pain and fever,

China is carrying out its most challenging containment operation since COVID-19, using surveillance drones, mass insecticide spraying, and electricity shutoffs to contain a chikungunya virus outbreak that has now reached other countries.

China’s chikungunya outbreak has infected 8,000 people in the south, prompting Canada, Taiwan, and the U.S. to issue travel alerts. Guangdong logged 2,892 new cases in a week. Authorities urge mosquito-bite prevention,