TAIPEI (Taiwan News) — A man in his 20s became the first domestic case of cholera this year after eating raw fish and seafood, reports said Thursday (July 6).

The Taiwanese man had no recent history of traveling, but had a habit of ordering all his meals from breakfast to lunch at restaurants, the Taiwan Centers for Disease Control (CDC) said. He first reported stomach pain and diarrhea on June 28, the day after he had raw fish and raw oysters, according to Radio Taiwan International (RTI).

The doctor sent him home with medicine, and his condition improved, though test results showed on July 5 he had contracted cholera of the O1-Ogawa serotype. The person he shared the meal with and the three relatives he lives with did not show any symptoms of cholera, the CDC said.

Taiwan recorded no domestic cholera infections in 2019 and 2021, one in 2020, and two last year, affecting people aged from 20 to more than 80. The most recent imported cholera case came from the Philippines in 2017.

Dirty water is a frequent source of cholera, so health officials advise against eating uncooked fish and shellfish. Seafood products that are not immediately consumed should be covered up and kept in a refrigerator, the CDC said.