A 38-year-old man has been diagnosed with H7N9 avian flu in Shanghai, China Central Television News reported via its official account at Twitter. The man is currently being treated in a hospital, CCTV News said, but it did not specify where.

The announcement represents the second reported case of H7N9 in China in the past two weeks. A 31-year-old woman, who was only identified by the surname Deng, was infected with the virus Nov. 28, according to the Chinese state news agency Xinhua. She was in critical condition and being treated in the provincial capital of Guangzhou Friday, Reuters said.

Most H7N9 bird flu infections are believed to be caused by exposure to infected poultry or contaminated environments, according to the U.S. Centers for Disease Control and Prevention. The CDC reported that H7N9 viruses have been found in poultry in China. “While some mild illnesses in human H7N9 cases have been seen, most patients have had severe respiratory illness, with about one-third resulting in death,” the CDC said.

The agency has not found any sustained evidence of person-to-person spread of the virus, although “some evidence points to limited person-to-person spread in rare circumstances,” the CDC said.

The H7N9 bird flu first afflicted three people in China in March 2013. Since then, it has infected more than 450 people, 175 of whom died. Infections were so serious that police in southwestern China detained three people for spreading rumors about the bird flu strain, Reuters reported.

The first case of H7N9 found outside China was reported in Malaysia Feb. 12. The virus was detected in a traveler from an affected area in China. According to the CDC, the new H7N9 virus has not yet been detected in people or birds in the U.S.