Medical malpractice is suspected of causing more than 200 people in south China's Guangdong province to become infected with the Hepatitis C virus.
The number, counted by patients themselves in the township of Zicheng in Zijin county, Heyuan city, has not been confirmed by local health authorities.
According to local residents, all of the infected had received injections at a clinic in the township, with suspected reused needles.
Experts have been organized to investigate, Yi Xuefeng, office director with the provincial disease prevention and control authorities, said Thursday.
"These cases were initially identified before 2010, and the incident cannot be deemed as an outbreak of the disease," said Yi.
Hepatitis C is viral and is mainly transmitted through contact with contaminated blood, although it can also spread through sexual contact and from mother to child during delivery. Infections can lead to liver cancer.