More H7N9 cases reported in China

The statement added that no epidemiological connection has been found between the two cases reported in Fujian.

In Shandong, experts confirmed an H7N9 bird flu case in the city of Zaozhuang on Sunday. The patient, a four-year-old boy surnamed Zhang, developed a fever on Saturday.

The boy is the son of Shandong's first confirmed H7N9 patient. But initial investigation found no evidence of human-to-human infection, according to a statement from the provincial public health department.

The statement said the boy is in stable condition.

Xu Jianguo, a researcher with the Chinese Center for Disease Control and Prevention, said on Sunday that the chance of a major H7N9 outbreak is slim, although the situation must not be taken lightly and monitoring should be intensified.

"The biggest technical obstacle for prevention is that we don't know where the virus-carrying birds are or where they will go," Xu said, adding that the epidemic is not likely to disappear soon.

Xu said human infections are not related to seasonal changes.

He called for focusing on effective efforts to control sources of infection.