Although more than 400 people have been infected with A(H7N9), reports of clusters of cases are rare. Based on publicly available information, only 14 H7N9 human cluster have been reported. Most of these clusters are family or neighborhood clusters of 2-3 individuals. These clusters are almost never officially reported by the Chinese public health authorities.
The most recent reported cluster is family cluster of two sisters from Dongyang in Zhejiang Province. An extended media report details the identifications and treatment of 3 children infected with H7N9 from Dongyang. Computer translation of the article reports that three infected children with ages ranging from 2-8 were identified over the course of four days in February, 2014. Two of the children were sisters from one family with different onset dates. The two children apparently observed, but did not participate, in the slaughter of several chickens by one of the parents. The report is not clear whether the third child from the same city, surname Ren, is related to or had contact with the two sisters.
The three children hospitalized in Dongyang are reported to have recovered and been released from the hospital between 4 and 12 days after admission. The article mentions that one health care worker treating the patient also had a fever, but apparently was not infected with H7N9. Although the two girls are a family cluster, the infections may have resulted from exposure to a common source rather than human to human transmission. This small family cluster is at least the 14th H7N9 cluster reported since March of 2013.
Hat tip to Pathfinder at FluTrackers.com