China bird flu cases now at 102

Story highlights

The cases include 20 deaths, and 102 infection cases

Seventy patients are hospitalized with the virus

The new strain wasn't known until three weeks ago

International experts in China to monitor the H7N9 strain

CNN  — 

The number of bird flu cases in China jumped Sunday to 102, including 20 deaths, the World Health Organization announced.

Seventy patients remain hospitalized with the virus. The WHO said there is still no evidence of human-to-human transmission.

So far the virus has mainly affected eastern China, with 11 deaths and 33 infection cases reported in Shanghai, 24 cases, including three deaths, in Jiangsu Province, 38 cases, including five deaths, in Zhejiang Province, while Anhui Province has confirmed three cases, with one ending in death.

Further afield, four people – including one in Beijing in northern China and three in central Henan Province – have tested positive for the H7N9 virus.

The current strain of bird flu, H7N9, was not detected in humans until last month.