Investigators were not able to find out how Ms. Zhou, 41 year old factor worker from the Sanming city contacted the bird flu virus. Zhou , is the seventh victim of bird flu infection in China, she was hospitalized after showing symptoms of fever and pneumonia. It is not yet known how she got the virus as it is said that she was no where in contact with poultry and moreover she did not take any chicken or duck meat. All the 66,172 poultry farms in the city of Sanming were vaccinated on the start of the month and there are no chances of the virus spreading from poultry. Moreover investigations after her death revealed that more than 230 birds collected near from Zhou's home was not found to have any infection and laboratory tests for the bird flu virus in people close to Zhou also proved negative.