A third farmworker has been diagnosed with bird flu, the CDC said Thursday, along with a new symptom that neither of the previous two cases had reported. The third person, who lives in Michigan, has a cough in addition to pink eye, whereas the two earlier cases had reported only pink eye. There is still no evidence that the virus, which is linked to sick dairy cows, is spreading between humans, the CDC said; the infected workers were employed on different farms and had been in direct contact with sick cows. The case is the second in Michigan since another farmworker contracted bird flu earlier this week, although the USDA has said that as many as 67 herds across nine states mostly in the middle of the country are affected. (The first case was reported in Texas in March.) The CDC is monitoring all dairy workers at the farm where the latest case occurred for symptoms and recommends that anyone who comes in regular direct contact with cattle wears protective equipment that can be cleaned.