Bird flu has led to a wide variety of symptoms during recent outbreaks, including common flu symptoms like cough and vomiting. Many have also had conjunctivitis or pink eye as their only symptom, which experts suspect is from contaminated milk from cows infected by bird flu being splashed onto workers.

The highly contagious H5N1 bird flu virus may be spreading through the air under certain conditions, according to a new study from the Czech Republic. Government veterinarians made the discovery while investigating a mysterious outbreak at a highly secured chicken farm last February.