Medical cases have proved that raising pigeons or frequent close contact are prone to cryptococcal pneumonia  Cryptococcus may not only exist in pigeon feces, but also spread through the air  in addition, frequent contact with Cryptococcus carriers may also be caused by infection  At the same time, there are healthy carriers of Cryptococcus
Xiao Zhang suffered from acute pneumonia and was diagnosed by the doctor as cryptococcal pneumonia
Xiao Zhang is autistic and never comes into contact with outsiders, and there are no Cryptococcus patients and Cryptococcus carriers in his family, so his illness is either caused by pigeon droppings or airborne infection