Fungi that can cause serious infections are more common in some parts of the United States and world. For example, the fungus that causes Valley fever (also called coccidioidomycosis) is found mainly in the southwestern United States. The fungi that cause histoplasmosis and blastomycosis occur most often in the eastern United States. These infections usually cause a lung infection that is often mistaken for flu or bacterial pneumonia.What types of activities are you doing? Harmful fungi can be found in air, dust, and soil. Histoplasma grows especially well in soil that contains bird or bat droppings. During activities like digging, gardening, cleaning chicken coops, and visiting caves you could inhale fungi that may cause infection.Do you have a dog or cat? People can get ringworm from their pets. Dogs and cats with ringworm sometimes have circular, hairless patches on their skin or other types of rashes. Adult animals do not always show signs of ringworm infection.