Infections are caused by infectious agents (pathogens) including: * Bacteria (Mycobacterium tuberculosis, Staphylococcus aureus, Escherichia coli, Clostridium botulinum, and Salmonella spp.) * Viruses and related agents such as viroids (HIV, Rhinovirus, Lyssaviruses such as Rabies virus, Ebolavirus and Severe acute respiratory syndrome coronavirus 2) * Fungi, further subclassified into: * Ascomycota, including yeasts such as Candida (the most common fungal infection), filamentous fungi such as Aspergillus,<unk>  species, and dermatophytes, a group of organisms causing infection of skin and other superficial structures in humans. * Basidiomycota, including the human-pathogenic genus Cryptococcus. * Parasites, which are usually divided into: * Unicellular organisms (e.g. malaria, Toxoplasma, Babesia) * Macroparasites (worms or helminths) including nematodes such as parasitic roundworms and pinworms, tapeworms (cestodes), and flukes (trematodes, such as schistosomes) * Arthropods such as ticks, mites, fleas, and lice, can also cause human disease, which conceptually are similar to infections, but invasion of a human or animal body by these macroparasites is usually termed infestation. (Diseases caused by helminths, which are also macroparasites, are sometimes termed infestations as well, but are sometimes called infections.) * Prions (although they do not secrete toxins)
field of Pneumocystis pneumonia
field of Legionnaires' disease
symptom of Cryptococcosis
complications of Melioidosis
complications of Lemierre's syndrome
symptom of Toxoplasmosis
complications of Yellow fever
complications of Diphtheria