text: <unk><unk><unk>  exists worldwide, in humans and animals. Serologic evidence indicates that most healthy children have been exposed by age 3 to 4.<unk><unk>  (PCP) occurs in immunosuppressed individuals and in premature, malnourished infants.
option_0: Pneumocystis jirovecii pneumonia epidemiology and demographics
option_1: Aspergillosis epidemiology and demographics
option_2: Eosinophilic pneumonia epidemiology and demographics
option_3: Sarcoidosis epidemiology and demographics
option_4: Bronchiolitis epidemiology and demographics
option_5: CMV pneumonitis epidemiology and demographics
option_6: Cryptogenic organizing pneumonia epidemiology and demographics
option_7: Hypersensitivity pneumonitis epidemiology and demographics