Pulmonary alveolar proteinosis (PAP) is a very rare disease. The yearly prevalence (number of patients that are affected by the disease) in USA is 6.9 persons per million. In Japan, the yearly prevalence is similar (6.2/million). In Europe, however, the prevalence in the general population has not been investigated in large studies. But it is assumed to be the same as in USA (6-7/million).
Though PAP is a rare disease the typical PAP patient can be characterised by being:
If you have other diseases such as HIV or certain types of bone marrow cancer it increases your risk of developing PAP.
If you work in environments where you inhale mineral dust such as silica, titanium oxide, aluminum, and indium-tin oxide or insecticides, you may also be at increased risk of developing PAP.