Multiple choice People with weakened immune systems are more prone to be infected by blastomycosis histoplasmosis mucormycosis pneumocystis pneumonia sporotrichosis Reveal answer Fill a bubble to check yourself D Correct answer Explanation Pneumocystis pneumonia is a disease caused by the fungus Pneumocystis jirovecii. It is one of the most frequent and severe opportunistic infections in people with weakened immune systems, particularly people with HIV/AIDS.