PATHOLOGY

Detailed explanation-1: -Typically, patients at risk are those with underlying disease states that alter host immunity, such as cancer, HIV, transplant recipients, or those taking immunosuppressive therapies and medications. Patients presenting with PCP may show signs of fever, cough, dyspnea, and, in severe cases, respiratory failure.

Detailed explanation-2: -Pneumocystis pneumonia is caused by the yeast-like fungus Pneumocystis jirovecii that most commonly presents as an opportunistic infection in HIV infected patients, but may present in a variety of people with weak immune systems.

Detailed explanation-3: -Pneumocystis jirovecii is the opportunistic fungal organism that causes Pneumocystis pneumonia (PCP) in humans. Similar to other opportunistic pathogens, Pneumocystis causes disease in individuals who are immunocompromised, particularly those infected with HIV.