Danny, a 54-year-old electrician, decided to visit his physician because of a persistent dry cough he has had for over a month. The doctor discovered a plethora of pathologies including shingles and a yeast infection in the lung and mouth. Blood tests rereleased that Danny's CD4 count was very low (about 150).
1. Possible diagnosis?
2. How does depressed CD4 count lead to the opportunistic infections Danny is suffering from?