Final answer:
Fungal infections can be opportunistic infections in patients who have AIDS, are immunosuppressed with medication, or are transplant patients receiving antirejection medicines.
Step-by-step explanation:
Opportunistic mycoses are fungal infections that mainly affect individuals who have a compromised immune system. Patients in the late stages of AIDS, those who are immunosuppressed with medication, and transplant patients receiving antirejection medicines are all susceptible to opportunistic fungal infections. These infections can be life-threatening and can manifest in various ways, such as Pneumocystis pneumonia, Candida spp. yeast infections, or other fungal infections.