Opportunistic infections are often caused by opportunistic pathogens, such as bacteria, viruses, fungi, and protozoans. Common opportunistic infections in HIV/AIDS patients include: Candida infections of the bronchi, trachea, esophagus, and lungs.

Klebsiella Pneumoniae infection is one of the dangerous infections that needs to be treated quickly, otherwise it will cause certain effects on the patient's health.

Opportunistic infections are infections that occur more frequently and are more severe in people with weakened immune systems; HIV-infected individuals are particularly concerned. Opportunistic infections are now less common thanks to advances in antiretroviral drugs.