Opportunistic Diseases During HIV Infection—Things Aren′t What They Used to Be, or Are They?

For infectious diseases fellows, diagnosing and treating an AIDS-defining opportunistic infection (OI) has become a rare event. It is a special situation theyare confronted with now and then in patients who present late during human immunodeficiency virus (HIV) infection or in sub-Saharan migrants with tuberculosis or another uncommon infection. At any time, several of our HIV infected patients are hospitalized. Many of them because of infections, but rather because of severe bacterial infections than AIDS defining OIs. We see Candida-associated esophagitis in our HIV-infected patients more often induced by treatment of an exacerbationofchronicpulmonarydisease, with glucocorticoids or other immunosuppressive treatments, than by HIV-associated immunodeficiency. More than 35 years ago, the medical community in the developed world faced a challenging epidemic of OIs such as Pneumocystis pneumonia, Toxoplasma gondii encephalitis, Cytomegalovirus retinitis, and hitherto rare malignant diseases, such as Kaposi sarcoma, mainly in young adults [1]. In retrospect, these were the clinical manifestations that heralded the arrival of the epidemic of HIV infection and AIDS in resource-rich countries. In the following 15 years, we learned a lot about the etiology and pathogenesis of HIV infection, the natural course of the associated progressive immunodeficiency, and the diagnosis, treatment, and primary and secondary prevention of the associated OIs. We found that the number of CD4 + T lymphocytes in circulation is a valuable surrogate marker for the severity of immunodeficiency and that individual OIs typically occur when the CD4 + T-cell count decreased to certain levels, giving us the possibility to start preventive antimicrobial strategies when this level was reached [2].The definition of clinical AIDS was revised over time to include not only OIs that almost exclusively occurred in patients with low CD4 + T-cell counts, but also diseases that can occur in immunocompetent individuals