In the United States, there are an estimated 650,000-900,000 individuals living with HIV infection.1Of these, approximately 200,000-250,000 are thought to be severely immunocompromised, with CD4+T cell counts of less than 200 cells/mm3.1-4Among this population, opportunistic infections cause a great deal of morbidity and mortality. In the past few years, the face of the epidemic concerning AIDS deaths and incidence of opportunistic illnesses has been changing. There have been significant advances in the treatment of HIV and AIDS. Combination therapy using three and four drugs including the potent protease inhibitors have played a significant role in decreasing the number of deaths due to AIDS. Because of the ability of these medications to decrease the amounts of HIV viral RNA to nearly undetectable levels, and in doing so, assisting in the reconstruction of the immune system, the occurrence of opportunistic infections has decreased.5Prophylactic medications to prevent opportunistic infections in the severely immunocompromised HIV-infected patient also have contributed greatly to decreasing the occurrence of these infections. These advances have changed the natural history of the AIDS epidemic. The number of cases of AIDS have decreased, and many of the previously commonly occurring opportunistic infections, the cause of AIDS-defining illnesses, are not as frequent. The incidence ofPneumocystis cariniipneumonia, toxoplasmic encephalitis, fungal infections, and cytomegalovirus (CMV) disease all have decreased.6Despite these advances, these devastating illnesses continue to contribute significantly to morbidity and mortality among the HIV-infected population, illustrating that more work needs to be done to further decrease the significant impact of opportunistic infections in the HIV-infected individual.Toxoplasmosis, Cytomegalovirus (CMV), Herpes Simplex Virus (HSV), and Syphilis are all important pathogens that co-infect patients with HIV infection, and all contribute significantly to the morbidity and mortality associated with HIV disease. Toxoplasmosis has been reported in 1-5 of patients with AIDS. Toxoplasmic encephalitis has been reported as the AIDS-defining illness in 45-60 of HIV-infected patients.7,8Cytomegalovirus is also a significant contributor to morbidity and mortality in the HIV-infected population. Cytomegalovirus-related disease has been reported to occur in 40 of HIV-infected patients.9The virus has been implicated in pathologic processes of the eye, gastrointestinal tract, and pulmonary system as well as involvement of almost every major organ system of the body.Herpes simplex virus also can have a serious impact on the course of HIV disease, with frequent relapses and recurrences, and is included in the Centers for Disease Control (CDC) criteria for an AIDS-defining illness.10Syphilis also has an impact on those dually infected with it and HIV. Several reports question the efficacy of routine therapy for syphilis in the HIV-infected patient. Given the relation between the spread of syphilis and HIV, the impact of co-infection with these organisms is monumental.Thus, with these disease entities exerting a profound impact on the health status of the HIV-infected individual, knowledge of the patient's serologic status concerning these pathogens perhaps could significantly affect the ability to predict the occurrence of disease. Prophylactic measures then could be instituted. This article will examine these four major causes of morbidity and mortality in the HIV-infected population and examine the role of screening for these various infections in this population.
展开▼
