From October 1987 to June 1988, we attempted to determine the prevalence of HIV infection among patients hospitalized with tuberculosis and the extent of immunosuppression among those tuberculosis patients infected with HIV. Of 178 consecutive patients, 18-65 years of age, who were hospitalized with newly diagnosed, previously untreated tuberculosis, 46% (82 out of 178) had clinical or serological evidence of HIV infection, 30% (54 out of 178) were HIV-seronegative, and 24% (42 out of 178) could not be assessed for the presence of HIV infection. Among the HIV-seropositive patients without an AIDS-defining diagnosis by non-tuberculous criteria, the median CD4 lymphocyte (CD4) count was 133 x 10(6) cells/l (range: 11-677 x 10(6]; among the HIV-seronegative patients, the median CD4 count was 613 x 10(6) cells/l (range: 238-1614 x 10(6); P less than 0.001). Among the HIV-seropositive patients, those with disseminated tuberculosis (median CD4 = 79 x 10(6) cells/l) and those with pulmonary tuberculosis who had radiographic evidence of mediastinal or hilar adenopathy (median CD4 = 45 x 10(6) cells/l) had the most severe CD4 depletion, whereas those with localized extrapulmonary tuberculosis (median CD4 = 242 x 10(6) cells/l) and those with pulmonary tuberculosis without adenopathy (median CD4 = 299 x 10(6) cells/l) were less severely immunosuppressed. Of the 178 patients, 6% (11 out of 178) were infected with strains of Mycobacterium tuberculosis resistant to both isoniazid and rifampin.

Pneumocystis carinii has taken on new importance with the emergence of the human immunodeficiency virus. It is the most common life-threatening opportunistic infection in the acquired immunodeficiency syndrome and eventually develops in 80% or more of those not receiving primary prophylaxis. This review focuses on the clinical presentation, diagnosis, treatment, and prophylaxis of P carinii pneumonia in patients with human immunodeficiency virus infection.

Mycobacterium tuberculosis bacteremia has recently been reported in patients infected with the human immunodeficiency virus (HIV). At our institution, tuberculosis occurs commonly among patients with and without HIV infection. We sought to determine the frequency of M. tuberculosis bacteremia among patients with newly diagnosed tuberculosis. During a 4-month period, mycobacterial blood cultures were obtained on all identifiable patients with newly diagnosed tuberculosis. Fifteen percent (9/59) of consecutive patients with tuberculosis had positive blood cultures for M. tuberculosis. Twenty-six percent (7/27) of patients known to be infected with HIV had positive mycobacterial blood cultures; two intravenous drug users who refused HIV-serologic testing also had positive mycobacterial blood cultures. M. tuberculosis bacteremia occurred at a higher rate among HIV-infected patients with an AIDS-defining opportunistic infection in addition to tuberculosis (3/3) than among HIV-infected patients without such an opportunistic infection (4/24; p less than 0.02). M. tuberculosis bacteremia occurred in 83% (5/6) of patients with disseminated tuberculosis and in 8% (4/53) of patients without disseminated tuberculosis (p less than 0.001). In all cases, tuberculosis was diagnosed in patients with M. tuberculosis bacteremia or else they died prior to the blood cultures demonstrating mycobacterial growth (mean time to detection of mycobacterial growth: 43 days). However, the frequent occurrence of M. tuberculosis bacteremia in HIV-infected patients with disseminated tuberculosis suggests that mycobacterial blood cultures may help confirm the diagnosis of tuberculosis in this group of patients.

THE etiologic agent of the acquired immunodeficiency syndrome (AIDS), human immunodeficiency virus (HIV), induces the progressive, time-dependent destruction of the T4 lymphocyte, a cell that is central to the integrity of the cellular immune system. Infections against which cellular immune mechanisms play an important defensive part therefore occur with markedly increased frequency in patients with severe HIV disease. Twelve of these infections were included in the initial definition of AIDS; however, the range of biologic agents capable of infecting persons with the disease is now known to be much broader, as has been recognized by recent modifications in the definition . . .

A s the population of patients with Human Immunodeficiency Virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) continues to increase in number, and with the advent of new improved.antiretroviral therapy that will hopefully increase survival, more patients with HIV disease are being seen on the surgical, obstet-, ric, and psychiatric wards. With greater frequency, internists and other specialists'will be asked to consult on nrvinfected patients who are pregnant, have .psychiatric symptoms, or require> "a surgical procedure for a nOn-AIDS related problem, such as appendicitis or cholecystitis. The art and science of preoperative/medical consultation has recently enjoyed greater attention in the .literature with specific growing populations (geriatric patients, patients with cardiovascular disease, erc.) targeted for academic discussion. Similarly, AIDS patients have unique needs. The devasting immunologic abnormalities found in persons infected with the AiDS retrovirus (which has a cytopathic . effect on. T4 helper cells in vitro and also affects B .cells and other parts of the immune 'system), results in clinical disorders not frequently encoun:tered on nonmedical wards. Most importantly, the general rule of "one patient, one disease" is usually not applicable to patients with severe HIV infection. They are prone to multiple simultaneous diseases, which are often of a more severe nature than is usual for the specific pathogen involved. This review will touch upon some 'of the major considerations the internist/subspecialist should consider when called in for consuli:atio~.

A''s the AIDS epidemic continues to spread, man.y , hospitals (and not only those located in large urban areas) are becoming increasingly overwhelmed by the sheer number and complexity , of these patients. The issues being faced by the medical community are multiple, encompassing diverse medical and social problems,such as hous-z ing, discrimination, outpatient -management, and difficult ethical considerations. Only those hospitalsand staff that have learned to deal in'a compassionate, appropriate, and organized manner ' with these issues will emerge financially and emotionally intact (and even possibly enriched) from this disastrous disease. Therefore, the thrust of this review, while dealing with the various infectious processes encountered in this population, will be directed more towards prevention, prophylaxis, and.potential outpatient therapy\rather than the highly technical and sophisticated hdspitalbased approach. While the etiologic agent of AIDS, the retrovirus Human Immunodeficiency Virus (HIV, or HIV-:1), causes destruction of the immune system and the T4.lymphocyte in particular, and can directly cause clinical syndromes such as HIV meningitis and HIV neuropathy, opportunistic infections are the major life-threatening manifestation of immunosuppression associated with HIvinfection. Zidovudine (AZT), an antiretroviral drug, is curi'entlt the only, FDA-approved agent that directly combats HIV. In recent controlled trials, significant decreases in the number and severity of opportunistic infections have been observed in patients receiving AZT vs. placebo-treated controls. The exact role ' that AZT. Will play in terms of modifying treatment' of opportunistic infections is currently undetermined, but is a subject of much investigation. , A broad spectrum of infectious agents have been identified as capable of producing disease in patients with AIDS; some are common, some rare, many are life-threatening, and a few are even relatively benign. This review will consider those most frequently encountered and which are most amenable to outpatient management and prophylaxis.