Toxoplasma serology, parasitemia and antigenemia in patients at risk for toxoplasmic encephalitis.

In order to further characterize the pathogenesis of Toxoplasma gondii infection in patients with AIDS and AIDS-related complex (ARC), a cohort of HIV- and Toxoplasma-infected individuals were identified and prospectively followed. Four hundred and 10 HIV-infected individuals followed in the San Francisco General Hospital AIDS Clinic were screened for antibodies to Toxoplasma between November 1986 and November 1988. Of the 67 (16%) individuals seropositive for Toxoplasma antibodies, 33 (49%) were followed monthly for a mean duration of 7.5 months. One hundred and 11 follow-up blood samples were obtained in order to determine Toxoplasma serology and the incidence of parasitemia. In general, Toxoplasma immunoglobulin (Ig) G antibodies remained stable over time. Detection of Toxoplasma antigenemia and parasitemia was uniformly negative, including those specimens obtained from two individuals within 45 days of their developing toxoplasmic encephalitis.

Occupational exposure to aerosolized pentamidine.

Occupational exposure to aerosolized pentamidine has raised questions regarding transmission of tuberculosis and the effect of the drug itself. To estimate the exposure of a health care worker, we measured the ambient concentration of aerosolized pentamidine in field conditions in 36 m3 unventilated treatment room. The amount of pentamidine averaged in three different environmental air samples over a four-hour period was 4.5 +/- 3.6 x 10(-5) mg/m3. This amount is very small compared to the doses received by the patients in whom long-term adverse effects are few. The greater risk to health care workers is probably transmission of tuberculosis from undiagnosed cases, especially in populations with an increased incidence of tuberculosis. Tuberculosis control measures such as improved ventilation and masks should also decrease exposure to ambient air pentamidine until toxicity studies determine long-term adverse effects, if any, of aerosolized pentamidine.

Lack of effect of prophylactic aerosolized pentamidine on the detection of Pneumocystis carinii in induced sputum or bronchoalveolar lavage specimens.

Two independent studies were undertaken to determine the effect of prophylactic treatment with aerosolized pentamidine on the laboratory diagnosis of Pneumocystis carinii pneumonia in individuals at risk for or with the acquired immunodeficiency syndrome. The first study was a retrospective analysis to determine the effect of prophylactic treatment with aerosolized pentamidine on the diagnostic yield and sensitivity of detection of P carinii in induced sputum specimens. The results of examinations of 110 induced sputum specimens from patients who had not received aerosolized pentamidine were compared with the findings in 57 specimens from patients who had. There was no statistically significant difference between the two groups for the diagnostic yield in induced sputum specimens (48% vs 47%) or in bronchoalveolar lavage fluid specimens subsequently obtained from patients with nondiagnostic induced sputum examinations (33% vs 37%). The sensitivity of induced sputum specimens for identifying P carinii was 76% to 78% for patients who had not received aerosolized pentamidine and 71% to 75% for patients who had received the drug. The second study was a prospective comparison of 118 bronchoalveolar lavage fluid specimens to determine the effect of prophylactic treatment with aerosolized pentamidine on the number of organisms present. One hundred eighteen bronchoalveolar lavage fluid specimens were quantitatively examined and scored according to the number of clumps of P carinii present. No statistically significant difference was seen in the number of clumps of P carinii found in specimens from patients who had received aerosolized pentamidine vs the number of clumps found in specimens from patients who had not. In conclusion, prophylactic treatment with aerosolized pentamidine had no effect on (1) the diagnostic yield and sensitivity of detection of P carinii in induced sputum specimens or (2) the number of organisms detected in bronchoalveolar lavage fluid specimens obtained from individuals at risk for or with the acquired immunodeficiency syndrome.

[Disorders of the nervous system associated with the acquired immunodeficiency syndrome (AIDS)-clinical approach].

The acquired immunodeficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV) and characterized by disorders of the nervous system in addition to opportunistic infection and cancer. Centers for Disease Control (CDC) recommend the classification system consisting of four major groups. Group I is patients with acute HIV infection, and Group II is asymptomatic carriers. Group III is those with persistent generalized lymphadenopathy (PGL). Group IV includes five subgroups: IVA with constitutional disease, IVB with neurologic disease, IVC with secondary infectious diseases, IVD with secondary cancers and IVE with other conditions. The nervous system disorders are classified into two types: one is produced by HIV itself and not directly related to immunodeficiency, and the other caused by opportunistic infectious agents and cancers. The former is further divided into two kinds: atypical aseptic meningitis and acute inflammatory demyelinating polyneuropathy (AIDP) occur mainly in Group I and II, whereas HIV encephalopathy, distal symmetric polyneuropathy (DSPN) and vacuolar myelopathy in Group III and IV. Group I or II patients have no apparent medical problems. Therefore, when neurologists see patients with risk factors for HIV infection presenting with atypical meningitis or AIDP, it is of utmost importance to have a high index of suspicion and to look for evidence of HIV infection.

Comparison of nosocomial infections due to Staphylococcus aureus and enterococci in a general hospital.

Hospital acquired infections caused by enterococci are increasing in incidence. This increase has been attributed, in part, to widespread use of cephalosporin antibiotics which lack activity against enterococci. To test this hypothesis, we compared patients having nosocomial enterococcal pulmonary and wound infections with those patients having nosocomial staphylococcal infections for antecedant cephalosporin use. In a six month period, we found 14 instances of nosocomial enterococcal wound and respiratory infections; 13 were superinfections (occurring during or up to one week after administration of antimicrobials). Seven had coexisting pathogens noted. In the same six month period, 30 instances of Staphylococcus aureus nosocomial respiratory tract and wound infections were found and only 13 were superinfections (p less than 0.002 compared with enterococcal superinfections). Nine had coexisting pathogens noted. The mean age, gender distribution and underlying illnesses in the Staphylococcus aureus and enterococcal superinfection groups were comparable. Of the 14 instances of enterococcal nosocomial infections, 11 were associated with administration of a cephalosporin compared with seven of 30 for staphylococcal infections (p less than 0.002). Nosocomial enterococcal infections are commonly associated with antimicrobial therapy and the use of cephalosporins may selectively predispose patients to increased risk of enterococcal superinfections.

Dapsone-trimethoprim for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

All patients with the acquired immunodeficiency syndrome and a first episode of Pneumocystis carinii pneumonia seen at the San Francisco General Hospital between November 1984 and April 1985 were evaluated for oral treatment with dapsone (100 mg/d) plus trimethoprim (20 mg/kg body weight X d). All 15 patients who met the entry criteria improved clinically and radiographically within 3 to 10 days after starting treatment. Repeat pulmonary function tests and gallium lung scans after 3 weeks of therapy also showed improvement. Although side effects occurred in 14 patients, in only 2 were they severe enough to require stopping therapy. Both of these patients had worsening skin rash, and dapsone-trimethoprim therapy was stopped after 10 days. When compared with trimethoprim-sulfamethoxazole or pentamidine used to treat P. carinii pneumonia in similar patients, oral dapsone-trimethoprim is at least as effective, seems to be better tolerated, and may have a lower frequency of serious side effects.

Dapsone treatment of Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

All patients with the acquired immunodeficiency syndrome treated for their first episode of Pneumocystis carinii pneumonia at San Francisco General Hospital between 1 April 1985 and 15 July 1985 were evaluated for their response to treatment with dapsone (100 mg/day) by mouth for 21 days. Of 44 patients evaluated, 18 were eligible for the study. Of these 18 patients, the conditions of 7 of them worsened or failed to improve during treatment with dapsone and they were considered treatment failures. These patients were changed to standard therapy after 4 to 8 days of dapsone therapy. The remaining 11 patients (61%) improved within 3 to 10 days after dapsone therapy was started. Side effects of dapsone therapy were noted in 6 of 11 patients (of these 11 patients, 5 had a rash, 1 had a rash and abnormal liver enzymes, and 1 had abnormal liver enzymes), but in none of the patients were these side effects severe enough to require the cessation of medication. Based on comparison with historical controls, oral dapsone therapy alone appeared to be less effective than standard therapy or the combination of dapsone plus trimethoprim for P. carinii pneumonia in patients with acquired immunodeficiency syndrome.

Oral therapy for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. A controlled trial of trimethoprim-sulfamethoxazole versus trimethoprim-dapsone.

BACKGROUND: Antimicrobial drugs that can be taken orally are needed for the treatment of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Preliminary data indicate that dapsone with trimethoprim may be an effective alternative to trimethoprim-sulfamethoxazole, which is frequently toxic. METHODS: In a double-blind trial, 60 patients with AIDS and mild-to-moderately-severe first episodes of P. carinii pneumonia (partial pressure of oxygen in arterial blood, greater than 60 mm Hg while breathing room air) were randomly assigned to 21 days of treatment with either trimethoprim-sulfamethoxazole (20 and 100 mg per kilogram of body weight per day, respectively) or trimethoprim-dapsone (20 mg per kilogram per day and 100 mg per day). RESULTS: The orally administered treatment failed because of progressive pneumonitis in 3 of the 30 patients assigned to trimethoprim-sulfamethoxazole and in 2 of the 30 assigned to trimethoprim-dapsone (P greater than 0.3). Major toxic effects required a switch to intravenous pentamidine for 17 patients (57 percent) in the trimethoprim-sulfamethoxazole group, as compared with 9 (30 percent) in the trimethoprim-dapsone group (P less than 0.025). With trimethoprim-sulfamethoxazole, there were more instances of severe chemical hepatitis (six, as compared with one in the trimethoprim-dapsone group) and marked neutropenia (five vs. one). Intolerable rash (three in each treatment group) and severe nausea and vomiting (two in each group) occurred with equal frequency with both drug combinations. Methemoglobinemia occurred in most of the patients treated with trimethoprim-dapsone, but it was asymptomatic and the level exceeded 20 percent in only one patient. Mild hyperkalemia (serum potassium level, 5.1 to 6.1 mmol per liter) also occurred in 53 percent of the patients treated with trimethoprim-dapsone. CONCLUSIONS: In patients with AIDS, oral therapy with trimethoprim-sulfamethoxazole and with trimethoprim-dapsone are equally effective for mild-to-moderate first episodes of P. carinii pneumonia, but with trimethoprim-dapsone there are fewer serious adverse reactions than with trimethoprim-sulfamethoxazole.

Atovaquone for salvage treatment and suppression of toxoplasmic encephalitis in patients with AIDS. Atovaquone/Toxoplasmic Encephalitis Study Group.

To examine the efficacy of atovaquone as salvage therapy in patients with AIDS-related toxoplasmic encephalitis, 93 patients with AIDS and toxoplasmic encephalitis who were intolerant of standard therapy (pyrimethamine plus sulfadiazine or clindamycin) or for whom such therapy was failing were treated with atovaquone tablets (750 mg four times daily) for 18 weeks. Plasma levels of atovaquone were measured with high-pressure liquid chromatography, and the clinical and radiological responses and survival were compared according to median plasma concentration groups. During the acute-therapy phase (the first 6 weeks), the conditions of 52% and 37% of the patients, respectively, were clinically or radiologically improved; the conditions of 26% and 15% remained clinically or radiologically improved by week 18. Median survival for all patients was 189 days (Kaplan-Meier estimate). A post-hoc analysis revealed a positive relationship between clinical and radiological responses and median atovaquone plasma concentrations. Survival time among patients with high or medium median steady-state plasma concentrations (319 and 289 days) was significantly better than that among those with low plasma concentrations (114 days; P = .003 and P = .006, respectively).

Aerosolized pentamidine for prophylaxis against Pneumocystis carinii pneumonia. The San Francisco community prophylaxis trial.

BACKGROUND AND METHODS: Pneumocystis carinii pneumonia (PCP) is the most frequent life-threatening opportunistic infection associated with human immunodeficiency virus (HIV) infection. To assess the possible value of aerosolized-pentamidine prophylaxis in different doses, a controlled clinical trial was begun in 1987 with 408 subjects at 12 treatment centers. The participants were randomly assigned to receive 30 mg of pentamidine every two weeks, 150 mg every two weeks, or 300 mg every four weeks. RESULTS: Eighteen months after randomization, the subjects in the 300-mg arm had had 8 confirmed episodes of PCP while receiving treatment, as compared with 22 in the 30-mg arm (P = 0.0008). The 150-mg arm had intermediate results but ones not significantly different from those of the 300-mg arm. Participants with previous episodes of PCP and CD4-cell counts less than 200 per cubic millimeter were at the highest risk for PCP. CONCLUSIONS: Aerosolized pentamidine was effective for prophylaxis against PCP in patients infected with HIV, according to the dose and schedule of administration. It and zidovudine were well tolerated together and had independent prophylactic benefits.

Morbidity and mortality of patients with AIDS and first-episode Pneumocystis carinii pneumonia unaffected by concomitant pulmonary cytomegalovirus infection.

To determine the significance of cytomegalovirus (CMV) pulmonary coinfection with Pneumocystis carinii pneumonia in AIDS, we examined the association of long- and short-term survival and morbidity (as defined by length of hospital stay) with recovery of CMV from bronchoscopy specimens and an indirect measure of virus titer in bronchoalveolar lavage fluid (the time to develop CMV cytopathology in culture) in 111 patients diagnosed with a first episode of P. carinii pneumonia. Compared with 57 individuals from whom CMV was not isolated, the 54 individuals from whom CMV were isolated did not differ in baseline characteristics, long-term survival (213 versus 275 days, p = 0.97), acute death rate (19% in both, p = 1.0), or length of hospital stay (19.7 versus 21.1 days, p = 0.68). Also, the time to develop CMV cytopathology in culture did not correlate with acute or long-term survival. Our observations thus do not support the use of CMV-specific antiviral therapy in AIDS patients with P. carinii pneumonia who also have evidence of pulmonary CMV infection.

Seroprevalence of human T-lymphotropic virus, hepatitis C virus, and human immunodeficiency virus in Asian American potential bone marrow donors.

BACKGROUND: Asian Americans are generally underrepresented both as volunteer blood and bone marrow donors. STUDY DESIGN AND METHODS: To investigate the risk of transfusion transmission of viruses that is associated with increasing participation by Asian American donors, antibodies to human T-lymphotropic virus (HTLV), hepatitis C, and human immunodeficiency virus in Asian American volunteers recruited as potential bone marrow donors were measured. A total of 1354 Asian Americans were enrolled in the study, of whom 54 percent were Chinese, 26 percent Japanese, 9 percent Filipino, 4 percent Korean, 3 percent Indian, and 5 percent of other Asian or mixed Asian and other ethnicity. The majority of the study population was aged 20 through 49 and of high socioeconomic status, as indicated by education and income. Viral antibodies were measured with both screening enzyme-linked immunosorbent assays and supplemental testing, and polymerase chain reaction was used to resolve discrepant HTLV results. RESULTS: Confirmed seroprevalence rates for HTLV were 0.15 percent with one manufacturer's Western blot and 0.3 percent with the other; however, no sample was positive for HTLV types I or II in polymerase chain reaction. Confirmed seroprevalence to hepatitis C virus was 0.5 percent. No subject was seropositive for human immunodeficiency virus. CONCLUSION: On the basis of the moderate size and high education level of this study population, it is concluded that Asian American volunteer bone marrow donors do not pose a greater risk for transmission of HTLV type I or II, human immunodeficiency virus, or hepatitis C virus than does the average American blood donor.

Comparison of atovaquone (566C80) with trimethoprim-sulfamethoxazole to treat Pneumocystis carinii pneumonia in patients with AIDS.

BACKGROUND: Both trimethoprim-sulfamethoxazole and pentamidine are effective as treatments for Pneumocystis carinii pneumonia, but adverse effects frequently limit their use. Atovaquone (566C80) is a new hydroxynaphthoquinone with activity against P. carinii. METHODS: We conducted a double-blind, multicenter study in patients with the acquired immunodeficiency syndrome and mild or moderately severe P. carinii pneumonia. They were randomly assigned to 21 days of orally administered treatment three times daily with either atovaquone (750 mg) or trimethoprim (320 mg) plus sulfamethoxazole (1600 mg). RESULTS: Of the 322 patients with histologically confirmed P. carinii pneumonia, 160 received atovaquone and 162 received trimethoprim-sulfamethoxazole. Of those who could be evaluated for therapeutic efficacy, 28 of 138 patients given atovaquone (20 percent) and 10 of 146 patients given trimethoprim-sulfamethoxazole (7 percent) did not respond (P = 0.002). Treatment-limiting adverse effects required a change of therapy in 11 patients in the atovaquone group (7 percent) and 33 patients in the trimethoprim-sulfamethoxazole group (20 percent) (P = 0.001). Therapy involving only the initial drug was successful and free of adverse effects in 62 percent of those assigned to atovaquone and 64 percent of those assigned to trimethoprim-sulfamethoxazole. Within four weeks of the completion of treatment, there were 11 deaths in the atovaquone group (4 due to P. carinii pneumonia) and 1 death in the trimethoprim-sulfamethoxazole group (P = 0.003). Diarrhea at entry was associated with lower plasma drug concentrations (P = 0.009), therapeutic failure (P < 0.001), and death (P < 0.001) in the atovaquone group but not in the trimethoprim-sulfamethoxazole group. CONCLUSIONS: For the treatment of P. carinii pneumonia, atovaquone is less effective than trimethoprim-sulfamethoxazole, but it has fewer treatment-limiting adverse effects.

Evaluation of an indirect fluorescent-antibody stain for detection of Pneumocystis carinii in respiratory specimens.

Two prospective studies were undertaken to evaluate a commercial indirect fluorescent-antibody (IFA) stain for the detection of Pneumocystis carinii in respiratory specimens from individuals at risk for or with the acquired immunodeficiency syndrome. The first study compared IFA with Diff-Quik (DQ; a rapid Giemsa-like stain) for detecting P. carinii in 95 induced sputa obtained from 77 asymptomatic patients who had survived one previous episode of P. carinii pneumonia and who were being treated prophylactically with aerosolized pentamidine. Only one induced sputum specimen was found to contain P. carinii; organisms were detected by both stains. The second study compared the performance of the IFA stain versus DQ, modified toluidine blue O, and Gomori methenamine silver stains for detecting P. carinii in symptomatic individuals at risk for or with acquired immunodeficiency syndrome. Of 182 specimens examined, P. carinii was detected in 105 by one or more stains; the DQ stain detected 73 (70%), the modified toluidine blue O stain detected 75 (71%), the Gomori methenamine silver stain detected 76 (72%), and the IFA stain detected 95 (90%). The IFA stain was more sensitive (P less than 0.01) than the other traditional stains for detecting P. carinii; however, a subsequent clinical evaluation revealed that a subset of IFA-positive-only specimens were from patients whose clinical symptoms resolved without specific anti-P. carinii therapy.

Diagnosis of Pneumocystis carinii pneumonia: improved detection in sputum with use of monoclonal antibodies.

With the dramatic increase in the frequency of Pneumocystis carinii pneumonia associated with human immunodeficiency virus infection, there has been a need for more rapid and less invasive diagnostic techniques. Recent studies have shown that examination of induced sputum can establish the diagnosis of P. carinii pneumonia in about 55 percent of cases. To assess whether a recently developed indirect immunofluorescent stain using monoclonal antibodies was more sensitive than Giemsa or toluidine blue O stains in detecting P. carinii in sputum, we undertook two prospective studies. Of 63 patients at one institution from whom sputum specimens were obtained, 49 were ultimately given a diagnosis of P. carinii pneumonia, 46 of them by staining of sputum. The sensitivity of the three stains in detecting P. carinii was 45 of 49 (92 percent) for immunofluorescence; 37 of 49 (76 percent) for Diff-Quik (a Giemsa-type stain); and 39 of 49 (80 percent) for toluidine blue O. There were no false positive immunofluorescent stains. In a similar study of a series of 25 patients at another institution, a diagnosis of P. carinii pneumonia was made in 23 of 25 patients by staining of induced sputum. We conclude that examination of induced sputum is a rapid, sensitive, and inexpensive method for diagnosing P. carinii pneumonia and that indirect immunofluorescence is a practical and highly sensitive staining technique for establishing this diagnosis.

Trimethoprim-sulfamethoxazole (TMP-SMZ) dose escalation versus direct rechallenge for Pneumocystis Carinii pneumonia prophylaxis in human immunodeficiency virus-infected patients with previous adverse reaction to TMP-SMZ.

Trimethoprim-sulfamethoxazole (TMP-SMZ) is the most effective Pneumocystis carinii pneumonia (PCP) prophylactic agent, but adverse reactions are common among human immunodeficiency virus (HIV)-infected patients and limit its use. This randomized, double-blind controlled trial compared 2 methods of TMP-SMZ reintroduction, 6-day dose escalation and direct rechallenge, for PCP prophylaxis in HIV-infected patients who had experienced previous treatment-limiting reactions. The primary end point was the ability to take single-strength TMP-SMZ daily for 6 months. Seventy-five percent of the dose-escalation group and 57% of the direct-rechallenge group continued to receive daily single-strength TMP-SMZ for 6 months (P= .014). Among premature discontinuations, 58% of the dose-escalation group and 70% of the direct-rechallenge group were due to adverse reactions. None of these reactions was serious. This study provides evidence that it is possible to successfully reintroduce TMP-SMZ to a significant proportion of HIV-infected patients who have experienced mild-to-moderate treatment-limiting adverse reactions.