Demographic and HIV-specific characteristics of participants enrolled in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

The risks and benefits of initiating antiretroviral treatment (ART) at high CD4 cell counts have not been reliably quantified. The Strategic Timing of AntiRetroviral Treatment (START) study is a randomized international clinical trial that compares immediate with deferred initiation of ART for HIV-positive individuals with CD4 cell counts above 500 cells/μL. We describe the demographics, HIV-specific characteristics and medical history of this cohort.

METHODS

Data collected at baseline include demographics, HIV-specific laboratory values, prior medical diagnoses and concomitant medications. Baseline characteristics were compared by geographical region, gender and age.

RESULTS

START enrolled 4685 HIV-positive participants from 215 sites in 35 countries. The median age is 36 years [interquartile range (IQR) 29-44 years], 27% are female, and 45% self-identify as white, 30% as black, 14% as Latino/Hispanic, 8% as Asian and 3% as other. The route of HIV acquisition is reported as men who have sex with men in 55% of participants, heterosexual sex in 38%, injecting drug use in 1% and other/unknown in 5%. Median time since HIV diagnosis is 1.0 year (IQR 0.4-3.0 years) and the median CD4 cell count and HIV RNA values at study entry are 651 cells/μL (IQR 584-765 cells/μL) and 12,754 HIV RNA copies/mL (IQR 3014-43,607 copies/mL), respectively.

CONCLUSIONS

START has enrolled a diverse group of ART-naïve individuals with high CD4 cell counts who are comparable to the HIV-positive population from the regions in which they were enrolled. The information collected with this robust study design will provide a database with which to evaluate the risks and benefits of early ART use for many important outcomes.

The use of tetanus toxoid to elucidate the delayed-type hypersensitivity response in an older, immunized population

Tuberculin reactivity decreases with age despite epidemiologic evidence that the elderly are more likely to have been infected. Whether this phenomenon is due to lack of antigenic stimulus or host inability to mount a delayed type hypersensitivity (DTH) response is unclear. In order to determine if the DTH response to tetanus toxoid in an exposed population is a useful tool to understand the phenomenon of lack of tuberculin reactivity in the remotely exposed elderly, a trial of skin testing was undertaken. Seventy-seven residents of a Veterans Affairs domiciliary were skin-tested using solutions of tetanus toxoid, candida and mumps skin test antigen. The 35 subjects who had negative reaction to the tetanus skin test were randomized into two groups: one which received tetanus vaccination before repeat skin testing and one which did not. Positive skin test reactions occurred in 42 patients to tetanus toxoid, 44 to mumps and 37 to candida. Of the 35 randomized, 27 were available for repeat skin tests. None reacted to the repeat tetanus skin test although 5 reacted to other antigens to which they had previously been nonreactive. Tetanus toxoid was equal to other antigens in its ability to elicit a DTH response originally; however antigenic stimulation with vaccination did not elicit positive skin test in nonreactors. Lack of DTH response to tetanus toxoid in recently vaccinated patients implies that nonresponse was secondary to host factors rather than lack of antigenic stimulation.

An uncommon Helicobacter isolate from blood: evidence of a group of Helicobacter spp. pathogenic in AIDS patients

An unusual Helicobacter sp. was isolated from the blood of a human immunodeficiency virus (HIV)-infected patient. This organism had spiral morphology, with single amphitrichous flagella, and was negative for hippurate hydrolysis, production of urease, and reduction of nitrate. 16S rRNA gene sequence analysis verified that the isolate was a species of Helicobacter, most closely related to an undescribed Helicobacter-like isolate from Vancouver, British Columbia, Canada, and to Helicobacter westmeadii, a recently described species from Australia. Both organisms had also been isolated from the blood of HIV-infected patients. These blood isolates, along with Helicobacter cinaedi, form a cluster of closely related Helicobacter spp. that may represent an emerging group of pathogens in immunocompromised patients.

A randomized, placebo-controlled study of rifabutin added to a regimen of clarithromycin and ethambutol for treatment of disseminated infection with Mycobacterium avium complex

Current guidelines suggest that disseminated Mycobacterium avium complex (MAC) infection be treated with a macrolide plus ethambutol or rifabutin or both. From 1993 to 1996, 198 AIDS patients with MAC bacteremia participated in a prospective, placebo-controlled trial of clarithromycin (500 mg b.i.d.) plus ethambutol (1,200 mg/d), with or without rifabutin (300 mg/d). At 16 weeks, 63% of patients in the rifabutin group and 61% in the placebo group (P = .81) had responded bacteriologically. Changes in clinical symptoms and time to survival were similar in both groups. Development of clarithromycin resistance during therapy was similar in the two groups; of patients who had a bacteriologic response, however, only 1 of 44 (2%) receiving rifabutin developed clarithromycin resistance, vs. 6 of 42 (14%) in the placebo group (P = .055). Thus, rifabutin had no impact on bacteriologic response or survival but may protect against development of clarithromycin resistance in those who respond to therapy.

Rates of tuberculosis infection in healthcare workers providing services to HIV-infected populations. Terry Beirn Community Programs for Clinical Research on AIDS

OBJECTIVE

To assess the prevalence of tuberculosis (TB) or a positive skin test in healthcare workers (HCWs) providing services to human immunodeficiency virus (HIV)-infected individuals and to determine prospectively the incidence of new infections in this population.

DESIGN

This prospective cohort study enrolled 1,014 HCWs working with HIV-infected populations from 10 metropolitan areas. Purified protein derivative (PPD) tuberculin skin tests were placed at baseline and every 6 months afterwards on those without a history of TB or a positive PPD. Demographic, occupational, and TB exposure data also were collected.

SETTING

Outpatient clinics, hospitals, private practice offices, and drug treatment programs providing HIV-related healthcare and research programs.

PARTICIPANTS

A voluntary sample of staff and volunteers from 16 Community Programs for Clinical Research on AIDS units.

RESULTS

Factors related to prior TB or a positive skin test at baseline included being foreign-born, increased length of time in health care, living in New York City, or previous bacille Calmette-Guerin vaccination. The rate of PPD conversion was 1.8 per 100 person years of follow-up. No independent relation was found between the amount or type of contact with HIV-infected populations and the risk of TB infection.

CONCLUSION

These data provide some reassurance that caring for HIV-infected patients is not related to an increased rate of TB infection among HCWs in these settings.

A controlled trial of isoniazid in persons with anergy and human immunodeficiency virus infection who are at high risk for tuberculosis. Terry Beirn Community Programs for Clinical Research on AIDS

BACKGROUND

Patients with human immunodeficiency virus (HIV) infection and latent tuberculosis are at substantial risk for the development of active tuberculosis. As a public health measure, prophylactic treatment with isoniazid has been suggested for HIV-infected persons who have anergy and are in groups with a high prevalence of tuberculosis.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled trial of six months of prophylactic isoniazid treatment in HIV-infected patients with anergy who have risk factors for tuberculosis infection. The primary end point was culture-confirmed tuberculosis.

RESULTS

The study was conducted from November 1991 through June 1996. Over 90 percent of the patients had two or more risk factors for tuberculosis infection, and nearly 75 percent of patients were from greater New York City. After a mean follow-up of 33 months, tuberculosis was diagnosed in only 6 of 257 patients in the placebo group and 3 of 260 patients in the isoniazid group (risk ratio, 0.48; 95 percent confidence interval, 0.12 to 1.91; P=0.30). There were no significant differences between the two groups with regard to death, death or the progression of HIV disease, or adverse events.

CONCLUSIONS

Even in HIV-infected patients with anergy and multiple risk factors for latent tuberculosis infection, the rate of development of active tuberculosis is low. This finding does not support the use of isoniazid prophylaxis in high-risk patients with HIV infection and anergy unless they have been exposed to active tuberculosis.

Early manifestations of disseminated Mycobacterium avium complex disease: a prospective evaluation

A nested case-control study was conducted in two trials of prophylaxis for Mycobacterium avium complex (MAC) infection to describe the specific signs, symptoms, and laboratory abnormalities of MAC disease in AIDS. Patients had < or =200/mm3 CD4 cells and a prior AIDS-defining illness. Of 571 patients, 102 (17.9%) developed MAC bacteremia during a mean follow-up of 256 days. Among cases of MAC disease, 90 were compared with 180 matched controls. Patients with MAC disease were more likely than controls to have lower weights (66.3 vs. 71.1 kg, P = .001) and Karnofsky scores (74.3 vs. 84.4, P < .001); a higher proportion had fever (48% vs. 26%, P = .003), abdominal pain (23% vs. 13%, P =.05), decreased hemoglobin levels (10.9 vs. 12.1 g/dL, P < .001), and elevated alkaline phosphatase (203 vs. 138 U/L, P=.04) and lactate dehydrogenase (334 vs. 280 U/L, P = .02) levels. Characteristics of MAC disease that occurred before bacteremia were weight loss (3 months prior), fever (2 months), and anemia and elevated lactate dehydrogenase (1 month). These data suggest that patients have symptomatic MAC disease for several months prior to the occurrence of bacteremia.

Geographic and seasonal variation in Mycobacterium avium bacteremia among North American patients with AIDS

Analysis of geographic risk was performed for Mycobacterium avium complex (MAC) bacteremia among North American patients with AIDS. Monthly mycobacterial blood cultures were taken from patients who were placebo recipients in a prospective evaluation of MAC prophylaxis. Of 571 patients, 102 (17.9%) acquired MAC bacteremia during an average follow-up of 256 days. The area with the highest risk for MAC was the South Central region (27.9%; P < 0.02), whereas the area with the lowest risk was Canada (11.3%; P = 0.12). When the southern states were combined and compared with the northern states and Canada, the incidence of MAC bacteremia was higher in the southern states (21.6% versus 14.0%, P < 0.03). Proportional hazards analysis was performed for the difference between the North and South and controlled for baseline CD4 cell count. In this analysis, time to MAC was significantly longer in the North (hazard ratio = 0.587, 95% confidence interval 0.390 to 0.883, P = 0.01). Although overall variation in seasonality was not marked, there was a significant decrease in cases in the North during the summer months (P < 0.01). We conclude that geographic location is a risk factor for MAC bacteremia in patients with advanced AIDS, with decreased risk in northern North America.

Mycobacterium szulgai infection of the lung: case report and review of an unusual pathogen

The nontuberculous mycobacteria are responsible for considerable morbidity in the immunocompromised and immunocompetent host, especially in the older patient with chronic fibrotic or cavitary disease of the lung. Mycobacterium szulgai is a slow growing mycobacterium infrequent in nature and man. Except from a snail and a tropical fish, it has been isolated only from humans and nearly always represents a true pathogen. Three-drug therapy using in vitro susceptibilities as a guide for 12 to 18 months increases the likelihood of success. We present a patient who developed M szulgai pulmonary infection 30 years after an episode of pulmonary tuberculosis. After successful therapy for his M szulgai infection, this patient developed chronic pulmonary histoplasmosis. We review the 25 years of clinical experience with this mycobacteria; particular emphasis is on the presentation and treatment of this very unusual infection.

Nontuberculous mycobacterial infections

The acquired immunodeficiency syndrome (AIDS) pandemic has led to greater understanding and respect for the pathogenic potential of non-tuberculous mycobacteria. Mycobacterium avium complex (MAC) has emerged as the most common systemic bacterial infection in AIDS, causing debilitating disseminated disease in late-stage HIV-infected patients. With the release of the macrolide antibiotics, clarithromycin and azithromycin, effective and well-tolerated therapeutic regimens for MAC have been developed which prolong survival and increase quality of life. The macrolides and rifabutin are also effective as preventive therapy for MAC in patients with AIDS. Mycobacterium kansasii, which causes pulmonary disease similar to tuberculosis as well as disseminated disease in AIDS, is treatable with isoniazid, rifampin and ethambutol. Clinical syndromes and therapeutic options for other non-tuberculous mycobacteria in AIDS are also reviewed.

Cigarette smoking, bacterial pneumonia, and other clinical outcomes in HIV-1 infection. Terry Beirn Community Programs for Clinical Research on AIDS

Cigarette smoking has been associated with impaired immune defenses and an increased risk of certain infectious and neoplastic diseases in HIV-1 seronegative populations. We examined the relationship between cigarette smoking and clinical outcome in a prospective cohort of 3221 HIV-1-seropositive men and women enrolled in the Terry Beirn Community Programs for Clinical Research on AIDS. Differences in clinical outcomes between never, former, and current cigarette smokers were assessed using proportional hazards regression analysis. After adjustment for CD4+ cell count, prior disease progression, use of antiretroviral therapy, and other covariates, there was no difference between current smokers and never smokers in the overall risk of opportunistic diseases [relative hazard (RH) = 1.05; 95% confidence interval (CI) 0.90-1.23; p = 0.52] or death (RH = 1.00; 95% CI 0.86-1.18; p = 0.97). However, current smokers were more likely than never smokers to develop bacterial pneumonia (RH = 1.57; 95% CI 1.14-2.15; p = 0.006), oral candidiasis (RH = 1.37; 95% CI 1.16-1.62; p = 0.0002), and AIDS dementia complex (RH = 1.80; 95% CI 1.11-2.90; p = 0.02). In addition, current smokers were less likely to develop Kaposi's sarcoma (RH = 0.58; 95% CI 0.39-0.88; p = 0.01) and several other non-respiratory tract diseases. If confirmed by other studies, these findings have important clinical implications.

Nontuberculous mycobacteria in patients with human immunodeficiency virus infection

Because of their often profound immune suppression, persons with HIV-infection are, increasingly, being identified as having morbidity related to mycobacteria. Indeed, mycobacterial disease is now the second most frequent cause of illness in AIDS patients receiving PCP prophylaxis with the majority of these patients in the United States having disease caused by M. avium complex (MAC). This section reviews the epidemiology, clinical presentation, treatment protocols, and prophylaxis strategies for MAC, as well as the other species of nontuberculosis mycobacteria being diagnosed in the setting of HIV infection. These organisms typically cause extrapulmonary, often disseminated disease in HIV infected persons, although pulmonary disease may occur. The prompt diagnosis and successful treatment of these infections can prolong the life and enhance its quality for affected patients with HIV coinfections.

The impact of human immunodeficiency virus infection on drug-resistant tuberculosis

Infection with human immunodeficiency virus (HIV) has been associated with increased rates of single- and multidrug-resistant (MDR) tuberculosis in the New York City area. In order to examine the relationship of HIV infection to drug-resistant tuberculosis in other selected regions of the United States, we established a registry of cases of culture-proven tuberculosis. Data were collected from sites participating in an NIH-funded, community-based HIV clinical trials group. All cases of tuberculosis, regardless of HIV status, which occurred between January 1992 and June 1994 were recorded. Overall, 1,373 cases of tuberculosis were evaluated, including 425 from the New York City area, and 948 from seven other metropolitan areas. The overall prevalence of resistance to one or more drugs was 20.4%, and 5.6% of isolates were resistant to both isoniazid and rifampin (MDR). In the New York City area, HIV-infected patients were significantly more likely than persons not known to be HIV-infected, to have resistance to at least one drug (37% versus 19%) and MDR (19% versus 6%). In other geographic areas, overall drug resistance was 16%, and only 2.2% of isolates were MDR. In multiple logistic regression analyses, HIV infection was shown to be a risk factor for drug-resistant tuberculosis, independent of geographic location, history of prior therapy, age, and race. We concluded that HIV infection is associated with increased rates of resistance to antituberculosis drugs in both the New York City area and other geographic areas. MDR tuberculosis is occurring predominantly in the New York City area and is highly correlated with HIV infection.

Long-term follow-up of symptomatic HIV-infected patients originally randomized to early versus later zidovudine treatment; report of a Veterans Affairs Cooperative Study. VA Cooperative Study Group on AIDS Treatment

Following a 4-year controlled trial comparing early and later zidovudine treatment, we conducted an additional 3-year follow-up. Of the original 338 patients, 275 participated. Clinical outcome measures were AIDS and death. In the early therapy group (n = 170), 67 patients progressed to AIDS compared with 85 in the later therapy group (n = 168); the relative risk (RR) comparing early with later therapy was 0.72% (95% confidence interval [CI] 0.52-0.99; p = 0.044). The early therapy group had 74 deaths compared with 73 in the later therapy (RR = 0.98; 95% CI, 0.71-1.36; p = 0.91). The early group had a peak CD4+ count increase at 1-2 months and a delay of 1 year before CD4+ counts fell below baseline. For patients who received zidovudine for more than the median duration (20.3 months) before their first AIDS diagnosis, the RR for death was 2.08 (95% CI, 1.36-3.19, p = 0.001). Additional factors independently associated with poor prognosis following AIDS were a CD4+ count of < 100 cells/mm3 and increased severity of the first AIDS diagnosis, whereas use of another antiretroviral agent was associated with improved survival. We conclude that early zidovudine therapy delays progression to AIDS but does not affect survival. Patients who progress to AIDS while on prolonged zidovudine monotherapy many benefit from a change to other antiretroviral therapy(ies).

Two-stage tuberculin skin testing in individuals with human immunodeficiency virus infection. Community Programs for Clinical Research on AIDS

In this study we estimated occurrence of the booster effect in a population infected with the human immunodeficiency virus (HIV) and assessed the relation between the booster effect, T-lymphocyte CD4 cell counts, tuberculosis risk categories, and HIV exposure categories. Patients were recruited from 13 participating sites of the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). A two-stage tuberculin skin test was applied to 709 HIV-infected patients using the Mantoux method. An induration reading < 5 mm on the first test and > or = 5 on the second skin test defined the booster effect. Overall, 18 patients, or 2.7% (95% confidence interval, 1.6 to 4.2) experienced the booster effect. Boosted responses were seen in eight (2.1%) anergic patients, six (4.5%) nonanergic patients, and four (2.5%) with anergy status unknown. Boosting was noted in 1 of the 131 women enrolled. Age, race, CD4 cell count, injection drug use, anergy status, tuberculosis risk categories, and HIV exposure categories were not predictive of boosting. The booster effect occurs in a small percentage of HIV-infected patients tested, thus identifying small numbers of patients with latent tuberculosis infection. The two-stage procedure is probably of limited value in the diagnosis of latent tuberculosis in HIV-infected persons.

Efficacy of rifabutin in the treatment of disseminated infection due to Mycobacterium avium complex. The Rifabutin Treatment Group

The incidence of infection with Mycobacterium avium complex (MAC) is increasing among patients with AIDS. Although numerous antimicrobial regimens have been proposed as treatment for this infection, it is unclear which therapy is most effective. For this reason, we prospectively evaluated rifabutin (600 mg/d) vs. a placebo, each in combination with clofazimine and ethambutol, for the treatment of MAC bacteremia. Patients in the rifabutin group had a significantly higher rate of microbiological response (defined as either sterilization of the blood or at least a 2-log10 reduction in mycobacterial titers). By week 4 of therapy, 7 of 11 patients receiving rifabutin, vs. 0 of 13 in the placebo group, had responded (P < .001). Similar results were seen at later time points (7 of 10 vs. 1 of 8 responded to rifabutin by week 8, and 6 of 9 vs. 1 of 7 responded to a placebo by week 12). These results indicate that, in combination with other antimicrobial agents, rifabutin may be effective in the treatment of disseminated MAC infection.

Delayed-type hypersensitivity skin tests are an independent predictor of human immunodeficiency virus disease progression. Department of Veterans Affairs Cooperative Study Group

Delayed-type hypersensitivity (DTH) testing was evaluated as a predictor of human immunodeficiency virus (HIV) disease progression in 336 symptomatic patients with baseline CD4 cell counts of 200-500/mm3 who were participating in a randomized trial of early versus late therapy with zidovudine. Patients with a response of > 2 mm to any of seven antigens were categorized as reactive; those without were anergic. Anergic patients were significantly more likely than reactive patients to have HIV disease progression as evidenced by decrease in CD4 cell count (52% vs. 27%), development of AIDS (33% vs. 17%), or death (18% vs. 9%) (P < or = .02), irrespective of time of zidovudine initiation. By multivariate analysis, DTH results were an independent predictor of HIV progression separate from CD4 cell count, p24 antigen positivity, or level of beta 2-microglobulin. DTH skin tests are an independent predictor of HIV disease progression and may be of value in the evaluation of a patient's immune status.

Two controlled trials of rifabutin prophylaxis against Mycobacterium avium complex infection in AIDS

BACKGROUND

Disseminated Mycobacterium avium complex infection eventually develops in most patients with the acquired immunodeficiency syndrome (AIDS). This infection results in substantial morbidity and reduces survival by about six months.

METHODS

We conducted two randomized, double-blind, multicenter trials of daily prophylactic treatment with either rifabutin (300 mg) or placebo. All the patients had AIDS and CD4 cell counts < or = 200 per cubic millimeter. The primary end point was M. avium complex bacteremia as assessed monthly by blood culture. The secondary end points were signs and symptoms associated with disseminated M. avium complex infection, adverse events, hospitalization, and survival.

RESULTS

In the first trial, M. avium complex bacteremia developed in 51 of 298 patients (17 percent) assigned to placebo and 24 of 292 patients (8 percent) assigned to rifabutin (P < 0.001). In the second trial, bacteremia developed in 51 of 282 patients in the placebo group (18 percent) and 24 of 274 patients in the rifabutin group (9 percent) (P = 0.002). Rifabutin significantly delayed fatigue, fever, decline in the Karnofsky performance score (by > or = 20 percent), decline in the hemoglobin level (by more than 10 percent), elevation in alkaline phosphatase, and hospitalization. The incidence of adverse events was similar with rifabutin and placebo. Overall survival did not differ significantly between the two groups, although there were fewer deaths with rifabutin (33) than with placebo (47) during the double-blind phase (P = 0.086). The distribution of minimal inhibitory concentrations of rifabutin among the isolates of M. avium complex did not differ significantly between the treatment groups.

CONCLUSIONS

Rifabutin, given prophylactically, reduces the frequency of disseminated M. avium complex infection in patients with AIDS and CD4 counts < or = 200 per cubic millimeter.

A controlled trial of early versus late treatment with zidovudine in symptomatic human immunodeficiency virus infection. Results of the Veterans Affairs Cooperative Study

BACKGROUND

Zidovudine is recommended for asymptomatic and early symptomatic human immunodeficiency virus (HIV) infection. The best time to initiate zidovudine treatment remains uncertain, however, and whether early treatment improves survival has not been established.

METHODS

We conducted a multicenter, randomized, double-blind trial that compared early zidovudine therapy (beginning at 1500 mg per day) with late therapy in HIV-infected patients who were symptomatic and had CD4+ counts between 0.2 x 10(9) and 0.5 x 10(9) cells per liter (200 to 500 per cubic millimeter) at entry. Those assigned to late therapy initially received placebo and began zidovudine when their CD4+ counts fell below 0.2 x 10(9) per liter (200 per cubic millimeter) or when the acquired immunodeficiency syndrome (AIDS) developed.

RESULTS

During a mean follow-up period of more than two years, there were 23 deaths in the early-therapy group (n = 170) and 20 deaths in the late-therapy group (n = 168) (P = 0.48; relative risk [late vs. early], 0.81; 95 percent confidence interval, 0.44 to 1.59). In the early-therapy group, 28 patients progressed to AIDS, as compared with 48 in the late-therapy group (P = 0.02; relative risk, 1.76; 95 percent confidence interval, 1.1 to 2.8). Early therapy increased the time until CD4+ counts fell below 0.2 x 10(9) per liter (200 per cubic millimeter), and it produced more conversions from positive to negative for serum p24 antigen. Early therapy was associated with more anemia, leukopenia, nausea, vomiting, and diarrhea, whereas late therapy was associated with more skin rash.

CONCLUSIONS

In symptomatic patients with HIV infection, early treatment with zidovudine delays progression to AIDS, but in this controlled study it did not improve survival, and it was associated with more side effects.

Nosocomial outbreak of respiratory tract colonization with Mycobacterium fortuitum: demonstration of the usefulness of pulsed-field gel electrophoresis in an epidemiologic investigation

Between August 1989 and January 1990, 16 patients on an alcoholism rehabilitation ward (ARW) developed positive sputum cultures for Mycobacterium fortuitum. During a 2-wk surveillance period, six of 43 ARW patients but none of 20 staff members had positive sputum cultures. In addition, none of 54 patients and staff on an adjacent ward sharing the same ice machine and water supply had positive cultures, and none of 92 acid-fast bacilli cultures performed on all sputum specimens from all other inpatient sources during the same 2-wk period were positive. The only exposure factor common to all cases was the use of one or both of the ward showers. Compared with 36 ARW control patients, cases were more likely to report clinical criteria for chronic bronchitis (odds ratio, 6.6; 95% confidence interval, 1.5 to 28.6; p = 0.02). Using phenotype analysis, plasmid profiles, and pulsed-field gel electrophoresis of large genomic DNA restriction enzyme fragments, the 16 case isolates were found to be identical. This strain of M. fortuitum was also cultured from a tap connected to the water line supplying the ARW showers, but not from the showers themselves. No further cases were identified after the showers were disconnected and decontaminated. To our knowledge, this is the first clinical use of pulsed-field gel electrophoresis for genetic comparison of mycobacterial strains. It demonstrates the important potential of this technique for studying the epidemiology of mycobacterial infections. Showers should be considered a possible source of nosocomial respiratory tract colonization with M. fortuitum.

Use of ciprofloxacin for successful eradication of bacteremia due to Campylobacter cinaedi in a human immunodeficiency virus-infected person

A 36-year-old homosexual man who was infected with human immunodeficiency virus presented with a 2-month history of fever and intermittent diarrhea. Stool cultures were negative for bacterial pathogens, ova, parasites, and acid-fast organisms. An initial blood culture became positive after 5 days for a curved, gram-negative rod that was identified later as Campylobacter cinaedi. The patient received a series of antibiotic regimens, including a 2-week course of erythromycin followed by a 2-week course of tetracycline, but follow-up blood cultures continued to yield C. cinaedi. The patient was then treated with a 2-week course of oral ciprofloxacin; he remained asymptomatic 11 weeks later, at which time a blood culture was negative for C. cinaedi. To the best of our knowledge, this is the first documented case of symptomatic bacteremia due to C. cinaedi that was successfully treated with ciprofloxacin.

Stability of positive tuberculin tests: are boosted reactions valid?

To determine the stability and presumed significance of tuberculin skin tests, we followed a cohort of 380 tuberculin-positive patients living in chronic care facilities. Each patient had a positive reaction (greater than or equal to 10 mm induration to 5 tuberculin units of purified protein derivative) to one of three sequential baseline tuberculin tests. One year after the initial series, each patient had a single repeat skin test. Reversion to a negative test occurred in 98 (26%) of the 380 patients. Decreases in induration of 6 mm or more occurred in 88 (90%) of the reverters. Initially positive tests were more likely (p less than 0.001) to remain stable than tests that were "boosted" to positive reactions on the second or third initial administration. Stable responses were found in 96% of those whose tests had greater than or equal to 15 mm induration compared with 61% of those with reactions of 10 to 14 mm induration. Increasing age also was associated with a high rate of reversion. The instability of boosted tuberculin reactions brings into question the clinical significance of these tests. We propose limiting tuberculin testing to two sequential tests.

Aerosol pentamidine prophylaxis following Pneumocystis carinii pneumonia in AIDS patients: results of a blinded dose-comparison study using an ultrasonic nebulizer

PURPOSE

To compare the efficacy and safety of three different doses of prophylactic aerosol pentamidine in patients with one prior episode of Pneumocystis carinii pneumonia (PCP) and the acquired immunodeficiency syndrome.

PATIENTS AND METHODS

The design of the study was a double-blind, randomized, dose-comparison clinical trial conducted at 13 medical centers within the United States. In stage I of the trial, patients were randomized to receive either 5 mg, 60 mg, or 120 mg of aerosol pentamidine delivered biweekly with the Fisoneb (Fisons, Inc., Rochester, New York) ultrasonic nebulizer. After 24 weeks of therapy, patients entered stage II of the trial, where the 5-mg group was re-randomized to either the 60-mg or 120-mg group.

RESULTS

One hundred seventy-five patients entered stage I of the trial and received prophylaxis for a mean of 123.6 days. Seven assigned to the 5-mg biweekly dosing schedule had a confirmed recurrence of PCP, compared with none in the 60-mg group (p = 0.007) and three in the 120-mg group (p = 0.304). During stage II of the trial, eight patients in the 60-mg group and one additional patient in the 120-mg group had recurrent PCP. After 52 weeks of observation, the likelihood of being PCP-free was 88.0% in the 60-mg group and 93% in the 120-mg group (p = 0.712). Minor adverse events related to aerosol pentamidine administration included cough, taste perversion, chest pain, bronchospasm, and dyspnea. These side effects were more common in the 60-mg and 120-mg treatment groups and resulted in withdrawal from the study by one patient. Serious events were more common after 24 weeks of therapy and included asymptomatic hypoglycemia (five), pancreatitis (two), pneumothorax (one), and extrapulmonary pneumocystosis (one).

CONCLUSIONS

These results demonstrate that biweekly administration of 60 mg or 120 mg of aerosol pentamidine significantly decreases PCP recurrence when compared with a 5-mg regimen or findings in historic controls and is generally well tolerated. There is no significant difference in effect or safety between these two dosing regimens in patients followed for at least 52 weeks of therapy.

Disseminated Mycobacterium fortuitum successfully treated with combination therapy including ciprofloxacin

We report a case of disseminated Mycobacterium fortuitum in a 76-yr-old male with no identifiable predisposing factors except chronic interstitial lung disease. Recurrent, progressive pulmonary symptoms and radiographic findings were followed by the development of multiple, culture-positive peripheral lesions. The patient responded rapidly and completely to combination therapy consisting primarily of ciprofloxacin, minocycline, and surgical drainage. Our experience supports the cautious use and further study of fluorinated quinolones for M. fortuitum infections caused by susceptible isolates.

Prevalence of human immunodeficiency virus and hepatitis B virus in unselected hospital admissions: implications for mandatory testing and universal precautions

The prevalence of human immunodeficiency virus (HIV) and hepatitis B virus in serial unselected hospital admissions was determined to examine the potential efficacy of a system of universal blood and body fluid precautions versus a system based on selected or unselected screening. Serum was obtained from 616 (97%) of the 636 patients admitted during a 1-month period and interviews were completed on 540. Of the 616, 23 (3.7%) were confirmed positive for HIV, and 12 (2.0%) of 612 for hepatitis B surface antigen. Of 33 infected persons, only 8 were known to be positive on admission and only 22 were in "high-risk" groups; therefore, selective precautions would not have been effective. Mandatory testing would have required 1216 tests to identify 25 infected persons and would leave in doubt the presence of other transmissible diseases. On the basis of these data, it appears that universal precautions are a logical system of infection control.

Severe pancreatitis in an AIDS patient in association with cytomegalovirus infection

We have reported a case of pancreatitis caused by CMV in an AIDS patient. Although CMV has caused clinical disease of other gastrointestinal organs, pancreatic involvement has previously been demonstrated only in autopsy specimens. The etiology of "idiopathic" pancreatitis in AIDS patients should be investigated, as therapeutic intervention may be available for some of these persons.

Presumptive diagnosis and treatment of pulmonary tuberculosis based on radiographic findings

We analyzed the outcome of therapy for 139 patients who were treated for a presumptive diagnosis of pulmonary tuberculosis based on radiographic abnormalities. Patients who had acid-fast bacilli seen on sputum smears and patients who had received adequate therapy for tuberculosis in the past were excluded from the analysis. Accuracy of the diagnosis was determined by comparison of clinical and radiographic findings after 3 months of isoniazid, rifampin, and ethambutol, as well as the results of sputum cultures. Of 139 patients started on therapy presumptively, 66 (48%) were determined to have current tuberculosis (16 had positive cultures, 43 because of improvement in their chest films, and 7 because of clinical improvement). Adverse reactions requiring change of therapy occurred in six of 72 (8.3%) patients determined to have inactive tuberculosis. One patient had both tuberculosis and carcinoma found at bronchoscopy after 3 months of therapy. For purposes of comparison, chest radiographs of 59 patients documented by culture to have current tuberculosis were reviewed. Of these, 45 (70%) were improved at 3 months. Presumptive therapy is of benefit in that it stops progression of the disease at an early stage and decreases the potential for spread of tuberculous infection. In addition, such therapy coupled with systematic reevaluation of patients substantiates the diagnosis or indicates that further evaluation is needed. These benefits must be weighed against the adverse reactions and costs of overtreating patients with inactive disease. Determining the appropriateness of presumptive therapy must be based on local factors including prevalence of tuberculosis and available resources.

Evaluation of a third sequential tuberculin skin test in a chronic care population

To evaluate factors that might influence the accuracy of tuberculin tests in identifying elderly persons recently infected with Mycobacterium tuberculosis, we performed as many as 3 sequential administrations of 5 tuberculin units of purified protein derivative in 1,726 persons residing in chronic care facilities. Significant reactions (greater than or equal to 10 mm of induration) to 1 of 3 tests were found in 702 (40.7%) persons. Of these, 68% were found with Test 1, 22.5% with Test 2, and 9.5% with Test 3. Of 1,146 persons with nonsignificant reactions to Test 1, 13.8% had significant reactions on Test 2, and of 769 persons with nonsignificant reactions to Tests 1 and 2, 8.7% had significant reactions on Test 3. Males, nonwhites, and persons between 50 and 79 yr of age had a greater proportion of significant reactions for each of the first 2 tests but not for the third test. These data indicate that continued boosting of the tuberculin reaction occurs in a substantial number of persons who receive a third sequential test. Marked increases in the size of reactions caused by boosting may explain high apparent conversion rates found in facilities where the third test is delayed for one year.

Knowledge of AIDS among hospital workers: behavioral correlates and consequences

Incidents of suboptimal care being rendered to AIDS patients have been documented. Using a voluntary anonymous questionnaire, we surveyed the employees of a large urban hospital in order to evaluate the knowledge, attitudes and professional behavior of the staff regarding AIDS. Responses were obtained from 1194 (60%) of the staff. Poor knowledge of the transmission of AIDS was documented, with 50% of workers stating that AIDS can be spread through ordinary non-sexual contact and 23% through the air by a cough or a sneeze. One-third of employees believed that they should be able to refuse to care for patients with AIDS. Extreme anxiety in dealing with AIDS patients was noted by 25% of employees, and only 16% of the employees would volunteer to work on an AIDS ward. Knowledge regarding AIDS was demonstrated to be a predictor of positive attitudes, appropriate professional behavior and lower anxiety in dealing with AIDS patients. The goal of hospital education programs on AIDS must be to ensure the incorporation of accurate information into the belief system of workers.

Evaluation of combination chemotherapy in a lightly anesthetized animal model of Pseudomonas pneumonia

Gram-negative bacillary pneumonia is a major cause of morbidity and mortality in hospitalized patients. The use of synergistic combinations of aminoglycosides and beta-lactams for therapy of this infection has been recommended but remains controversial. We designed a new model of Pseudomonas pneumonia in a lightly sedated guinea pig by using a long-acting anesthetic to impair natural respiratory defenses. We used this model to compare the efficacy of ceftazidime and tobramycin alone and in combination in the therapy of Pseudomonas pneumonia. The two antibiotics were shown to be synergistic in vitro for the strain of Pseudomonas aeruginosa tested. Treated animals receiving both antibiotics had fewer viable bacteria remaining in lung tissues (P less than 0.05) and exhibited a trend towards improved survival in comparison to animals receiving a single drug. In this model of Pseudomonas pneumonia, in vitro synergy was reflected by increased efficacy in vivo.

Activities of pefloxacin and ciprofloxacin in experimentally induced Pseudomonas pneumonia in neutropenic guinea pigs

Pefloxacin and ciprofloxacin are two new quinoline carboxylic acid derivatives that have activity in vitro against a wide range of gram-negative bacteria, including Pseudomonas aeruginosa. Using a well-standardized model of Pseudomonas pneumonia in neutropenic guinea pigs, we tested the efficacy in vivo of these new agents. Both were highly effective in increasing survival and decreasing bacterial counts in the lungs of surviving animals. Pefloxacin and ciprofloxacin were significantly better (P less than 0.05) than aminoglycosides or beta-lactams tested in prior studies with this model, and they were as effective as combination therapy with aminoglycosides and beta-lactams. Resistance to either ciprofloxacin or pefloxacin did not emerge during the study period. Further studies with these drugs in the therapy of Pseudomonas sp. infections are warranted.

Once-daily ceftriaxone for skin and soft tissue infections

We prospectively compared once-daily administration of ceftriaxone with cefazolin given every 8 h for the treatment of skin and soft tissue infections. Thirty-one patients received cefazolin for a mean of 4.5 days, and 26 patients received ceftriaxone for a mean of 4.0 days. All patients had a satisfactory response. Adverse reactions were few and reversible. Ceftriaxone given as a single daily intramuscular injection is effective therapy for skin and soft tissue infections.

Adverse reactions to trimethoprim-sulfamethoxazole in patients with the acquired immunodeficiency syndrome

We reviewed the charts of 38 patients with the acquired immunodeficiency syndrome who were treated for Pneumocystis carinii pneumonia. Only 5 of 37 patients started on trimethoprim-sulfamethoxazole were able to complete treatment; in 29 patients drug toxicity occurred and in 19 treatment was changed due to adverse reactions that included rash, fever, neutropenia, thrombocytopenia, and transaminase elevation. Pentamidine was given to 30 patients (1 as initial treatment); toxicity occurred in 13 but only 4 required a change in drug. Adverse reactions from pentamidine included fever, rash, neutropenia, transaminase elevation, azotemia, and hypoglycemia. Patients received trimethoprim-sulfamethoxazole a median of 9.5 days, and pentamidine, a median of 12.5 days. Toxicity from trimethoprim-sulfamethoxazole appeared earlier than toxicity associated with pentamidine (7.5 versus 9.5 days of treatment). In patients with the acquired immunodeficiency syndrome, trimethoprim-sulfamethoxazole has a higher incidence of adverse reactions than pentamidine (p less than 0.005).

Amdinocillin therapy of experimental animal infections

Amdinocillin has been shown to have broad coverage in vitro against many strains of Enterobacteriaceae. Synergy has been demonstrated in vitro with several other beta-lactam antibiotics. The rabbit model of meningitis was used to study the in vivo effectiveness of amdinocillin when combined with other beta-lactams for serious infections. Organisms that showed an enhanced in vitro bactericidal effect from the combination of amdinocillin and another beta-lactam showed more rapid elimination of the organisms in vivo.