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Setting QuantiFERON®-TB Gold Plus (QFT-Plus), recently approved for use in the United States, is a new-generation QuantiFERON assay that differs from its predecessors in that it uses an additional antigen tube containing peptides to elicit both CD8+ and CD4+ T-lymphocyte responses. Objective To assess the sensitivity of QFT-Plus compared with QuantiFERON®-TB Gold In-Tube (QFT-GIT) in participants with active TB. Design Adult patients with active TB at three US and two Japanese sites were eligible for this study if they had culture-confirmed TB and were either untreated or had received 14 days of anti-tuberculosis treatment. Results We enrolled 164 participants, nine of whom had indeterminate results. Excluding indeterminate values, there were 150 QFT-GIT-positive results among 159 tests and 146 QFT-Plus-positive results among 157 tests, with sensitivities of respectively 94.3% (95%CI 89.5-97.4) and 93.02% (95%CI 87.8-96.5%). The estimated sensitivities for the two tests were not significantly different (P = 0.16). Overall test agreement was 98.7%, with a κ statistic of 0.89 (95%CI 0.75-1.00). Conclusion In this multisite study, we found that QFT-Plus had similar sensitivity to QFT-GIT in adult patients with active TB.

We hypothesized that dosing vancomycin to achieve trough concentrations of >15 mg/liter overdoses many adults compared to area under the concentration-time curve (AUC)-guided dosing. We conducted a 3-year, prospective study of vancomycin dosing, plasma concentrations, and outcomes. In year 1, nonstudy clinicians targeted trough concentrations of 10 to 20 mg/liter (infection dependent) and controlled dosing. In years 2 and 3, the study team controlled vancomycin dosing with BestDose Bayesian software to achieve a daily, steady-state AUC/MIC ratio of ≥400, with a maximum AUC value of 800 mg · h/liter, regardless of trough concentration. For Bayesian estimation of AUCs, we used trough samples in years 1 and 2 and optimally timed samples in year 3. We enrolled 252 adults who were ≥18 years old with ≥1 available vancomycin concentration. Only 19% of all trough concentrations were therapeutic versus 70% of AUCs ( P < 0.0001). After enrollment, median trough concentrations by year were 14.4, 9.7, and 10.9 mg/liter ( P = 0.005), with 36%, 7%, and 6% over 15 mg/liter ( P < 0.0001). Bayesian AUC-guided dosing in years 2 and 3 was associated with fewer additional blood samples per subject (3.6, 2.0, and 2.4; P = 0.003), shorter therapy durations (8.2, 5.4, and 4.7 days; P = 0.03), and reduced nephrotoxicity (8%, 0%, and 2%; P = 0.01). The median inpatient stay was 20 days among nephrotoxic patients versus 6 days ( P = 0.002). There was no difference in efficacy by year, with 42% of patients having microbiologically proven infections. Compared to trough concentration targets, AUC-guided, Bayesian estimation-assisted vancomycin dosing was associated with decreased nephrotoxicity, reduced per-patient blood sampling, and shorter length of therapy, without compromising efficacy. These benefits have the potential for substantial cost savings. (This study has been registered at ClinicalTrials.gov under registration no. NCT01932034.)

Background: Ambient air pollution and tuberculosis (TB) have an impact on public health worldwide, yet associations between the two remain uncertain. Objective: We determined the impact of resident...

BACKGROUND Isoniazid-resistant (INHr) Mycobacterium tuberculosis isolates often have katG mutations, and katG is a virulence factor in animal models. It is unclear if katG mutations or other mutations influence the characteristics of human disease. OBJECTIVE To determine if the presence of INHr-conferring mutations were associated with distinct clinical features of tuberculosis (TB). METHODS In a retrospective case-control study, INHr-conferring mutations were determined by DNA sequencing. We examined associations between clinical characteristics in patients with INHr M. tuberculosis (stratified by groups of relevant INHr-conferring mutations, including katG-S315T and inhA-C(-)15T mutations) and pan-susceptible (PS) isolates. RESULTS Twenty-nine INHr TB cases and 50 PS controls were evaluated. Disease characteristics were not statistically different between INHr and PS cases. However, patients infected with non-katG mutants were associated with a higher rate of sputum culture conversion at 1 month after adjustment for relevant covariates (adjusted OR [aOR] 4.4, 95%CI 1.1-23.6, P = 0.04). Patients infected with katG mutants were associated with a higher rate of unilateral disease (aOR 4.7, 95%CI 1.0-34.3, P = 0.05). CONCLUSIONS Most INHr TB cases with non-katG mutations have disease associated with faster response to treatment, and most cases with katG mutants have localized lung involvement.

Rifabutin was recommended in place of rifampin during treatment of HIV-related tuberculosis (TB) to facilitate concomitant potent antiretroviral therapy, but this approach has not been evaluated in a prospective study.To evaluate the activity of intermittent rifabutin-based therapy.Patients with culture-confirmed TB were treated under direct supervision with 2 mo of rifabutin, isoniazid, pyrazinamide, and ethambutol (given daily, thrice-weekly, or twice-weekly per the local tuberculosis control program), followed by 4 mo of twice-weekly rifabutin plus isoniazid.Culture-positive treatment failure or relapse.A total of 169 eligible patients were enrolled. Most had advanced HIV disease; the median CD4 cell count and HIV-RNA level were 90 cells/mm3 (interquartile range, 35-175) and 5.3 log10 copies/ml (interquartile range, 4.8-5.7), respectively. Nine (5.3%) patients had culture-positive treatment failure (n = 3) or relapse (n = 6). Eight of these nine (89%) cases had isolates with acquired rifamycin resistance. Treatment failure or relapse was associated with baseline CD4 lymphocyte count, being 12.3% (9/73; 95% confidence interval, 6.5-22.0%) among patients with CD4100 cells/mm3 versus 0% (0/65; 95% confidence interval, 0.0-4.5%) among those with higher CD4 lymphocyte counts (p0.01). One hundred thirty-seven (81%) patients received antiretroviral therapy during TB treatment. Adverse events were common, but only two patients (1%) permanently discontinued study drugs.Intermittent rifabutin-based therapy for HIV-related TB was well tolerated, but there was a high risk of treatment failure or relapse with acquired rifamycin resistance among patients with low CD4 lymphocyte counts.

Human immunodeficiency virus (HIV)-related tuberculosis can be life-threatening for the individual, transmissible to others, and difficult to diagnose. We review the clinical, radiographic, and histopathologic features of HIV-related tuberculosis, and the ways in which these features are affected by the degree of immunodeficiency. At CD4 cell counts greater than 350 cells/microL, HIV-related tuberculosis has a similar presentation to tuberculosis in HIV-uninfected adults, predominantly pulmonary involvement with fibronodular and/or cavitary infiltrates. With progressive immunodeficiency, extrapulmonary involvement becomes increasingly common. Pulmonary involvement remains common at all stages of HIV disease, but the radiographic pattern is very different among persons with advanced immunodeficiency, in whom the most common abnormalities are intrathoracic adenopathy, focal lower or middle lobe infiltrates, and diffuse miliary or nodular infiltrates. The keys to the diagnosis of HIV-related tuberculosis are knowledge of the epidemiology of tuberculosis, recognition of the ways that immunodeficiency changes the clinical presentation, and an assiduous effort to obtain specimens for mycobacterial smear and culture.

The objective of this study is to compare how likely positive tuberculin skin test (TST) and T-SPOT(®).TB (TSPOT) results predict risk factors for tuberculosis in a predominantly immigrant patient population at risk of latent TB infection (LTBI) and with rheumatologic conditions requiring immunomodulatory therapy (IMT).Prospective study conducted at a referral rheumatology clinic. Inclusion criteria included patients on various IMT, including immunosuppressive drugs that could predispose to TB progression. We studied risk factors associated with LTBI, test results, and tests' agreement.We studied 101 patients. Eighty (79.2 %) were from countries where TB is prevalent and Bacille Calmette-Guérin vaccination is placed routinely. Seventy-four (73.3 %) had rheumatoid arthritis and 92 (90.7 %) were on IMT. Among patients with both TST and TSPOT results, 25 (30.9 %) were TST(+) and 20 (24.7 %) had TSPOT(+) results. Fifteen patients (18.5 %) had TST(+)/TSPOT(+) results, and 51 (63.0 %) had TST(-)/TSPOT(-) results (agreement = 81.5 %; kappa = .54 [95 % CI, .34-.74; P.001]). Each TSPOT(+) and TST(+) results were independently associated with immigrant status and prior residence in a TB prevalent country after adjustment for immunosuppressive therapy: Adjusted OR(TSPOT+)=6.6 (95 % CI, 1.2-123.3; P = .027); and adjusted OR(TST+)=11.2 (95 % CI, 2.0-209.5; P = .003). Seven out of 10 TST(+)/TSPOT(-) cases had a TST ≥15 mm induration, including three cases with history of TST conversion.TST(+) and TSPOT(+) results predict risk factors associated with LTBI independent of immunosuppressive IMT. Some TST(+)/TSPOT(-) results were unlikely to be false-negatives. The combined use of TST and TSPOT appears to be a reasonable diagnostic strategy to evaluate for LTBI in this population.

Keywords: tuberculosis; HIV infection; antiretroviral therapy; rifampin; rifabutin; protease inhibitor; drug–drug interactions; immune reconstitution

To identify sites of tuberculosis transmission and to determine the contribution of HIV-infected patients to tuberculosis morbidity in an urban area, we prospectively evaluated 249 patients with culture-proven tuberculosis in central Los Angeles. Restriction fragment length polymorphism (RFLP) analysis was performed on Mycobacterium tuberculosis isolates to identify patients infected with the same strain. Using RFLP and clinical and epidemiologic data, we identified the most likely source case and site of transmission for 79 patients. Homelessness, birth in the United States and Native American ethnicity were independent predictors of being a source case, but HIV infection was not. Three homeless shelters were sites of tuberculosis transmission for 55 (70%) of the 79 patients. HIV-infected patients constituted 27% (66/249) of the study population, but only 17% (13/79) of patients were infected by an HIV-infected source case. We conclude that transmission of tuberculosis in central Los Angeles was highly focal, and that the major transmission sites were three homeless shelters. HIV- infected tuberculosis patients did not play a major role in spread of tuberculosis. Tuberculosis control measures targeted at specific homeless shelters can reduce tuberculosis morbidity in urban areas where homelessness is common and the incidence of tuberculosis is high.

Brainstem tuberculoma is an uncommon entity especially in the immunocompetent adult. The authors describe the case of a 32-year-old immunocompetent woman with no systemic signs or symptoms of tuberculosis, presenting with sudden-onset hemiparesis and diplopia. MRI of brain revealed an enhancing lesion in the midbrain and thalamus. Cerebrospinal fluid examination was normal. Chest imaging was consistent with miliary tuberculosis; however initial expectorated sputum was culture negative. Bronchosopy sputum culture was positive for Mycobacterium tuberculosis. Her PPD was negative. Patient became asymptomatic with treatment for tuberculosis and follow-up MRI showed complete resolution of the lesion a year later. We conclude that a high index of suspicion is essential to make an early diagnosis of intracranial tuberculoma, since often, traditional TB tests like PPD and sputum examinations can be negative.

This study examined whether adding levofloxacin to a standard four-drug regimen improved the 8-week culture response and compared effectiveness of 9 versus 6 months of intermittent therapy for human immunodeficiency virus-related pansusceptible pulmonary tuberculosis. Patients were randomized to receive either four or five drugs, the fifth being levofloxacin. Patients who completed induction therapy were randomized to complete 9 versus 6 months of intermittent therapy with isoniazid and rifampin. In the randomized induction phase, 97.3% of patients in the four-drug group and 95.8% in the five-drug group had sputum culture conversion at 8 weeks (P = 1.00). In the continuation phase, one patient (2%) assigned to 9 months and two patients (3.9%) assigned to 6 months of therapy had treatment failure/relapse (P = 1.00). In conclusion, this study showed that levofloxacin added no benefit to a highly effective, largely intermittent, four-drug induction regimen. Both 9 and 6 months of intermittent therapy were associated with low treatment failure/relapse rates.

We evaluated 85 human immunodeficiency virus (HIV)-negative patients with tuberculosis for clinical features and CD4 cell counts. Thirty-seven patients had low CD4 cell counts (mean +/- SD, 341 +/- 116 cells/microL), and 48 patients had normal CD4 cell counts (mean +/- SD, 830 +/- 254 cells/microL). CD4 cell counts were most strongly correlated with total lymphocyte counts (r = 0.84). If total lymphocyte count was excluded, depressed CD4 cell counts were significantly associated with low serum albumin levels, extensive pulmonary disease, low body-mass index, and low hematocrit. Of these four variables, multivariate linear discriminant analysis revealed that the serum albumin level was the best single predictor of low CD4 cell counts and that the other three variables did not improve predictive value. Because these four variables are markers of severe tuberculosis, these findings suggest that disease severity is associated with greater depression of the total lymphocyte and CD4 cell counts. The CD4 cell counts returned to normal levels in most patients after 1 month of therapy.

The current vancomycin therapeutic guidelines recommend the use of only trough concentrations to manage the dosing of adults with Staphylococcus aureus infections. Both vancomycin efficacy and toxicity are likely to be related to the area under the plasma concentration-time curve (AUC). We assembled richly sampled vancomycin pharmacokinetic data from three studies comprising 47 adults with various levels of renal function. With Pmetrics, the nonparametric population modeling package for R, we compared AUCs estimated from models derived from trough-only and peak-trough depleted versions of the full data set and characterized the relationship between the vancomycin trough concentration and AUC. The trough-only and peak-trough depleted data sets underestimated the true AUCs compared to the full model by a mean (95% confidence interval) of 23% (11 to 33%; P = 0.0001) and 14% (7 to 19%; P < 0.0001), respectively. In contrast, using the full model as a Bayesian prior with trough-only data allowed 97% (93 to 102%; P = 0.23) accurate AUC estimation. On the basis of 5,000 profiles simulated from the full model, among adults with normal renal function and a therapeutic AUC of ≥400 mg · h/liter for an organism for which the vancomycin MIC is 1 mg/liter, approximately 60% are expected to have a trough concentration below the suggested minimum target of 15 mg/liter for serious infections, which could result in needlessly increased doses and a risk of toxicity. Our data indicate that adjustment of vancomycin doses on the basis of trough concentrations without a Bayesian tool results in poor achievement of maximally safe and effective drug exposures in plasma and that many adults can have an adequate vancomycin AUC with a trough concentration of

The diagnosis and treatment of tuberculosis in immunocompromised patients is often challenging. Although HIV infection is the greatest risk factor for TB; there are a growing number of cases of TB in patients on immunosuppressive therapy. Here we present two challenging cases of tuberculosis in immunocompromised hosts.

Background. Tuberculosis causes inflammation and muscle wasting. We investigated how attenuation of inflammation relates to repletion of body composition during treatment in an underserved population. Design. Twenty-four patients (23 to 79 years old) with pulmonary tuberculosis and inflammation (pretreatment albumin = 2 . 9 6 ± 0 . 1 3 g/dL, C-reactive protein [CRP] = 6 . 7 1 ± 1 . 3 4 μg/dL, and beta-2-microglobulin = 1 . 6 8 ± 0 . 1 0 μg/L) were evaluated and had BIA over 24 weeks. Results. Weight increased by 3 . 0 2 ± 0 . 8 1 kg (5.5%; 𝑃 = 0 . 0 0 7 ) at week 4 and by 8 . 5 9 ± 0 . 9 7 kg (15.6%; 𝑃 < 0 . 0 0 0 1 ) at week 24. Repletion of body mass was primarily fat, which increased by 2 . 0 9 ± 0 . 5 2 kg at week 4 and 5 . 0 5 ± 0 . 5 6 kg at week 24 ( 𝑃 = 0 . 0 0 4 and 𝑃 < 0 . 0 0 0 1 versus baseline). Fat-free mass (FFM), body cell mass (BCM), and phase angle did not increase until study week 8. Albumin rose to 3 . 6 5 ± 0 . 1 4 g/dL by week 4 ( 𝑃 < 0 . 0 0 1 ) and slowly increased thereafter. CRP levels declined by ~50% at each interval visit. Conclusions. During the initial treatment, acute phase reactants returned towards normal. The predominant accrual of fat mass probably reflects ongoing, low levels of inflammation.

Study Objective. To characterize the bidirectional interaction between twice-daily nelfinavir and twice-weekly rifabutin and isoniazid in patients with tuberculosis and human immunodeficiency virus (HIV) infection. Design. Prospective cohort study. Setting. Three clinical research centers. Patients. Seven patients with HIV-related tuberculosis. Intervention. Rifabutin 300 mg and isoniazid 15 mg/kg (maximum dose 900 mg) twice/week were administered for at least 2 weeks during the continuation phase of tuberculosis treatment. Antiretroviral therapy with nelfinavir 1250 mg twice/day and two nucleoside reverse transcriptase inhibitors was then added. Measurements and Main Results. Patients underwent blood sampling for pharmacokinetic analysis during the continuation phase of tuberculosis therapy and after a median of 21 days after the addition of antiretroviral treatment. When rifabutin was coadministered with nelfinavir, its area under the concentration-time curve from 0–21 hours (AUC0–21) increased 22% (geometric mean 5.01 μg•hr/ml [90% confidence interval (CI) 3.25–7.71] with nelfinavir vs 4.10 μg•hr/ml [90% CI 3.18–5.27] without nelfinavir; geometric mean ratio 1.22 [90% CI 0.78–1.92]). Also, the AUC0–21 for the active metabolite, desacetylrifabutin, increased significantly (geometric mean ratio 3.46, 90% CI 1.84–6.47, p=0.009). In the presence of rifabutin, the pharmacokinetic parameters of nelfinavir and its principal metabolite M8 were similar to those of patients not taking rifabutin. No drug interaction between nelfinavir and isoniazid was detected. Conclusions. Coadministration of rifabutin and isoniazid without dosage adjustment during twice-weekly tuberculosis therapy with nelfinavir-based antiretroviral therapy resulted in rifabutin exposures within the acceptable ranges for safety and efficacy. Therefore, this combination is an appropriate option for the simultaneous treatment of tuberculosis and HIV infection when tuberculosis therapy is given twice weekly.

In this study, we found that a subpopulation of CD4+CD25+ (85% Foxp3+) cells from persons with latent tuberculosis infection (LTBI) inhibits growth of M. tuberculosis (M. tb) in human monocyte-derived macrophages (MDMs). A soluble factor, Rho GDP dissociation inhibitor (D4GDI), produced by apoptotic CD4+CD25+ (85% Foxp3+) cells is responsible for this inhibition of M. tb growth in human macrophages and in mice. M. tb-expanded CD4+CD25+Foxp3+D4GDI+ cells do not produce IL-10, TGF-β and IFN-γ. D4GDI inhibited growth of M. tb in MDMs by enhancing production of IL-1β, TNF-α and ROS, and by increasing apoptosis of M. tb-infected MDMs. D4GDI was concentrated at the site of disease in tuberculosis patients, with higher levels detected in pleural fluid than in serum. However, in response to M. tb, PBMC from tuberculosis patients produced less D4GDI than PBMC from persons with LTBI. M. tb-expanded CD4+CD25+ (85% Foxp3+) cells and D4GDI induced intracellular M. tb to express the dormancy survival regulator DosR and DosR-dependent genes, suggesting that D4GDI induces a non-replicating state in the pathogen. Our study provides the first evidence that a subpopulation of CD4+CD25+ (85% Foxp3+) cells enhances immunity to M. tb, and that production of D4GDI by this subpopulation inhibits M. tb growth., Author Summary Most people who are infected with Mycobacterium tuberculosis (M. tb) have latent tuberculosis infection (LTBI) with protective immunity. Patients with active tuberculosis have severe disease and ineffective immunity. Understanding how LTBI individuals control infection without developing disease provides important insight into the mechanisms of protective immunity against tuberculosis, and this information is essential for development of an effective vaccine. It is known that a lymphocyte population called T-cells contributes significantly to protective immunity against tuberculosis infection. In the current study, using human and murine models of M. tb infection, we found that a soluble factor, Rho GDP dissociation inhibitor (D4GDI), produced by a subpopulation of T-cells (CD4+CD25+Foxp3+) inhibits M. tb growth. We also found that D4GDI induces M. tb genes that are expressed during the non-replicative state. Our results suggest that D4GDI has a previously undescribed positive effect on immunity by enhancing host antimicrobial activity. These findings also may aid in understanding the factors that induce LTBI. Further, this information will facilitate development of improved vaccines and immunotherapeutic strategies to prevent and treat tuberculosis, respectively.

To investigate the relationship between isoniazid resistance and HIV infection in patients with tuberculosis, we evaluated data in the Los Angeles County tuberculosis registry on 1,506 patients for whom drug susceptibility results were available. Among 235 HIV-infected patients, isoniazid resistance was less common than in 1,271 patients who were HIV-seronegative or who had not been tested for HIV, with an unadjusted odds ratio of 0.3. After adjustment for other factors that affect drug resistance (ethnicity, country of birth, prior diagnosis of tuberculosis, and cavitation), the frequency if isoniazid resistance remained lower than that in patients without HIV infection, with an odds ratio of 0.4 (95% confidence interval, 0.2 to 0.8; p = 0.02). We conclude that in Los Angeles, a setting where there is no ongoing outbreak of drug-resistant tuberculosis, isoniazid-resistant tuberculosis is not more common in HIV-infected patients.

Background The occurrence of acquired rifamycin resistance despite use of directly observed therapy for tuberculosis is associated with advanced human immunodeficiency virus (HIV) disease and highly intermittent administration of antituberculosis drugs. Beyond these associations, the pathogenesis of acquired rifamycin resistance is unknown. Methods We performed a pharmacokinetic substudy of patients in a trial of treatment with twice-weekly rifabutin and isoniazid. Results A total of 102 (60%) of 169 patients in the treatment trial participated in the pharmacokinetic substudy, including 7 of 8 patients in whom tuberculosis treatment failure or relapse occurred in association with acquired rifamycin-resistant mycobacteria (hereafter, "ARR failure or relapse"). The median rifabutin area under the concentration-time curve (AUC(0-24)) was lower for patients with than for patients without ARR failure or relapse (3.3 vs. 5.2 microg*h/mL; P = .06, by the Mann-Whitney exact test). In a multivariate analysis adjusted for CD4+ T cell count, the mean rifabutin AUC(0-24) was significantly lower for patients with ARR failure or relapse than for other patients (3.0 microg*h/mL [95% confidence interval {CI}, 1.9-4.5] vs. 5.2 microg*h/mL [95% CI, 4.6-5.8]; P = .02, by analysis of covariance). The median isoniazid AUC(0-12) was not significantly associated with ARR failure or relapse (20.6 vs. 28.0 microg*h/mL; P = .24, by the Mann-Whitney exact test). However, in a multivariate logistic regression model that adjusted for the rifabutin AUC(0-24), a lower isoniazid AUC(0-12) was associated with ARR failure or relapse (OR, 10.5; 95% CI, 1.1-100; P = .04). Conclusions Lower plasma concentrations of rifabutin and, perhaps, isoniazid were associated with ARR failure or relapse in patients with tuberculosis and HIV infection treated with twice-weekly therapy.

Human immunodeficiency virus (HIV)-related tuberculosis can be life-threatening for the individual, transmissible to others, and difficult to diagnose. We review the clinical, radiographic, and histopathologic features of HIV-related tuberculosis, and the ways in which these features are affected by the degree of immunodeficiency. At CD4 cell counts greater than 350 cells/microL, HIV-related tuberculosis has a similar presentation to tuberculosis in HIV-uninfected adults, predominantly pulmonary involvement with fibronodular and/or cavitary infiltrates. With progressive immunodeficiency, extrapulmonary involvement becomes increasingly common. Pulmonary involvement remains common at all stages of HIV disease, but the radiographic pattern is very different among persons with advanced immunodeficiency, in whom the most common abnormalities are intrathoracic adenopathy, focal lower or middle lobe infiltrates, and diffuse miliary or nodular infiltrates. The keys to the diagnosis of HIV-related tuberculosis are knowledge of the epidemiology of tuberculosis, recognition of the ways that immunodeficiency changes the clinical presentation, and an assiduous effort to obtain specimens for mycobacterial smear and culture.

To determine if the use of corticosteroids for presumed Pneumocystis carinii pneumonia exacerbated undiagnosed tuberculosis or increased the likelihood of reactivation tuberculosis, we reviewed medical records of 144 hospitalized HIV-infected patients who received antipneumocystis therapy. Ninety-four patients (Group C) received corticosteroids and 50 patients (Group NC) did not. One hundred and thirty-seven patients (97%) had acid-fast stains and mycobacterial cultures performed. Group C and Group NC were similar in ethnicity, distribution of HIV risk factors and CD4 cell count. Eight (9%) Group C patients and seven (14%) Group NC patients had culture-proven tuberculosis during their hospitalization. After a median followup of 16 mo after discharge, one (2%) Group C patient and two (4%) Group NC patients developed tuberculosis. Only one patient in Group C died of tuberculosis, despite receiving antituberculosis therapy. We conclude that the use of corticosteroids for presumed P. carinii pneumonia does not increase morbidity from undiagnosed tuberculosis or increase the frequency of reactivation tuberculosis.

The most significant pulmonary opportunistic infections in the tropics are tuberculosis and pneumococcal pneumonia. Guidelines for the diagnosis and management of these and other pulmonary manifestations of HIV are discussed. Ultimately, unless concerted efforts are made to treat underlying HIV infection in regions most devastated by AIDS, the impact of these diseases will continue to grow.

To determine if chest radiographic findings differ in adult tuberculosis patients with recent and remote infection, we reviewed the chest radiographs of 103 patients with tuberculosis in Los Angeles and performed RFLP analyses of their Mycobacterium tuberculosis isolates. Patients whose isolates had identical or closely related RFLP patterns were considered a "cluster." Most patients in large clusters (more than seven patients) had tuberculosis from recent infection, whereas most unclustered patients had tuberculosis from remote infection. Mediastinal adenopathy or pleural effusions were classified as typical of recent infection, and upper lobe infiltrates, cavitation, or fibrosis were classified as characteristic of remote infection. Radiographic patterns were typical of remote infection in 62% of patients and were characteristic of recent infection in 23% of patients. The distribution of these radiographic patterns was similar in clustered and unclustered patients, both with or without human immunodeficiency virus (HIV) coinfection. However, mediastinal adenopathy and pleural effusions were significantly more common in HIV-infected patients. We conclude that: (1) chest radiographic findings in adults with tuberculosis of recent infection are similar to those in patients with remote infection; (2) the distinctive chest radiographic findings in HIV-infected patients with tuberculosis are not due to an increased frequency of recent infection.

The purpose of this study was to determine the efficacy and toxicity of a standard antituberculosis regimen in patients with human immunodeficiency virus (HIV) infection. We prospectively evaluated 89 patients with tuberculosis and HIV infection at an urban medical center. Eighty-two patients received isoniazid, rifampin, and pyrazinamide, with or without ethambutol, for 2 mo, followed by isoniazid and rifampin for 7 mo. Seven patients received other regimens because of drug resistance or intolerance. Therapy was self-administered in 57 patients and directly observed in 32 cases. All patients showed rapid clinical improvement during the first month of therapy, and sputum cultures reverted to negative after 3 mo in 52 of 54 patients from whom specimens were obtained. Adverse reactions to isoniazid or rifampin prompted alterations in antituberculosis regimens in five patients (6%). Forty patients (45%) died during follow-up, and tuberculosis was a potential contributory cause of death in three cases. Treatment failure occurred in five patients (6%), four of whom were noncompliant with therapy. The fifty patient had an isoniazid-resistant organism. No relapses occurred in 916 patient-months of follow-up posttreatment. We thus conclude that the 9-mo regimen used for treatment of drug-susceptible tuberculosis in HIV-infected patients is effective and well tolerated.

To evaluate the relationship between the clinical presentation of tuberculosis and the CD4 cell count in patients with human immunodeficiency virus (HIV) infection, we evaluated clinical and laboratory features of 97 HIV-infected patients with tuberculosis in whom CD4 cell counts were available. Extrapulmonary tuberculosis was found in 30 (70%) of 43 patients withor = 100 CD4 cells/microL, 10 (50%) of 20 patients with 101 to 200 CD4 cells/microL, seven (44%) of 16 patients with 201 to 300 CD4 cells/microL, and five (28%) of 18 patients with300 CD4 cells/microL (p = 0.02). Mycobacteremia was found in 18 (49%) of 37 patients withor = 100 CD4 cells/microL, three (20%) of 15 patients with 101 to 200 CD4 cells/microL, one (7%) of 15 patients with 201 to 300 CD4 cells/microL, and none of eight patients with300 CD4 cells/microL (p = 0.002). Acid-fast smears were more often positive in patients with low CD4 cell counts. Positive tuberculin skin tests were more common in patients with high CD4 counts. On chest roentgenograms, mediastinal adenopathy was noted in 20 (34%) of 58 patients withor = 200 CD4 cells/microL and four (14%) of 29 patients with200 CD4 cells/microL (p = 0.04). Pleural effusions were noted in six (10%) of 58 patients withor = 200 CD4 cells/microL and eight (28%) of 29 patients with200 CD4 cells/microL (p = 0.04). The CD8 cell counts did not correlate with the manifestations of tuberculosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Context. —Recent studies suggest that many tuberculosis cases in urban areas result from recent transmission. Delineation of the epidemiologic links between patients is important to optimize strategies to reduce tuberculosis transmission. Objective. —To identify epidemiologic links among recently infected urban patients with tuberculosis. Design. —Prospective evaluation of patients with tuberculosis. Setting. —Central Los Angeles, Calif. Patients. —A total of 162 patients who had culture-proven tuberculosis. Interventions. —Patients were prospectively interviewed to identify their contacts and whereabouts. The IS6110-based and pTBN12-based restriction fragment length polymorphism analyses were performed onMycobacterium tuberculosisisolates. Patients whose isolates had identical or closely related restriction fragment length polymorphism patterns were considered a cluster. Unconditional logistic regression was used to identify independent predictors of clustering. Main Outcome Measures. —Relationship of clinical and epidemiologic variables to clustering. Results. —A total of 96 (59%) of 162 patients were in 8 clusters. Only 2 of the 96 clustered patients named others in the cluster as contacts. The degree of homelessness was an independent predictor of clustering. Compared with non-clustered patients, patients in 6 clusters were significantly more likely to have spent time at 3 shelters and other locations when at least 1 patient in the cluster was contagious, and these locations were independent predictors of clustering. Among nonhomeless persons, clustered patients were significantly more likely than non-clustered patients to have used daytime services at 3 shelters. Conclusions. —(1) Traditional contact investigation does not reliably identify patients infected with the sameM tuberculosis strain, and (2) locations at which the homeless congregate are important sites of tuberculosis transmission for homeless and nonhomeless persons. Measures that reduce tuberculosis transmission should be based on locations rather than on personal contacts.

Recent laboratory studies indicate that genetic diversity exists in human strains of Pneumocystis carinii . Structural and functional variability in infecting strains could result in differences in host-parasite interactions and the natural history of P carinii pneumonia. We report 5 unusual cases in which the clinical presentation mimicked tuberculosis. All patients were cared for at a university-based public hospital clinic in Los Angeles, Calif, during a 2-year period. These patients were chronically ill, had lost weight, and each had cavities or cystic spaces as the primary radiographic findings. None were receiving aerosol pentamidine and only one had a history of smoking. Four patients were initially treated for tuberculosis and the fifth for disseminated Mycobacterium avium complex. Pneumocystis carinii was the only pathogen identified in each case. The unusual clinical presentations delayed the diagnosis of P carinii in all 5 cases. Practitioners must be aware of the variable presentations of P carinii pneumonia. Arch Intern Med. 1997;157:351-355

Objective. —To determine the relative frequencies of primary and reactivation tuberculosis in the urban homeless. Design. —Prospective evaluation of homeless tuberculosis patients. Setting. —Central Los Angeles, Calif. Patients. —Thirty-four homeless patients with culture-proven tuberculosis. Interventions. —IS61 10-based restriction fragment length polymorphism (RFLP) analysis was performed onMycobacterium tuberculosisisolates. If results were inconclusive, pTBN12-based RFLP analysis was performed. Main Outcome Measure. —Clustering ofM tuberculosisisolates. A cluster consisted of two or more isolates with indistinguishable RFLP patterns. Results. —Twenty-four of 34 homeless patients had clustered isolates in six clusters. Conclusions. —The minimum percentage of cases due to primary tuberculosis in the homeless was estimated to be 53%, compared with the traditional estimate of 10% in the general population. The results suggest that primary tuberculosis caused the majority of tuberculosis cases in this population of the urban homeless in central Los Angeles. (JAMA. 1996;275:305-307)