Research on the treatment of rifampin-susceptible tuberculosis-Time for a new approach.

In the Perspective, William Burman and colleagues advocate improving the safety and acceptability of treatment, rather than treatment-shortening, of rifampin-susceptible tuberculosis.

Lower Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection Among People Experiencing Homelessness Tested in Outdoor Encampments Compared With Overnight Shelters: Denver, Colorado, June-July 2020.

BACKGROUND: A better understanding of the risk for coronavirus disease 2019 (COVID-19) that people experiencing homelessness (PEH) face in congregate shelters versus unsheltered encampments is critical for an effective pandemic response. METHODS: We analyzed factors associated with current and past severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among PEH in day and overnight shelters and encampments in Denver, Colorado, during June 2-July 28, 2020, and constructed multivariable logistic regression models to examine risk factors for SARS-CoV-2 RNA and seropositivity with age, race/ethnicity, testing location, testing month, and symptom status as predictor variables. RESULTS: A total of 823 participants were tested for SARS-CoV-2 RNA, and 276 individuals were tested for SARS-CoV-2 antibodies. A greater percentage of PEH at overnight shelters tested positive for SARS-CoV-2 RNA (8.6% vs 2.5%, P < .01) and antibodies (21.5% vs 8.7%, P = .03) compared with encampments. In regression models, testing at an overnight shelter compared with testing at encampments (odds ratio [OR] = 3.03, 95% confidence interval [CI]: 1.16-9.02) had increased odds of a positive SARS-CoV-2 RNA result. Age >60 years compared with age <40 years (OR = 5.92; 95% CI: 1.83-20.3), Hispanic ethnicity (OR = 3.43; 95% CI: 1.36-8.95), and non-Hispanic Black race compared with non-Hispanic White race (OR = 3.07; 95% CI: 1.16-8.26), and testing at an overnight shelter compared to testing at encampments (OR = 2.45; 95% CI: 1.04-6.17) had increased odds of a positive antibody result. CONCLUSIONS: Our findings support the need for continuing assessment of mitigation strategies in shelters, increasing access to individual rooms and linkage to housing options for PEH, and supporting people to remain in encampments when these options are not available.

Opposing associations of depression with sexual behaviour: implications for epidemiological investigation among gay, bisexual and other men who have sex with men.

OBJECTIVE: The aim of this report is to investigate the nature of the relationship between depression and condomless sex (CLS) among gay, bisexual and other men who have sex with men (GBMSM). METHODS: Data are from the Antiretrovirals, Sexual Transmission Risk and Attitude (ASTRA) study of people living with HIV and attending one of eight HIV outpatient clinics in England (2011-2012) and the Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) study of HIV-negative/unknown status individuals attending one of 20 genitourinary medicine clinics in England (2013-2014). This analysis included GBMSM only. For each study, the prevalence of depressive symptoms (Patient Health Questionnaire-9 score ≥10) was presented according to three categories of sex in the past 3 months (considering anal/vaginal sex with men/women and anal sex with men in separate definitions): (1) no sex, (2) condom-protected sex only and (3) CLS. Multinomial logistic regression with 'condom-protected sex only' as the reference group was used to adjust for age and (for ASTRA participants) time since HIV diagnosis. RESULTS: There were opposing associations of depression with recent sexual behaviour: the prevalence of depression was higher among those who reported no sex and those who reported CLS, compared with those who reported condom-protected sex only. Among the 2170 HIV-positive GBMSM in ASTRA, considering anal/vaginal sex with men/women, the prevalence of depressive symptoms was 32%, 20% and 28%, respectively, among men reporting no sex (n=783), condom-protected sex only (n=551) and CLS (n=836) (global p<0.001). Among the 1477 HIV-negative GBMSM in AURAH, the prevalence of depressive symptoms was 12%, 8% and 13%, respectively, for no sex (n=137), condom-protected sex only (n=487) and CLS (n=853) (global p=0.017). Patterns were similar after adjustment and when only considering anal sex between men. CONCLUSIONS: Depression may be linked both to lack of sexual activity and to sexual risk taking. When investigating associations between depression and CLS, it is important to separate out individuals reporting condom-protected sex only from those reporting no sex.

Attitudes to disclosure of HIV-serostatus to new sexual partners and sexual behaviours among HIV-diagnosed gay, bisexual and other men who have sex with men in the UK.

We assessed attitudes to disclosure to new sexual partners and association with sexual behaviours among HIV-diagnosed gay, bisexual, and other men who have sex with men (GBMSM) in the UK Antiretrovirals, Sexual Transmission Risk and Attitudes (ASTRA) study in 2011-12. Among 1373 GBMSM diagnosed with HIV for ≥3 months and reporting sex in the past three months (84% on antiretroviral therapy (ART), 75% viral load (VL) ≤50c/mL), 56.3% reported higher sexual disclosure ("agree" or "tend to agree" with "I'd expect to tell a new partner I'm HIV-positive before we have sex"). GBMSM on ART with self-reported undetectable VL had lower disclosure than those on ART without self-reported undetectable VL and those not on ART. Higher sexual disclosure was associated with higher prevalence of CLS in the past three months; this was due to its association with CLS with other HIV-positive partners. Higher sexual disclosure was more common among GBMSM who had CLS with other HIV-positive partners only (72.1%) compared to those who had higher-risk CLS with HIV-serodifferent partners (55.6%), other CLS with HIV-serodifferent partners (45.9%), or condom-protected sex only (47.6%). Findings suggest mutual HIV-disclosure and HIV-serosorting were occurring in this population. Knowledge of VL status may have impacted on disclosure to sexual partners.

Condomless sex in HIV-diagnosed men who have sex with men in the UK: prevalence, correlates, and implications for HIV transmission.

OBJECTIVE: HIV transmission is ongoing among men who have sex with men (MSM) in the UK. Sex without a condom (condomless sex, CLS) is the main risk factor. We investigated the prevalence of and factors associated with types of CLS. METHODS: Cross-sectional questionnaire study in UK HIV clinics in 2011/2012 (ASTRA). MSM diagnosed with HIV for ≥3 months reported on anal and vaginal sex, CLS with HIV-serodifferent partners (CLS-D) and CLS with HIV-seroconcordant (CLS-C) partners in the previous 3 months. Mutually exclusive sexual behaviours were as follows: (1) Higher HIV risk CLS-D (not on antiretroviral therapy (ART) or clinic-recorded viral load(VL) >50 c/mL), (2) Other CLS-D, (3) CLS-C without CLS-D, (4) Condom-protected sex only and (5) No anal or vaginal sex. Associations were examined of sociodemographic, HIV-related, lifestyle, and other sexual measures with the five categories of sexual behaviour. We examined the prevalence of higher HIV risk CLS-D incorporating (in addition to ART and VL) time on ART, ART non-adherence, and recent sexually transmitted infections (STIs). RESULTS: Among 2189 HIV-diagnosed MSM (87% on ART), prevalence of any CLS in the past 3 months was 38.2% (95% CI 36.2% to 40.4%) and that of any CLS-D was 16.3% (14.8%-17.9%). The five-category classification was as follows: (1) Higher HIV risk CLS-D: 4.2% (3.5% to 5.2%), (2) Other CLS-D: 12.1% (10.8% to 13.5%), (3) CLS-C without CLS-D: 21.9% (20.2% to 23.7%), (4) Condom-protected sex only: 25.4% (23.6% to 27.3%) and (5) No anal or vaginal sex: 36.4% (34.3% to 38.4%). Compared with men who reported condom-protected sex only, MSM who reported any CLS in the past 3 months had higher prevalence of STIs, chemsex-associated drug use, group sex, higher partner numbers, and lifetime hepatitis C. Prevalence of higher HIV risk CLS-D ranged from 4.2% to 7.5% according to criteria included. CONCLUSION: CLS was prevalent among HIV-diagnosed MSM, but CLS-D with higher HIV transmission risk was overall low. CLS-D is no longer the most appropriate measure of HIV transmission risk behaviour among people with diagnosed HIV; accounting for VL is important.

Failure of outpatient antibiotics among patients hospitalized for acute bacterial skin infections: What is the clinical relevance?

BACKGROUND: Infectious Diseases Society of America guidelines recommend that patients hospitalized for acute bacterial skin infections after failure of outpatient antibiotic therapy be managed as "severe" infections; however, the clinical relevance of apparent failure of outpatient therapy is not clear. METHODS: This was a secondary analysis of a multicenter, retrospective cohort of adults and children hospitalized for cellulitis, abscess, or wound infection. We compared clinical features, laboratory and microbiology findings, antibiotic treatment, and outcomes among patients who received outpatient antibiotics prior to admission and those who did not. RESULTS: Of 533 patients, 179 (34%) received outpatient antibiotics prior to admission. Compared with those who did not, patients who received antibiotics prior to admission less frequently had fever (18% vs 26%, P=.04) and leukocytosis (33% vs 51%, P<.001). In the 202 cases where a microorganism was identified, Staphylococcus aureus was more common among those who received antibiotics prior to admission (75% vs 58%, P=.02), particularly methicillin-resistant S aureus (41% vs 27%, P=.049), whereas aerobic gram-negative bacilli were less common (3% vs 13%, P=.03). After hospitalization, clinical failure occurred with similar frequency between the 2 groups (12% vs 11%, P=.73). CONCLUSIONS: Patients hospitalized with skin infections after apparently failing outpatient therapy had clinical features suggestive of less severe infection and similar outcomes compared with patients who did not receive antibiotics prior to admission. Our results suggest that inpatient treatment for patients not responding to outpatient therapy should focus on methicillin-resistant S aureus, not gram-negative pathogens.

Macrophage migration inhibitory factor (MIF) is a critical mediator of the innate immune response to Mycobacterium tuberculosis.

Macrophage migration inhibitory factor (MIF), an innate cytokine encoded in a functionally polymorphic genetic locus, contributes to detrimental inflammation but may be crucial for controlling infection. We explored the role of variant MIF alleles in tuberculosis. In a Ugandan cohort, genetic low expressers of MIF were 2.4-times more frequently identified among patients with Mycobacterium tuberculosis (TB) bacteremia than those without. We also found mycobacteria-stimulated transcription of MIF and serum MIF levels to be correlated with MIF genotype in human macrophages and in a separate cohort of US TB patients, respectively. To determine mechanisms for MIF's protective role, we studied both aerosolized and i.v. models of mycobacterial infection and observed MIF-deficient mice to succumb more quickly with higher organism burden, increased lung pathology, and decreased innate cytokine production (TNF-α, IL-12, IL-10). MIF-deficient animals showed increased pulmonary neutrophil accumulation but preserved adaptive immune response. MIF-deficient macrophages demonstrated decreased cytokine and reactive oxygen production and impaired mycobacterial killing. Transcriptional investigation of MIF-deficient macrophages revealed reduced expression of the pattern recognition receptor dectin-1; restoration of dectin-1 expression recovered innate cytokine production and mycobacterial killing. Our data place MIF in a crucial upstream position in the innate immune response to mycobacteria and suggest that commonly occurring low expression MIF alleles confer an increased risk of TB disease in some populations.

Population pharmacokinetics of rifapentine and desacetyl rifapentine in healthy volunteers: nonlinearities in clearance and bioavailability.

Rifapentine is under active investigation as a potent drug that may help shorten the tuberculosis (TB) treatment duration. A previous rifapentine dose escalation study with daily dosing indicated a possible decrease in bioavailability as the dose increased and an increase in clearance over time for rifapentine and its active metabolite, desacetyl rifapentine. This study aimed to assess the effects of increasing doses on rifapentine absorption and bioavailability and to evaluate the clearance changes over 14 days. A population analysis was performed with nonlinear mixed-effects modeling. Absorption, time-varying clearance, bioavailability, and empirical and semimechanistic autoinduction models were investigated. A one-compartment model linked to a transit compartment absorption model best described the data. The bioavailability of rifapentine decreased linearly by 2.5% for each 100-mg increase in dose. The autoinduction model suggested a dose-independent linear increase in clearance of the parent drug and metabolite over time from 1.2 and 3.1 liters · h(-1), respectively, after a single dose to 2.2 and 5.0 liters · h(-1), respectively, after 14 once-daily doses, with no plateau being reached by day 14. In clinical trial simulations using the final model, rifapentine demonstrated less-than-dose-proportional pharmacokinetics, but there was no plateau in exposures over the dose range tested (450 to 1,800 mg), and divided dosing increased exposures significantly. Thus, the proposed compartmental model incorporating daily dosing of rifapentine over a wide range of doses and time-related changes in bioavailability and clearance provides a useful tool for estimation of drug exposure that can be used to optimize rifapentine dosing for TB treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT01162486.).

CDC/NIH Workshop. Tuberculosis biomarker and surrogate endpoint research roadmap.

The Centers for Disease Control and Prevention and National Institutes of Health convened a multidisciplinary meeting to discuss surrogate markers of treatment response in tuberculosis. The goals were to assess recent surrogate marker research and to provide specific recommendations for (1) the qualification and validation of biomarkers of treatment outcome; (2) the standardization of specimen and data collection for future clinical trials, including a minimum set of samples and collection time points; and (3) the creation ofa specimen repository to support biomarker testing. This article summarizes these recommendations and provides a roadmap for their implementation.

The spectrum of engagement in HIV care and its relevance to test-and-treat strategies for prevention of HIV infection.

For individuals with human immunodeficiency virus (HIV) infection to fully benefit from potent combination antiretroviral therapy, they need to know that they are HIV infected, be engaged in regular HIV care, and receive and adhere to effective antiretroviral therapy. Test-and-treat strategies for HIV prevention posit that expanded testing and earlier treatment of HIV infection could markedly decrease ongoing HIV transmission, stemming the HIV epidemic. However, poor engagement in care for HIV-infected individuals will substantially limit the effectiveness of test-and-treat strategies. We review the spectrum of engagement in care for HIV-infected individuals in the United States and apply this information to help understand the magnitude of the challenges that poor engagement in care will pose to test-and-treat strategies for HIV prevention.

Rip Van Winkle wakes up: development of tuberculosis treatment in the 21st century.

The increase in drug-resistant tuberculosis and the global pandemic of human immunodeficiency virus infection-related tuberculosis threaten global tuberculosis control. There are needs for improved therapy in all aspects of tuberculosis treatment: treatment of latent infection, active drug-susceptible disease, and particularly, drug-resistant disease. Fortunately, at this time of great need, the field of tuberculosis drug development has reemerged after >30 years of inactivity. I review the specific needs for new treatment regimens, the pathways of tuberculosis drug development, and the agents that are currently in clinical development. There is renewed interest in the rifamycin class; studies in the mouse model suggest that higher doses of rifampin or rifapentine may markedly improve the treatment of drug-susceptible disease. Fluoroquinolones may allow shorter treatment durations for drug-susceptible disease, though initial phase 2B trials have shown inconsistent activity. Novel drugs, such as TMC207, OPC-67683, PA824, SQ109, and PNU-100480, may improve the treatment of drug-resistant and drug-susceptible tuberculosis.

Treatment of active tuberculosis in HIV-coinfected patients: a systematic review and meta-analysis.

BACKGROUND: Patients with human immunodeficiency virus (HIV) infection and tuberculosis have an increased risk of death, treatment failure, and relapse. METHODS: A systematic review and meta-analysis of randomized, controlled trials and cohort studies was conducted to evaluate the impact of duration and dosing schedule of rifamycin and use of antiretroviral therapy in the treatment of active tuberculosis in HIV-positive patients. In included studies, the initial tuberculosis diagnosis, failure, and/or relapse were microbiologically confirmed, and patients received standardized rifampin- or rifabutin-containing regimens. Pooled cumulative incidence of treatment failure, death during treatment, and relapse were calculated using random-effects models. Multivariable meta-regression was performed using negative binomial regression. RESULTS: After screening 5158 citations, 6 randomized trials and 21 cohort studies were included. Relapse was more common with regimens using 2 months rifamycin (adjusted risk ratio, 3.6; 95% confidence interval, 1.1-11.7) than with regimens using rifamycin for at least 8 months. Compared with daily therapy in the initial phase (n=3352 patients from 35 study arms), thrice-weekly therapy (n=211 patients from 5 study arms) was associated with higher rates of failure (adjusted risk ratio, 4.0; 95% confidence interval, 1.5-10.4) and relapse [adjusted risk ratio, 4.8; 95% confidence interval, 1.8-12.8). There were trends toward higher relapse rates if rifamycins were used for only 6 months, compared with > or =8 months, or if antiretroviral therapy was not used. CONCLUSIONS: This review raises serious concerns regarding current recommendations for treatment of HIV-tuberculosis coinfection. The data suggest that at least 8 months duration of rifamycin therapy, initial daily dosing, and concurrent antiretroviral therapy might be associated with better outcomes, but adequately powered randomized trials are urgently needed to confirm this.

Skin and soft-tissue infections requiring hospitalization at an academic medical center: opportunities for antimicrobial stewardship.

BACKGROUND: Although complicated skin and soft-tissue infections (SSTIs) are among the most common infections requiring hospitalization, their clinical spectrum, management, and outcomes have not been well described. METHODS: We report a cohort of consecutive adult patients hospitalized for SSTI from 1 January through 31 December 2007 at an academic medical center. Cases meeting inclusion criteria were reviewed and classified as cellulitis, cutaneous abscess, or SSTI with additional complicating factors. RESULTS: In total, 322 patients were included; 66 (20%) had cellulitis, 103 (32%) had cutaneous abscess, and 153 (48%) had SSTI with additional complicating factors. Injection drug use, diabetes mellitus, and alcohol abuse were common comorbidities. Serum inflammatory markers were routinely measured and blood cultures and imaging studies were routinely performed in each group. Of 150 patients with a positive culture result for an abscess, deep tissue, or blood, Staphylococcus aureus or streptococci were identified in 145 (97%). Use of antibiotics with broad aerobic gram-negative activity (61%-80% of patients) or anaerobic activity (73%-83% of patients) was frequent in each group. The median duration of therapy for cellulitis, cutaneous abscess, and SSTI with additional complicating factors was 13 (interquartile range [IQR], 10-14), 13 (IQR, 10-16), and 14 (IQR, 11-17) days, respectively. Treatment failure, recurrence, or rehospitalization due to SSTI within 30 days occurred in 12.1%, 4.9%, and 9.2% of patients, respectively. CONCLUSIONS: Hospitalizations for SSTI were common; more than half were due to cellulitis or cutaneous abscess. Frequent use of potentially unnecessary diagnostic studies, broad-spectrum antibiotic therapy, and prolonged treatment courses in these patients suggest targets for antimicrobial stewardship programs.

Effects of tuberculosis, race, and human gene SLCO1B1 polymorphisms on rifampin concentrations.

Rifampin has concentration-dependent activity against Mycobacterium tuberculosis. However, marked intersubject variation of rifampin concentrations occurs. In this study, we evaluated rifampin pharmacokinetics in relation to tuberculosis, geographic region, race, and single nucleotide polymorphisms of the human transporter genes SLCO1B1, SLCO1B3, and MDR1. Seventy-two adults with pulmonary tuberculosis from Africa, North America, and Spain were evaluated during multidrug intensive-phase therapy, and their results were compared to those from 16 healthy controls from North America. Rifampin pharmacokinetic values were similar between tuberculosis patients and controls (geometric mean [GM] area under the concentration-time curve from 0 to 24 h [AUC(0-24)] of 40.2 versus 40.9 µg.h/ml; P = 0.9). However, in multivariable analyses, the rifampin AUC(0-24) was significantly affected by rifampin dosage (in mg/kg of body weight), polymorphisms in the SLCO1B1 gene, and the presence of tuberculosis by geographic region. The adjusted rifampin AUC(0-24) was lowest in patients with tuberculosis from Africa compared to that in non-African patients or control subjects. The adjusted rifampin AUC(0-24) was also 36% lower among participants with SLCO1B1 genotype c.463CA than that among participants with SLCO1B1 genotype c.463CC (adjusted GM, 29.8 versus 46.7 µg.h/ml; P = 0.001). Polymorphisms in the SLCO1B1 gene associated with lower rifampin exposure were more frequent among black subjects. In conclusion, marked intersubject variation of the rifampin AUC(0-24) values was observed, but the mean values of the AUC(0-24) did not significantly vary between patients with tuberculosis and healthy controls. Lower rifampin exposure was associated with the polymorphism of the SLCO1B1 c.463C>A gene. When adjusted for the patient mg/kg dosage and transporter gene polymorphisms, rifampin exposure was lower in patients with tuberculosis, which suggests that additional absorption or metabolic processes affect rifampin exposure with tuberculosis disease.

Evaluation of time to detection of Mycobacterium tuberculosis in broth culture as a determinant for end points in treatment trials.

Time to detection of Mycobacterium tuberculosis in broth culture was examined for utility as a treatment efficacy end point. Of 146 patients in a phase IIB trial, a decreased mean time to detection was found in 5 with treatment failure. Time to detection in an analysis-of-covariance model was associated with lung cavities, less intensive treatment, and differences in the bactericidal effects of treatment regimens.

High-dose rifapentine with or without moxifloxacin for shortening treatment of pulmonary tuberculosis: Study protocol for TBTC study 31/ACTG A5349 phase 3 clinical trial.

INTRODUCTION: Phase 2 clinical trials of tuberculosis treatment have shown that once-daily regimens in which rifampin is replaced by high dose rifapentine have potent antimicrobial activity that may be sufficient to shorten overall treatment duration. Herein we describe the design of an ongoing phase 3 clinical trial testing the hypothesis that once-daily regimens containing high dose rifapentine in combination with other anti-tuberculosis drugs administered for four months can achieve cure rates not worse than the conventional six-month treatment regimen. METHODS/DESIGN: S31/A5349 is a multicenter randomized controlled phase 3 non-inferiority trial that compares two four-month regimens with the standard six-month regimen for treating drug-susceptible pulmonary tuberculosis in HIV-negative and HIV-positive patients. Both of the four-month regimens contain high-dose rifapentine instead of rifampin, with ethambutol replaced by moxifloxacin in one regimen. All drugs are administered seven days per week, and under direct observation at least five days per week. The primary outcome is tuberculosis disease-free survival at twelve months after study treatment assignment. A total of 2500 participants will be randomized; this gives 90% power to show non-inferiority with a 6.6% margin of non-inferiority. DISCUSSION: This phase 3 trial formally tests the hypothesis that augmentation of rifamycin exposures can shorten tuberculosis treatment to four months. Trial design and standardized implementation optimize the likelihood of obtaining valid results. Results of this trial may have important implications for clinical management of tuberculosis at both individual and programmatic levels. TRIAL REGISTRATION: NCT02410772. Registered 8 April 2015,https://www.clinicaltrials.gov/ct2/show/NCT02410772?term=02410772&rank=1.

Relapse associated with active disease caused by Beijing strain of Mycobacterium tuberculosis.

The role of microbial factors in outcomes of tuberculosis treatment has not been well studied. We performed a case-control study to evaluate the association between a Beijing strain and tuberculosis treatment outcomes. Isolates from patients with culture-positive treatment failure (n = 8) or relapse (n = 54) were compared with isolates from randomly selected controls (n = 296) by using spoligotyping. Patients with Beijing strains had a higher risk for relapse (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.0-4.0, p = 0.04) but not for treatment failure. Adjustment for factors previously associated with relapse had little effect on the association between Beijing strains and relapse. Beijing strains were strongly associated with relapse among Asian-Pacific Islanders (OR 11, 95% CI 1.1-108, p = 0.04). Active disease caused by a Beijing strain was associated with increased risk for relapse, particularly among Asian-Pacific Islanders.