Acquired rifamycin resistance among patients with tuberculosis and HIV in new York City, 2001-2023

Introduction

Acquired rifamycin resistance (ARR) in tuberculosis (TB) has been associated with HIV infection and can necessitate complicated TB treatment regimens, particularly in people living with HIV (PLWH). This work examines clinical characteristics and treatment outcomes of PLWH who developed ARR from 2001 to 2023 in New York City (NYC) to inform best practices for treating these patients.

Methods

PLWH who developed ARR 2001-2023 were identified from the NYC TB registry.

Results

Sixteen PLWH developed ARR; 15 were diagnosed 2001-2009 and the 16th was diagnosed in 2017. Median CD4 count was 48/mm3. On initial presentation, 14 had positive sputum cultures; of these, 12 culture-converted prior to developing ARR. Ten patients completed a course of TB treatment but subsequently relapsed; in six of these cases, ARR was discovered upon relapse, triggering treatment with a non-rifamycin-containing regimen, while in the other four, ARR was discovered during a second round of rifamycin-containing treatment. Three patients were lost to follow-up during their initial course of TB treatment and later returned to care; after being restarted on a rifamycin-containing regimen, ARR was discovered. Finally, three patients culture-converted during their first course of treatment but subsequently had cultures that grew rifamycin-resistant Mycobacterium tuberculosis prior to treatment completion, leading to changes in their treatment regimens. Among the 16 patients, eight died before being cured of TB, seven successfully completed treatment, and one was lost to follow-up.

Conclusions

PLWH should be monitored closely for the development of ARR during treatment for TB, and sputum culture conversion should be interpreted cautiously in this group. Collecting a final sputum sample may be especially important for PLWH, as treatment failure and relapse were common in this population. The decrease in the number of cases of ARR among PLWH during the study period may reflect the decrease in the total number of PLWH diagnosed with TB in NYC in recent years, improved immune status of PLWH due to increased uptake of antiretroviral drugs, and improvements in the way anti-TB regimens are designed for PLWH (such as recommending daily rather than intermittent rifamycin dosing).

Rifampin Mono-Resistant Tuberculosis in New York City, 2010-2021: A Retrospective Case Series

Background

Although relatively rare, rifampin mono-resistant tuberculosis (RMR TB) poses important challenges to effective TB treatment and control. Information on the burden of RMR TB and treatment outcomes is needed to inform diagnosis and management.

Methods

Standardized variables were collected from the New York City (NYC) tuberculosis surveillance system for patients treated for RMR TB in NYC during 2010-2021.

Results

Of 7097 TB cases reported in 2010-2021, 31 (<1%) were treated clinically as RMR TB. Five (16%) of these patients had HIV. Seventeen patients (55%) had TB that was rifampin-resistant by both molecular and phenotypic drug susceptibility testing; 2 (6%) had rifampin resistance by phenotypic tests, and molecular tests were not done; and 12 (39%) were identified based only on molecular tests. Among these 12, 7 were rifampin-sensitive by phenotypic tests, and phenotypic testing could not be done for the other 5. Ten of the 31 (32%) were diagnosed in 2010-2015; the other 21 (including 10/12 diagnosed by molecular tests alone) were diagnosed in 2016-2021. Of the 31 patients, 21 (68%) completed treatment (median treatment duration of 18 months). Although the interval between tuberculosis treatment initiation and change to a non-rifamycin-containing regimen decreased significantly during the study period, the overall duration of treatment did not decrease significantly between 2010 and 2021.

Conclusions

Molecular drug susceptibility tests identified cases of RMR TB that were not detected by phenotypic testing and helped enable timely adjustment of tuberculosis treatment regimens. Short-course regimens are needed to reduce duration of treatment for RMR TB.

Cohort study of the mortality among patients in New York City with tuberculosis and COVID-19, March 2020 to June 2022

Both tuberculosis (TB) and COVID-19 can affect the respiratory system, and early findings suggest co-occurrence of these infectious diseases can result in elevated mortality. A retrospective cohort of patients who were diagnosed with TB and COVID-19 concurrently (within 120 days) between March 2020 and June 2022 in New York City (NYC) was identified. This cohort was compared with a cohort of patients diagnosed with TB-alone during the same period in terms of demographic information, clinical characteristics, and mortality. Cox proportional hazards regression was used to compare mortality between patient cohorts. One hundred and six patients with concurrent TB/COVID-19 were identified and compared with 902 patients with TB-alone. These two cohorts of patients were largely demographically and clinically similar. However, mortality was higher among patients with concurrent TB/COVID-19 in comparison to patients with TB-alone, even after controlling for age and sex (hazard ratio 2.62, 95% Confidence Interval 1.66-4.13). Nearly one in three (22/70, 31%) patients with concurrent TB/COVID-19 aged 45 and above died during the study period. These results suggest that TB patients with concurrent COVID-19 were at high risk for mortality. It is important that, as a high-risk group, patients with TB are prioritized for resources to quickly diagnose and treat COVID-19, and provided with tools and information to protect themselves from COVID-19.

Bedaquiline for the Treatment of Multidrug-resistant Tuberculosis in the United States

BACKGROUND

In 2012, the Food and Drug Administration approved use of bedaquiline fumarate as part of combination therapy for multidrug-resistant tuberculosis (MDR TB). We describe treatment outcomes, safety, and tolerability of bedaquiline in our case series.

METHODS

Data on patients started on bedaquiline for MDR TB between September 2012 and August 2016 were collected retrospectively through 4 TB programs using a standardized abstraction tool. Data were analyzed using univariate methods. Adverse events were graded using the Common Terminology Criteria for Adverse Events.

RESULTS

Of 14 patients, 7 (50%) had MDR, 4 (29%) had pre-extensively drug-resistant (XDR), and 3 (21%) had XDR TB. All had pulmonary TB, 5 (36%) had pulmonary and extrapulmonary TB, and 9/13 (69%) were smear positive. One patient (7%) had HIV coinfection, 5 (36%) had diabetes mellitus, and 5/14 (36%) had previous treatment TB. All patients were non-US-born and 5/14 (36%) had private insurance. All patients achieved sputum culture conversion within a mean of 71 days (26-116); 5 after starting bedaquiline. Twelve (86%) completed treatment and 1 (7%) moved out of the country. One patient (7%) had QTc prolongation >500 milliseconds and died 20 months after discontinuing bedaquiline of a cause not attributable to the drug. Common adverse events were peripheral neuropathy 7/14 (50%), not customarily associated with bedaquiline use, and QTc prolongation 6/14 (43%).

CONCLUSIONS

Of 14 patients, 1 (7%) had an adverse event necessitating bedaquiline discontinuation. Safety, culture conversion, and treatment completion in this series (7%) support use of bedaquiline for the treatment of MDR/XDR TB.

Linezolid use for treatment of multidrug-resistant and extensively drug-resistant tuberculosis, New York City, 2000-06

Rationale Linezolid may be effective for the treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB); however, serious adverse events are common and there is little information on the management of these toxicities.

METHODS

We retrospectively reviewed public health and medical records of 16 MDR TB patients, including 10 patients with XDR TB, who were treated with linezolid in New York City between January 2000 and December 2006, to determine treatment outcomes and describe the incidence, management and predictors of adverse events.

RESULTS

Linezolid was added to MDR TB regimens for a median duration of 16 months (range: 1-29). Eleven patients (69%) completed treatment, four (25%) died and one (6%) discontinued treatment without relapse. Myelosuppression occurred in 13 (81%) patients a median of 5 weeks (range: 1-11) after starting linezolid, gastrointestinal adverse events occurred in 13 (81%) patients after a median of 8 weeks (range: 1-57) and neurotoxicity occurred in seven (44%) patients after a median of 16 weeks (range: 10-111). Adverse events were managed by combinations of temporary suspension of linezolid, linezolid dose reduction and symptom management. Five (31%) patients required eventual discontinuation of linezolid. Myelosuppression was more responsive to clinical management strategies than was neurotoxicity. Leucopenia and neuropathy occurred more often in males and older age was associated with thrombocytopenia (P < 0.05).

CONCLUSIONS

The majority of MDR TB patients on linezolid had favourable treatment outcomes, although treatment was complicated by adverse events that required extensive clinical management.

Inhaled furosemide is not effective in acute asthma

As previous studies have suggested that inhaled furosemide may have a protective effect against certain types of provocative challenges in asthmatic subjects, we investigated the role of furosemide in treating acute asthma exacerbations. Twenty-four patients (n = 24) with acute asthma were entered into the study on presenting to the emergency department. They were blindly randomized to receive one of three drug regimens: (1) inhaled furosemide (40 mg) (n = 8); (2) inhaled metaproterenol (15 mg) (n = 7); or (3) the combination of furosemide (40 mg) and metaproterenol (15 mg) (n = 9). We measured FEV1 at entry (time 0) and 15, 30, 45, and 60 min after inhalation of the individual drugs or the combination from a face mask nebulizer. At entry, the three groups did not differ significantly in age (mean +/- SEM = 37.6 +/- 3.6, 38.5 +/- 3.6, and 41.0 years, respectively; p = 0.770), baseline FEV1 (1.01 +/- 0.27, 1.04 +/- 0.27, and 1.25 +/- 0.14 L, respectively; p = 0.620), or theophylline levels (2.87 +/- 1.8, 7.39 +/- 2.8, and 5.29 +/- 2.6 micrograms/ml, respectively; p = 0.498). Pretreatment and posttreatment potassium levels were similar among the three groups. Inhalation of furosemide alone resulted in a 14.9 +/- 10.5 percent change in FEV1 percent from baseline, which was not statistically significant. In contrast, metaproterenol alone resulted in a 42.9 +/- 15.2 percent increase in FEV1 percent (F ratio = 6.226; p = 0.0028). The combination of furosemide and metaproterenol resulted in a change in FEV1 percent that was not statistically different compared with metaproterenol alone (FEV1 percent = 41.9 +/- 12 percent). No significant adverse effects occurred in any of the groups.