QuantiFERON-TB Gold In-Tube as a Confirmatory Test for Tuberculin Skin Test in Tuberculosis Contact Tracing: A Noninferiority Clinical Trial.

Background: Screening strategies based on interferon-γ release assays in tuberculosis contact tracing may reduce the need for preventive therapy without increasing subsequent active disease. Methods: We conducted an open-label, randomized trial to test the noninferiority of a 2-step strategy with the tuberculin skin test (TST) followed by QuantiFERON-TB Gold In-Tube (QFT-GIT) as a confirmatory test (the TST/QFT arm) to the standard TST-alone strategy (TST arm) for targeting preventive therapy in household contacts of patients with tuberculosis. Participants were followed for 24 months after randomization. The primary endpoint was the development of tuberculosis, with a noninferiority margin of 1.5 percentage points. Results: A total of 871 contacts were randomized. Four contacts in the TST arm and 2 in the TST/QFT arm developed tuberculosis. In the modified intention-to-treat analysis, this accounted for 0.99% in the TST arm and 0.51% in the TST/QFT arm (-0.48% difference; 97.5% confidence interval [CI], -1.86% to 0.90%); in the per-protocol analysis, the corresponding rates were 1.67% and 0.82% in the TST and TST/QFT arms, respectively (-0.85% difference; 97.5% CI, -3.14% to 1.43%). Of the 792 contacts analyzed, 65.3% in the TST arm and 42.2% in the TST/QFT arm were diagnosed with tuberculosis infection (23.1% difference; 95% CI, 16.4% to 30.0%). Conclusions: In low-incidence settings, screening household contacts with the TST and using QFT-GIT as a confirmatory test is not inferior to TST-alone for preventing active tuberculosis, allowing a safe reduction of preventive treatments. Clinical Trials Registration: NCT01223534.

Retrospective study of tolerability and efficacy of linezolid in patients with multidrug-resistant tuberculosis (1998-2014).

INTRODUCTION: Although linezolid is known to be effective when used as an adjunct therapy in the treatment of patients with multidrug-resistant tuberculosis (MDR-TB), the clinical experience is limited. In this study the efficacy and adverse effects of linezolid treatment were evaluated. METHODS: A retrospective study of tolerability and efficacy of linezolid in MDR-TB patients was performed in Madrid, Spain. Demographic characteristics, microbiological and clinical features and data on treatment tolerability were collected. Regimens were constructed with a target of prescribing, at least, five anti-tuberculosis agents likely to be effective. Linezolid, at a dosage of 1200 or 600 mg daily, was included to complete the treatment if no other sensitive drugs were available. Vitamin B6 was used to reduce toxicity. Treatment outcome and clinical status at last contact were compared between patients with linezolid-containing regimens and with those without linezolid-containing regimens. RESULTS: During the period 1998-2014, 55 patients with MDR-TB received treatment. In 21 of these patients, linezolid was added. The median of linezolid administration was 23.9 months (IQT 13.1-24.7). Patients using linezolid showed a greater resistance to drugs, with a median of 6 (IQR 5-7) compared with those who did not use it, with a median of 4 drugs (IQR 3-5) (p<0.001). The median time to sputum culture conversion of the patients in the linezolid group (73.5 days) did not differ significantly from those in the non-linezolid group (61 days) (p=0.29). There were no significant differences in the outcomes of the two patient groups. There were no reported adverse events in 81% of patients assigned to linezolid therapy. Only four patients developed toxicity attributed to linezolid. The most serious adverse event in these patients was anemia observed in the two patients treated with 1200 mg per day. One of them also developed moderate paresthesia. In both cases the dosage was reduced to 600 mg per day, with improvement of the anemia and paresthesias. No patients stopped linezolid therapy. CONCLUSION: A daily dosage of 600 mg of linezolid was well tolerated without stopping treatment in any case. The efficacy of the treatment and the outcomes were similar in both the linezolid and non-linezolid group.

[New tuberculosis drugs in resistant and multiresistant tuberculosis]. / Nuevos fármacos antituberculosos en la tuberculosis resistente y multirresistente.

Drug-resistant tuberculosis is a globally emerging problem with a rising incidence. According to the WHO in 2008, 17% of strains of Mycobacterium tuberculosis, in untreated cases were resistant to at least one drug and 3.6% were resistant to rifampicin and isoniazid, which is called multidrug-resistant tuberculosis. The problem is greater in patients previously treated and in some countries, where rates of multidrug resistance reach 60%. Approximately 5% of multidrug-resistant tuberculosis patients are also resistant to any fluoroquinolone and at least one injectable drug, being called extensively drug-resistant tuberculosis. The treatment of these forms of tuberculosis requires the use of second-line drugs, which causes higher cost, higher toxicity and a longer duration of treatment. There is a need for new compounds with efficacy and safety profiles better than those currently used to treat these forms of tuberculosis. In the last decade different drugs have being reassessed and appeared, which are at different stages of development.

[Outcome and treatment among patients with multidrug-resistant tuberculosis]. / Evolución y tratamiento de pacientes con tuberculosis multirresistente.

BACKGROUND AND OBJECTIVE: Although progress has been made to reduce the global incidence of tuberculosis, the emergence of multidrug-resistant tuberculosis during the past decade threatens to limit these results. The aim of this study is to evaluate the geographic distribution, clinical and microbiological characteristics and outcomes of multidrug-resistant tuberculosis patients in Spain. PATIENTS AND METHODS: Retrospective study between January 1998 and December 2010 of patients attended in Cantoblanco-La Paz Hospital Isolation Internal Medicine Unit. RESULTS: Forty-seven patients were studied, with a mean age of 36 years. There were 33 male. Sixty-four per cent were immigrants and the mean residence time in Spain was 12 months. Twenty-six patients (55.3%) were new cases. Patients were resistant to a median of 5 drugs (interquartile range [IQR] 3-7) and 3 patients had extensively drug-resistant tuberculosis. Cultures became negative after a median of 68.5 days (IQR 49.5-91.8). The median length of hospitalization was 2.75 months (IQR 1.3-4.6). They were treated during a median of 22.4 months (IQR 15.3-24.3). The overall success rate was 93%. A directly observed treatment was carried out in 79% of patients. Sixty-eight per cent patients presented side effects. In 75% of the cases the effects were mild and moderate with no need to replace the drug. Fourteen patients were followed up for a median of 40.5 months (IQR 7.4-55) and no clinical or bacteriological manifestation of disease was detected. CONCLUSIONS: Most patients with multidrug-resistant tuberculosis can be cured with the use of appropriate and intensive regimens, management of side effects and implementation of strategies to improve adherence to treatment.