Trial supports shorter regimens for resistant TB
A clinical trial conducted in seven countries found that two shortened, bedaquiline-containing regimens had superior efficacy in treating rifampicin-resistant tuberculosis (TB) compared with a 9-month injectable-containing regimen, with fewer cases of hearing loss, investigators reported today in The Lancet.
The STREAM stage 2 trial randomized patients aged 15 years or older with rifampicin-resistant TB to receive one of four treatments: the long regimen (the 20-month regimen recommended by the World Health Organization from 2011 to 2018), the control regimen (a 9-month regimen with the second-line injectable kanamycin), the oral regimen (9 months with bedaquiline replacing the injectable), and the 6-month regimen (containing bedaquiline and supplemented with 8 weeks of kanamycin). The primary outcome was favorable status (negative cultures for Mycobacterium tuberculosis) at 76 weeks, with additional analysis of serious adverse events.
Of the 517 participants in the modified intention-to-treat (mITT) analysis, 133 of 187 (71%) on the control regimen had a favorable outcome, compared with 162 of 196 (83%) on the oral regimen, for a difference of 11 percentage points (95% confidence interval [CI], 2.9 to 19.0), adjusted for HIV status and randomization protocol. By 76 weeks, 108 of 202 (53%) participants in the control regimen and 106 of 211 (50%) allocated to the oral regimen had an adverse event of grade 3 or 4, with hearing loss more frequent among those who received the control regimen (18 [9%] vs 4 [2%]).
Of the 134 participants in the mITT population who were allocated to the 6-month regimen, 122 (91%) had a favorable outcome, compared with 87 of 127 (69%) assigned to the control regimen, for an adjusted difference of 22.2 percentage points. Six of 143 (4%) recipients of the 6-month regimen had grade 3 or 4 hearing loss.
"In conclusion, STREAM stage 2 has shown that two short-course, bedaquiline-containing regimens are not only non-inferior but superior to a 9-month injectable-containing regimen," the investigators wrote. "These two regimens offer promising treatment options for patients with MDR [multidrug-resistant] or rifampicin-resistant tuberculosis. However, safer and simpler alternatives are still needed."
Nov 8 Lancet study
Veterinary antibiotic sales continue to decline in United Kingdom
A report today from the United Kingdom's Veterinary Medicines Directorate (VMD) shows that sales of antibiotics for use in UK livestock continue to decline.
The data in the 2021 UK Veterinary Antibiotic Resistance and Sales Surveillance Report (UK-VARSS) show that sales of antibiotics for use in food-producing animals, adjusted by animal population, fell by 6% compared with 2020 and 55% compared with 2014. Sales of highest-priority critically important antibiotics (HP-CIAs), which are considered the most vital antibiotics for human medicine, fell by 18% compared with 2020 and 83% compared with 2014. They accounted for 0.4% of total antibiotic sales for livestock in 2020—a new low.
The report also showed that antibiotic usage, including use of HP-CIAs, in 2020 fell across most animal species, with some increases observed in turkeys, game birds, and salmon. Use of HP-CIAs in UK pigs has fallen by 97% since 2015, and by 96% in UK poultry since 2014.
Clinical surveillance of antimicrobial resistance (AMR) in Escherichia coli from animal species shows some encouraging trends as well. Of the HP-CIAs tested, resistance to fluoroquinolones and third-generation cephalosporins was low or not detected for any animal species tested in 2021. In addition, the number of Salmonella isolates from cattle, pigs, chickens, and turkeys that were fully susceptible to the panel of antibiotics tested increased in 2021.
But the report does note an increase in the percentage of pigs carrying extended-spectrum beta-lactamase (ESBL)/AmpC-producing E coli, which are resistant to third-generation cephalosporins.
"Surveillance of antibiotic consumption and antibiotic resistance is one of the central pillars of the work we do on AMR," VMD Head of AMR Policy and Surveillance Kitty Healy, PhD, MRCVS, wrote in the forward to the report. "It has the potential to be more valuable still as we strive to continuously enhance our own surveillance programmes, and to link them with similar programmes in people, food, the environment and beyond."
Nov 8 UK VARSS report