Antibiotic resistance in H. pylori should influence treatment strategy in Asia-Pacific, suggests new study
The increasing resistance to certain antibiotics in Helicobacter pylori (H. pylori) eradication therapies is associated with a reduction in treatment efficacy in Asia-Pacific countries, and treatments should be adapted accordingly, according to a systematic review and meta-analysis.
“The rise in clarithromycin and levofloxacin resistance in the past 25 years in most countries in the Asia-Pacific region is concerning, and this should prompt the development of effective strategies to control antibiotic resistance,” said the researchers led by Dr Kuo Yu-Ting from the National Taiwan University Hospital Bei-Hu Branch in Taipei, Taiwan.
“First-line treatment strategies should be adapted to resistance patterns on a country-by-country basis … [and] prospective studies are warranted to continuously monitor the prevalence of antibiotic resistance in H. pylori in the Asia-Pacific region,” said Kuo and co-authors.
The systematic review and meta-analysis involved two analyses of studies published between January 1990 and September 2016 – analysis of primary antibiotic resistance (observational studies and RCTs; 176 articles from 24 countries) and analysis of efficacy of first-line H. pylori eradication therapy (RCTs only; 170 articles from 16 countries).
Study participants were adults (aged ≥18 years) diagnosed with H. pylori using a standard diagnostic method, with no history of receiving eradication therapy for H. pylori, and no antibiotic use in the 2 weeks prior to recruitment.
Primary H. pylori resistance prevalence was most evident for metronidazole (mean prevalence, 44 percent), followed by levofloxacin, clarithromycin, tetracycline, and amoxicillin (mean prevalence, 18, 17, 4, and 3 percent, respectively). [Lancet Gastroenterol Hepatol 2017;doi:10.1016/S2468-1253(17)30219-4]
There was a marked increase in resistance to clarithromycin, metronidazole, and levofloxacin between the years prior to 2000 and 2011–2015 (7 percent to 21 percent for clarithromycin, 36 percent to 45 percent for metronidazole, and 2 percent to 27 percent for levofloxacin), while resistance to amoxicillin and tetracycline did not change drastically over time.
According to the researchers, the increase in clarithromycin resistance could be attributed to the rise in consumption of macrolides, while metronidazole resistance, which was higher in developing countries and lower in countries with higher socioeconomic status, may be linked to the use of this antibiotic for conditions such as parasite infestations or dental infections in developing countries.
Countries with high clarithromycin resistance rates (>20 percent) had a reduced efficacy of clarithromycin-containing H. pylori treatment regimens (<80 percent). Conversely, countries with low clarithromycin resistance (<15 percent) demonstrated higher efficacy of clarithromycin triple therapy (>80 percent).
“These findings collectively suggest that, although clarithromycin-based triple therapy can still be used as the standard first-line treatment in countries where clarithromycin resistance is lower than 15 percent, alternative first-line regimens, such as bismuth quadruple therapy or nonbismuth quadruple therapies, should be considered in countries with high clarithromycin resistance,” said Kuo and co-authors.
The researchers acknowledged the significant heterogeneity between studies, which was influenced by the study regions, periods, resistance-measuring methods, and region-specific infections.
“Our findings provide policy makers with the necessary evidence to decide optimal first-line eradication regimens according to local prevalence of primary antibiotic resistance and develop effective strategies to control the rising antibiotic resistance in their countries,” they said.