Predictors of triple therapy treatment failure among H. pylori infected patients attending at a tertiary hospital in Northwest Tanzania: a prospective study

BACKGROUND: Helicobacter pylori (H.pylori) infection is a common medical problem in resource limited areas. The treatment outcome after triple therapy has not been well studied in developing countries and preliminary data suggests a high rate of treatment failure. This study investigated the triple therapy treatment failure rate and associated factors among dyspeptic patients receiving H. pylori first line therapy at a tertiary hospital, Tanzania. METHODS: A prospective study in the Gastroenterology unit of the Bugando Medical Centre (BMC) was conducted between October 2015 and May 2017. All dyspeptic patients with stool antigen tests positive for H.pylori were given first line therapy, and stool antigen testing was repeated within 7 days and 5 weeks after completion of the treatment. Biopsies were taken before initiation of therapy and analysed for clarithromycin and quinolone resistance mutations using polymerise chain reaction (PCR) and sequencing. Adherence and other social-demographic characteristics were documented. RESULTS: A total of 210 patients were enrolled; the median age was 35 years (interquartile range, 27–48). First line treatment failure as defined by positive stool antigen 5 weeks post treatment was observed in 65/210 (31%) of patients. Independent predictors of first line treatment failure were presence of clarithromycin resistance mutations (OR: 23.12, 95% CI (9.38–56.98), P < 0.001) and poor adherence (OR: 7.39, 95% CI (3.25–16.77), P < 0.001). The sensitivity and specificity of stool antigen testing within 7 days after completion therapy in detecting treatment failure was 100 and 93.2%, respectively. CONCLUSION: Nearly one-third of patients with clarithromycin resistance mutations and poor adherence develop first line treatment failure. Routine stool antigen testing within seven days after completion of therapy can be considered in order to initiate second line treatment early to prevent associated morbidities.