Risk population of Helicobacter pylori infection among Han and Tibetan ethnicities in western China: a cross-sectional, longitudinal epidemiological study.

BACKGROUND: China has a high prevalence of Helicobacter pylori infection, with high mortality from gastric cancer. However, there is no established nationwide screening programme for the primary prevention of gastric cancer in China. This study aimed to investigate the prevalence of Helicobacter pylori infection in Sichuan province in western China and to identify high-risk subpopulations for screening.

METHODS: A high-volume hospital-based cross-sectional study included symptomatic patients who underwent (14)C-urine breath tests from April, 2013, to March, 2014. Patients with gastric cancer or lymphoma were excluded. Positivity, severity, and disintegrations per minute from (14)C-urine breath tests were analysed. Longitudinal prevalence at Sichuan province was retrieved through a literature search of the Chinese Academic Journals Full-text Database.

FINDINGS: A total of 16751 individuals were analysed in the present cross-sectional study (median age 47 years, IQR 38-57; 47·5% male). Additionally, nine hospital-based cross-sectional studies (18 703 individuals) were included in the meta-analysis. The overall prevalence of Helicobacter pylori infection declined dramatically from 56·6% to 41·1% between 2008 and 2014. People younger than 20 years had the lowest prevalence (31·9%), while adults aged 40-49 years had the highest prevalence (42·5%). The ethnic minority population (predominantly Tibetan) presented a higher prevalence (58·9%) than the Han Chinese population (40·8%), while meta-analysis found a higher risk among Tibetan people compared with Han Chinese people (OR 1·37, 95% CI 1·24-1·52, p=0·008). Although overall prevalence was similar between males and females (1·01, 0·96-1·06, p=0·661), proportions of severe infection were significantly higher among adult and older infected females (>20 years old) compared with adult and older males (2·87, 2·50-3·30, p<0·001).

INTERPRETATION: Screening for H pylori infection is optional for symptomatic patients aged 20-39 years, but screening is recommended for patients from ethnic minority populations, women, and patients older than 40 years in regions of China with intermediate prevalence of H pylori. Cost-effectiveness of screening strategies needs further investigation.

FUNDING: National Natural Science Foundation of China (No 81301866) and Outstanding Young Scientific Scholarship Foundation of Sichuan University, from the Fundamental Research Funds for the Central Universities of China (No 2015SCU04A43).