This study aims to determine the regional prevalence of Helicobacter pylori infection, bacterial strain differences, and the prevalence of gastric cancer in two provinces of Laos, a multi-ethnic country where these factors may vary by region and ethnicity. The study also evaluates whether H. pylori eradication therapy contributes to disease prevention. Residents aged 18 years or older in Luang Prabang Province and Champasak Province underwent stool antigen testing, and H. pylori-positive individuals received eradication therapy. High-risk participants aged ≥40 years underwent upper gastrointestinal endoscopy for early detection of gastric cancer.

This population-based study was conducted in Laos to investigate geographic variation in Helicobacter pylori infection, bacterial strains, and the prevalence of precancerous and cancerous gastric lesions. Laos is a multi-ethnic nation, and differences in H. pylori prevalence and strain distribution are expected across ethnic groups and regions. The goal of this study is to assess the current burden of infection and evaluate the effectiveness of eradication therapy as a preventive strategy for gastric cancer.

Eligible participants were residents aged ≥18 years living in Luang Prabang Province (North) and Champasak Province (South). The study received approval from the Ethics Committee of the Ministry of Health of Laos. All participants received an explanation of the risks and benefits of screening and provided written informed consent.

The study procedures were conducted as follows:

1. Stool H. pylori antigen rapid test was performed for all enrolled participants.
2. Participants aged ≥40 years who tested positive were considered a high-risk group and underwent upper gastrointestinal endoscopy for early detection of precancerous gastric lesions and gastric cancer.
3. All H. pylori-positive participants received 14-day triple therapy consisting of lansoprazole, amoxicillin, and clarithromycin.
4. Eradication was assessed using a follow-up stool antigen test at 8 months after treatment in Luang Prabang Province and 6 months after treatment in Champasak Province.

Screening in Luang Prabang Province was conducted between December 2023 and October 2024, and screening in Champasak Province between October 2024 and June 2024.

Inclusion Criteria:

• Age ≥18 years
• Resident of Luangprabang or Champasak Province
• Able to provide written informed consent

Exclusion Criteria:

• Severe comorbidities contraindicating screening or treatment
• Allergy to medications used in triple therapy
• Pregnant or breastfeeding women (if applicable)

Study Locations

1. Luangprabang Province, Lao PDR
2. Champasak Province, Lao PDR

Individual participant data will not be shared. Due to ethical and regulatory considerations in Laos, and because the dataset includes sensitive health information collected from community residents, de-identified participant-level data will not be made publicly available.