What are the causes and prevention of Helicobacter pylori (H. pylori) infection?

Causes and Prevention of Helicobacter pylori Infection

H. pylori infection is primarily transmitted through person-to-person contact via oral-oral or fecal-oral routes, with poor sanitation, crowded living conditions, and contaminated food and water being the major risk factors for acquisition.

Transmission Routes

Person-to-Person Transmission

• Oral-oral route: Through saliva, vomitus, or dental plaque 1
• Fecal-oral route: Through contact with fecal matter from infected individuals 2
• Intrafamilial clustering: Higher rates of infection among family members, suggesting household transmission 2

Environmental Transmission

• Contaminated water:

  • Untreated or inadequately treated water, particularly in developing countries 3
  • Waterborne transmission linked to consumption of H. pylori-contaminated well water 2

• Food-related transmission:

  • Consumption of food prepared under unsanitary conditions 3
  • Raw vegetables fertilized with human feces (particularly in developing countries) 4
  • Possible presence in milk, vegetables, and meat products 3

Geographic and Socioeconomic Factors

• Higher prevalence in developing countries (>80%) compared to developed countries (<40%) 5
• Most infections occur during childhood, especially in developing regions 2
• Prevalence varies by geographic area, age, race, ethnicity, and socioeconomic status 2

Risk Factors for H. pylori Acquisition

1. Poor socioeconomic status 3
2. Inadequate sanitation practices 2
3. Crowded or high-density living conditions 2
4. Lack of clean drinking water 3
5. Poor personal hygiene 3
6. Institutional living (orphanages, nursing homes) 2

Prevention Strategies

Personal Hygiene

• Regular handwashing with soap and water, especially:
  • Before food preparation and consumption
  • After using the toilet
  • After contact with potentially contaminated surfaces 6

Food Safety

• Thoroughly wash fruits and vegetables with clean water 3
• Properly cook foods to kill potential H. pylori bacteria 4
• Avoid consumption of raw vegetables fertilized with human waste 4
• Maintain adequate nutritional status with frequent consumption of fruits, vegetables, and vitamin C, which appears protective against H. pylori infection 2

Water Safety

• Consume properly treated or chlorinated water 4
• Avoid untreated water, especially in areas with poor sanitation 2

Household Practices

• Avoid sharing utensils, toothbrushes, or drinks with potentially infected individuals 7
• Maintain clean living environments to reduce transmission risk 6

Community-Level Interventions

• Improve sanitation infrastructure and access to clean water 6
• Public health education about transmission and prevention 6
• Screening and treatment programs in high-prevalence areas 6

Special Considerations

Transmission Differences by Region

• In developed areas: Person-to-person transmission within families appears dominant 5
• In rural developing areas: More complex transmission involving contaminated food, water, and non-parental caretakers 5

Declining Prevalence

• H. pylori infection rates are decreasing globally with improvements in:
  • Hygiene practices
  • Sanitation
  • Living conditions
  • Access to clean water 6, 2

Understanding and addressing these transmission routes and risk factors is crucial for preventing H. pylori infection and its associated diseases, including gastritis, peptic ulcers, and gastric cancer.