Helicobacter pylori (H. pylori ) is a spiral shaped bacterium that infects the human stomach and duodenum.
Many peptic ulcers and some types of gastritis are caused by H. pylori infection. Most humans who are infected will never develop symptoms.
H. pylori is the only known organism that can thrive in the stomach’s highly acidic environment. It is helix-shaped (hence the name helicobacter) and can literally screw itself into the stomach lining to colonize.
H. pylori damages the stomach and duodenal tissue causing inflammation and ulcers. The damage is believed to occur because of H. pylori's shape and characteristics.
Its spiral shape and movement enables it to penetrate the protective lining of the stomach. When it penetrates the stomach, excess acid irritates the stomach and duodenum thus causing an ulcer.
Infection may be symptomatic or asymptomatic (without visible ill effects). Up to 70% of infection is estimated to be asymptomatic.
Helicobacter Pylori Infection Rates
About 2/3 of the world population is estimated to be infected by the bacterium. In the West (Western Europe, North America, Australia) the infection rate is around 25% . The Third World has much higher infection rates. This may be attributed to poor sanitary conditions.
In the US, infection is primarily in the older generations. About 50% for those over the age of 60 compared are thought to be infected compared to 20% of those under 40 years.
The infection rates can be attributed to hygiene standards and widespread use of antibiotics. H. pylori can be spread through contaminated food or water.
A strain of H. pylori that is antibiotic resistant has recently appeared. In addition there is a metronidazole (antibiotic and antiparasitic drug) resistant strain of H. pylori present in the UK population.
Preventing Helicobacter Pylori Infection
It is important to frequently wash your hands thoroughly. It is also vital to eat food that has been prepared in a clean environment.
Drink water from a safe and clean source may also help you from getting a H. pylori infection.
Helicobacter Pylori Testing
H. pylori infection can be detected with blood antibody or stool antigen tests.
It can also be detected with the carbon urea breath test. In carbon urea breath test, the patient drinks labelled urea( carbon 14 or carbon 13) which the bacterium metabolises producing labelled carbon dioxide that can be detected in the breath.
H. pylori can also be detected using endoscopy.
Helicobacter Pylori Treatment
In gastric ulcer patients where H. pylori is detected, the normal procedure is eradication to allow the ulcer to heal.
A standard first-line therapy is a one week triple-therapy of amoxicillin, clarithromycin and omeprazole. Sometimes a different proton pump inhibitor is substituted, or metronidazole is used in place of amoxicillin in those allergic to penicillin.
This therapy has revolutionised the treatment of gastric ulcers and has made a cure of the disease possible.
In the absence of antibiotic based treatments, H. pylori infection apparently persists for life. The human immune system is not able to eradicate it.
However, an increasing number of infected individuals are found to harbour bacteria resistant to first-line antibiotics.
This may result in initial treatment failure. Additional rounds of antibiotic therapy may therefore be required. For more resistant cases, a quadruple therapy may be used.
Bismuth compounds are also effective in combination with the above drugs.
After treatment of H. pylori, it is necessary to repeat the tests to determine if H. pylori has been eliminated.
Only breath tests or endoscopy with biopsy can be used to prove that the bacterium has been eliminated.
The blood test may remain positive for months or years even after eliminating the H. pylori bacterium.