Helicobacter pylori infection

A peptic ulcer is a sore or hole in the lining of the stomach or duodenum (the first part of the small intestine). People of any age can get an ulcer and women are affected just as often as men. Over 25 million Americans will suffer from an ulcer at some point during their lifetime. The good news is that most ulcers are caused by an infection with the bacterium, Helicobacter pylori, and can be cured in about two weeks with antibiotics.

• Most ulcers are caused by an infection, not spicy food, acid or stress.

• The most common ulcer symptom is burning pain in the stomach.

• Your doctor can test you for H. pylori infection. • Antibiotics are the new cure for ulcers.

• Eliminating H. pylori infections with antibiotics means that your ulcer can be cured for good.

Epidemiology and Demographics
Approximately two-thirds of the world's population is infected with H. pylori. In the United States, H. pylori is more prevalent among older adults, African Americans, Hispanics, and lower socioeconomic groups.

Approximately 25 million Americans suffer from peptic ulcer disease at some point in their lifetime. Each year there are 500,000 to 850,000 new cases of peptic ulcer disease and more than one million ulcer-related hospitalizations.

Risk Factors
Persons with active gastric or duodenal ulcers or documented history of ulcers should be tested for H. pylori, and if found to be infected, they should be treated. To date, there has been no conclusive evidence that treatment of H. pylori infection in patients with non-ulcer dyspepsia is warranted. Testing for and treatment of H. pylori infection are recommended following resection of early gastric cancer and for low-grade gastric MALT lymphoma. Retesting after treatment may be prudent for patients with bleeding or otherwise complicated peptic ulcer disease. Treatment recommendations for children have not been formulated. Pediatric patients who require extensive diagnostic work-ups for abdominal symptoms should be evaluated by a specialist.

Pathophysiology & Etiology
Helicobacter pylori (H. pylori) is a bacterium that lives on the lining of the stomach. Although we used to think that spicy food, acid, and stress were the major causes of ulcers, we now know that nine out of ten ulcers are caused by H. pylori. Medicines that reduce stomach acid may make you feel better, but your ulcer may come back. Here's the good news: Since most ulcers are caused by this bacterial infection, they can be cured with the right antibiotics.

Helicobacter pylori (H. pylori) is a spiral-shaped bacterium that is found in the gastric mucous layer or adherent to the epithelial lining of the stomach. H. pylori causes more than 90% of duodenal ulcers and up to 80% of gastric ulcers. Before 1982, when this bacterium was discovered, spicy food, acid, stress, and lifestyle were considered the major causes of ulcers. The majority of patients were given long-term medications, such as H2 blockers, and more recently, proton pump inhibitors, without a chance for permanent cure. These medications relieve ulcer-related symptoms, heal gastric mucosal inflammation, and may heal the ulcer, but they do NOT treat the infection. When acid suppression is removed, the majority of ulcers, particularly those caused by H. pylori, recur. Since we now know that most ulcers are caused by H. pylori, appropriate antibiotic regimens can successfully eradicate the infection in most patients, with complete resolution of mucosal inflammation and a minimal chance for recurrence of ulcers.

Natural History
The road to a cure for ulcers has been a long and bumpy one. Recent news that ulcers are caused by a bacterium and can be cured with antibiotics has changed traditional thinking. Physicians and consumers have not been informed of the good news.

Early 20th Century

Ulcers are believed to be caused by stress and dietary factors. Treatment focuses on hospitalization, bed rest, and prescription of special bland foods. Later, gastric acid is blamed for ulcer disease. Antacids and medications that block acid production become the standard of therapy. Despite this treatment, there is a high recurrence of ulcers. 1982

Australian physicians Robin Warren and Barry Marshall first identify the link between Helicobacter pylori (H. pylori) and ulcers, concluding that the bacterium, not stress or diet, causes ulcers. The medical community is slow to accept their findings. 1994 A National Institutes of Health Consensus Development Conference concludes that there is a strong association between H. pylori and ulcer disease, and recommends that ulcer patients with H. pylori infection be treated with antibiotics. 1995 Data show that about 75 percent of ulcer patients are still treated primarily with antisecretory medications, and only 5 percent receive antibiotic therapy. Consumer research by the American Digestive Health Foundation finds that nearly 90 percent of ulcer sufferers are unaware that H. pylori causes ulcers. In fact, nearly 90 percent of those with ulcers blame their ulcers on stress or worry, and 60 percent point to diet. 1996

The Food and Drug Administration approves the first antibiotic for treatment of ulcer disease. 1997

The Centers for Disease Control and Prevention (CDC), with other government agencies, academic institutions, and industry, launches a national education campaign to inform health care providers and consumers about the link between H. pylori and ulcers. This campaign reinforces the news that ulcers are a curable infection, and the fact that health can be greatly improved and money saved by disseminating information about H. pylori. Medical researchers sequence the H. pylori genome. This discovery can help scientists better understand the bacterium and design more effective drugs to fight it.

Diagnosis
Several methods may be used to diagnose H. pylori infection. Serological tests that measure specific H. pylori IgG antibodies can determine if a person has been infected. The sensitivity and specificity of these assays range from 80% to 95% depending upon the assay used. Another diagnostic method is the breath test. In this test, the patient is given either 13C- or 14C-labeled urea to drink. H. pylori metabolizes the urea rapidly, and the labeled carbon is absorbed. This labeled carbon can then be measured as CO2 in the patient's expired breath to determine whether H. pylori is present. The sensitivity and specificity of the breath test ranges from 94% to 98%. Upper esophagogastroduodenal endoscopy is considered the reference method of diagnosis. During endoscopy, biopsy specimens of the stomach and duodenum are obtained and the diagnosis of H. pylori can be made by several methods: The biopsy urease test - a colorimetric test based on the ability of H. pylori to produce urease; it provides rapid testing at the time of biopsy. Histologic identification of organisms - considered the gold standard of diagnostic tests. Culture of biopsy specimens for H. pylori, which requires an experienced laboratory and is necessary when antimicrobial susceptibility testing is desired.

'Your health care provider may choose to use any of the following tests to determine if your ulcer is caused by H. pylori.


 * Blood tests: A blood test can confirm if you have H. pylori. To perform this test, your health care provider sends your blood sample to a lab.
 * Breath tests: A breath test can determine if you are infected with H. pylori. In this test, you drink a harmless liquid and in less than 1 hour, a sample of your breath is tested for H. pylori.
 * Endoscopy: Your health care provider may decide to perform an endoscopy. This is a test in which a small tube with a camera inside is inserted through the mouth and into the stomach to look for ulcers. During the endoscopy, small samples of the stomach lining can be obtained and tested for H. pylori.

History and Symptoms
The most common ulcer symptom is gnawing or burning pain in the abdomen between the breastbone and the belly button. The pain often occurs when the stomach is empty, between meals and in the early morning hours, but it can occur at any other time. It may last from minutes to hours and may be relieved by eating food or taking antacids. Less common symptoms include nausea, vomiting, or loss of appetite. Sometimes ulcers bleed. If bleeding continues for a long time, it may lead to anemia with weakness and fatigue. If bleeding is heavy, blood may appear in vomit or bowel movements, which may appear dark red or black.

Risk Stratification and Prognosis
Recent studies have shown an association between long-term infection with H. pylori and the development of gastric cancer. Gastric cancer is the second most common cancer worldwide; it is most common in countries such as Colombia and China, where H. pylori infects over half the population in early childhood. In the United States, where H. pylori is less common in young people, gastric cancer rates have decreased since the 1930s.

Treatment
If you have an ulcer, you should be tested for H. pylori, and if found to be infected, you should be treated with antibiotics. Antibiotics are the new cure for ulcers; therapy is 1-2 weeks of one or two antibiotics and a medicine that will reduce the acid in the stomach. This treatment is a dramatic medical advance because eliminating H. pylori with antibiotics means that there is a greater than 90% chance that the ulcer can be cured for good. Remember, it is very important to continue taking all of this medicine until it is gone, even when you begin to feel better. If you are having side effects that make it hard to take your medicine, talk to your health care provider.

Therapy for H. pylori infection consists of 10 days to 2 weeks of one or two effective antibiotics, such as amoxicillin, tetracycline (not to be used for children <12 yrs.), metronidazole, or clarithromycin, plus either ranitidine bismuth citrate, bismuth subsalicylate, or a proton pump inhibitor. Acid suppression by the H2 blocker or proton pump inhibitor in conjunction with the antibiotics helps alleviate ulcer-related symptoms (i.e., abdominal pain, nausea), helps heal gastric mucosal inflammation, and may enhance efficacy of the antibiotics against H. pylori at the gastric mucosal surface. Currently, eight H. pylori treatment regimens are approved by the Food and Drug Administration (FDA) (Table 1); however, several other combinations have been used successfully. Antibiotic resistance and patient noncompliance are the two major reasons for treatment failure. Eradication rates of the eight FDA-approved regimens range from 61% to 94% depending on the regimen used. Overall, triple therapy regimens have shown better eradication rates than dual therapy. Longer length of treatment (14 days versus 10 days) results in better eradication rates.

Primary Prevention
Since the source of H. pylori is not yet known, recommendations for avoiding infection have not been made. In general, it is always wise for persons to wash hands thoroughly, to eat food that has been properly prepared, and to drink water from a safe, clean source.

Secondary Prevention
CDC, with partners in other government agencies, academic institutions, and industry, is conducting a national education campaign to inform health care providers and consumers of the link between H. pylori and stomach and duodenal ulcers. CDC is also working with partners to study routes of transmission and possible prevention measures, and to establish an antimicrobial resistance surveillance system to monitor the changes in resistance among H. pylori strains in the United States.

Acknowledgements
The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.