H. pylori----

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What is H. pylori?

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.

How common is H. pylori infection?

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.

What illnesses does H. pylori cause?

Most persons who are infected with H. pylori never suffer any

symptoms related to the infection; however, H. pylori causes chronic

active, chronic persistent, and atrophic gastritis in adults and

children. Infection with H. pylori also causes duodenal and gastric

ulcers. Infected persons have a 2- to 6-fold increased risk of

developing gastric cancer and mucosal-associated-lymphoid-type (MALT)

lymphoma compared with their uninfected counterparts. The role of H.

pylori in non-ulcer dyspepsia remains unclear.

What are the symptoms of ulcers?

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. The most common ulcer symptom is

gnawing or burning pain in the epigastrium. This pain typically

occurs when the stomach is empty, between meals and in the early

morning hours, but it can also occur at other times. It may last from

minutes to hours and may be relieved by eating or by taking antacids.

Less common ulcer symptoms include nausea, vomiting, and loss of

appetite. Bleeding can also occur; prolonged bleeding may cause

anemia leading to weakness and fatigue. If bleeding is heavy,

hematemesis, hematochezia, or melena may occur.

Who should be tested and treated for H. pylori ?

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.

How is H. pylori infection diagnosed?

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.

What are the treatment regimens used for H. pylori eradication?

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.

FDA-Approved Treatment Options

FDA-approved treatment options

Omeprazole 40 mg QD + clarithromycin 500 mg TID x 2 wks, then

omeprazole 20 mg QD x 2 wks

-OR-

Ranitidine bismuth citrate (RBC) 400 mg BID + clarithromycin 500 mg

TID x 2 wks, then RBC 400 mg BID x 2 wks

-OR-

Bismuth subsalicylate (Pepto Bismol®) 525 mg QID + metronidazole 250

mg QID + tetracycline 500 mg QID* x 2 wks + H2 receptor antagonist

therapy as directed x 4 wks

-OR-

Lansoprazole 30 mg BID + amoxicillin 1 g BID + clarithromycin 500 mg

TID x 10 days

-OR-

Lansoprazole 30 mg TID + amoxicillin 1 g TID x 2 wks**

-OR-

Rantidine bismuth citrate 400 mg BID + clarithromycin 500 mg BID x 2

wks, then RBC 400 mg BID x 2 wks

-OR-

Omeprazole 20 mg BID + clarithromycin 500 mg BID + amoxicillin 1 g

BID x 10 days

-OR-

Lansoprazole 30 mg BID + clarithromycin 500 mg BID + amoxicillin 1 g

BID x 10 days

*Although not FDA approved, amoxicillin has been substituted for

tetracycline for patients for whom tetracycline is not recommended.

**This dual therapy regimen has restrictive labeling. It is indicated

for patients who are either allergic or intolerant to clarithromycin

or for infections with known or suspected resistance to

clarithromycin.

Are there any long-term consequences of H. pylori infection?

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.

How do people get infected with H. pylori?

It is not known how H. pylori is transmitted or why some patients

become symptomatic while others do not. The bacteria are most likely

spread from person to person through fecal-oral or oral-oral routes.

Possible environmental reservoirs include contaminated water sources.

Iatrogenic spread through contaminated endoscopes has been documented

but can be prevented by proper cleaning of equipment.

What can people do to prevent H. pylori infection?

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.

What is the Centers for Disease Control and Prevention (CDC) doing to

prevent H. pylori infection?

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.

How can I get more information about H. pylori?

1. NIH Consensus Development Conference. Helicobacter pylori in

peptic ulcer disease. JAMA 272:65-69, 1994.

2. Soll, AH. Medical treatment of peptic ulcer disease. Practice

guidelines. [Review]. JAMA 275:622-629, 1996. [published erratum

appears in JAMA 1996 May 1;275:1314].

3. Hunt, RH. Helicobacter pylori: from theory to practice.

Proceedings of a symposium. Am J Med 1996; 100 (5A) supplement.

4. The American Gastroenterological Association, American Digestive

Health Foundation, 7910 Woodmont Avenue, 7th floor, Bethesda, MD

20814, (301) 654-2055 telephone, (301) 654-5920 fax.

5. The National Digestive Diseases Information Clearinghouse,

National Institute of Diabetes and Digestive and Kidney Diseases,

National Institutes of Health, 2 Information Way, Bethesda, MD 20892-

3570, (301) 654-3810 telephone.

6. Hunt RH, ABR. Canadian Helicobacter pylori Consensus

Conference. Can J. Gastroenterol 1998, 12(1):31-41.

7. European Helicobacter pylori Study Group. Current European

concepts in the management of H. pylori information. The Maastricht

Consensus. Gut 1997; 41, 8-13.

For further information, contact:

Health Communications Activity

Division of Bacterial and Mycotic Diseases

National Center for Infectious Diseases

Centers for Disease Control and Prevention

1600 Clifton Road, MS-A49

Atlanta, GA 30333

1-888-MY-ULCER (1-888-698-5237)