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.
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.
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
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.
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.
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.
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
Omeprazole 40 mg QD + clarithromycin 500 mg TID x 2 wks, then omeprazole
20 mg QD x 2 wks
Ranitidine bismuth citrate (RBC) 400 mg BID + clarithromycin 500
mg TID x 2 wks, then RBC 400 mg BID x 2 wks
Bismuth subsalicylate (Pepto BismolŪ) 525 mg QID + metronidazole
250 mg QID + tetracycline 500 mg QID* x 2 wks + H2 receptor antagonist
therapy as directed x 4 wks
Lansoprazole 30 mg BID + amoxicillin 1 g BID + clarithromycin 500
mg TID x 10 days
Lansoprazole 30 mg TID + amoxicillin 1 g TID x 2 wks**
Rantidine bismuth citrate 400 mg BID + clarithromycin 500 mg BID
x 2 wks, then RBC 400 mg BID x 2 wks
Omeprazole 20 mg BID + clarithromycin 500 mg BID + amoxicillin
1 g BID x 10 days
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.
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
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.
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.
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
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
6. Hunt RH, Thompson 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.