Test Overview
Helicobacter pylori tests are used to detect
a
Helicobacter pylori (H. pylori)
infection in the stomach and upper part of the small intestine (duodenum). H. pylori can cause
peptic ulcers. But most people with
H. pylori in their digestive systems do not develop
ulcers.
Four tests are used to detect H. pylori:
- Blood antibody test. A blood test checks to see
whether your body has made
antibodies to H. pylori
bacteria. If you have antibodies to H. pylori in your
blood, it means you either are currently infected or have been infected in the
past.
- Urea breath test. A urea breath test checks to see
if you have H. pylori bacteria in your stomach. This test can show if you have an H. pylori infection. It can also be used to see if treatment has worked to get rid of H. pylori.
- Stool antigen test. A stool antigen test checks
to see if substances that trigger the
immune system to fight an H. pylori infection (H. pyloriantigens) are present in your feces (stool). Stool
antigen testing may be done to help support a diagnosis of H. pylori infection or to find out whether treatment for an
H. pylori infection has been successful.
- Stomach biopsy. A small sample (biopsy) is taken from the lining of your stomach and
small intestine during an
endoscopy. Several different tests may be done on the
biopsy sample. For more information, see the medical test
Upper Gastrointestinal Endoscopy.
Why It Is Done
A Helicobacter pylori (H. pylori) test is done to:
- Find out whether an infection with
H. pylori bacteria may be causing an
ulcer or irritation of the stomach lining (gastritis).
- Find out whether treatment
for an H. pylori infection has been successful.
How To Prepare
Blood antibody test
You do not need to do anything before you have a blood antibody
test.
Stool antigen test
Medicines may change the results of this test. Be sure to
tell your doctor about all the prescription and nonprescription medicines you
take. Your doctor may recommend that you stop taking some of your medicines.
- Do not take antibiotics or medicines containing bismuth (such as Pepto-Bismol) for 1 month before the test.
- Do not take proton pump
inhibitors (such as Prilosec or Nexium) for 2 weeks before the test.
Stomach biopsy or urea breath test
Do not eat or drink for at least 6 hours before a breath test or
a stomach biopsy.
Many medicines may change the results of this test. Be sure to
tell your doctor about all the prescription and nonprescription medicines you
take. Your doctor may recommend that you stop taking some of your medicines.
- Do not take antibiotics or medicines containing bismuth (such as Pepto-Bismol) for 1 month before the test.
- Do not take proton pump inhibitors for 2 weeks before the test.
- Do not take H2
blockers, such as Pepcid, Zantac, Axid, or Tagamet, for 24 hours before the
test.
Talk to your doctor about any concerns you have
about the need for the test, its risks, how it will be done, or what the
results may mean. To help you understand the importance of this test, fill out
the
medical test information form(What is a PDF document?).
How It Is Done
Blood antibody test
The health professional taking a sample of your blood
will:
- Wrap an elastic band around your upper arm to stop the flow of
blood. This makes the veins below the band larger so it is easier to put a
needle into the vein.
- Clean the needle site with
alcohol.
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
blood.
- Remove the band from your arm when enough blood is
collected.
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure on the site and then put on a
bandage.
Urea breath test
The breath sample is collected when you blow into a balloon or
blow bubbles into a bottle of liquid. The health professional taking a sample
of your breath will:
- Collect a sample of your breath before the
test starts.
- Give you a capsule or some water to swallow that
contains tagged or radioactive material.
- Collect samples of your
breath at different times. The breath samples will be tested to see if
they contain material formed when H. pylori comes into
contact with the tagged or radioactive material.
- The urea breath test
usually takes about 30 minutes.
Stool antigen test
The stool sample for this test may be collected at home. If you
are in the hospital, a health professional will help you collect the
sample.
To collect the sample, you need to:
- Pass stool into a dry container. Either solid
or liquid stools can be collected. Be careful not to get urine or toilet tissue
in with the stool sample.
- Replace the container cap and label the
container with your name, your doctor's name, and the date the sample was
collected.
- Wash your hands well after collecting the sample to
avoid spreading bacteria.
- Deliver the sealed container as soon as
possible to your doctor's office or directly to the lab.
Your doctor may also use a cotton swab inserted into your rectum
to collect a stool sample during an exam.
Stomach biopsy
- Endoscopy is used to collect samples of
tissue from the stomach and duodenum. The doctor may collect up to ten tissue
samples. For more information, see the topic
Upper Gastrointestinal Endoscopy.
- The
tissue samples are tested in the lab to see if they contain H. pylori.
- In rare cases, a biopsy sample may be placed in a
container that promotes the growth of H. pylori
bacteria. This is called an H. pylori culture. If
bacteria grow in the culture, tests (called
susceptibility or sensitivity testing) can determine
which antibiotic to use to treat the infection.
How It Feels
Blood antibody test
The blood sample is taken from a vein in your arm. An elastic
band is wrapped around your upper arm. It may feel tight. You may feel nothing
at all from the needle, or you may feel a quick sting or pinch.
Urea breath test
A urea breath test does not normally cause discomfort.
Stool antigen test
Collecting a stool sample normally does not cause any
discomfort.
If your doctor collects the sample during a rectal exam, you may
feel some pressure or discomfort as the cotton swab is inserted into your
rectum.
Stomach biopsy
You may notice a brief, sharp pain when the intravenous (IV)
needle is placed in a vein in your arm. The
local anesthetic sprayed into your throat usually
tastes slightly bitter and will make your tongue and throat feel numb and
swollen. Some people report that they feel as if they cannot breathe at times
because of the tube in their throat, but this is a false sensation caused by
the anesthetic. There is always plenty of breathing space around the tube in
your mouth and throat. Remember to relax and take slow, deep breaths.
You may experience some gagging, nausea, bloating, or mild
abdominal cramping as the tube is moved. Even though you won't be able to talk
during the procedure because you have a tube in your throat, you can still
communicate. If the discomfort is severe, alert your doctor with an agreed-upon
signal or a tap on the arm.
The IV medicines will make you feel sleepy. Other side
effects—such as heavy eyelids, difficulty speaking, a dry mouth, or blurred
vision—may last for several hours after the test. The medicines may also
cause you not to remember much of what happens during the test.
Risks
Blood antibody test
There is very little chance of a problem from having a blood
sample taken from a vein.
- You may get a small bruise at the site. You can lower the
chance of bruising by keeping pressure on the site for several
minutes.
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other medicines that thin your blood can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
Urea breath test
There are no known risks or complications with a urea breath
test. If radioactive carbon is used, the amount of radioactivity exposure is
extremely small—less than you normally get from being outside during the
day.
Stool antigen test
There are no risks or complications with a stool sample. But
if you do not wash your hands well after collecting the sample, you may spread
germs.
Stomach biopsy
There is a slight risk (1 in 10,000) of puncturing the wall of
the
esophagus, stomach, or duodenum during an endoscopy to
collect stomach biopsy samples. The biopsy may also cause some bleeding at the
site where the samples are collected. But the bleeding usually stops
without treatment. For more information, see the medical test Upper
Gastrointestinal Endoscopy.
Results
Helicobacter pylori tests are used to detect
a
Helicobacter pylori (H. pylori) infection in the
stomach and upper part of the small intestine (duodenum).
Results from the urea breath test or a stool
antigen test are usually available within a few
hours. Results from a blood
antibody test are usually available within 24 hours.
Results from biopsy samples obtained by
endoscopy are usually available within 48 hours.
Results from a biopsy sample that is cultured can take up to 10 days.
Blood antibody test| Normal: | The blood sample does not contain H. pylori antibodies. |
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| Abnormal: | The blood sample contains H. pylori
antibodies. |
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Urea breath test| Normal: | The breath sample does not contain the tagged
hydrocarbon. |
|---|
| Abnormal: | The breath sample contains the tagged
hydrocarbon. |
|---|
Stool antigen test| Normal: | The stool sample does not contain H. pylori antigens. |
|---|
| Abnormal: | The stool sample contains H. pylori
antigens. |
|---|
What Affects the Test
Reasons you may not be able to have the test or why the results may
not be helpful include the following:
- Most urea breath tests now use tagged carbon rather than radioactive carbon. If you are pregnant, the radioactive
urea breath test for H. pylori
is not usually done, because
the radiation could harm your child.
- Use of
antibiotics may affect the results of the urea breath
test, the stool antigen test, and stomach
biopsy by reducing the number of H. pylori bacteria in the stomach and
duodenum.
- The use of lansoprazole
(Prevacid), rabeprazole (Aciphex), sucralfate (Carafate), omeprazole
(Prilosec), famotidine (Pepcid), ranitidine (Zantac), nizatidine (Axid),
cimetidine (Tagamet), or medicines containing bismuth (such as Pepto-Bismol)
can also interfere with the results of the urea breath test, the stool antigen test, and stomach
biopsy.
- A stomach biopsy may not detect an H. pylori infection that is present if the biopsy samples are taken from
areas that are not infected by the H. pylori
bacteria.
- Rough handling, contamination, or inadequate
refrigeration of the blood sample can cause inaccurate blood antibody test
results.
- When a blood antibody test is done early in an
H. pylori infection, the results may be
falsely negative because the level of antibodies is
too low to measure.
- The likelihood of infection with
H. pylori increases with age. Older adults are more
likely to have detectable amounts of the bacteria in their body.
What To Think About
- Most urea breath tests now use tagged carbon rather than radioactive carbon. If you are pregnant, the radioactive
urea breath test for H. pylori
is not usually done, because
the radiation could harm your child.
- The stool antigen test
is the least expensive of the four tests for Helicobacter pylori, but it may not be as accurate as the
other tests. The stomach biopsy is very accurate, but it is the most expensive
and most risky of the four tests.
- A negative stool antigen test
does not always mean that an H. pylori infection is not
present (false-negative).
- Although many people are infected with H. pylori bacteria, only a few of them will develop peptic ulcer disease.
For this reason, other factors (such as a person's symptoms) should be
considered when interpreting the results of an H. pylori
test.
- Blood tests for H. pylori may be
positive for several years after the infection, so the urea breath test, the stool antigen test,
or a biopsy may be used to find out if treatment has been
effective.
- If your symptoms don't go away, an endoscopy may be needed.
For more information, see the medical test
Upper Gastrointestinal Endoscopy.
- Having an infection with H. pylori
increases your chances of having cancer of the stomach. But the risk is very
low.
- For some people who have taken medicine to treat a Helicobacter pylori (H. pylori)
infection, a follow-up test may be needed to make sure the infection is cured.
The American College of Gastroenterology recommends a follow-up test to check
for H. pylori infection whenever:1
- A peptic ulcer is caused by H. pylori infection.
- Stomach (gastric) mucosa-associated
lymphoid tissue (MALT) lymphoma is caused by H. pylori
infection.
- Upset stomach (dyspepsia) symptoms are present even
after H. pylori infection was tested for and
treated.
- Resection of early stomach (gastric) cancer has been
done.
References
Citations
- Chey WD, et al. (2007). American College of
Gastroenterology guideline of the management of Helicobacter pylori infection. American Journal of Gastroenterology, 102(8): 1808–1825.
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis:
Saunders.
- Fischbach FT, Dunning MB III, eds. (2009).
Manual of Laboratory and Diagnostic Tests, 8th ed.
Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Credits
| By | Healthwise Staff |
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| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
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| Specialist Medical Reviewer | Jerome B. Simon, MD, FRCPC, FACP - Gastroenterology |
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| Last Revised | January 4, 2012 |
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