- 1. Helicopacterpylori AL-KALAMOON UNIVERSITY NUTRITION
DEPARTMENT DR.LOUAY LABBAN
2.
- INTRODUCTION Helicobacter pylori, also known as H. pylori, is a
bacterium that is commonly found in the stomach. It is present in
approximately one-half of the world's population.
3.
- The vast majority of people infected with H. pylori infection
have no symptoms and will never develop problems
4. Helicobacter pylori
- is a gram negative, microaerophilic, curved bacillus. It is
motile, has flagellae and has a special affinity for human gastric
mucosa.
- Since its initial discovery it has been implicated in the
pathogenesis of a number of gastroduodenal disorders including
acute and chronic gastritis, gastric and duodenal ulceration,
gastric cancer and gastric MALT lymphoma
5.
- Up to 50% of the population in developed countries such as
Australia will have evidence ofH. pyloriinfection by the age of 50
years. The organism is present in up to 92% of patients with active
chronic gastritis, 88-100% with duodenal ulceration, 58-100% with
gastric ulceration and 46-94% with gastric cancer. In duodenal
ulcer disease eradication of the organism has been shown to
markedly reduce ulcer recurrence rates and possibly change the
natural history of the disease.
6.
- However, H. pylori is capable of causing a number of
gastrointestinal disorders, including ulcers, and, much less
commonly, stomach cancer. It is not clear why some people get these
conditions and others do not.
7.
- In the United States and other developed countries, infection
is unusual during childhood but becomes more common during
adulthood. However, in developing countries, most children are
infected with H. pylori before age 10.
8.
- RISK FACTORS H. pylori is probably spread by consuming food or
water contaminated with fecal matter. Children living in developing
countries may become infected after swimming in contaminated pools,
streams, or rivers, by drinking contaminated water, or by eating
uncooked vegetables.
9.
- H. pylori causes changes to the stomach and duodenum (the first
part of the small intestine,show figure 1 ). The bacteria invades
the protective tissue that lines the stomach. This leads to the
release of certain enzymes and toxins. These enzymes and toxins may
directly or indirectly injure the cells of the stomach or
duodenum.
10.
- As a result of these changes, the stomach and duodenum are more
vulnerable to damage from digestive juices, such as stomach acid.
This results in chronic inflammation in the walls of the stomach
(gastritis) or duodenum (duodenitis).
11.
- SYMPTOMS Most individuals with chronic gastritis or duodenitis
have no symptoms. However, some people develop more serious
problems, including stomach or duodenal ulcers. Ulcers can cause a
variety of symptoms or no symptoms at all.
12.
- Common complaints include pain or discomfort (usually in the
upper abdomen), bloating, feeling full after eating a small amount
of food, lack of appetite, nausea, vomiting, and dark or
tar-colored stools. Ulcers that bleed can cause a low blood count
and fatigue.
13.
- Less commonly, chronic gastritis causes abnormal changes in the
stomach lining, which can lead to certain forms of cancer. It is
uncommon to develop cancer as a result of H. pylori infection.
14.
- Nevertheless, because so many people in the world are infected
with H. pylori, it is considered to be an important cause of
stomach cancer. People who live in countries in which infection
occurs at an early age are at greatest risk of stomach cancer.
15.
- DIAGNOSIS There are several ways to diagnose H. pylori. The
most commonly used tests include one or more of the following:
16.
- Blood tests Blood tests can detect specific antibodies
(proteins) that the body's immune system develops in response to
the H. pylori bacterium.
17.
- Breath tests Breath tests (known as urea breath tests) require
that the patient drink a specialized solution containing a
substance (13C [carbon]- or 14C-labeled urea) that is broken down
by the H. pylori bacterium. The breakdown products can be detected
in a person's breath.
18.
- Stool tests Tests are available that detect H. pylori proteins
in stool.
19.
- Endoscopy Testing may include endoscopy of the upper
gastrointestinal tract to confirm certain gastrointestinal
conditions, such as peptic ulcer, as well as infection with H.
pylori. However, endoscopy is not required for the diagnosis of H.
pylori.
20.
- During an endoscopy, a flexible tube is inserted through the
mouth into the esophagus, stomach, and upper region of the small
intestine.
21.
- The tube contains a light and camera, which can be used to
examine the various areas. Small tissue samples (biopsy samples)
can be taken from the stomach, which are then tested for H.
pylori.
22. WHO SHOULD BE TESTED?
- Patients with symptoms Diagnostic testing for H. pylori
infection is recommended for people with active gastric or duodenal
ulcers and those with a past history of ulcers.
23.
- Although H. pylori infection is the most common cause of
ulcers, not all patients with ulcers have H. pylori. Certain
medications (eg, aspirin, ibuprofen (Motrin, Advil), naproxen
(Aleve)) can also cause peptic ulcers. Thus, testing for H. pylori
is recommended.
24.
- Patients without symptoms H. pylori testing is usually not
recommended for people who have no symptoms and no past history of
peptic ulcer disease.
25.
- However, it may be considered for selected people, such as
those with a family history or concern about stomach cancer,
particularly individuals of Chinese, Korean, or Japanese descent;
these groups have a higher incidence of stomach cancer.
26.
- Nonulcer (functional) dyspepsia Because H. pylori infection is
so common, researchers have tried to determine if other illnesses
could be caused or worsened by the infection. One example of this
is a condition known as nonulcer (functional) dyspepsia
27.
- It is generally reserved for patients who require endoscopy for
other reasons (eg, evaluation of stomach pain, follow up of peptic
ulcer disease, or for the diagnosis or follow up of stomach
cancer).
28.
- Functional dyspepsia causes recurrent or persistent pain or
discomfort in the upper abdomen. It has no identifiable cause.
29.
- In general, studies suggest that few, if any, patients with
functional dyspepsia benefit from treatment of H. pylori infection.
Most patients with functional dyspepsia are tested for H. pylori
before treatment is recommended.
30. 31. 32. 33. 34.
- Methods of detection of H. pylori
- The organism is usually present in the gastric antrum and lives
beneath the mucus layer. One of its special characteristics is its
ability to produceurease,an enzyme that is not normally found in
the human stomach.
35.
- Various methods have been developed for detectingH. pylori ,
including :
- using endoscopic biopsy samples where the
36.
-
- on histological examination
-
- the polymerase chain reaction
-
- a positive rapid urease test performed on the sample
- serological tests forH. pyloriantibodies performed on blood or
less commonly saliva
- 13 C or14 C urea breath tests
37. Serological tests for H. pylori
- These are non invasive laboratory tests for antibody againstH.
pylori . Various methods exist, including : Elisa
38.
- Tests for IgG antibodies are the most sensitive as once
infected with the organism an IgG response is seen in 95%, an IgA
response in 68-80% and IgM response in only 14% of infected
patients. The majority of tests are performed on blood and the
sensitivity of salivary antibody tests is low, probably as the
majority of salivary antibodies are IgA rather than IgG. It is
important that serological tests are locally validated.