Helicobacter pylori infection

Content

Introduction

Helicobacter pylori infection is an infection of the lining of the stomach caused by the bacterium helicobacter pylori (Hp).

Helicobacter pylori commonly lives in the stomach where it can survive both by lowering gastric acidity by producing a substance (enzyme) called urease, both by penetrating, thanks to its helical shape from which it takes its name, into the innermost and less acidic layer of the gastric mucosa.

It has been calculated that helicobacter pylori could be present in the stomach of about 25 million Italians, and the number could be even higher in developing countries. In these countries the infection is established early in childhood while in the industrialized countries with a western lifestyle, infection is more frequent in adulthood.

It generally does not cause health problems. However, in some people it causes a chronic inflammation of the stomach called gastritis (Video).

If the infection occurs at a young age it can cause atrophic gastritis which can give rise to a gastric ulcer and, rarely, to the onset of MALT lymphoma (mucosa associated lymphoid tissue), a rare stomach cancer; the elimination of the bacterium can lead to the regression of the lymphoma in 60-80% of cases.

Less rarely, the infection is associated with the development of gastric carcinoma, the second most common cancer in the world, especially in countries such as China or Colombia where helicobacter pylori is present in more than half of the infant population.

On the other hand, duodenal ulcers appear more frequently in people whose infection occurs at a later age.

Symptoms

In many cases the infection does not cause disturbances (it is asymptomatic); infected people, therefore, do not experience any signs of the presence of helicobacter pylori. In other cases, although present, the disturbances are not specific. They can range from digestive difficulties, nausea, belching (dyspepsia), disorders of digestive tract diseases (for example, duodenal ulcer).

Causes

According to current knowledge, man is the only reservoir of this bacterium and its transmission most likely takes place via the oral or fecal-oral route. It is therefore possible to contract Helicobacter pylori through direct contact with the feces, vomit or saliva of infected people or by eating or drinking food and water contaminated with fecal material of human origin.

Diagnosis

In the presence of gastrointestinal disorders and suspicion of helicobacter pylori infection, the doctor may request specific tests to search for the bacterium. The simplest is the breath test (urea breath test) carried out on samples of exhaled air. Another test is the detection of the microorganism's antigens on small amounts of feces.

Both tests can be influenced by the intake of drugs that inhibit stomach acid secretion and, for this reason, these drugs should be stopped for about two weeks before the tests are performed. In cases where it is not possible to stop them, a test has been available for some years that searches for antigens in the faeces without the result being influenced by the use of drugs that inhibit gastric acid secretion.

The search for helicobacter pylori by non-invasive tests is generally required in people with digestive difficulties (dyspepsia) under the age of 60 and without major complaints (symptoms).Non-invasive tests are also recommended in people who are forced to take non-steroidal anti-inflammatory drugs (NSAIDs) or gastric acid secretion inhibitors (proton pump inhibitors) for a long time. They are also useful for confirming the elimination (eradication) of the bacterium after treatment.

After 60 years of age and / or in the presence of disorders (symptoms) that suggest infection such as fever, weight loss, anemia, intestinal bleeding, feeling of stopping food after swallowing or the presence of family members with stomach cancer , gastroscopy is required more often with the removal of small amounts of tissue (biopsies). A rapid test for the presence of helicobacter pylori (rapid urease test) can be performed on the biopsies, which will subsequently be confirmed with the result of the examination histological.

It is not recommended to search for antibodies in the blood because, in case of positivity, it would not allow to understand whether it is an "infection in progress or an" infection that has already been overcome and, consequently, whether or not drug therapy is necessary.

Therapy

Treatment for the elimination of helicobacter pylori is essential in all cases of gastric or duodenal ulcer, precancerous stomach lesions, MALT lymphoma and for those who must constantly take non-steroidal anti-inflammatory drugs (NSAIDs).

The therapy consists in the assumption of drugs that act on the acid secretion of the stomach (the so-called proton pump inhibitors) in association with antibiotics, variously combined with each other, for a duration of two weeks.

Until a few years ago, the most widely used treatment was based on the administration of an acid secretion inhibitor associated with the antibiotics amoxicillin and clarithromycin for 14 days (read La Bufala).

Following the resistance of the bacterium to antibiotics and non-negligible adverse events emerging from the studies carried out, the most recent guidelines recommend basing the choice of treatment taking into account the health conditions and the geographical area of ​​residence of the person to be treated.

After the conclusion of therapy, but not earlier than four weeks after the end, a non-invasive test (urea breath test) must always be performed to confirm that the infection has been eliminated.

Prevention

Since the main routes of transmission seem to be oral or fecal-oral, the prevention measures essentially consist in:

  • wash your hands well, several times a day, before and after food preparation, always before meals, before and after using the toilets
  • eat hygienically safe and properly washed or cooked foods
  • drink potable water, or if you are unsure of potability, or are traveling to non-industrialized countries, bottled water

Often the infection is contracted as children. For the little ones, a risk factor is given by the mothers' habit of tasting their baby food before feeding them.

Complications

The most common complication of helicobacter pylori infection is chronic superficial or atrophic gastritis. Furthermore, helicobacter pylori is the most common cause of peptic ulcer, both gastric and duodenal. It is also an important risk factor for cancer. of the stomach. In 40% of cases it is associated with lymphoma MALT gastric, a rare form of cancer.

Helicobacter pylori infection can also be associated with iron deficiency anemia (sideropenic) and therefore testing for helicobacter pylori is recommended in people with iron deficiency anemia with no other apparent cause. of idiopathic thrombocytopenic purpura.

Although it has been hypothesized that helicobacter pylori infection may be associated with numerous extraintestinal diseases, there is currently insufficient evidence to support these hypotheses.

Living with

When helicobacter pylori infection does not cause ailments (in the majority of cases), infected people live with the bacterium without health consequences.

The medical community recommends researching the bacterium and administering the cure to eliminate it only if symptoms (symptoms) attributable to it occur.

Antibiotic therapy is effective in most cases and resistance is not common. However, it does not protect against subsequent reinfections which, however, only occur in 1% of cases per year; therefore, it is advisable to observe the general prevention rules.

Bibliography

Epicenter. Helicobacter pylori

Mayo Clinic. Helicobacter pylori (H. pylori) infection (English)

In-depth link

Saleem N, Howden CW. Update on the Management of Helicobacter pylori Infection. Current Treatment Options in Gastroenterology. 2020; 1-2

Shah SC, Iyer PG, Moss SF. AGA Clinical Practice Update on the Management of Refractory Helicobacter pylori Infection: Expert Review. [Synthesis]. Gastroenterology. 2021; 160:1831-1841

World Gastroenterology Organization Global Guidelines. Helicobacter pylori. May 2021

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