Helicobacter

CASE 1

• A 38 year old woman has a history of mid-epigastric pain for the past 4 weeks. The pain is relieved temporarily by taking food but is worsened by eating pepper. Last week, the patient developed some intermittent nausea and noticed that her stools were mostly black and tarry (consistent with the presence of hematin, derived from hemoglobin). She has not vomited.

• There is no fever on examination, but the epigastrium is tender to deep palpation. A blood count reveals a depressed hemoglobin and hematocrit. The peripheral smear show small and pale erythrocytes.

• Based on these findings, the physician suspects bleeding from an upper gastrointestinal source.

• The patient is in a location where an endoscopist is available, so she is taken for gastroduodenoscopy. A peptic ulcer is seen in the duodenum and is coagulated to stop the bleeding (see below).

Questions:

1. What is the relationship between Helicobacter pylori and duodenal ulcer?
2. How does the bacteria facilitate the development of an ulcer? How long might this process take?
3. How can a bacterium like H. pylori survive in the stomach where the pH is 1-2?
4. What product does the bacterium make that can be detected in the breath and is diagnostic of this infection?
5. What other clinical diseases of the gastrointestinal tract are associated with chronic H. pylori infection?
6. How is this infection acquired?
6. Are all H. pylori equally virulent? How do strain in the developing world differ from those in the industrialized world?
7. Is it necessary to treat this patient with antibiotics? If so, what kind of treatment would be recommended?