Internal Medicine

0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:12

666 Helicobacter Pylori

➣Prevalence has decreased dramatically over past 50 years; high

prevalence in those >60 years of age

➣Low lifetime risk in current children/young adults

■Country of birth:

➣Developed countries – infection now infrequent

➣Developing countries – infection still frequent

■Socioeconomic status in childhood: Infection related to sanitation,

crowding, etc.

Transmission

■Infection usually acquired in early childhood

■Adult infection or reinfection rare

■Transmitted human-to-human

■Oral-oral transmission more common in developed countries

■Fecal-oral transmission more common in developing areas

■No likely natural animal reservoir

Signs and Symptoms

■Most infected individuals (>80%) will never develop associated dis-

ease/symptoms

■Symptoms related to associated disease, not infection

■No physical findings associated with infection

■Physical findings of peptic ulcer are epigastric tenderness

■Physical findings of gastric neoplasm are weight loss, abdominal

mass, etc.

tests

Specific Diagnostic Tests

■Blood: whole blood or serum antibody tests (qualitative and quan-

titative)

■Stool: fecal antigen test

■Breath: C13 and C14 urea breath tests

■Endoscopic:

➣Biopsy urease test

➣Histology with or without special stains

➣Culture

■Antibody tests may remain positive after eradication of infection and

should not be used as a follow-up test

■Antibody tests are not accurate enough for clinical use in low-

prevalence populations.