Table 2.

Suggested approach for diagnosis, treatment and confirmation

	Diagnosis	First-line treatment regimens	Confirmation*
Children	Endoscopy:	Susceptible to CLA+MET.	Stool antigen test.
	Positive culture.	PPI-AMO-CLA 14 days with standard dose.	Urea breath test (if child able to cooperate).
	Or	Resistant CLA susceptible MET.
	Positive histology.	PPI-AMO-MET 14 days or bismuth-based.
	And	Resistant MET susceptible CLA.
	One other biopsy-based test (RUT or PCR).	PPI-AMO-CLA 14 days or bismuth-based.
		Resistant CLA+MET.
		PPI-AMO-MET 14 days with high-dose amoxicillin or bismuth-based.
		Unknown.
		High-dose PPI-AMO-MET 14 days or bismuth-based.
Low-risk adults	Urea breath test.	Low CLA resistance (<15%)†.	Urea breath test.
	Stool antigen test.	PPI-AMO-CLA.	Stool antigen test.
	Serum serology (in validated areas).	High CLA resistance (>15%) +Low MET resistance.	Avoid serology.
		PPI-AMO-MET.
		+Low dual CLA and MET resistance (<15%).
		Bismuth quadruple or concomitant non-bismuth-containing quadruple.
		+High dual CLA and MET resistance (>15%).
		Bismuth-containing quadruple therapies‡.
High-risk adults	Endoscopy:		Urea breath test.
	Positive RUT.		Stool antigen test.
	Or		Avoid serology.
	Positive histology.
	Or
	Positive culture.

*To be performed 4–8 weeks after the completion of therapy with no PPI for 2 weeks and no antibiotics for 4 weeks.

†Patients who have previously taken clarithromycin and/or metronidazole should be considered high risk for dual resistance.

‡If bismuth not available, levofloxacin, rifabutin and high-dose dual (PPI+AMO) may be considered.

AMO, amoxicillin; CLA, clarithromycin; MET, metronidazole; PPI, proton pump inhibitor; RUT, rapid urease test.