Table 3.

The H. pylori virulence factors associated with peptic ulcer disease

Region	Virulence factor (High risk marker)	Odds ratio	Analytic method	Reference
East Asia	≥ 2 copies of EPIYA-C motifs of CagA increases DU risk (vs. 1 copy)	2.3	DNA sequencing	[30]
Southeast Asia	cagA-genopositive	2.8	PCR	[58]
	vacA m1 (vs. m2)	1.5	PCR	[58]
Middle East	vacA s1 (vs. s2)	3.1	PCR	[36]
	vacA m1 (vs. m2)	1.8	PCR	[36]
Asia	dupA-genopositive increases DU risk	1.6	PCR	[63]
Western countries	cagA+ (vs. cagA-)	1.7	PCR or Immunoblot	[20]
	vacA s1 (vs. s2)	1.7	PCR	[59]
	vacA s1/m1 (vs. s2/m2)	2.0	PCR	[20]
	babA2-genopositive	2.1	PCR	[45]
	BabA-L (vs. BabA-negative)	54.8	Immunoblot	[46]
	BabA-H (vs. BabA-negative)	19.8	Immunoblot	[46]
	dupA cluster positive increases DU risk	2.1	PCR	[66]
	iceA1-genopositive	1.3	PCR	[70]
	oipA “on” (vs. oipA “off”)	4.0	DNA sequencing or immunoblot	[74]

PCR Polymerase chain reaction