Table 3

Association between type of H. pylori strain, CagA/VacA antibodies by immunoblotting, presence of cagA/vacA genes by PCR, and risk of gastric cancer

	No. of cases	No. of controls	Gastric cancer risk
	No. of cases	No. of controls		OR (95% CI)
By immunoblotting
H. pylori neg^a	15	105	1 (Reference)
Type II strain^b	1	34	0.2 (0.0–1.8)
Intermediate strain^c	34	102	2.0 (1.0–4.0)
Type I strain^d	16	67	1.8 (0.8–4.0)
H. pylori neg^a	15	105	1 (Reference)
CagA neg	2	39	0.4 (0.1–1.7)
CagA pos^e	49	164	1.9 (1.0–3.7)
H. pylori neg^a	15	105	1 (Reference)
VacA neg	34	131	1.6 (0.8–3.1)
VacA pos	17	72	1.8 (0.8–3.8)
By PCR
H. pylori neg^a	43	198	1 (Reference)
cagA neg	1	13	0.4 (0.0–3.2)
cagA pos	27	113	1.2 (0.7–2.1)
H. pylori neg^a	43	198	1 (Reference)
vacA s2	1	2	2.3 (0.2–27)
vacA s1	27	124	1.1 (0.6–2.0)
H. pylori neg^a	43	198	1 (Reference)
vacA m2	1	20	0.2 (0.0–1.8)
vacA m1	24	99	1.2 (0.7–2.2)

^a H. pylori neg, negative on all tests performed.
^b CagA and VacA negative.
^c CagA positive or VacA positive.
^d CagA and VacA positive by immunoblotting.
^e pos, postive.