Mixed genotypes were found in 24% of patients who were Chinese residents of Hong Kong . Another report indicated that the prevalence of mixed infections was 23.3% of all H. pylori-infected samples isolated from patients who lived in southern Taiwan . In this study, we found that the prevalence of H. pylori mixed infections was 28.6% (20/70) in patients who were residents of northern Taiwan. This discrepancy in the prevalence of mixed infections in Chinese populations may be explained by the different analysis strategies and the fact that enrolled subjects were from different geographic regions [34, 35].