Huang Y, Fan XG, Tang ZS, Liu L, Tian XF, Li N. Detection of Helicobacter pylori DNA in peripheral blood from patients with peptic ulcer or gastritis. APMIS 2006;114:851–6. Cases of Helicobacter bacteremia have been reported from time to time. Helicobacter pylori is the most important representative of Helicobacterium, yet whether it can result in bacteremia has rarely been studied. In this study, we examined H. pylori DNA in peripheral blood and gastric mucosa of patients with peptic ulcer or chronic gastritis by polymerase chain reaction (PCR). We found H. pylori DNA in 15 of 20 gastric samples, and 9 of these specimens were positive for H. pylori culture. H. pylori DNA amplified by PCR was positive in the peripheral blood of three patients, who all had duodenal ulcers. Gastric biopsy specimens from these three patients were all positive for H. pylori genes and H. pylori was isolated from these specimens. After the 16S rRNA gene sequences of three specimens from the same patient were obtained, we found that they were identical, which suggested that they are the same strain. Our findings suggest that H. pylori exists not only in gastric mucosa but also in peripheral blood, and it is possible that H. pylori can result in bacteremia.