Fecal and oral shedding of Helicobacter pylori from healthy infected adults

Context Helicobacter pylori commonly infects humans; however, its mode of t ransmission remains unknown. Objective To determine how humans-the primary host for H pylori-shed the or ganism into the environment. Design Controlled clinical experimental study conducted from February throu gh December 1998. Setting Clinical research unit of a hospital in northern California. Patients Sixteen asymptomatic H pylori-infected and 10 uninfected adults. Intervention A cathartic (sodium phosphate) and an emetic (ipecac) were giv en to all infected subjects and an emetic was given to 1 uninfected subject . Main Outcome Measure Confirmed H pylori isolates cultured from stool, air, or saliva before and after catharsis and emesis and from vomitus during eme sis. Isolates were fingerprinted using repetitive extragenic palindromic (R EP) polymerase chain reaction and species identity was confirmed by sequenc ing the 16s ribosomal RNA gene. Results All vomitus samples from infected subjects grew H pylori, often in high quantities. Air sampled during vomiting grew H pylori from 6 (37.5%) o f the 16 subjects. Saliva before and after emesis grew low quantities of H pylori in 3 (18.8%) and 9 (56.3%) subjects, respectively. No normal stools and only 22 (21.8%) of 101 induced stools grew the organism, although 7 (50 .0%) of 14 subjects had at least 1 positive culture (2 stool culture sample s were contaminated by fungus and were not included). Fingerprints of isola tes within subjects were identical to one another but differed among subjec ts. No samples from uninfected subjects yielded H pylori. Conclusions Helicobacter pylori can be cultivated uniformly from vomitus an d, occasionally, from saliva and cathartic stools. The organism is potentia lly transmissible during episodes of gastrointestinal tract illness, partic ularly with vomiting.