Prevalence of asymptomatic Tropheryma whipplei carriage among humans and nonhuman primates.
BACKGROUND
The reservoir of the agent of Whipple disease is unknown. Asymptomatic carriage of Tropheryma whipplei in human stool and saliva is controversial.


METHODS
Stools and saliva specimens from 231 workers at a sewage treatment facility and from 10 patients with Whipple disease, stool specimens from 102 healthy people, and stool specimens from 127 monkeys or apes were tested for T. whipplei DNA by a quantitative real-time polymerase chain reaction with probe detection. Genotyping and culture of T. whipplei-positive samples were performed.


RESULTS
Asymptomatic carriage in stool was found in humans (ranging from a prevalence of 4% in the control group to 12% among a subgroup of sewer workers) but not in monkeys and apes. The T. whipplei load in stool was significantly lower in carriers than in patients with Whipple disease (P < .001). There was a significant prevalence gradient associated with employment responsibilities at the sewage treatment facility: workers who cleaned the underground portion of the sewers were more likely than other workers to carry T. whipplei in stool. Seven of 9 sewer workers tested positive 8 months later. Patients with Whipple disease were significantly more likely to have T. whipplei-positive saliva specimens (P = .005) and had a significantly greater T. whipplei load in saliva (P = .015), compared with asymptomatic stool carriers from the sewage facility. All non-stool carriers had T. whipplei-negative saliva specimens. T. whipplei strains were heterogeneic among sewer workers but identical within individual workers.


CONCLUSIONS
Chronic asymptomatic carriage of T. whipplei occurs in humans. Bacterial loads are lower in asymptomatic carriers, and the prevalence of carriage increases with exposure to sewage.
Fenollar
Florence
F
Université de la Méditerranée, Unité des Rickettsies, CNRS UMR 6020, Faculté de Médecine, Marseille cedex, France.
Trani
Michèle
M
Davoust
Bernard
B
Salle
Bettina
B
Birg
Marie-Laure
ML
Rolain
Jean-Marc
JM
Raoult
Didier
D
D000328:Adult; D000368:Aged; D000818:Animals; D001483:Base Sequence; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*; D017931:DNA Primers; D005243:Feces / Q000382:microbiology; D005260:Female; D005602:France / Q000453:epidemiology; D000882:Haplorhini; D015186:Hominidae; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D018419:Primate Diseases / Q000453:epidemiology* / Q000382:microbiology; D012463:Saliva / Q000382:microbiology; D012722:Sewage / Q000382:microbiology*; D054851:Tropheryma / Q000235:genetics / Q000302:isolation & purification*; D008061:Whipple Disease / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary*
D017931:DNA Primers; D012722:Sewage