Enterohemorrhagic Escherichia coli Excretion by Child and Her Cat

摘要

To the Editor: EnterohemorrhagicEscherichia coli (EHEC) can causesevere hemorrhagic colitis character-ized by gastrointestinal symptoms andbloody diarrhea as well as hemolyticuremic syndrome (1). Cattle and smallruminants are the major natural reser-voir of these foodborne pathogens(1,2). Human infections may alsodevelop after direct contact withcows, goats, sheep, and deer (1).Although domestic dogs and cats areknown as rare EHEC carriers (3,4), nohuman EHEC infections associatedwith pet contact have been reported.Here we report the first case of anEHEC strain infecting both a childand her domestic cat.A 2-year-old girl with bloody diar-rhea and vomiting subsequently testedpositive for EHEC serotype O145:H–.The isolated strain harbored the path-ogenicity-associated genes stx1, stx2,eae, and hly, as tested by PCR. Anenterohemolytic phenotype was alsopresent. After notification of the localhealth authority, a rigorous search forthe possible source of the girl's infec-tion was started. When asked forinstances of animal contact, her par-ents mentioned the family cat, whichthe girl often handled. The cat isrestricted to the house, has no contactwith other animals, and is fed onlycanned catfood. The animal strictlyuses a litter box, which is cleaned reg-ularly by the parents. No gastrointesti-nal symptoms in the cat were record-ed. Repeated stool samples from thecat grew a strain of EHEC O145:H–that showed the identical pathogenici-ty gene pattern as the girl's isolate.Moreover, a restriction fragmentlength polymorphism analysis provedthe clonal identity of both strains.Because both the girl and the cat con-tinuously excreted the EHEC strain,the cat was assumed to be a possiblesource of the girl's infection or rein-fection. The cat's infection was treat-ed with probiotics, but the child'sEHEC positivity did not change. After3 months, the girl spontaneouslystopped excreting EHEC, while thecat's stool samples remained EHECpositive. The cat was then treated byperoral autovaccination with the heat-inactivated EHEC strain for 10 con-secutive days and subsequentlystopped shedding EHEC. In the Table,the clinical course and laboratoryfindings of both girl and cat aresummarized