The first reported case of human illness from E. coli O146:H28 was recorded this year in Switzerland in a two-day-old boy. While this strain of E. coli was known to be pathogenic because it produces Shiga toxins, it had not previously produced symptoms in infected humans. Researchers speculate that the newborn contracted the bacteria from his mother during childbirth. This incident is one of only a handful of known mother-to-child E. coli cases, the first of which was recorded in France in 2005. The Swiss newborn was healthy immediately following his birth, according to a report on the illness published in the January issue of Clinical Infectious Diseases. Two days later, however, he began vomiting. At six days old, he developed hemolytic uremic syndrome (HUS) – a disease characterized by kidney failure. Over 90 percent of HUS cases are a result of E. coli infections. The newborn also experienced seizures as a result of his illness. Finally, at 11 days old, he was released from the hospital in good condition. After a sample of the baby’s feces tested positive for Shiga toxin-producing E. coli (STEC), doctors concluded that this was the source of his illness. STEC was also discovered in a sample of the mother’s stool. A DNA analysis of the strain found in the mother revealed that it was genetically indistinguishable from the one discovered in the newborn. “We postulate that the mother is a healthy carrier, who transmitted the STEC by the fecal-oral route to the newborn during delivery,” concludes the disease report. Researchers note that the type of Shiga toxin produced by this strain of E. coli is not one of the ones most commonly associated with HUS in patients. This newborn likely developed HUS because his bowel was sterile at the time of delivery, allowing the foreign pathogen to multiply easily, uninhibited by other bugs. The authors say it is important to rule out atypical HUS (HUS that is not due to E. coli infection) when diagnosing newborns with the condition. “Even though infectious HUS is a very rare condition in this age group, the search for this entity is mandatory.”
