Azithromycin clears Shiga toxin-producing entergoaggregative E. coli infection
MedWire News: Patients with Shiga toxin-producing enteroaggregative Escherichia coli (STEC) infection should be treated with azithromycin, say German researchers who believe the antibiotic reduces the duration of bacterial shedding.
Their findings, published in JAMA, challenge the current recommendation that antibiotics should be withheld from patients with STEC due to an increased risk for hemolytic uremic syndrome (HUS).
"Among long-term carriers receiving decolonization therapy, no clinical or laboratory measures indicated induction of HUS, corroborating our finding suggesting that oral azithromycin most likely may be used safely for decolonization of STEC O104:H4 long-term carriage," write Johannes Knobloch (University Hospital Schleswig-Holstein, Lübeck) and co-authors.
They add that no patient was reinfected with the strain, suggesting that azithromycin resistance had not occurred.
The study examined the impact of antibiotic therapy in an outbreak of STEC O104:H4 that occurred in Lübeck between May and June 2011. Of the 65 patients assessed, four were children.
Twenty-two patients with HUS were given azithromycin to prevent meningitis an average of 11.8 days after onset of symptoms. A further 43 patients, including 15 HUS patients who responded to eculizumab, were not given the antibiotic. The patients were followed up for an average of 39.9 days after symptom onset.
Patients with and without HUS did not significantly differ in age or time of confirmed carriage. Nor were there significant differences in the control group for patients with and without HUS for age, gender, or duration of carriage.
Analysis showed that patients who received antibiotics were significantly less likely to be carrying STEC more than 28 days after onset than controls (4.5 vs 81.4%).
Furthermore, all 22 patients given antibiotics had at least three STEC-negative stool samples after treatment and no recurrence, whereas 57.7% of controls continued to carry STEC for at least 42 days after onset of symptoms.
The researchers later gave 15 of the long-term carrier patients a 3-day course of azithromycin, and these individuals subsequently had clean stool samples.
Knobloch et al note that long-term carriers of STEC may experience persistent diarrhea. Furthermore, patients are restricted in their ability to work in catering and healthcare settings while they continue to shed STEC in stool samples, causing a significant financial and social burden.
The team therefore concludes: "These findings warrant confirmation for other STEC strains, as well as prospective evaluation and possible clinical trials."
By Lynda Williams