Our approach to patients with suspected or confirmed Shiga toxin-producing Escherichia coli infection

CBC: complete blood count; HUS: hemolytic uremic syndrome; IVF: intravenous fluids; STEC: Shiga toxin-producing Escherichia coli; NSAID: nonsteroidal anti-inflammatory drug.
* Features that lower suspicion for STEC include fever at the time of presentation, absence of abdominal pain, diarrhea duration greater than a week at presentation, diarrhea that abates within hours of presentation, evidence of disease chronicity, and known contact with a patient with a microbiologically proven non-STEC bacterial diarrheal infection.
¶ We favor rectal swabs for expediency in obtaining a specimen. In children, rectal swabs have comparably sensitivity to stool specimens.
Δ In children, we usually use normal saline, administered as a bolus of at least 20 mL/kg followed by 2 L per m² per day. In adults, we also suggest aggressive isotonic volume expansion, but the volume of fluid administration should also be informed by other clinical considerations (in particular, any cardiopulmonary issues that could be exacerbated). Peripheral edema is expected, but we do not aggressively administer fluids if there are signs of central volume overload.
◊ For the first 24 hours, we check CBC every 8 to 12 hours to monitor the effectiveness of IVF volume expansion, targeting a reduction in the hemoglobin concentration.
§ Other UpToDate authors use more general diagnostic criteria for HUS: the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (defined as a reduction in glomerular filtration rate typically presenting as an abnormally elevated serum creatinine).
¥ The first day of diarrhea is considered the first day of illness.
‡ In the rare event that there is a post-discharge decrease in the platelet count, we typically readmit the patient for an additional day or two of IVF.
† A decrease in platelets is often the first laboratory manifestation of HUS. Based on our clinical experience, a 5% increase in platelet counts between days 5 and 9 of illness (or stabilization of platelet counts later in illness) suggests that the risk for HUS has passed. We have used the 5% threshold to manage many patients without adverse event, but it has not been systematically evaluated.
** A negative stool culture is often requested prior to return to daycare, school, or other sensitive settings (eg, occupation with food preparation). We typically obtain a stool culture prior to discharge from the hospital, as this is more convenient than submitting an outpatient specimen.