1. India is on high alert against the deadly strain of Shiga toxin-producing E coli ( STEC 0104: H4)
2. Has infected over 1823 cases across 12 European nations (Austria, Czech Republic, Denmark, France, Netherlands, Norway, Spain, Sweden, Switzerland, Britain and the United States) including 520 cases of hemolytic uremic syndrome (HUS). Twelve HUS cases were fatal, and 6 deaths were reported among non-HUS cases. (17 deaths in Germany and I in Sweden)
3. The Food Safety and Standards Authority of India has informed its officials to watch out for all food items, especially fruits and vegetables, coming in from Europe.
4. The FOOD source IS organic Spanish cucumbers. cucumbers, tomatoes, and lettuce are top suspects.
5. E coli is a common bacteria in the GI tract and part of the normal bacterial flora. However some E coli strains produces a toxin that could produce serious infection. The infection is acquired by consuming contaminated food or water.
6. The incubation period is 3-4 days in conventional strain but in the STEC 0104: H4 strain it is 7-12 days. Most patients' symptoms resolve within 5 to 7 days. However, HUS STEC 0104: H4 can develop a week after diarrhea begins.
7. Symptoms range from mild to severe bloody diarrhoea, mostly without fever. The strain STEC 0104: H4 is causing severe symptoms, including stomach cramps, bloody diarrhea, vomiting, and fever. However, fever is not usually high.
8. As per WHO, this STEC 0104:H4 strain of E coli "is a unique strain that has never been isolated from patients before" and there may be "various characteristics that make it more virulent and toxin-producing".
9. The hemolytic-uremic syndrome (HUS) is characterized by the simultaneous occurrence of a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury.
10. Microangiopathic hemolytic anemia: Hemoglobin levels are usually less than 8 g/dL. The Coomb's test is negative and the peripheral blood smear is characterized by the large number of schistocytes and helmet cells. There is no correlation between the severity of the anemia and the severity of the renal disease.
11. Thrombocytopenia: Platelet counts are generally around 40,000/mm3. There is no correlation between the degree of thrombocytopenia and the severity of the renal disease.
12. Acute renal injury: The severity of renal involvement ranges from hematuria and proteinuria to severe renal failure and oligoanuria, which occur in one-half of cases. Hypertension is also frequently observed. Although as many as 50 percent of those with HUS require dialysis during the acute phase, the prognosis for recovery of renal function is generally favorable.
13. Up to 10% of patients with this latest infection with STEC 0104: H4 strain may develop HUS, with a case-fatality rate ranging from 3% to 5%.
14. Normally HUS is the most common cause of acute renal failure in young children but this strain (STEC 0104: H4) is affecting female adults above the age of 20.
15. It can cause neurological complications like seizure, stroke and coma in 25% of HUS patients and chronic renal sequelae, usually mild, in around 50% of survivors.
16. Normally HUS can be Typical HUS or atypical HUS. Typical HUS is Shiga-like toxin (Stx) associated HUS and atypical HUS is non-shiga toxin (NStx) associated HUS.
17. Typical Stx HUS occurs after a prodromal episode of bloody diarrhea. It normally affects children under the age of five years. On the other hand atypical non-shiga toxin associated (NStx) HUS is a heterogeneous disorder distinguished clinically by the absence of diarrhea or Shiga toxin-producing E. coli infection, but with microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury.
18. Typical HUS primarily follows an infection with Shiga toxin producing strains of E coli. The most common serotype is O157:H7, which is found in 70 percent of cases. The annual incidence is 2 to 3 per 100,000 children less than five years of age. The current strain is different Shiga toxin–producing E coli O104:H4.
19. This disorder is commonly observed during the summer.
20. The differential diagnosis includes : other enteric infections, Henoch-Schönlein purpura, systemic vasculitis, sepsis, and disseminated intravascular coagulation.
21. There is no known effective therapy to prevent progression from the bloody diarrheal phase (acute infectious phase) to the post diarrheal phase of HUS.
22. Therapy is supportive. One can give antibiotics but NOT anti motility agents. Some research has shown that administering antibiotics may in fact increase their risk of developing HUS, but the CDC recommends that clinicians ultimately determine treatment according to each individual patient. There may be indications for antibiotics in patients with severe intestinal inflammation if perforation is of concern. Of note, isolates of STEC O104:H4 from patients in Germany have demonstrated resistance to multiple antibiotics.
23. Patients may require red blood cell transfusions when the Hb is below 6 g/dL.
24. Platelets are transfused when there is active bleeding or prior to a required invasive procedure in patients with platelet counts less than 30,000/mm3
25. Dehydration is corrected as per requirement.
26. Dialysis is done as per standard indications.
27. Hypertension is managed by fluid restriction, antihypertensive agents, and dialysis if needed. Nifedipine is the drug of choice in initial phase to be substituted with ACE inhibitors later.
28. Parenteral diazepam, phenytoin, and fos-phenytoin are used for seizures.
29. One can try plasma exchange in cases with significant neurologic symptoms.
30. Do not use antithrombotic agents or oral Shiga toxin-binding agent.
31. In general, prognosis is excellent with mortality rates below 5 percent. 5% of patients will have significant long-term sequelae of either stroke or end-stage renal failure. In patients who require renal transplantation, recurrence of HUS is rare.
32. All stools submitted for testing from patients with acute community-acquired diarrhea should be cultured for STEC O157:H7. These stools should be simultaneously assayed for non-O157 STEC with a test that detects the Shiga toxins or the genes encoding these toxins
33. It is often difficult to isolate STEC in stool by the time a patient presents with HUS.
34. WHO does not recommend any trade restrictions related to this outbreak.
