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H Maxwell
Journal Issue: 
Volume 37: Issue 2: 2007




Diarrhoeal-associated HUS is a common cause of acute renal failure, particularly  in  young  children.   The  diagnosis  is  made  by  the  presence  of  the following triad of findings: haemolytic anaemia (<10g/dl), thrombocytopenia (<150x109/l)  and  a  creatinine  value  that  is  above  the  upper  limit  of  normal  for  age. Ninety per cent of cases follow a diarrhoeal prodrome, and of these the majority
are  due  to  enterohaemorrhagic E. coli or  VTEC.   Sporadic  and  epidemic  cases occur  and  sources  of  infection  include  undercooked  meat, contact  with  far animals and their faeces, and contaminated water, fruit, or vegetables.

Typically, children  under  three  years  of  age  are  affected  and  present  with  abdominal pain and diarrhoea. The diarrhoea is often watery and soon becomes bloody. There may also be vomiting. The diarrhoea lasts on average for eight days, and the colitis can be  so  severe  that  children  may  present  with  an  acute  abdomen.  Perforation, bowel infarction, and  intussusception  are  rare  complications.   Rectal  prolapse  is  a  more common complication.  Diagnosis of VTEC infection is by stool culture and serology.

Ten  per  cent  of  patients  with  VTEC  infection  go  on  to  develop  HUS.  Of  these, 50–60% will develop acute renal failure requiring dialysis. Extrarenal manifestations include  seizures  and  somnolence, with  cerebral  infarcts  and  oedema  being  less common complications.  Pancreatitis and altered glucose tolerance can occur and cardiac ischaemia has been reported. On average, dialysis is required for 8–10 days; those requiring dialysis for longer than four weeks are unlikely to make a full renal
recovery. Acute  mortality  is  5–10%,  being  more  common  in  patients  with neurological involvement.  End-stage renal failure develops in 3–5%, and up to 25% may  be  left  with  renal  impairment.  At  one  year  after  the  illness, a  normal  GFR, normal BP, and absence of proteinuria are predictive of a complete recovery.