hus
Table of Contents
haemolytic uraemic syndrome (HUS)
Introduction
- 1st defined as a syndrome in 1955
- causes a similar clinical condition to thrombotic thrombocytopenic purpura (TTP) but with:
- being more common in children
- less neurologic abnormalities
- more renal impairments
- ADAMTS13 levels above 5%
- positive test for shiga-toxin/enterohemorrhagic E. coli (EHEC) (if this is negative then it is termed atypical HUS)
Epidemiology
- 1.5 per 100,000 people are affected per year
Clinical features
- usually have initial bloody diarrhoea due to a shiga toxin E.coli gastroenteritis after eating contaminated food, the first symptoms of infection can emerge anywhere from 1 to 10 days later, but usually after 3 to 4 days
- most common form of transmission is ingestion of undercooked meat, unpasteurized fruits and juices, contaminated produce, contact with unchlorinated water, and person-to-person transmission in daycare or long-term care facilities
- mini-epidemics occasionally occur from the sale of contaminated foods
- HUS typically develops about 5–10 days after the first symptoms, but can take up to 3 weeks to manifest, and occurs at a time when the diarrhea is improving
- fever
- anaemia with schistocytes
- neurologic symptoms
- mortality < 5%
- 25% of survivors have chronic renal failure
Aetiology
- most cases occur after infectious diarrhea due to a specific type of Shiga-toxin producing E. coli called O157:H7 (STEC)
- the binding action of Shiga-toxin also inactivates a metalloproteinase called ADAMTS13, the deficiency of which causes the closely related TTP.
- some are due to either:
- S. pneumoniae
- Shigella
- Salmonella
- certain medications
- Unlike typical HUS, atypical HUS does not follow STEC infection and is thought to result from one or several genetic mutations that cause chronic, uncontrolled, and excessive activation of complement
Rx
- supportive care
- may include dialysis, steroids, blood transfusions, or plasmapheresis.
hus.txt · Last modified: 2023/09/09 06:43 by gary1