VEROTOXIN-PRODUCING ESCHERICHIA-COLI AND HEMOLYTIC-UREMIC SYNDROME

The haemolytic uraemic syndrome, first described in 1955 by Gasser, is the number one cause of acute renal failure in infants. There are thr ee types of the haemolytic uraemic syndrome: the seasonal epidemic for m with prodromic diarrhoea and generally favourable outcome which usua lly occurs in infants, a less typical form without signs of digestive tract involvement and no seasonal prevalence which occurs more readily in older children and sometimes in families has a less favourable pro gnosis, and finally drug- or disease-related forms. Currently, overall mortality due to haemolytic uraemic syndrome has been reduced to abou t 4%, usually as a result of damage to the central nervous system. Sev eral microorganism, including Shigella dysenteriae, Salmonella typhi, Campylobacter jejuni, Streptococcus pneumoniae, Rickittsiae and certai n viruses (Coksackiae, Influenzae, Epstein-Barr) have been identified as causative agents. In 1983, digestive tract infection due to an Esch erichia coli strain producing verotoxin was identified as capable of p roducing haemolytic uraemic:syndrome and more rarely thrombopenic thro mbotic purpura. The germ produces two exotoxins (whose effect is accen tuated by the E. coli lipopolysaccharide endotoxin) which lead to the glomerular microangiopathy causing haemolytic uraemic syndrome. Diagno sis is based on identification (monoclonal antibodies, ELISA, PCR) of the verotoxins themselves or the two encoding genes in stool samples. Symptomatic treatment is essential but the effectiveness of antibiotic s is still debated. Theoretically, antibiotics could worsen the syndro me by increasing endotoxin release from lysed bacteria, but inversely they could also prevent the syndrome if given early enough. Further re search is required to acquire precise epidemiological data and identif y animal reservoirs of verotoxin producing E. coli.