Hemolytic Uremic Syndrome

In the last decade infections caused by Escherichia coli O157:H7 and other verocytotoxigenic E. coli (VTEC) have emerged as a major public health concern in North America and in Europe, and increasingly in other areas of the world. Although absolute numbers of infections are low in comparison with other enteric pathogens such as Salmonella or Campylobacter, it is well-recognised that E. coli O157 can produce severe, potentially life-threatening, illness. As a consequence of this awareness, there has been a rapid expansion of our knowledge about these organisms and the diseases which they cause. In this article, the clinical, microbiological and epidemiological features of VTEC O157 infection are reviewed.

Many foodborne diseases are associated with consumption of meat and poultry. Some pathogens were not previously known (new pathogens), others have newly arisen as foodborne (emerging pathogens), and others have become more potent or associated with other products (evolving pathogens). Many of these pathogens may cause severe illness, besides gastroenteritis. Campylobacter jejuni is a leading cause of food-associated bacterial illness; Campylobacter jejuni O:19 and other serotypes are common etiological agents of Guillain–Barré syndrome, a neuropathy due to autoimmune response. Salmonella Typhimurium DT104 and other serotypes have been found to be multi-drug resistant; salmonellosis may lead to chronic reactive arthritis. Many outbreaks of enterohemorrhagic Escherichia coli have been associated with consumption of undercooked contaminated ground beef; complication may occur (e.g., hemolytic uremic syndrome and thrombotic thrombocytopenic purpura). Listeria monocytogenes is ubiquitous; listeriosis is of major public health concern because of the severity and non-enteric nature of the disease (meningitis or meningoencephalitis, septicemia, and abortion) and its ability to multiply at refrigeration temperature. Arcobacter butzleri is a potential foodborne pathogen, and has been isolated from raw poultry, meat, and meat products; but its role in causing human illness is not fully understood. Mycobacterium avium subsp. paratuberculosis can be transmitted by ingestion of raw and processed meats; the organism may contribute to Crohn’s disease, a chronic intestinal enteritis. Beef, pork, lamb, and/or poultry have been reported as sources of infection for the abovementioned organisms but have not been generally associated with disease outbreaks of some of the pathogens.

The typical form of hemolytic uremic syndrome (HUS) is the major complication of Shiga toxin-producing Escherichia coli (STEC) infections. HUS is a critical health problem in Argentina since it is the main cause of acute renal failure in children and the second cause of chronic renal failure, giving account for 20% of renal transplants in children and adolescents in our country. In spite of the extensive research in the field, the mainstay of treatment for patients with HUS is supportive therapy, and there are no specific therapies preventing or ameliorating the disease course. In this review, we present the current knowledge about pathogenic mechanisms and discuss traditional and innovative therapeutic approaches, with special focus in national status and contributions made by Argentinean groups.

Feedlot cattle slaughtered at a large abattoir in northern Italy during 2002 were examined for intestinal carriage and carcass contamination with Escherichia coli O157:H7. Carcass samples were taken following the excision method described in the Decision 471/2001/EC, and fecal material was taken from the colon of the calves after evisceration. Bacteria were isolated and identified according to the MFLP-80 and MFLP-90 procedures (Food Directorate's Health Canada's). Eighty-eight non-sorbitol-fermenting E. coli O157:H7 isolates were obtained from 12 of the 45 calves examined. In particular, E. coli O157:H7 isolates were found in 11 (24%) fecal and five (11%) carcass samples. PCR analysis showed that all 11 fecal samples and five carcass samples carried eae-gamma1-positive E. coli O157:H7 isolates. In addition, genes encoding Shigatoxins were detected in O157:H7 isolates from nine and two of those 11 fecal and five carcasses, respectively. A representative group of 32 E. coli O...

Thrombotic microangiopathy (TMA) arises in a variety of clinical circumstances with the potential to cause significant dysfunction of the kidneys, brain, gastrointestinal tract and heart. TMA should be considered in all patients with thrombocytopenia and anaemia, with an immediate request to the haematology laboratory to look for red cell fragments on a blood film. Whilst TMA of any aetiology generally demands prompt treatment, this is especially so in thrombotic thrombocytopenic purpura (TTP) and atypical haemolytic uraemic syndrome (aHUS), where organ failure may be precipitous, irreversible and fatal. In all adults, urgent, empirical plasma exchange (PE) should be started within 4-8 hours of presentation for a possible diagnosis of TTP, pending a result for ADAMTS13 activity (a disintegrin and metalloprotease thrombospondin, number 13). A sodium citrate plasma sample should be collected for ADAMTS13 testing prior to any plasma therapy. In children, Shiga toxin-associated haemolyt...