Outbreak of haemolytic uraemic syndrome in Germany
27 May 2011 - An outbreak of severe illness is causing concern in Germany, where 3 women have died and 276 cases of haemolytic uraemic syndrome (HUS) have been reported since the second week of May. HUS, which can lead to kidney failure, is a complication of an infection by particular Escherichia coli bacteria. While most E.coli bacteria are harmless, a group called enterohaemorrhagic E. coli (EHEC) can produce toxins, known as Shiga toxins or verotoxins, which damage blood cells and the kidneys. EHEC bacteria that produce these toxins are known as Shigatoxin-producing E. coli (STEC) or verocytotoxin-producing E.coli (VTEC), respectively. Many people have been hospitalized, several requiring intensive care, and new cases continue to be identified, the latest having an onset of 25 May. Some other countries have reported cases, notably Sweden, which has reported ten HUS cases, with two in intensive care. All the people affected recently visited Germany, mostly northern Germany.
The outbreak is unusual in that it has developed very rapidly, and an unusually high number of cases affect adults (86% are in people aged 18 years or older), particularly women (67%), instead of the normal high-risk groups, which are young children and the elderly. Nevertheless, cases have also been reported in school-aged children. The unusual E. coli serogroup O104 is suspected of being the pathogen likely to be associated with this outbreak. The epidemiological investigation into the source of the outbreak is under way. Although the source has not yet been determined, cucumbers are under suspicion, and the Robert Koch Institute in Germany is advising people, as a precautionary measure, to avoid eating tomatoes, cucumbers and lettuces, in addition to taking the usual hygiene measures in handling fruit and vegetables.
Germany notified WHO of the outbreak, under the International Health Regulations (IHR), as a potential public health event of international concern, and WHO is sharing information with health authorities in other countries. WHO has also offered technical assistance and stands ready to facilitate collaboration between laboratories to assist countries without the capacity to detect the unusual E. coli serogroup O104. WHO will maintain close contact with the relevant authorities.
EHEC can cause bloody diarrhoea and abdominal pain. People who develop these symptoms who are in or have recently visited Germany, particularly northern Germany, should seek medical advice urgently. The complication of HUS can cause acute kidney failure and can develop after the diarrhoea has resolved. Treatment with anti-diarrhoeal products or antibiotics is not usually recommended, as these may worsen the situation.
Regular hand washing, particularly before food preparation or consumption and after toilet contact, is highly recommended, particularly for people who care for small children or are immunocompromised, as the bacterium can be passed from person to person, as well as through food, water and direct contact with animals.
WHO does not recommend any restrictions in travel to or trade with Germany.
Haemolytic uraemic syndrome (HUS) is a life-threatening disease characterized by acute renal failure (uraemia), haemolytic anaemia, and a low platelet count (thrombocytopenia). It predominantly but not exclusively affects children. It results from EHEC infection, and it is estimated that up to 10% of EHEC-affected patients may develop HUS, with a mortality rate ranging up to 5%. Overall, HUS is the most common cause of acute renal failure in young children. It can cause neurological complications (such as seizure, stroke and coma) in 25% of HUS patients and chronic renal sequelae, usually mild, in around 50% of survivors.
Shigatoxin-producing E. coli (STEC) or enterohaemorrhagic E. coli (EHEC) is a severe strain of E. coli bacterium that is commonly found in the gut of animals, mainly ruminants. EHEC produces toxins, known as verotoxins or Shiga-like toxins because of their similarity to the toxins produced by Shigella dysenteriae. They can cause severe foodborne disease. STEC is transmitted to humans primarily through consumption of contaminated foods, such as raw or undercooked ground meat products and raw milk, contaminated water, direct contact with animals or contact with infected people. It is destroyed by thorough cooking of foods until all parts reach a temperature of 70 °C or higher. Symptoms of disease include abdominal cramps and diarrhoea, which may be bloody. Fever and vomiting may also occur. Most patients recover within 10 days, although in a few cases (particularly in young children and the elderly), the infection may lead to a life-threatening disease, such as HUS. Preventive measures for STEC infections are similar to those recommended for other foodborne diseases, including basic good food hygiene practice, as described in the WHO Five keys to safer food.