Press Release

Case of Shiga toxin-producing Escherichia coli O157:H7 infection under CHP investigation

25 October 2013

The Centre for Health Protection (CHP) of the Department of Health is today (October 25) investigating a case of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infection affecting a boy aged 12, and hence reminded members of the public to maintain good personal, food and environmental hygiene against intestinal infections.

The patient, with a history of chronic illness, developed bloody diarrhoea and vomiting on October 19. He attended the Accident and Emergency Department of Queen Elizabeth Hospital on October 21 and was admitted to the Paediatric Ward for further management. He is currently in stable condition.

His stool specimen grew STEC O157:H7 upon laboratory testing by the Public Health Laboratory Services Branch of the CHP.

Preliminary investigation by the CHP revealed that the patient has travelled to Shenzhen on October 12 and consumed undercooked beef in a restaurant there. Otherwise, he described no recent consumption of unpasteurised milk or raw food, nor contact with animals or visit to farms. His home contacts have remained asymptomatic so far.

Investigation is continuing.

This is the second case of STEC reported to the CHP this year. Eight cases were reported in 2012 while three were filed in 2011. The CHP has expanded notification of all STEC infections, in addition to the classical Escherichia coli (E. coli) O157:H7, since June 10, 2011.

"E. coli is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless. Some strains, however, such as STEC, can produce powerful toxins and cause severe food-borne disease. The most recognised serogroup of STEC is E. coli O157:H7," a spokesman for the CHP explained.

Preventive measures for STEC infections are similar to those recommended for other food-borne diseases. The public is advised to observe good personal and food hygiene:

• Wash hands properly with liquid soap and water before eating or handling food, and after going to the toilet or changing diapers;
• Cook food and boil water thoroughly before consumption. Most food-borne viruses and bacteria (including STEC) can be killed when food is cooked or reheated long enough at sufficient high temperature. When cooking or reheating, the core temperature of the food should reach at least 75 degrees Celsius;
• Avoid eating unpasteurised milk or undercooked food; and
• Consult a doctor immediately if symptoms of STEC infections, particularly bloody diarrhoea, develop.

The public may visit the CHP's website ( www.chp.gov.hk/en/content/9/24/23315.html ) for more information on STEC infection.