Hong Kong health officials report investigating a case of Shiga toxin-producing Escherichia coli (STEC) infection in a 33-year-old woman. The patient, with good past health, has developed abdominal pain and diarrhea with blood-stained stool since September 18. She attended the Accident and Emergency Department of Tuen Mun Hospital the next day and hospitalization was not required. The patient has been in a stable condition all along.

E. coli/National Institute of Allergy and Infectious Diseases (NIAID)
E. coli/National Institute of Allergy and Infectious Diseases (NIAID)

Her stool specimen grew STEC upon laboratory testing by the Public Health Laboratory Services Branch of the Centre for Health Protection (CHP).

Initial inquiries by the CHP revealed that the patient had no recent travel history. She also has no recent history of consumption of unpasteurized milk or raw food, nor contact with animals or visits to farms. Her home contacts have remained asymptomatic. The CHP’s investigations are ongoing.

“Escherichia coli (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 recognized serogroup of STEC is E. coli O157:H7,” a spokesman for the CHP explained.

In addition, health officials are also investigating a case of mad honey poisoning, reminding the public to buy honey from a reliable source or apiary.


The male patient, aged 50 with good past health, developed abdominal pain, sweating and dizziness around an hour after consuming honey alone at home on September 21. He attended Tseung Kwan O Hospital and was admitted for management on the same day and was discharged on September 24 in stable condition.

Grayanotoxin was detected in the patient’s urine sample and the honey remnant upon testing by the Hospital Authority Toxicology Reference Laboratory, which matches with the clinical diagnosis, grayanotoxin poisoning.

Initial inquiries revealed that the honey was brought from Nepal by the patient’s family. Investigations are ongoing.

“Mad honey poisoning is caused by ingestion of honey containing grayanotoxins derived from plants belonging to the Ericaceae family, including rhododendrons. Grayanotoxins are neurotoxins which can affect nerves and muscles. Symptoms of poisoning include nausea, vomiting, diarrhea, dizziness, weakness, excessive perspiration, hypersalivation and paraesthesia shortly after ingestion. In severe cases, hypotension, bradycardia or shock may occur,” a spokesman for the CHP explained.