Public Should Be Vigilant Against Bacillary Dysentery

Ruzanna Harutyunyan's picture

The Centre for Health Protection (CHP) of the Hong Kong Department of Health urged members of the public to observe personal and food hygiene following the notification of 19 cases of laboratory-confirmed bacillary dysentery (shigellosis) so far this month.

Initial investigations by the CHP indicated that 18 of these cases acquired infection locally while the remaining one was an imported case.

These cases, comprising 10 females and nine males aged between two to 58, developed gastrointestinal symptoms including fever, diarrhea, vomiting and abdominal pain from August 26 to September 12.

All of them have recovered and their stool samples were positive for Shigella sonnei. Their family contacts presently do not have any symptoms. Health advice was given to them.

According to food histories provided, five of the local cases, which involved two males and three females aged from two to 28 who did not know each other, had taken meals from a fast food restaurant in Tsuen Wan one to four days before onset of symptoms.

Further investigations are underway.

There were 17, 17, 6 cases in September of 2005, 2006 and 2007 respectively.

Bacillary dysentery is an intestinal infection caused by a group of Shigella bacteria which can be found in human gut. The illness is characterised by sudden onset of fever, diarrhoea with abdominal cramps and nausea or vomiting. The stool may contain blood and mucus.

The incubation period usually lasts for one to three days, but can be up to seven days.


The disease is transmitted directly by faecal material of a patient/carrier or indirectly through contaminated food and water. Infection may occur after consuming a small number of the germs. The infection can spread among household members or in institutions.

The public are reminded to observe good personal, food and environmental hygiene at all times to prevent food-borne diseases. When dining out:

* Only patronise reputable and licensed restaurants;

* Do not patronise illegal food hawkers;

* Cook food thoroughly;

* Avoid eating raw seafood;

* Be a discerning consumer in choosing cold dishes, including sashimi and raw oysters in a buffet;

* Drink boiled water;

* Use two sets of chopsticks and eating utensils to handle raw and cooked food;

* Do not try to use salt, vinegar, wine and wasabi to kill bacteria as they are not effective;

* Always wash hands before eating and after going to toilet.