The Centre for Health Protection is following up on a British report concerning four cases of hepatitis-E infection involving four men on a world cruise.

According to the UK Health Protection Agency the cruise took place January 7 to March 28. The passenger capacity of the cruise ship was 1,800. Passengers were mainly British but also included Americans, Australians, South Africans, Danish and Irish.

The cruise stopped in Hong Kong February 26 and 27. During its stay 250 passengers disembarked while 180, including two Hong Kong people, embarked.

The UK Health Protection Agency has been working with the cruise operator and port health authority to distribute health advice to all passengers. People who have been aboard the vessel should seek medical advice if they come down with hepatitis symptoms.

Hepatitis-E is a viral infection highly endemic in Central and Southeast Asia, and North and West Africa, as well as Mexico. It is acquired by ingestion of contaminated food or water. Its incubation period ranges two weeks to two months. Symptoms include fever, malaise, anorexia, nausea, abdominal pain, dark urine and jaundice.

The centre has received 25 hepatitis-E infection reports so far this year. There were 33, 34 and 64 reports in 2005, 2006 and 2007.

To prevent infection practise good personal and food hygiene and ensure seafood, especially shellfish, is cooked thoroughly before consumption.