Norovirus found in shellfish in Canterbury river mouths

September 5, 2011

Health Warning – Norovirus found in shellfish in Canterbury river mouths

The Community and Public Health division of Canterbury District Health Board has issued a health warning after shellfish were found to have extremely high levels of norovirus.

The contaminated shellfish are in areas around the river mouths of the Avon/Otakaro, the Heathcote/Opawaho and at other locations around the Avon-Heathcote Estuary/Ihutai.

Canterbury Medical Officer of Health Dr Alistair Humphrey says people should not collect or eat shellfish from anywhere in the Avon-Heathcote Estuary /Ihutai, including along the causeway, until further notice.

Norovirus is found in the faeces and vomit of infected people and individuals can be infected through direct contact with another person who is sick, through eating contaminated food (such as shellfish) or water, or touching surfaces and objects contaminated with the virus.

“Recent tests have confirmed that shellfish have become contaminated with very high levels of norovirus,” Dr Humphrey says.

“This is because of the ongoing direct discharge of sewage into the Avon and Heathcote rivers as well as the direct discharge into the Estuary as a result of the February and June earthquakes.”

Monitoring of these sites will continue and the public will be informed when it is safe to gather shellfish again, he says.

“In the meantime people should not be gathering shellfish to eat from these waters. Signage has been placed in these areas to warn people not to gather shellfish. Vandalising or ignoring these signs can have serious consequences,” Dr Humphrey says.

Symptoms often begin suddenly and include vomiting, diarrhoea and stomach-aches. People may also have a fever, chills, headache and muscle aches. The illness is usually brief, although symptoms may persist for several days and may become life-threatening in the young, elderly, and the immune-compromised. Anyone who suffers from these symptoms should contact their General Practice for medical advice.

“We would also like to remind people that contact with river and sea water in and around Christchurch City should be avoided. The only areas where water quality has been found to be acceptable are Pegasus Bay beaches north of the Waimakariri River, the lower Waimakariri River (except after heavy rainfall), Spencerville Beach and Taylors Mistake south including Lyttelton Harbour/Whakaraupo,” Dr Humphrey says.

However, contact with water in these areas should be avoided following heavy rainfall for a period of up to 48 hours.”

The sites where water quality is affected are listed on Environment Canterbury’s website.

For more information on affected sites visit: http://ecan.govt.nz/services/online-services/monitoring/Pages/water-contamination-christchurch-post-22-feb-2011-earthquake.aspx

ENDS

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