DIRECTOR GENERAL OF HEALTH PRIVILEGED STATEMENT UNDER SECTION 37 OF THE FOOD ACT 1981
Director General of Health Dr Karen Poutasi, today warned the public, food premises and other food retailers that due to
bacteriological contamination of watercress, they should not eat or serve cress harvested from creeks, rivers or
streams, unless it is washed and cooked thoroughly in boiling water.
Watercress retailers should also advise their customers of this safety warning.
The warning comes after initial results of a study undertaken by Regional Public Health at Hutt Valley Health and
Choice Health, Wairarapa into the contamination of watercress, indicated that the cress contained unacceptable levels of
bacteriological contamination, which can cause gastro-intestinal illness. It is also likely that protozoa (e.g.
Giardia), parasites and viruses which also cause illness may be present. Watercress is contaminated through the water it
grows in.
Boiling watercress will destroy most bacteria, protozoa, parasites and viruses which may be present.
Symptoms of gastro-intestinal illness include nausea, abdominal pain, diarrhoea and vomiting which usually lasts from
one to five days. In some cases the symptoms may last longer. Serious illness can also occur in susceptible groups of
the population such as the elderly, young or immuno-compromised. People who have symptoms and are concerned should seek
medical advice from their General Practitioner.
Although the survey was undertaken in the greater Wellington region and the Wairarapa, the warning to boil all
watercress harvested from creeks, streams and rivers is applicable to all areas of New Zealand.
If people have watercress at home, they should ensure that hands, equipment or any surfaces which come into contact with
raw watercress are washed in warm soapy water. Raw watercress should not come into contact with other foods. In
particular it should not be served in salads or used as garnishes.
The Ministry of Health in conjunction with Public Health Services have initiated an education campaign for suppliers and
retailers of watercress about the potential food safety risk associated with watercress harvested from creeks, streams
and rivers.
For further information please contact your local Public Health Service.
signed by Dr Karen Poutasi, Director-General of Health