Public health officials are trying to trace the path of a typhoid outbreak that has hospitalised 10 people in Auckland.
The Auckland Regional Public Health Service (ARPHS) said it was tracing people who had been in touch with the people confirmed to have had the disease, and was trying to control its spread.
Typhoid is a serious illness which can be potentially fatal, although it is treatable with antibiotics.
Symptoms include a high fever developing over several days, headaches, general weakness and muscle aches.
Stomach pain and constipation are also common, with some victims suffering diarrhoea.
Medical Officer of Health David Sinclair said the disease was spread mainly through water and food, but could be spread person to person.
Dr Sinclair said the outbreak had developed over the past 10 days or so and the patients were from a range of places in central and southern parts of Auckland.
He said those in hospital were quite unwell.
"These are people who have been admitted to hospital because their symptoms are quite severe, and quite a large proportion of people who develop typhoid fever do get admitted to hospital for antibiotic treatment and assessment."
Most of the typhoid cases in New Zealand were imported, from people coming back into the country, either with symptoms or as carriers, mainly from the Pacific or southeast Asia.
Dr Sinclair said basic hand-washing was one of the best methods of protection and urged anyone with symptoms to see a doctor.