Health authorities in Hawke's Bay say around 80 seasonal fruit pickers have been affected by a flu illness which is circulating in the region.
Hawke's Bay District Health Board's (DHB's) Medical Officer of Health Nick Jones said one of the workers, who are from the Pacific, was hospitalised. However she has since been discharged.
"Two cases have been confirmed as having H1N1, which was a flu strain that had been circulating since 2009," he said.
He said Hawke's Bay DHB was closely managing the situation and working with Hastings Health Centre and other primary care organisations to monitor if the infection became more widespread.
Dr Jones said people in the wider community needed to be aware that flu was circulating in the community and take precautions, such as regular hand-washing and staying home if they became ill.
"If anyone experienced flu-like symptoms such as fever, aches and pains, they should stay home," he said.
"If their symptoms progressed and worsened they should call their GP or Healthline."
Anyone in an emergency medical situation is urged to call 111.