Twenty people from the top of the south are now being checked for possible swine flu infection, including seven in Marlborough.

The Nelson Marlborough public health service is aware of 10 people who flew into New Zealand on Flight NZ1 from Los Angeles last Saturday as well as eight people from Flight NZ5. A further two travellers from Mexico or the United States who entered the country during the past two weeks are also being followed up.

Medical officer of health Jill Sherwood said assessing the passengers on Flight NZ1 that arrived on April 25 is the priority, as that flight carried the Auckland Rangitoto College students who have been confirmed as having Influenza A. “We have had 20 passengers from this flight come to the Nelson Marlborough region. Thirteen in Nelson Tasman and seven in Marlborough. Six of these people report influenza-like symptoms,” Dr Sherwood said. All passengers were being given antiviral medicine and had been asked to stay in isolation.

Tamiflu is recommended only for travellers on Flight NZ1 as a precautionary measure in case they have been exposed to the swine influenza virus which has so far killed an estimated 149 people in Mexico. Dr Sherwood said the people who had displayed symptoms were being followed up at home and all have mild symptoms.

“We have 17 other people that we are following up, including some from the flight that had the Northcote students on. These students have not tested positive for influenza A,” said Dr Sherwood adding that some of these people are in voluntary isolation.

Public health service district manager Peter Bassett said the 20 people identified in Nelson Marlborough have had swabs taken for testing, results of which should be through by Thursday.

Meanwhile, local pharmacists are experiencing a slight increase in customers asking for the anti-viral treatment Tamiflu, stocks of which are high after the bird-flu threat six years ago.