A middle-aged couple in Eastfield are believed to have contracted the virus. The couple, who have children, have been told by their GP to stay indoors and not answer the door.

A woman in Crossgates has been told to stay at home after suffering with flu-like symptoms, and has been given the drug Tamiflu.

Elsewhere in the region a pupil at Beverley High School has contracted the virus and parents at the girls' secondary school have been told by letter.The patient is not in school.

The news comes a week after Matthew Fitzpatrick, who is a year 10 pupil at the fee-paying Hymers College in Hull, became one of two people in the East Riding to be confirmed as having swine flu by the Health Protection Agency.

And a temporary worker with a Scarborough employment agency has also been confined to their home after learning a member of their family had contracted the virus.

Suzanne Burnett, managing director of Castle Employment, said: "We have had our first possible case this morning. They called in to say they couldn't go to work because their partner had suspected swine flu.

"We already have plans in place to deal with the situation should the flu become a problem. It is another reminder that this is arriving in Scarborough and businesses need to be aware that it is going to have an impact."

The town's first suspected case was confirmed at Seamer and Irton Primary School yesterday.

The boy is believed to have contracted it while on holiday, and has not been at school for two weeks. The school remains open although parents, who received a letter from headteacher Jonathan Wanless, have been advised to keep any children suffering flu-like symptoms at home.

At St Augustine's School a pupil has been told to stay at home after suffering with flu-like symptoms. It has not been confirmed whether she has contracted the virus.

Other schools and colleges have already sent out letters to parents informing them of preventative measures to protect students and staff. Yorkshire Coast College has been displaying 'Catch it, kill it, bin it' posters throughout the college and making antiseptic gel and tissues widely available in public areas, workshops and offices.

The headteacher at Braeburn Infants School, Kate Tate, said she had issued a letter to parents after concerns were brought to her attention.

Meanwhile, chemists in Scarborough have been distributing the drug Tamiflu to patients suffering with what is believed to be the virus.

Lisa Kellett, owner of Barrowcliff Pharmacy, said they had supplied some Tamiflu prescriptions, as had the chemist at Morrison's. Those two chemists, both with late-night opening, have been specially allocated by the primary care trust to distribute Tamiflu to patients.

Their batches have been increased and they are now well-stocked should the outbreak take hold.

The UK has moved from the "containment" to the "treatment" phase of swine flu as the number of people catching the virus continues to rise. Health Secretary Andy Burnham said that cases are doubling every week and if it continues at this rate there could be over 100,000 cases per day by the end of August.