Two new cases of swine flu have been diagnosed in the UK, one in a child, the health secretary, Alan Johnson, said today.
The child is a pupil at one of the five schools that have already been closed due to the outbreak.
Johnson said there was no evidence of "sustained" person to person transmission of the virus in Britain. But he warned in a Commons statement: "This does remain a serious situation which could rapidly escalate."
The new cases bring the UK total to 34. Johnson told MPs an alternative quick-response system was being developed in case the outbreak escalates before a dedicated flu helpline is opened in the autumn.
The exams regulator Ofqual was meeting today to discuss contingency plans for pupils disrupted by the outbreak. It is understood that children could sit exams elsewhere or, if they are sick with the virus, be awarded a grade based on papers or coursework they have completed.
Johnson and the chief medical officer, Sir Liam Donaldson, will give a further update on the outbreak later today.
Laboratory tests are being carried out on 390 people who may have the H1N1 virus, the Health Protection Agency said.
News of the latest cases came as South Hampstead high school, in north-west London, became the first of the five closed schools to reopen.
Four other schools – Paignton community and sports college, in Devon; Alleyn's school, in Dulwich, south-east London; Downend school, in south Gloucestershire; and the private preparatory Dolphin school, in Battersea, south London – remain closed.
GCSE exams began across the UK today with a design and technology practical test, under the OCR board. It was not known whether pupils at any of the affected schools were sitting this exam.
Schools hit by the illness are rescheduling exams or asking for special consideration for GCSE and A-level pupils. A Department for Children, Schools and Families spokeswoman confirmed that officials were working with Ofqual and the exam boards to put in place contingency plans.
She said: "Arrangements will be made on a case by case basis, so that all students are fairly treated. Basing final results on other evidence, like coursework or modules already completed (also known as special consideration), is just one contingency arrangement, and would only happen in specific circumstances where a student was unable to take a particular exam.
"This is a tried and tested system that exam boards use to award students grades if they are unable to take an exam for a given reason."
Alleyn's school, which closed after five year seven pupils were diagnosed with swine flu on Monday, said it was rescheduling A-level exams in art, biology and foreign languages for next week.
The government today pledged £6m in aid to help poor countries in the global fight against swine flu. The money from the Department for International Development will be given to the World Health Organisation and the UN for drugs, logistics and training to assist efforts to stop the spread of the virus and to prepare countries for a pandemic.
