Health secretary York Chow Yat-ngok has urged people, especially children, to be alert to the risks of catching swine flu when studying or travelling abroad this summer. He was responding to questions from lawmakers yesterday about how safe it was for parents to send their children on overseas study tours. With two months to go until schools break for the summer holiday, many Hong Kong parents are preparing to send their children on such tours. 'Whether children should or should not go [on study tours] I think should be up to them,' Dr Chow said. 'If a child or anyone has chronic diseases or is prone to complications, I think they should not go abroad,' he told a special meeting of the Legislative Council's health services panel. Children were twice as likely as adults to catch swine flu, Dr Chow said. Wilson Poon King-yan, assistant tour manager for the educational division of major travel agent Wing On Travel, said the number of students applying to join its overseas tours had dropped since the global swine flu outbreak began. 'Having said that, the number of people joining such tours has still increased by 5 per cent from the same period last year. I would say that, without the outbreak, the increase would be even bigger,' he said. Mr Poon said no parents had contacted the agency to cancel their bookings for such tours. 'However, safety is always our top priority. If there is any real concern on the flu, we will abandon or defer these tours,' he said. Litz USA Student Service, which helps students in the city study in the United States, said it had reminded students joining its overseas study tours to observe good personal hygiene. 'We have already asked them to wear surgical masks on the plane no matter if they are ill or not. Also, they should watch their personal hygiene during their stay in the US,' Teresa Mak, a company consultant, said. Apart from summer study tours, the organisation also arranges for Hong Kong students to study at high schools and universities in the US. Ms Mak said the company had sent newsletters about swine flu to those students last week. 'We told them to wear masks when taking the plane even if they are healthy. We also asked them not to fly back to the city if they feel uncomfortable and to see a doctor to see if they are unhealthy,' she said.