H1N1 flu spreads at ``unbelievable'' speed:
A/H1N1 flu is spreading at an ``unbelievable'' speed, with ``a very severe form of disease'' attacking the lungs of healthy young people, the World Health Organization has warned in an interview published by French daily Le Monde on Saturday.
Two more confirmed cases of influenza A/H1N1 turn up, Australian Department of health and aging said on Wednesday.