Health officials say a Tamiflu-resistant strain of swine flu has spread between hospital patients. Five patients on a unit treating people with severe underlying health conditions at the University Hospital of Wales, Cardiff, were infected. Three appear to have acquired the infection in hospital. They are thought to be the first confirmed cases of person-to-person transmission of a Tamiflu-resistant strain in the world. <br/>There have been several dozen reports around the world of people developing resistance to Tamiflu while taking the drug – but they have not passed on the strain to others. <br/>The UK has bought enough doses of Tamiflu, which can shorten the duration of swine flu and reduce the risk of complications, for half the population. <br/>