Mexican health authorities said on Thursday they confirmed 300 swine flu cases and 12 deaths due to the virus among a total of 679 people tested so far. Less than half of the suspected cases tested have been confirmed as swine flu, and a series of visits to the families of victims also turned up relatively few suspected cases. Authorities had previously listed 260 confirmed cases, and said the number of cases appeared to be stabilizing. Health Secretary Jose Cordova said one encouraging sign was that the daily number of people admitted to government-run Social Security hospitals with swine flu symptoms had fallen from a high of 212 people on April 20 to 46 on Thursday. Health workers have so far visited the homes of 77 suspected victims and found only two cases in which relatives tested positive for an A-type flu virus that could be related to the swine strain. Cordova said on Thursday that authorities had approved or spent 1.6 billion pesos ($116 million) for medical supplies and equipment so far in the epidemic. The World Health Organization's flu chief, reacting to comments from Mexican officials, cautioned that case numbers often go up and down, and said the WHO had yet to see concrete evidence that swine flu, believed to have killed 168 people in Mexico, was levelling off. "What's happening in one part of the country is not necessarily what's happening in another part of the country." New cases of swine flu were confirmed in the United States and Europe a day after the WHO said the virus threatened to become a global epidemic and raised its alert level to Phase 5, the second-highest stage, for the first time. Health officials in the United States said on Thursday the number of confirmed cases had risen to 109. President Barack Obama told Americans the government was "taking the utmost precautions and preparations" to stop the virus.