The government stepped up preventive measures against the spread of swine flu, ordering travelers returning from Mexico to undergo medical checks at airports or other points of entry. In a meeting attended by Prime Minister Binyamin Netanyahu, Deputy Health Minister Ya'acov Litzman and others, it was decided to increase stocks of antiviral medicines above the levels recommended by the World Health Organization, a statement from the Prime Minister's Office said. The Health Ministry will be kept in charge, for the time being, of containing the flu and monitoring passengers arriving at all the air and sea ports, especially Ben-Gurion. There, a special clinic, manned by doctors with expertise in infectious disease, was set up to examine all those who say they have just been to Mexico, where the outbreak began last week. The ministry will continue to monitor people who were in Mexico in the past week and ask them to remain at home in case they develop symptoms of fever, respiratory problems and coughing in the next few days. Netanyahu decided on Thursday that the Health Ministry would remain responsible for handling the issue, despite concern that the flu was spreading in Israel. If the flu caused a fatality or spread "out of control," responsibility would likely be transferred over to the Defense Ministry, defense officials said. At a news conference held after Thursday's meeting with Netanyahu, Health Ministry director-general Avi Israeli reiterated the government's warning for Israelis to avoid visiting Mexico for now. "We tell all Israelis not to go to Mexico, and to cancel their trips to Mexico for the time being," he said. He said those arriving in Israel who had been in Mexico within the preceding seven days would be examined on the spot, and Israelis cleared to proceed to their homes would be told to remain indoors for a week from the date they left Mexico. As Israel has stores of Tamiflu and Relenza - two drugs that significantly reduce flu complications - equal to 17 percent of the population, rather than the recommended 25%, the ministry has received extra funding to increase stocks of the medications. With additional supplies, Israel's medicines-to-population rate will be much higher than both the global average and World Health Organization recommendations, joining the five leading countries in this regard. The Foreign Ministry will halt the departure of Israeli delegations to Mexico until further notice. Travel warnings will be issued to Israelis, and the Foreign Ministry has contacted Mexican authorities requesting that they suspend the dispatch of delegations and tourists to Israel. Netanyahu will chair a daily meeting on the swine flu threat and has asked all relevant officials to monitor developments. The Health Ministry - whose information line at (03) 695-1541 or *3090 is very busy handling calls - will launch an information campaign to explain to the public how to reduce the risk of infection. The Defense Ministry has asked all government ministries to prepare lists of "essential staff" who would be required to continue working if swine flu evolved into a nationwide epidemic, defense officials said Thursday. "We need to know who is essential and will be needed to keep things running in case the virus spreads out of control," explained one official. In addition, Deputy Defense Minister Matan Vilna'i has ordered the coordinator of the government activities in the territories to coordinate containment efforts with the Palestinian Authority, Egypt and Jordan. Doctors have been deployed at all of Israel's border crossings to inspect people who have visited Mexico before entering Israel. "If the virus spreads and can no longer be contained, or people begin to die from it, responsibility will likely be transferred over to the Defense Ministry," one official said. According to the official, once granted authority, the Defense Ministry would be able to shut down schools, factories and other institutions in an effort to stop the outbreak. Decisions on closures, the official said, would require governmental approval on a case-by-case basis. Meanwhile, the WHO's secretary-general, Dr. Margaret Chan, raised the level of preparedness to Phase 5, one level below the highest, as a sign that it fears a global outbreak of swine flu. This means that the WHO could recommend additional measures to combat the outbreak, including calls for vaccine manufacturers to switch production from seasonal flu vaccines to a pandemic vaccine. "All countries should immediately now activate their pandemic preparedness plans," she said in Geneva. "It really is all of humanity that is under threat in a pandemic." Chan said a Phase 5 alert meant there was sustained transmission among humans in at least two countries, Mexico and the US. To reduce the risk of infection, the WHO advises sneezing and coughing only into disposable tissues and throwing them directly into the trash (and if you don't have a tissue, sneeze into a sleeve, but not into your hand); regularly washing hands or using alcohol-based hand sanitizers; and not shaking hands or exchanging kisses. Any adult who has been infected is regarded as contagious for about a week after first showing the symptoms. Children may be contagious for up to two weeks. Swine flu cannot be spread by eating pork; the virus is spread mainly by coughing or sneezing or skin contact with an infected person. Various countries are working on developing a vaccine against the new virus strain, which is a combination of human, avian and pig flu viruses. But it won't be available before the fall, and the work could interfere with production of ordinary human flu vaccines for the autumn and winter seasons. Meanwhile, a leading British public health expert said that, given the widespread presence of swine flu virus across many countries, containment was probably not feasible, and efforts needed to focus increasingly on mitigation. Writing in the on-line edition of the British Medical Journal, Prof. Richard Coke of the London School of Hygiene and Tropical Medicine noted that almost all cases reported so far had been in developed countries with robust surveillance systems. This new strain is, at this stage, sensitive to antiviral drugs, he said. However, although many developed countries, including most of Western Europe and the US, have sizeable stockpiles of antiviral drugs, most low- and middle-income countries have low or nonexistent stocks. He added that scientific evidence showed that border screening was an ineffective means of control and that the WHO was resisting calls to issue recommendations for travel restrictions. In addition, he said the current crisis with the H1N1 strain made it "easy to forget the threat still posed by H5N1 and other strains of flu. Immunity to H1N1 will not offer protection to H5N1 if that also becomes readily transmissible between humans," he warned.