New Delhi: Twenty-one people tested positive for swine flu on Sunday. Three cases each were reported from Safdarjung, Ram Manohar Lohia and Lok Nayak hospitals. Among private hospitals, Max Hospital in Saket, Apollo Hospital in Sarita Vihar and Fortis Vasant Kunj reported one case each. A senior official in the state health department said at least seven patients were taking treatment at home. “One patient who was confirmed positive for swine flu got the tests done in Delhi and is admitted at Pushpanjali Crosslay Hospital in Ghaziabad,” said the official. “Three people have died in swine fluin Delhithis year,” he added.TheDelhi government has designated 22 hospitals, including five private ones, for treatment of swine flu. Most patients infected with the influenza virus tend to reach a critical stageif they ignoretheearly symptoms. “If a patient has severe symptoms such as high fever, difficulty in breathing, blood in sputum and lower respiratory tract infection, he or she should visit a doctor immediately. Many times, we tend to start medication on the basis of clinical evidence without waiting for thetest reports.Acting fastisimportant to save such patients,” said Dr Randeep Guleria, professor of medicine at AIIMS. The disease was at its most virulent form when it initially spread in 2009. Till May 2010, 1,035 people had died of it in India and more than 10,000 were infected. “In 2011 and 2012, few such cases were reported.This year,however,there has been a noticeable rise in swine flu cases. It could be due to prolonged winter or because the virus which was always present in the environment is settling down again,” said a senior doctor. H1N1influenza or swinefluistreatable with Tamiflu and preventive vaccinations are also available, Guleria said. The influenza spreads from person to person through coughing, sneezing or through touch, said Dr Monica Mahajan, senior consultant, internal medicine at Max Hospital Saket. One should avoid spitting in public, maintain good hygiene and try to avoid contact with affected individuals, said Dr B D Athani, the medical superintendent at Safdarjung Hospital. VIRAL ATTACK • 21 people tested positive for swine flu on Sunday • 3 cases each reported from Safdarjung, RML and Lok Nayak hospitals • Max Saket, Apollo Sarita Vihar, Fortis Vasant Kunj and Pushpanjali Crosslay Ghaziabad reported one case each • At least seven patients are being treated at home • Tests for H1N1 cases being carried out at National Institute of Communicable Diseases, AIIMS, Patel Chest Institute and 5 private labs