<!– /11440465/Dna_Article_Middle_300x250_BTF –>After a year of lying low, the dreaded swine flu virus is back with 744 deaths and 6,113 cases being recorded so far this year.Swine flu is caused by the H1N1 virus. Its symptoms include fever, cough, body ache, loose motions and generalised weakness.A senior official with the state directorate of health services noted that the spurt in swine flu cases this year was because of changes in the weather and the intensity of the virus. “A variation in the minimum and maximum temperature can cause a rise in swine flu cases,” he said, adding that occurrence of H1N1 cases was seen largely in the February to April and July to September periods.The first swine flu death in India, that of a 14-year-old girl — was recorded in Pune in 2009. According to the state public health department’s statistics, the year 2010 saw 6,118 positive cases and 669 fatalities, followed by just 42 positive cases and six deaths in 2011. The year 2012 saw 1,560 cases and 135 fatalities, and in 2013, though the number of patients testing positive for the virus fell to 643, deaths rose marginally to 149, and in 2014, just 43 deaths and 115 cases were reported.However, it was in 2015 that the highest number of swine flu positive cases and deaths were recorded at 8,553 and 905 respectively. The next year, it fell to a much lower 82 cases and 26 deaths.A health department official said that as on Friday, the number of patients testing positive for swine flu stood at 6,113, while mortalities were 744. The deaths recorded in November were six, and in the fatalities recorded so far, 32 patients are from other states like Madhya Pradesh (24), Karnataka (five), Chhattisgarh, Andhra Pradesh and Gujarat (one each).The highest number of H1N1 deaths have been recorded in Nashik (77), followed by Nagpur (61), Pune rural (56), Ahmednagar (53), Pune city and Kolhapur (49 each). Mumbai accounts for 20 deaths.”Public awareness is rising. Government and private doctors have been trained to handle swine flu cases. Patients showing symptoms of swine flu are put on Oseltamivir tablets even before their test results are received,” the doctor stated.”A feature of influenza is that when there is an outburst in society, it reaches many individuals and creates a kind of herd immunity… leading to a declining trend of this particular strain. But this natural immunity is short-lived and lasts for just around eight to 12 months. After this wanes, there is a new outbreak and peak,” noted Dr Pradeep Awate, state surveillance officer.The state government has also decided to vaccinate high-risk groups like doctors, health workers, people with hypertension, diabetes, compromised immunity and pregnant women in the second and third trimester. So far, 37,408 individuals have been inoculated.It has also established the Maharashtra Communicable Diseases Prevention and Control Technical Committee under former Maharashtra director general, health services (DGHS), Dr Subhash Salunkhe.