Influenza Infection ( including H1N1) Specialist Doctor In Mumbai Influenza is an acute viral respiratory disease that affects individuals of all ages worldwide. When an infected person coughs, sneezes, or talks, virus within respiratory secretions can infect another person if it is inhaled or if it contacts the mucous membranes. Influenza virus can also be transmitted longer distances through the airborne route and if a person touches a surface contaminated by respiratory secretions and then touches their eyes, nose, or mouth. In tropical and subtropical climates, influenza activity may occur year – round, often peaking during cooler or rainy – season months. The seasonal epidemics are caused by human influenza A and B viruses. In 2009, a novel influenza A virus was first detected in the United States and spread quickly across the world. This new virus was designated (H1N1)pdm09 virus and it continues to circulate worldwide as a seasonal influenza virus. The typical incubation period is one to four days. It characteristically begins with abrupt onset of fever, non - productive cough, and body pain. Other symptoms include weakness, malaise, sore throat, nausea, nasal congestion, and headache. The complications include pneumonia, involvement of heart and other major organs. The groups at high risk for complications include adults more than 65 years of age, children less than 5 years of age, pregnant women and people with medical conditions. Hence, a consultation with a specialist should be sought at the earliest. There is need for hospitalization under care of a specialist for patients with significant dehydration and with severe illness. The antiviral should be started at the earliest opportunity, after due recommendation from a specialist. The annual influenza vaccination should be recommended strongly and it should kept in mind that new influenza vaccines are produced each year. Hence a guidance from an experienced consultant is a must, regarding choice of vaccine.