In the united state, it was first identified in military personnel in spring 1918. It is estimated that about 500 million people or one- third of the world’s population become infected with the virus.

By Shafaq Saleem Ahmed

Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and some time the lungs. It can cause mild to severe illness and at time can lead to death. The best way to prevent flu is by getting a flu vaccine each year. There are 4 types of influenza viruses A, B, C, & D.

Hundreds of viruses can caused coryza or the common cold, but a group of viruses called rhinoviruses. It is responsible for about 40% of all colds in adults. Typical symptoms include sneezing, excessive nasal secretion, dry cough and congestion. The uncomplicated common cold is not usually accompanied by a fever. Complications include asthma, bronchitis, ear infections, and laryngitis. Recent investigations suggest an association between emotional stress and the common cold.

Seasonal influenza is also caused by a flu virus. Its symptoms include chills, fever (usually higher than 101°F), headache, and muscular aches. Seasonal influenza can become life-threatening and may develop into pneumonia. It is important to recognize that influenza is a respiratory disease, not a gastrointestinal disease. Many people mistakenly report having seasonal flu when they are suffering from a gastrointestinal illness.

Hemagglutinin and neuraminidase type 1 (H1 N1) influenza, also known as swine flu, is a type of influenza caused by a new virus called influenza H1 N1 virus. The virus is spread in the same way that seasonal flu spreads, from person to person through coughing or sneezing or by touching infected objects and then touching one’s mouth or nose. Most individuals infected with the virus have mild disease and recover without medical treatment, but some people have severe disease and have even died. The symptoms of H1 N1 flu include fever, cough, runny or stuffy nose, headache, body aches fatigue. Some people also have vomiting and diarrhea. Most people who have been hospitalized for H1 N1 flu have had one or more preexisting medical conditions such as diabetes, heart disease, asthma, pregnancy. People infected with the virus can infect others from 1 day before symptoms occur to 5-7 days or more after they occur. Treatment of H1 N1 flu involves taking antiviral drugs such as Tamiflu and Relenza.

A vaccine is also available, but the H1 N1 flu vaccine is not a substitute for seasonal flu vaccine”

Authors : Shafaq Saleem Ahmed Student of medical physiology.