Influenza, commonly known as the flu, is primarily a respiratory disease that can be relatively benign or very deadly. It is caused by several different flu viruses and it is contagious, occurring in up to 20% of the population yearly. Among the symptoms are cough, fever, chills, fatigue and muscle aches. The so-called bird flu is highly contagious and dangerous because there is no human immunity to it and it could cause a pandemic. The worst example of a flu pandemic was the Spanish flu of 1918 that spread around the entire globe, infecting more than 25% of the population. At least 500 million were infected and it killed an estimated 50 to 100 million people!
Flu is best prevented by getting a yearly flu vaccine by injection or nasal spray (FluMist). Each year an attempt is made to identify the newest prevalent virus and create a vaccine for it. Thus a “flu shot” should be gotten every year for those at risk. If someone catches the flu, there are four antiviral drugs approved for treating the flu in the US—oseltamivir (Tamiflu), zanamivir (Relenza), rimantadine (Flumadine), and amantadine (generic). They should be taken within the first two days of the onset to be effective. Antibiotics are not effective unless there is a secondary bacterial infection, because antibiotics are ineffectual against viruses. But prevention by vaccination is clearly the best option.