http://cdc.gov/Features/GetSmart/
http://her.oxfordjournals.org/cgi/content/abstract/23/1/146
http://www.idsociety.org/Content.aspx?id=11984
i probably got confused by your reply to this
If you had the flu dude, you don't need penicillin. Antibiotics are useless against viral diseases and will only kill helpful bacteria in the absence of harmful bacteria.
with this
Wrong. An antibiotic can prevent oppertunistic cross-infections of the ears, sinus, eyes, throat, etc, while one's natural defenses are down.
Allow me to try to unconfuse you. See the part in green above? The part that reads, "Antibiotics are useless against viral diseases..."? Its not exactly true. If it had read "antibiotics won't cure a viral disease", it would be technically true, but misleading. You see, not all medical treatment is done with the aim of curing the underlying disease. Sometimes, medical treatment is undertaken with the intent of reducing pain. Sometimes, they treat the symptom, to make the patient more comfortable. And sometimes, medical treatment is intended to keep the patient from getting worse - especially when the patient's immune system is already beat down. Like happens with chemo. Or radiation treatment. Or HIV. Or the flu, even. The flu can kill - it kills thousands every year - sometimes millions. And do you know what the primary mechanism it kills with? Secondary bacterial infection leading to fatal pneumonia. So antibiotics just might keep grandpa or a baby with the flu from dying. Yes, technically, they don't "cure" the flu. But "not cure" is far different from "useless". Insulin doesn't "cure" diabetis - it just keeps you from deteriorating from it and dying. The HIV drugs don't "cure" HIV, they just delay or prevent the onset of full blown AIDS. Are we clear now?
Now lets get to the part in red. You know, the part that reads, "will only kill helpful bacteria in the absence of harmful bacteria..."? This little nugget of "wisdom", as it happens, is also WRONG! You see, its that little word, "only", that makes it wrong. Certainly, if the antibiotics are misused, that is ONE thing that could happen. Its not the ONLY thing. For one, they could kill you outright if you have an allergic reaction to them and go into anaphyllactic shock. You know what else they could do? They could PREVENT a dangerous bacteria from establishing a viable population IN THE FIRST PLACE! They call such treatment "preventative medicine", and such use of a drug a "prophyllactic" use. Just like calling condoms "prophyllactics" when they are used to prevent the spread of disease. Just like if the doctors are trying to keep Grandpa with the flu from dying of pneumonia...
Sorry for the big words and I hope this clears up your confusion.