Antibiotics, their misuse and the risk of antibiotic resistant bacteria, have been things I have blogged about before at some length (e.g. here). My main focus has been the misuse of antibiotics in agriculture: the routine use of antibiotics in animal feed. This practice is considered one of the main reasons why there has been such an increase in antibiotic resistant bacteria in recent years.

But an article on BBC discussing medical treatments that are known to be ineffective reminded me of another source of selective pressure for the evolution of antibiotic resistant strains of bacteria: misuse of antibiotics in people.

As a parent, I know full well the dread one feels when a child's eye starts looking red and oozy. That discharge in the corner of the eye tells you it is that dreaded ailment known as "pinkeye." Nothing to do but stay home from work and try to get a doctor's appointment...and start washing your hands like you have OCD to prevent spreading the germs.

You finally get to see the doctor, he takes one look, declares it pink eye...then prescribes antibiotics.

And therein is the problem. Antibiotics don't really work for pinkeye...it is a waste of money, effort in giving the poor mite drops, and it adds to the selective pressure for the evolution of antibiotic resistant bacteria, creating an actual health hazard.

Why do I say antibiotics don't work? Well, the majority of cases of pinkeye are caused by a virus. Antibiotics don't work against viral pinkeye. There is no reason at all to give antibiotics for viral pinkeye. The viral form has a more watery discharge, not green or yellow in color. If you child's pinkeye has a watery discharge, don't even bother with antibiotics. They do NOTHING except add to a growing health hazard, and viral pinkeye resolves itself in 7-10 days with no problems. It is, however, highly contageous in its early stages. It really is a good idea to avoid all contact with your eyes and to wash your hands like you have OCD.

What about bacterial pinkeye? In this case there is some logic to using antibiotics since antibiotics do affect bacteria. But first, how do you tell when it is bacterial? If the discharge is greenish or greenish-yellow rather than watery, it is probably bacterial. Anytime you see green or yellow discharge, that is a strong hint that your body is reacting to a bacteria because one of the immune cells that responds to bacterial infections is the neutrophil. These cells contain high doese of a protein called myeloperoxidase, a copper-containing protein that is part of the cell's anti-bacterial arsenal. Neutrophils respond in huge numbers to bacterial infections, and they act kind of like the Kamikaze pilots of the immune system, dying as they kill invading bacteria. The large number of dead and dying neutrophils are green because of the copper in the myeloperoxidase protein. Think of an old penny: turns green right? That is the copper oxidizing. Same happens with the copper atom in myeloperoxidase. So if the discharge is green, it means bacterial.

Problem is, it doesn't matter. Even with BACTERIAL pinkeye, there is no real evidence that antibiotics work to shorten the illness. According to an Oxford study, even in children with bacterial pinkeye, the cure rate did not differ significantly, 85% cured in 7 days for the antibiotic-treated group, compared to 80% for the placebo treated group. That means antibiotics don't really help if your child has pink eye! Again, all you are doing is adding to a growing health risk, antibiotic resistant bacteria.

So, eating meat that specifically says "raised without antibiotics" and not using antibiotics for pinkeye are two good ways you can help limit the evolution of antibiotic resistant bacteria. This does not mean you should not see a doctor if a child has pink eye. If for no other reason that the doctor may find other secondary infections that need treatment. But ASK your doctor if an infection is viral, and if so, don't use antibiotics: it is a waste of time andm money.