William Stewart the surgeon general of the United States of America has said “The time has come to close the book on infectious diseases. We have basically wiped out infection in America”. This sounds like pretty good news for a change doesn’t it? Except of course that he said it in 1967 and thus we all know that he was wrong.
Somehow I don’t imagine many people with medical degrees would be stupid enough to say something like that today. The fact is that with smallpox the only significant exception all the diseases that have troubled us in the past are still with humans today. (Yes that includes leprosy and the plague) In fact many of them due to antibiotic resistance have become much more difficult to treat than ever before. The first lecture I heard this year was by Dr Heather Hendrickson on a post antibiotic era we are entering when even trivial infections would often be fatal. Sounds pretty scary right. How did this happen? Well there are a number of ways we have misused antibiotics. It is estimated that about 70% of antibiotics used in the developed world are given to farm animals. This is not really a problem by itself but the farmers often don’t bother trying to find out which animals are sick instead they just put the antibiotics in stock feed for all of the animals. The more the bacteria are exposed though the more chances they get to become immune to antibiotics.
That is not to say those used by humans are necessarily put to good use either. Did you ask for antibiotics to treat the last cold you had? Hopefully not because the cold is caused by a virus and the antibiotics will have no effect. But how the antibiotics are used is not the only problem there are also not enough being developed not one entirely new antibiotic was found between the 1970s and 2003. Another issue is that if a drug company could develop a drug that people have to take every day for a month or a drug they have to take every day for the rest of their lives they make a little bit more money if they pick the later option.
is fortunate then that bacteria can themselves get sick. A virus is a non living* pathogen consisting of a piece of DNA in a protein capsid that can reprogram a cell to produce more viruses. While some viruses target cells of animals or plants others target bacteria. These bacteriophages can be used in the fight against bacteria in fact they already have been and they present a number of advantages over antibiotics. 1. They target specific bacteria while antibiotics usually affect any bacteria in the vicinity including those that help us. One scientist working with bacteriophages compared antibiotics and bacteriophages to a “bomb blast and a sneaky ninja” respectively. 2. Bacteriophages can evolve to counter bacterial resistance. Instead of having to find new ones every time bacteria become resistant we can use the same bacteriophages to counter bacteria again and again. 3. They multiply at the site of infection so only a tiny quantity is needed. But we need to discover a bacteriophage before we can use it so university science classes such as mine search for and study bacteriophages so that they may be used to treat illnesses and get practical experience in our study.
This all sounds very promising but bacteriophages are still relatively little known and it is too early to tell whether they are really the silver bullet doctors are hoping for. Then there are still those viruses that target us many of which we have no idea how to treat. So to the honourable surgeon general sorry Billy we got a long way to go mate.