IT seems that we have been talking about the threat of antibiotic resistance for as long as I can remember.
Various soothsayers have spread doom and gloom that we have only a few years left before being plunged back into a 19th century pre-antibiotic era that will make routine surgery and the use of chemotherapy and transplants possible no-go areas.
So far it has not come to pass but as in many walks of life, complacency in this regard is something to be guarded against.
The latest warning comes from the UK Government’s chief medical officer, Dame Sally Davis. She has urged the British government to add the development of antibiotic resistance by bacteria to the national risk register of civil emergencies. This is clearly something that is not going to go away on its own accord.
Predictable
The development of bacterial antibiotic resistance is as predictable as it is real. Darwin’s theory of evolution, that can be neatly summed up by the terms “natural selection” or “survival of the fittest” is ably illustrated by those bacteria that survive an onslaught from one or other antibiotic and live to multiply and propagate their resistant genes.
When one considers the short generation time of most bacteria and the huge number of organisms that are involved, it is only surprising that such resistance has not hit home far harder than it already has.
If one looks at the relative frequency of use of antibiotics in the European Union, then the UK is doing relatively well. The 2010 data show that there were 18.7 daily doses of antibiotics prescribed per 1,000 head of population every day, compared with 39.4 doses in Greece and 28.23 doses in France. This compares to those countries with the lowest usage at 11.05 doses for Estonia and 11.21 in the Netherlands.
However, in the global interconnected world in which we live, political, cultural and geographical boundaries no longer offer the sort of protection they once did. We have seen how SARS and swine flu can span the world in a matter of days: bacterial antibiotic resistance is probably more of a threat in the long term and can bide its time to spread more insidiously and completely.
We are all familiar with the simple measures that are encouraged to avoid the development of antibiotic resistance. Things like using the correct dose; completing the full course; and selecting the correct antibiotic on the basis of bacterial susceptibility.
Cardinal error
Whilst patients are notorious for failing to complete the whole course, medical doctors are also guilty of this cardinal error.
A family member of mine was recently treated in hospital for an incidental Group C Streptococcal infection with only two days of clarithromycin (because another attending doctor presumably thought it was not worth continuing with it), so there are lessons to be learnt and practices to be improved on across the board.
The CMO is aware of such practices and is quoted by the BBC as being shocked by the “woeful education” in antimicrobial resistance given to many medical students and doctors.
There are good examples of particular bacteria that have developed serious resistance to various antibiotics in the recent past and now present us with problems. These include the bacteria responsible for MRSA, TB and gonorrhea. There are increasing concerns now about commensal gut inhabitants such as E. coli and Klebsiella spp.
Not a one-track problem
Indeed, the recently published second volume of the CMO’s annual report suggests that there may be 5,000 human deaths annually (in England, Wales and Northern Ireland), from septicaemia caused by Gram-negative bacteria, half of which exhibit some form of antibiotic resistance.
The problem is not, though, a onetrack one of doctors and the public failing to use antibiotics correctly and sparingly. The overuse or misuse of antibiotics in food-producing animals has long since been recognised.
The EU has banned the use of antibiotics as growth promoters in livestock. However, a recent article in New Scientist magazine pointed out that half the world’s pigs live in China and over half of them consume feed with antibiotic growth promoters that have been shown to encourage the development of widespread antibiotic resistance in gut living bacteria.
As I said earlier, globalisation will ensure that such bacteria do not remain confined to Chinese pig farms for too long.
In the UK too, whilst antibiotic usage as growth promoters is banned there are many intensive pig farms that rely heavily on antibiotic-medicated pig feed to keep diseases such as respiratory infections at bay. And whilst it is always argued that this is “controlled” by prescription and under veterinary supervision, this may be something of a hollow claim.
Antibiotic usage in this manner may become “routine” under certain systems of production with high stocking rates, poor hygiene and inadequate ventilation. The bacteria so medicated will neither be aware that they are under the “watchful” eye of the prescribing veterinary surgeon, nor alter their behaviour as a result.
Indeed, I suspect that much of this prescribing is very much a rubberstamping exercise by the veterinary surgeon concerned and far from castigating or belittling their actions I fully understand the dilemma with which they may be faced.
Inadequate husbandry systems cannot be changed overnight especially when it might involve huge capital investment. And as we have seen from the horse meat scandal, the public at large is very much concerned with the price of food and more welfare friendly, less intensive pig production systems are likely to produce pork that requires a higher retail price if there is to be any profit left for the producer.
What can be done?
So what is to be done to prevent us going backwards into a brave new world where infections that we currently consider to be largely innocuous revert to being killers to which we have no answer? Research to find new classes of antibiotics is fundamental but there is no guarantee that these actually exist.
Currently, drug companies are loath to spend millions (billions) researching new antibiotics when other drugs to treat chronic lifelong conditions are so much more lucrative.
It may be necessary to earmark public money to support antibiotic research and when one considers the sums that are spent on other, frequently less worthy causes, this should not be too difficult.
As vets we can play our own small part by prescribing antibiotics to our patients with care and responsibility, particularly in food producing animals.
If we can at the same time promote the adoption of less intensive livestock production that needs less antibiotic input, then that will be to the good for all concerned too.
