Wednesday 22 November 2017

Antibiotic resistance - a serious threat to health

By Pete Wedderburn - ANimal Doctor

Pete Wedderburn
Pete Wedderburn
Do problems like minor infected cuts really need antibiotics?

Antibiotics have been one of the biggest scientific advances in the past century, as significant in the veterinary world as in the human medical sphere.

Back in 1928, Alexander Fleming was examining petri dishes used for bacterial cultures in his laboratory when he came back from holidays. He noticed that there were gaps in the growth of bacteria around patches of mould growth. "That's funny" he famously remarked, and he went on to isolate the chemical produced by the mould, naming it "penicillin".

It took over fifteen years for penicillin to be mass produced and distributed to doctors and vets, with the discovery revolutionising the treatment of diseases. Age-old scourges of mankind, including syphilis, gangrene and tuberculosis, could finally be cured with ease. Many other minor illnesses - such as throat infections - could now be cured. Complex surgery became possible without the fear of post-operative infections damaging the patient.

Many other antibiotics were discovered in the decades after penicillin, providing back up for the rare cases when penicillin failed. It seemed that mankind had finally defeated one of the biggest threats to human health: infectious diseases caused by bacteria.

From the start, it had been clear that some bacteria were resistant to antibiotics, but this did not seem to matter too much. New antibiotics were being discovered or invented at a rapid rate, so it was easy to move on to a better, stronger antibiotic if the first one didn't work. But from the early 1960's, the situation began to appear bleaker. Bacteria were found to be able to pass their resistance on, so that if one strain developed resistance, this could be passed on to other bacteria.

At the same time, as the decades passed, the rate of discovery of new antibiotics began to slow. Since the early 1980's, pharmaceutical companies have focussed more on other drugs (such as statins) that are seen to be more profitable.

The combination of more resistant infections combined with fewer new "better" antibiotics has led to the current crisis. In the past, resistant infections were associated predominantly with hospitals, care homes and vet clinics, but over the past decade, they are increasingly being found in the wider community as well.

Antibiotic resistance, like global warming, is now an immense threat to our future. If the drugs lose their effectiveness, key surgical procedures (such as organ transplants, intestinal surgery, caesarean sections and joint replacements) and important medical treatments that suppress the immune system (such as chemotherapy for cancer) will become too dangerous to perform. Furthermore, life threatening infectious diseases such as pneumonia, TB, HIV and malaria will again become common. At the moment, 700,000 human deaths happen every year due to antibiotic resistance. If current trends continue, by 2050 this will reach a figure of 10 million deaths every year; more people than currently die from cancer. The economic cost is equally shocking, with trillions of euro spent on wasted antibiotics that don't work and paying for the resulting medical outcomes.

So what can be done to solve this problem? A major report published last week makes ten recommendations, and global government action is needed to put these into place. These include major public awareness campaigns, incentives to do research to develop new antibiotics, and importantly, using antibiotics more sparingly in humans and animals. By 2020, the aim is for it to be compulsory that the prescription of antibiotics can only be allowed if there is data to support the choice.

At the moment, vets use antibiotics if they have a clinical impression that they are needed (for example, if a dog has a high temperature with bloody diarrhoea). And we choose the antibiotic which we know, from experience, is most likely to work. In the future, we may only be allowed to use antibiotics if we have done specific tests on the dog (e.g. bacterial cultures) that prove that they are appropriate. At the moment, it takes at least 48 hours to carry out such tests, but the report advises that new, rapid, tests need to be developed to remove this time lag.

Veterinary use of antibiotics falls into two main areas: farm animal use, and companion animal use, which mostly means pets. The reduction of antibiotic use on farms is a significant recommendation in the report, beyond the scope of this "pet vet" column. But companion animal vets use antibiotics every day, and we need to examine our own roles in this area. Our aim, as vets, is to cure our patients as rapidly as possible, with the smallest risk of treatment failure. With this in mind, it's easy to see why we are quick to use strong antibiotics for individual patients. We justify this as the best way of looking after animal welfare, and it's what owners want for their own pets. But do we need to look harder at the big picture?

Should we keep antibiotics as a second string to our bow, only for those cases of sore throats, itchy skin and ears, and upset digestive systems when a non-antibiotic choice has failed? Antibiotic resistance is a big challenge for my profession, and indeed for pet owners.

Wexford People

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