Tackling the rising threat of antimicrobial resistance

Antimicrobial resistance (AMR) is one of the greatest challenges facing human and animal health in the future. This was the view given by John Grant, Parklands Veterinary Group, at Monday’s NSA Northern Ireland sheep event held in Ballymena Livestock Market.

John said that a recent forecast highlighted the seriousness of the challenge AMR presents, with more people forecast to die from issues related to AMR than cancer by 2050.

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“Resistance to antibiotics is a growing worry across the world. Everyone will be personally hurt by it and there is a moral obligation on us to farm properly.”

As well as a moral obligation, John says that we are already seeing more stringent rules and regulations being enforced around antibiotic use. This is well documented in human health, with campaigns around the misuse of antibiotics in treating illnesses such as the common cold, for example.

It is also apparent in the pig and poultry sectors with a marked switch away from the use of in-feed antibiotics and a growing emphasis on vaccination use to prevent disease.

Antimicrobial resistance

Explaining how antimicrobial resistance is caused, John says that every time an antibiotic is used, we are potentially promoting resistance by killing off susceptible bacteria.

“This is not a new phenomenon. Bacteria change over time and this has happened for thousands of years. The big problem is that the rate at which it is occurring has increased. The rise of MSRA (Methicillin-resistant Staphylococcus aureus) has also brought AMR into the spotlight and such infections are going to lead to a marked change in how antibiotics are managed but also in how hospitals will be run in the future.”

While AMR is a rising threat worldwide, John is keen to point out that Ireland and north Europe are not serious offenders.

“The use of antibiotics in the world by people differs greatly. In north Europe, there is a focus on controlled usage. This compares favourably to Spain, Greece and south Europe, where antibiotic usage in people is 3.5 times that of north Europe and is streets ahead of Africa and Asia, where antibiotic usage is worryingly up to 15 times higher than in north Europe. This is having a marked effect on the occurrence of AMR.

“For example, Swedish tourists were swabbed on returning from holiday from other countries in north Europe and the Far East. Three per cent of those returning from north Europe were shown to have come in contact with ESBL (extended spectrum beta-lactamases), a bacterial infection related to E coli and Klebsiella and capable of causing serious illness. In contrast, 36% of those returning from the Far East tested positive as coming in contact with ESBL.”

Animal usage

The growing threat is casting a spotlight on all antibiotic use, including in animals. John sees this as more of a good news story for the sheep sector than a bad story.

“When we look at sheep farms, the use of antibiotics is low and this is something that can be used in promoting the high health benefits of Irish lamb. We are in a good position but we cannot afford to be complacent. We have to be open to change in how we run our systems – antibiotic use should be as little as possible but as much as is required.”

The main areas where Parklands Veterinary Group currently sees the most antibiotic usage are in treating lameness, enzootic abortion and E coli scour around lambing. All of these illnesses are preventable and John says that the starting point in many health programmes is in ensuring disease is kept out of the farm.

“Many strains of lameness or enzootic abortion are unfortunately brought into healthy flocks when purchasing sheep. External biosecurity should be the first line of defence. Isolating purchased animals and quarantining for at least three weeks should be the norm for identifying issues such as CODD or footrot. Treatments for sheep scab and worms should also be administered.”

The use of vaccinations is also seen as providing huge opportunities to reduce the need for antibiotic use. “If we look at lameness, for example, the first port of call is often jagging animals with an antibiotic. The use of the vaccine Footvax for footrot is a no brainer for the majority of farms with a significant problem. It has treatment properties and one treatment will give a 75% cure rate, with two treatments increasing this to 86%. We also need to be mindful of high-risk periods and put preventative plans in place. For example, using the vaccine before housing or in combination with targeted antibiotic treatment to bring a problem under control gives good results.”

Accurate identification of the illness causing lameness was also highlighted. “If you have CODD, there is little point treating it with normal antibiotics or using the vaccine. Once you have CODD, you have it for good and the only solution is to put a treatment programme in place with your vet.”

Biosecurity

Not enough use is made of internal biosecurity and isolating sick animals from the flock.

“Many farmers need to rethink how they look after sick sheep. If you think about it, you wouldn’t send a sick child to school. Sick animals need to be taken out of the flock to reduce the risk of disease spreading and allow preferential treatment. Animals should be kept isolated from other healthy animals until you are sure that the risk has passed.”

Cleaning and disinfecting equipment is also seen as hugely important. For example, trailers used in transporting sick or purchased sheep should be washed and disinfected between animals, while sheds and lambing facilities should be cleaned as early in the season as possible to allow a long interval and lower risk of bacteria surviving in the environment between use.

In terms of antibiotic treatment, the advice is that antibiotic usage should not be feared as it is a vital tool in addressing health issues when required. Great care should be placed by farmers and vets on using the appropriate antibiotic for the ailment being treated.

“The majority of sheep farmers can manage OK with the normal range of antibiotics such as penicillin or Norodine. Critical groups of Marbocyl or Baytril for example should be protected and only used where necessary. Early intervention will greatly increase the success of treatment and care should always be taken to administer the full treatment course prescribed as failing to do so can also promote resistance.”

John also points out that a tougher stance is also required in many cases with repeat offenders.

“If an animal doesn’t respond to a treatment and is continually requiring treatment, then you need to ask some tough questions as in most cases the overall health of the flock or herd will benefit from culling these animals.”