By Dr Philippa Binns
The World Health Organization (WHO) has called antibiotic resistance one of the biggest threats to human health today - and international travel is contributing to the problem.
Antibiotic resistance is when bacteria mutate or change their genes after coming into contact with an antibiotic. When this happens, the antibiotic no longer works against the bacteria.
We can all help to reduce the spread of antibiotic resistance by preventing infection in the first place, and by using antibiotics wisely and only when we really need them.
By Dr Philippa Binns
Why is antibiotic resistance a problem?
Many bacterial infections once easily cured with antibiotics are now much harder to treat, or even untreatable, because of antibiotic resistance. Examples include the methicillin-resistant Staphylococcus aureus (MRSA) bacteria commonly found in hospitals, and the bacteria that cause tuberculosis (Mycobacterium tuberculosis).
Resistant bacteria can pass on their genes to other bacteria, to form a new antibiotic-resistant ‘strain’ of bacteria that can spread to other people. If you get an antibiotic-resistant infection:
- you’ll have the infection for longer
- you may be more likely to develop complications from the infection
- you could remain infectious for longer and pass your infection to other people.
Unfortunately we now have multi-resistant bacteria, or ‘superbugs’, which are resistant to several different antibiotics. Some of these antibiotics - including vancomycin, carbapenem antibiotics, and fluroquinolone antibiotics - are usually reserved for when other treatments don’t work. With the pipeline of new antibiotics close to drying up, bacteria will ultimately become resistant to the antibiotics we have left unless we act now - there are already reports of infections caused by pandrug-resistant bacteria.
What is causing antibiotic resistance?
Overuse and misuse of antibiotics is the main reason and it is occurring worldwide.
Major causes of antibiotic resistance include:
- using antibiotics when they are not needed (e.g. for a viral infection)
- not taking antibiotics at the doses and times that are advised
- not restricting or regulating the use of antibiotics
- overusing antibiotics in veterinary medicine and in agriculture.
Despite some effective regulations around access and use of antibiotics in Australia, we are still one of the highest users of antibiotics in the OECD. In countries where antibiotics are freely available for purchase over the counter, which enables the potential for overuse and misuse, the challenge is even greater.
Where has antibiotic resistance spread?
Antibiotic resistance is a global issue that isn’t confined to healthcare settings or developing countries. There has been a rise in antibiotic-resistant infections in the wider community too over the last several years, both in Australia and overseas. For example, the proportion of MRSA infections in the Australian community rose from 10 to 20% between 2001 and 2010.
Increasingly we are also seeing antibiotic-resistant bacteria from overseas reaching Australia through returning travellers. This is presenting a major public health threat for many countries.
How is global travel spreading antibiotic resistance?
More and more people are travelling internationally for work, holidays, to visit family and friends, or to have medical procedures. This can mean greater contact with antibiotic-resistant infections from overseas that can be brought home and spread to others.
Antibiotic-resistant bacteria previously reported in other countries are now being seen to cause infections in Australia. Overuse and unregulated use of antibiotics is an important cause of antibiotic resistance in developing countries. Antibiotics are commonly bought without a prescription in some countries, including parts of Europe, Asia, Africa, and South America.
Which travellers get antibiotic-resistant infections?
Anyone can get an antibiotic-resistant infection. However, it can be a particular issue if you require or seek medical treatment or surgery overseas, especially in developing countries.
Infections caused by multi-drug resistant bacteria are increasing in healthcare settings in low and middle income countries. Invasive medical procedures, like organ transplantation and insertion of artificial devices, can further increase the chance of developing an antibiotic-resistant infection.
Emigrants returning to visit friends and family in their country of origin are particularly vulnerable. For instance, studies have found these travellers to be at greater risk of typhoid fever. Many don’t seek medical advice before they travel or take necessary steps to preventing infection, such as vaccination.
And of course, people who are immunocomprised are also at higher risk of any infection and should be particularly cautious if required to travel.
Which superbugs have been brought into Australia?
Some types of multi-resistant bacteria from overseas have now been identified in medical tourists and other travellers returning to Australia.
The New Delhi metallo-beta-lactamase-1 strain (NDM-10) often found in healthcare settings in India has found its way to Australia, as well as some parts of Europe, the US, Canada and Japan. Resistant strains of Escherichia coli, which often infect the urinary tract, have been found in travellers returning from the Indian subcontinent, South East Asia and China.
Australia has seen a rise in typhoid fever caused by multi-resistant Salmonella enterica subspecies (S. Typhi and S. Paratyphi). Increased travel to countries where this bacterial infection is endemic, particularly in India and Indonesia, has been identified as a cause. Increased cases of typhoid fever have also been seen in the US, UK and Canada.
Bacterial infections common to Australia, such as gonorrhoea and MRSA, have also been acquired by overseas travellers. Major cities in Australia have seen a rise in multi-resistant strains of Neisseria gonorrhoeae, often in travellers returning from the Western Pacific and South East Asia, but from countries further afield too, including the US, Hong Kong, Ireland and South Africa.
Resistant cases of tuberculosis currently in Papua New Guinea are also a threat to Australia, especially for Aboriginal and Torres Strait Islander peoples living in the north of the continent.
How can travellers avoid antibiotic-resistant infections?
Preventing infection in the first place helps to reduce the need for antibiotics and the spread of antibiotic resistance. Medical advice before and after travel is essential - especially when visiting developing countries or having medical procedures overseas.
Steps to help prevent infection
Practising good hand hygiene, safe sex, and being cautious about what you eat and drink can help to prevent bacterial infections. Always drink bottled or boiled water if it is from an untreated source; avoid ice; eat fruit you can peel; and avoid raw or reheated food.
Two very serious bacterial infections you can get from consuming contaminated water or food are cholera and typhoid. Both these diseases are preventable if you are vaccinated before you travel. Vaccination against these and other infections also protects the community as a whole, and can help to reduce the spread of antibiotic resistance.
Seeing a doctor at least 6 weeks before travel is best in case any vaccinations are needed, and to allow enough time to respond to any vaccination.
More information on cholera, typhoid and other vaccines for travellers is available from nps.org.au/vaccines.
Seeing a doctor after you travel
It’s a good idea for anyone who has invasive surgery or another procedure, or needs to go to hospital overseas for any other reason, to see their doctor when they return. Discuss the healthcare you received and any symptoms you notice.
Antibiotic-resistant bacteria may remain in the body for a while. So if you need to seek medical advice, or have a medical procedure in the year after returning from overseas, it is important to let your health professional know where you have travelled. For example, some data indicates that having a resistant Escherichia coli infection may increase your risk of further infection a few months later.
What else can we do to reduce antibiotic resistance?
In addition to simple steps to avoid infections and prevent them from spreading, we can all help to reduce antibiotic resistance by:
- understanding when antibiotics aren’t necessary, for example, for colds and flu because they are caused by viruses not bacteria
- telling a health professional that you only want an antibiotic if it is really necessary
- taking the right dose of antibiotic at the right time, as directed
- taking antibiotics for as long as advised
- not taking antibiotics leftover from a previous illness
- not sharing your antibiotics with others
- not using antibiotics purchased over the counter while overseas travelling unless you have sought advice from a qualified health professional.