Superbugs in the Covid era – Expert Q&A

Drug resistance is one of the top ten global health threats named by the World Health Organization for 2021.

In the past two years, the COVID-19 pandemic has shown what happens when infectious diseases spread before powerful treatments are developed. A major project led by the Office of the Prime Minister’s Chief Science Advisor is underway on infectious disease and drug-resistant infections (antimicrobial resistance), due this year.

Drug-resistant infections happen when bacteria, viruses, fungi or parasites evolve over time, and stop responding to medicines – such as antibiotics. Resistant superbugs like MRSA can emerge, raising the risk of disease spread, severe illness and death.

To mark World Antimicrobial Awareness Week starting today, the SMC asked experts about drug resistance in Aotearoa.

Dr Kristin Dyet, Senior Scientist in the Health and Environment Group and Technical Lead Antimicrobial Resistance, ESR (Institute of Environmental Science and Research Ltd), comments:

What is the scale of drug-resistant infections in New Zealand? Which drug-resistant bugs are we most worried about here? 

“Antimicrobial resistance is a global problem, and some countries have a much higher prevalence than others. Some drug-resistant organisms are endemic in New Zealand, including ‘methicillin-resistant Staphylococcus aureus’ (MRSA) and ‘Enterobacterales’ producing an extended spectrum beta-lactamase (ESBL), whereas other drug-resistant infections have either not been reported in New Zealand or are usually found in someone that has recently travelled overseas.

“I am not aware of data that summarises information on all drug-resistant infections in New Zealand. However when looking key bacteria, the rates of drug-resistant infections here are generally lower than what is observed in other countries. Of concern is the observation that numbers of drug-resistant infections in New Zealand are increasing.

“Infections caused by ‘carbapenemase-producing Enterobacterales’ (CPE) need to be closely monitored. CPE are resistant to nearly all antibiotics. They are found relatively infrequently in New Zealand although numbers were increasing until COVID border restrictions were introduced. Most cases with CPE are likely to have acquired their infections overseas, although there are an increasing number of reported cases likely to have acquired their CPE in New Zealand.”

Which population groups are most affected?

“The population group affected depends on what bacterium you are talking about. In the most recent survey of ‘methicillin-resistant Staphylococcus aureus’ (MRSA) the highest rates of MRSA were found in the youngest age group (0-4 years) with higher rates found in Māori and Pacific Peoples.

“By contrast Enterobacterales expressing an ‘extended-spectrum beta-lactamase’ (ESBL) are more common in older people, with the highest rates found in Asian, Pacific peoples and Middle Eastern/Latin American/African (MELAA) ethnic groups.”

What have we learned from the COVID-19 pandemic about drug-resistant infections? 

“We have observed reductions in a number of infections since the COVID-19 pandemic started, including a number of drug-resistant infections. Rates of some infections are likely to have reduced due to restrictions on international travel. Rates of other infections are likely to be affected by things such as social distancing and improved infection control measures used by the general population.”

Are new drugs being developed to replace those outsmarted by microbes? 

“We need to ensure that the antibiotics available to us now are functional for as long as possible. New drugs are being developed although this is an expensive, time consuming process. If we do manage to develop a new antibiotic, bacteria normally find a way to evade this new antibiotic in time.”

What are we doing to keep Kiwis safe from superbugs?

“The Ministry for Primary Industries and Ministry of Health launched New Zealand’s Antimicrobial Action Plan in 2017. A number of priority action areas were included in the ‘One Health’-based plan under five key headings: Awareness and understanding, Surveillance and research, Infection prevention and control, Antimicrobial stewardship and Governance, collaboration and investment. Although there is a desire, from a number of sectors, to achieve the objectives specified in the Action Plan to date there has been limited progress in a number of areas.

“One Health is a collaborative, multi-sectoral, and transdisciplinary approach to improve health outcomes by recognising the interconnection between people, animals, plants, and their environment. One Health Aotearoa is an alliance of New Zealand’s leading infectious diseases researchers committed to working together to address important health hazards in New Zealand, and beyond.”

Conflict of interest statement: Dr Dyet is a panel member for the Prime Minister’s Chief Science Advisor work on infectious disease, with a particular focus on drug-resistant infections (also known as antimicrobial resistance).

Professor Jack Heinemann, School of Biological Sciences, University of Canterbury, comments:

Why is antimicrobial resistance a problem?

“Antimicrobial resistance undermines both the delivery of pain relief and how we save lives. For example, infection risk may prevent the replacement of a painful hip and amputation will be used more to stop infections.”

Which population groups are most affected?

“Those suffering the most now from infectious disease, the old, newborns, the poor and ethnic minorities, will suffer the most from antimicrobial resistance.”

What have we learned from the COVID-19 pandemic about drug-resistant infections?

“Aotearoa New Zealand’s response to COVID-19 demonstrated the power of cooperation and teamwork for controlling infectious disease. Washing hands correctly, isolating, and increasing personal space all helped.”

What are we doing to keep Kiwis safe from superbugs? Are new drugs being developed to replace those outsmarted by microbes? 

“Probably new drugs are needed. But we also should rethink the commercial model for them because it contributes to overuse and antimicrobial resistance, as may overconsumption of antimicrobial hygiene products. They are unnecessary and accumulate in our homes, waste and surface waters. Even some products that we don’t think of as being “antimicrobial” may contribute to antimicrobial resistance. As with climate change, we make a large difference when individual small choices add up to a better world. #resistresistance.”

What can Kiwis do to help the fight against superbugs?

“Every Kiwi makes a valuable contribution by not needing a drug and thereby preserving the usefulness of the drugs we have. Governments that support a society where individual sacrifice leads to the betterment of all, also need our support.”

Conflict of interest statement: Professor Heinemann is a panel member for the Prime Minister’s Chief Science Advisor work on infectious disease, with a particular focus on drug-resistant infections (also known as antimicrobial resistance). He has no conflicts of interest.

Professor Dame Juliet Gerrard, Prime Minister’s Chief Science Advisor, comments:

What do we know about antimicrobial resistance?

“The ‘slow burning pandemic’ of antimicrobial resistance, largely driven by overuse and misuse of antimicrobial drugs, is well understood by scientists and healthcare practitioners. We understand how these microbes acquire and transmit resistance, the challenges of the drug discovery pipeline, and the deadly future that awaits us if we lose our ability to fight even the most common infections with safe and affordable drugs.

Which population groups are most affected?

“Harms resulting from inaction in the face of these threats will disproportionately affect Māori and Pacific peoples, whose health outcomes are significantly worse compared with other peoples in Aotearoa New Zealand, an inequity that has long been noted but not resolved, as we are seeing with COVID-19 cases in our current outbreak.

What can Kiwis do to help the fight against superbugs?

“Not only is the science underlying antimicrobial resistance clear – so too are the solutions. Tackling infectious disease and antimicrobial resistance (AMR) requires kotahitanga – unity, togetherness – across human, animal, plant, and environmental health, bringing everyone in Aotearoa New Zealand along on the journey. The challenges lie with infection prevention (rather than waiting for people to get sick and then being forced to focus on treatment), as well as curbing inappropriate use of antimicrobials through antimicrobial stewardship. It’s now a matter of resourcing antimicrobial stewardship, rolling up our sleeves and getting it done.”

Conflict of interest statement: Professor Dame Gerrard is leading PMCSA work on infectious disease, with a particular focus on drug-resistant infections (also known as antimicrobial resistance). This work will be delivered to the Prime Minister by the end of this year.

Professor Nigel French, Research Director for the School of Veterinary Science, Massey University, comments:

Which organisms are we most worried about affecting NZ’s animals – or that are carried by healthy animals and transmit to humans? 

“Quite a few organisms have the potential to be transmitted between animals and people (in both directions, of course) and some of these are resistant to antimicrobials. In 2014 we saw the emergence of a foodborne strain of Campylobacter transmitted from poultry to people that was resistant to two classes of antibiotic. This strain still present in New Zealand, but we don’t know how common it is as a cause of campylobacter infection in people today, or how important it is for public health – the last estimate was in 2019, which showed it was causing between 5 and 10% of human cases in Auckland and Manawatu.

“Another example is E. coli and related bacteria that cause drug-resistant urinary tract infections in people. A 2020 study in New Zealand showed that these can be carried in the faeces of pets in the same household as the human case, but the pet could be catching it from the person of course! Other examples for which there is some evidence of animal-to-human transmission include ‘methicillin-resistant Staphylococcus aureus’ (known as MRSA) and ‘Vancomycin-resistant enterococci’, although there is not enough data to see if this happens frequently in NZ or whether it is getting worse.

“We have excellent infectious disease surveillance systems in New Zealand, but we don’t collect sufficient comparable data from animal sources and humans for us to assess these things routinely, but this will improve with the recently-announced new investment in infectious diseases and the application of a more ‘One Health’ approach that considers humans, animals and the environment.” (See more detail on One Health below)

What have we learned from the COVID-19 pandemic about drug-resistant infections?

“The Covid pandemic has shown us how quickly infectious agents can be transmitted between people, and how important measures such as good hygiene, immunisation and avoiding contact with others if you are sick, help to protect you and prevent transmission to others. Prevention of infection remains the first line of defence when dealing with the emergence of any new pathogen, including antimicrobial-resistant organisms – if you don’t get infected in the first place you won’t need treatment with an antimicrobial, and this reduces the likelihood of antimicrobial resistance developing.”

Has greater use of hand sanitiser and deep cleaning during the pandemic had an impact on microbe resistance?

“More widespread use of antimicrobials, including sanitisers and disinfectants, can put selection pressure on populations of microbes, and this can lead to resistance; but it’s not clear whether increased use of these agents in the Covid pandemic has led to greater resistance in bacteria in New Zealand.”

What are we doing to keep Kiwis safe from superbugs? What is the One Health approach?  

“Infection prevention and judicious use of antimicrobials in humans and animals will help protect us from the emergence of superbugs, and ensure that – when we do need antibiotics – they still work effectively. We are relatively-low users of antimicrobials in animals, compared to other countries, but we need to continue to improve to reduce the risks to both humans and (other!) animals.

“A One Health approach recognises the need to take a holistic approach when dealing with issues such as antimicrobial resistance and emerging infectious diseases –  a surprisingly large number of infectious agents are shared between humans and animals, and many that cause disease in people do not cause symptoms in animals. Animals also need antimicrobials from time to time, to protect their welfare, and not surprisingly, many of the antibiotics used in animals are the same as those used in people.  Given the importance of humans, animals and the environment in transmitting antimicrobial-resistant infections, a One Health approach is essential. This doesn’t always happen due to ‘siloing’ and lack of communication between the relevant sectors, but New Zealand has a good track record in One Health and a large network of One Health practitioners.”

Are new drugs being developed to replace those outsmarted by microbes? 

“New drugs are being developed, but these will still need to be used judiciously, alongside infection prevention and control. As soon as they are used widely there is a risk that the organisms will evolve to develop resistance, and this can happen quite rapidly.”

What can everyday Kiwis do to help the fight against superbugs?

“Try to avoid getting infected in the first place by practicing good hygiene and following guidelines aimed at preventing you getting infected and transmitting your infection to others. This includes taking full advantage of immunisation programmes, cooking your food well, and avoiding drinking untreated water. If you don’t get infected you won’t need antibiotics – but if you do, always follow the advice of your health practitioner concerning their appropriate use.”

Conflict of interest statement: Professor French is Co-Director of One Health Aotearoa, Chief Scientist for the Food Safety Science and Research Centre, Member of the PMCSA panel on infectious disease and antimicrobial resistance, and Member of the Ministry of Health’s Covid-19 Technical Advisory Group.

Dr Htin Lin Aung, Department of Microbiology and Immunology, University of Otago, comments:

What is the scale of drug-resistant infections in New Zealand? Which drug-resistant bugs are we most worried about here? 

“‘Methicillin-resistant Staphylococcus aureus’ (MRSA) already poses challenges to clinical care in New Zealand. Of growing concern is the increasing prevalence of antimicrobial-resistant Enterobacterales, such as ‘Escherichia coli’ and ‘Klebsiella pneumoniae’ in both hospitalised and community patients.

“Furthermore, drug-resistant tuberculosis (TB) is the leading cause of death associated with antimicrobial resistance. While approximately less than 2% of total TB cases in New Zealand are drug-resistant TB, continuous surveillance for drug resistant-TB is required.”

What have we learned from the Covid-19 pandemic about drug-resistant infections? 

“The focus on COVID-19 (‘Covidisation’) has left several other public health threats on the back burner. One of these threats is the ‘slow-burning pandemic’ of antimicrobial resistance. It has the potential to lead to 10 million deaths per year by 2050 if no action is taken. The COVID-19 pandemic will undoubtedly magnify the ongoing antibiotic resistance crisis if there are no coordinated efforts to address antimicrobial resistance.”

What can everyday Kiwis do to help the fight against superbugs?

To help the fight against superbugs, people should:

  • importantly, only use antibiotics when prescribed by a doctor – not every infection requires antibiotics
  • never share antibiotics with others and never use leftover antibiotics
  • dispose of antibiotics properly
  • prevent infections by regularly washing hands
  • prepare food hygienically
  • get vaccinated.”

No conflict of interest.

Dr Joanna McKenzie, One Health epidemiologist, School of Veterinary Science, Massey University, comments:

What does drug resistance mean for pets?

“Antimicrobial resistance is an important issue for our pets and their owners. New Zealand is a pet-loving nation with over 60% of homes owning a companion animal, one of the highest rates in the world.

“Pets can be infected with bacteria that are resistant to antimicrobials, which can reduce the effectiveness of antibiotics used to treat them when they are sick, in exactly the same way as antimicrobial resistance impacts the health of people. Furthermore, healthy pets can carry bacteria that are resistant to antimicrobials, even though they don’t look sick, which if spread to their human family can potentially affect the health of their family.”

What is your advice for pet-owners?

“It is important that pet owners use antibiotics responsibly to preserve them for future use in animals and people and to reduce the development of antimicrobial resistance.

“Things you can do as a pet owner are:

  • ensure that you follow the instructions of the veterinarian when treating your pets with antibiotics, in particular:
  • give the recommended dose, and
  • complete the course of antibiotics – don’t just stop treatment when the animals are looking better.
  • It’s also extremely important not to use old antibiotics left over from previous treatments as these may no longer be effective. This can be dangerous for your pet’s health and sub-lethal doses of out-of-date antibiotics can cause resistance to develop in the surviving bacteria.

“Bacteria can spread from pets to their humans, which may result in transmission of antimicrobial resistance. Some antimicrobials used for treating pets are similar to antimicrobials used to treat sick people. If the bacteria carried by our pets become resistant to important antimicrobials for treating people, these resistant bacteria may spread to their owners, and may potentially lead to antimicrobial-resistant infections.

“To protect you and your family from resistant bacteria spreading from your pets, it’s very important to practice good hygiene when interacting with your pet. Don’t let them lick your face and always wash your hands with soap after handling your pet and after cleaning up their poop.”

No conflict of interest declared.