---

Food and Biological Security: Agricultural Fungicide

My Lords, I am grateful to those who have joined this debate, to the Library for its excellent briefing and to the University of Manchester and the British Society for Antimicrobial Chemotherapy among others who have prepared additional material on a subject that may at first appear niche and specialist. I hope that by the end of this debate it will be much more familiar to this Committee and far beyond, with its status lifted up in Defra’s and the Department of Health’s agenda. I must also thank my BSAC intern, Lorna Flintham, who has played a major part in my preparations for today.

The severity and widespread impact of fungal disease and fungicide use are often greatly overlooked. Annually more than 150 million severe cases of human fungal infections occur worldwide, resulting in about 1.7 million deaths a year. Many of those deaths are because the drugs that once worked to cure now work no longer because the fungi are resistant. That is not solely or even primarily because of medical use of drugs.

First, I shall make a quick distinction. Antifungals are human medicines used to treat fungal infections; fungicides are pesticides used to treat and prevent fungal plant infections, particularly in food crops. Some 4,000 tonnes of fungicide are sprayed on arable crops annually, accounting for 38% of pesticide use. They are not used without reason. The Irish potato famine, African wheat blight and the way our world coffee industry now sits in South America, and not where it originated in south Asia, are all the result of fungi defeating human efforts. The problem is what these fungicides are doing to our environment, food security and biosecurity.

First, there is their direct killing action. To date no policy document has shown an appreciation of the state of the UK’s soil microbiosphere and how it is being affected by biocides such as fungicides. We benefit hugely from mycorrhizal fungi and, indeed, many other fungi that break down materials that would otherwise literally cover our planet, but they are being eradicated by indiscriminate fungicide use in industrial agriculture in what is being termed a large microbial extinction event. Not only is this destroying environmental biodiversity but soils depleted of these microbes have lower crop yields. Some 80% of our

food is dependent on plants. Lower crop yields will push food security and supermarket prices only one way.

Then there is cross-resistance. Most fungi exposed to fungicides in a crop field will die, but some will survive and become inherently resistant to the fungicide due to natural selection. The fungicide will also stop working in the field. The key issue is that the fungicides that fungi are resistant to are extremely similar chemically to the antifungals we rely on to treat patients in healthcare. By developing resistance to fungicides, these fungi also develop cross-resistance to clinical antifungals. More and more patients are coming forward with resistant fungal infections that healthcare providers simply cannot treat.

Fungal diseases affect more than 1 billion people every year. For those billion people, antifungals are indispensable tools in fighting infection. Development of treatments for fungal diseases in humans is intrinsically more challenging than agricultural fungicides due to the shared characteristics of human and fungal cells—that is, it is very challenging to eradicate a fungal cell without also damaging the host, and therefore the utmost care must be taken to produce and protect effective antifungal drugs.

A new emerging antifungal drug, Olorofim, has been effectively trialled in the treatment of aspergillosis, a highly debilitating fungal lung infection with a 30% to 50% death rate even when the strain is not resistant to medication, which 20% of cases are. Olorofim could make a real difference to the patient population, but there is a big problem: its efficacy is threatened by ipflufenoquin, a newly developed agricultural fungicide. These two drugs use the same mechanism of action to kill fungi, a big problem considering cross-resistance and the spread of resistance from our fields to our hospitals. As a government priority, the approval of ipflufenoquin for use in agriculture and other commercial sectors should be paused pending further investigation into the cross-resistance risk. I hope the Minister, to whom I have given prior notice of all the questions in this speech, will be able to directly respond on that issue.

We should not allow the approval of a pesticide that could undermine decades of antifungal drug development and risk the well-being—the life—of thousands of patients who could benefit from it. There is an opportunity here to truly benefit physically vulnerable people, which most of the affected patients are, who are absolutely reliant on this new breakthrough medication, which is a spin-out from University of Manchester research.

Further, the Government need to assess the feasibility of ring-fencing certain mechanisms of action for human antifungals. Ring-fencing could prevent the fungi in our environment being exposed to similar chemicals that we use to treat fungal disease in healthcare, ultimately safeguarding effective antifungals for the future. In addition, to promote the safe deployment of novel fungicides, regulators should introduce new criteria when approving antifungal compounds for commercial use. Are the Government looking at that?

Our infrastructure could greatly benefit from developing a risk management framework to evaluate the likelihood of cross-resistance emerging between new agricultural

antifungals and existing clinical agents before they are approved for use. This is a genie that, once out of the bottle, cannot be put back in. In doing so, we could stop the inevitable inefficacy of antifungals in future and allow our UK antifungal innovation to remain competitive.

Unsurprisingly, it has to be noted that the climate emergency will only increase the pressure to act. The UK Food Security Report 2021 mentions fungal pathogens only three times in 322 pages, although it notes that:

“Warmer temperatures can also encourage fungal diseases such as potato blight”,

backing up what the science has told us in multiple directions—that the effect of the climate emergency on plant diseases, of which 80% are fungi-based, will lower crop yields. In humans, fungi such as the valley fever pathogen are known to thrive in warmer soils. More frequent severe storms, floods and hurricanes are also increasingly dispersing harmful fungi across hundreds of miles to human hosts, potentially causing infection outbreaks through what were previously rare diseases. Here in Parliament, we need to seriously consider how fungicide use will fit into the growing pressure from fungal diseases in a warming world.

I turn to broader issues. Increasing our fungicide use in agriculture is not the answer; in fact, we clearly have to massively decrease it. Innovation should not automatically mean new synthetic chemicals. Yes, we need to make further research funds available to replenish our antifungals and fungicides but, much more, we need to explore innovative agricultural practices that reduce our reliance on fungicides. The Minister has frequently expressed agreement with me about the need for agro-ecological practices. To put it another way, as does the Exeter researcher Jamie Lorimer, we need to use life to manage life—using mechanisms that have been around for hundreds of millions of years.

Our approach to agriculture is outdated and comes from a time when we were not aware of the environmental and human risks of pesticide use. In that vein, I strongly urge His Majesty’s Government to share their plans and ask the Minister when we will see the updated UK national action plan for the sustainable use of pesticides.

I acknowledge to the Government that striking the balance between prioritising our food security and safeguarding our clinical treatments is an impossible challenge, but it is an essential one that we have to meet as best we possibly can. Managing fungal crop disease has always been essential to our ability to feed the population, but we cannot afford a haphazard, piecemeal approach that will hurt our public health and our NHS. We need integrated, “one health” considerations of the impact of the climate emergency and responsible fungicide legislation.

Mitigating these risks will require the Government to work collaboratively with cross-sector stakeholders: clinicians, industry representatives from agritech and pharma and third-sector organisations in both those spaces, and farmers. Globally, as we are reminded by reports of a new disease outbreak in China, no one is safe until everyone is safe.

Are the Government working with the Quadripartite, the organisation that brings together the WHO, the FAO, the UNEP and the WOAH, to look at the specific antifungal and fungicide issues I have outlined? Are they seeking mechanisms to reserve particular actions of chemicals for human drug use? Urgently, we need to delay the approval of ipflufenoquin in the UK pending further investigation and to leverage international mechanisms to address the approval of this chemical worldwide. Ultimately, no one is safe until everyone is safe. I look forward to the debate and hope for urgent consideration of the issues raised.

1.11 pm