Who remembers the cantaloupe Listeria outbreak of 2011? It was the deadliest foodborne illness outbreak in the USA since outbreak records began in the 1970s, sickening at least 147 people and killing 33. It was followed by another deadly US cantaloupe outbreak, which killed 3 people, this time from Salmonella, the following year.

In the decade since there have been multiple outbreaks linked to melons, including two major outbreaks in Australia in 2016 and 2018 caused by Salmonella and Listeria respectivelytimeline of the deadly Listeria outbreak from cantaloupes (2011).  Image:  US Centers for Disease Control and Prevention

The Australian melon industry was badly affected by the 2018 outbreak, and growers left the industry as consumer confidence plummeted and sales decreased.  Something had to be done so the industry partnered with government agencies to create an initiative to safeguard melon consumers from food safety risk, called – appropriately – Safe Melons. 

The initiative was led by Dr Sukhvinder Pal (SP) Singh, a food safety champion in the Australian produce industry, and one smart cookie.

It proved to be a resounding success, reaching an astonishing 99 percent of the country's commercial melon growers and resulting in a reduction in food safety incidents for melons in Australia to zero for the last six years.  Meanwhile, incidents have continued in other countries, such as the 2023 Salmonella outbreak from cantaloupes in the USA which resulted in 407 cases, 158 hospitalisations and 6 deaths, or the 2021 Salmonella outbreak linked to Galia melons in the United Kingdom.

Here’s how it worked.

The initiative used a two-pronged approach: monitoring and support.  The monitoring component was a confidential microbial food safety surveillance program designed to function as an early warning system to predict food safety failures and prevent them from becoming a crisis. 

The monitoring aimed to detect Listeria monocytogenes, Salmonella species and Shiga-toxin E. coli (O157:H7) in samples collected from various stages of the growing, harvesting and post-harvest handling stages of the supply chain.

The sampling plan was scientifically designed to be inclusive of all melon types and all melon-growing regions in Australia. Samples were collected from melon production fields (soil, fruit, and harvesting equipment), processing facilities (contact and non-contact surfaces and fruit) and markets (wholesale and retail) with a target of 1,300 samples per year for three years.

Any problematic results – for example, when Salmonella was detected multiple times in a processing environment after an extreme weather event in 2022, or when Listeria monocytogenes was detected in samples taken because of a flood in 2023 – the results were reported back to the affected growers and processors immediately, along with technical recommendations to mitigate risks and promote continual improvements. 

During and after the project, the microbial data was also anonymised and aggregated so results at regional, state and national levels could be shared with various audiences.  Case studies on growers and packers who achieved good food safety outcomes were also shared to champion food safety leaders in the industry.

The second component of the project, support, aimed to increase the food safety knowledge of growers and convert knowledge into practice and behavioural change.  It included site visits and one-on-one consultations with major growers, regional workshops and ‘roadshows’, education for regulatory personnel and policy-makers, and even a food safety helpdesk service to address melon-related food safety enquiries.

Growers and packing shed staff were coached in the adoption of a food safety toolbox and best practice guides were shared. Food safety experts walked through production fields and processing facilities with growers, helping with microbial hazard assessments and providing risk mitigation advice. 

The helpdesk allowed growers and regulatory officials to benefit from unbiased technical advice when they needed to make decisions about food safety practices.

Questions posed to the helpdesk included requests for help with environmental monitoring programs, postharvest packaging and decay, responses to extreme weather events, postharvest wash water quality, sanitisers and fungicides, fertiliser selection, and wildlife incursion management.

Says SP of the project “The success of this project was dependent on the grower/packer’s engagement on highly sensitive topic of microbial food safety. The level of engagement clearly indicates that stakeholders trust the monitoring and support services provided by an independent team of experts and were interested in risk mitigation.”  Singh (2024)

The project concluded with an evaluation of its outcomes compared to the key performance indicators (KPIs) set at the outset, a concise list of recommendations for continued melon safety, and recommendations for future research and development projects.

The outcome was a success, reducing the number of melon-related food safety incidents to zero, contributing to increased consumer confidence in Australian melons and almost certainly saving lives that would have been lost if there had been another serious Listeria or Salmonella outbreak. Well done.

“Zero product recalls and food safety incidents are perceived as an ambitious and unrealistic goal”, says SP in the project report, “but it is the minimum goal that all industries should be aiming for.” Agreed!