Are food and packaging a source of infection for the COVID-19 virus (SARS-CoV-2)?
At the present time, there is no evidence or reports of COVID-19 being spread via food. This is despite the innumerable meals eaten across the globe since the beginning of the pandemic. Similarly, there was no evidence of viral transmission through food consumption during previous outbreaks of MERS and SARS [1][2]. There are also no known reports of other coronavirus or respiratory virus infections due to food consumption or contact with food packaging [2][3][4].
Specific data on survival of SARS-CoV-2 on surfaces, including packaging and food, is limited. Coronaviruses that infect humans have a relatively low environmental stability on dry surfaces and their persistence in the environment depends on several factors including temperature, surface type, humidity, viral strain, quantity of the virus. Coronaviruses cannot multiply in food and don’t survive well outside of a host [4].
Whilst droplet and aerosol infection are the main ways COVID-19 is thought to spread, it is possible that transmission could occur through smear infections, but based on the above knowledge, smear infection (e.g. from food or packaging to mucous membrane) is only likely to occur during a short period after surface contamination.
Most reports to date (with the exception of some experimental studies [5]) have identified presence of the virus on food, without giving an indication of viral load or viability. Other recent publications [6][7] have evaluated the survival of SARS-CoV-2 on different surfaces, but these findings resulted from experiments in a controlled environment and should be interpreted with caution in the real-life environment. The presence of SARS-CoV-2 in food may indicate poor food safety practices but does not necessarily translate into an infection risk for consumers. Primary infection with SARS-CoV-2 is via the respiratory route and foodborne transmission has not been demonstrated.
The current global opinion confirms that the risk of contracting COVID-19 from food, packaging and the environment, while not nil, is significantly lower than the risk of contracting COVID-19 from an infected person. This assertion is consistent with that of the International Commission on Microbiological Specifications for Foods (ICMSF), which concluded from risk-based perspective, that it is very unlikely contamination of food with SARS-CoV-2 would result in infection. This likelihood is even lower for food products or packaging that are transported over a period of days or weeks [3][8].
Is testing of food, food packaging, and surfaces for SARS-CoV-2 useful in a food business?
There is currently no commonly available test for SARS-CoV-2 in food. However, tests are available for the detection of SARS-CoV-2 components (e.g. RNA) on surfaces and packaging. To date, the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC) and the European Food Safety Authority (EFSA) do not recommend this type of environmental testing for infection control or to support hygiene and sanitation approaches. No official sources in Australia currently recommend the use of this sort of targeted assay as a routine approach to the management of SARS-CoV-2 in a food business.
Current SARS-CoV-2 tests detect fragments of the virus, such as RNA, rather than the virus itself. Therefore, they do not provide direct information on the viability of the virus or viral numbers. Consequently, they cannot be used to directly assess the risk of contracting COVID-19 from the tested sample. These factors should be considered when interpreting test results for COVID-19 exposure health risk assessment purposes.
Scientific opinion indicates the risk of contracting COVID-19 from food, food packaging and the environment, while not nil, is significantly lower than the risk of contracting COVID from an infected person via direct contact or respiratory aerosols. The use of environmental SARS-CoV-2 testing without an accompanying COVID-19 exposure risk assessment might be considered an unnecessary burden for food businesses already facing multiple COVID-19 pandemic-associated challenges.
SARS-CoV-2 testing of food or surfaces in a food business should only be considered where end users have a good understanding of how to interpret results, and the corrective actions required to treat the risk, if detected. SARS-CoV-2 environmental tests cannot be used to provide guarantees that a food, package or site is “COVID-19 free”.
Before commencing an environmental monitoring program for SARS-CoV-2, a food business must have a clear understanding of the purpose of testing, how to interpret results, and what actions should be taken following a positive detection of the virus. An environmental screening procedure for SARS-CoV-2 should consider the difference between routine environmental sampling and testing intended to protect product from potential contact with the virus, as opposed to surveillance for the potential presence of SARS-CoV-2 specifically in a food business where the main objective is to provide confidence regarding management to reduce staff and/or customer exposure risk.
Test methods used to detect SARS-CoV-2 must be reliable, robust, reproducible and validated for use on the surface being sampled and tested. Third party accreditation of the testing laboratory (NATA in Australia and IANZ in New Zealand) for SARS-CoV-2 viral RNA (or other viral component) testing in environmental samples is recommended.
Because these tests detect the presence or absence of viral material (typically RNA), a positive result is only an indication that SARS-CoV-2 was likely present on the tested surface at some time. Test results cannot be used to determine infection and food safety risks of the tested surface, but rather as a hygiene indicator with respect to the potential presence of SARS-CoV-2. Positive test results may be used as an indicator for further investigation of potential sources, e.g. the effectiveness of SARS-CoV-2-specific control measures, including clinical, cleaning and sanitization.
Negative test results do not indicate the absence of SARS-CoV-2, rather that it was not detected on a surface. Results may be used as a general indicator of hygiene status and sanitisation procedure efficacy with respect to SARS-CoV-2.
Enhanced monitoring of surfaces using routine indicators of pathogen contamination and sanitary status (e.g. coliform/E. coli, Salmonella, Listeria, ATP, total [heterotrophic] bacterial counts) in conjunction with SARS-CoV-2 testing may assist with the assessment of the overall efficacy of clinical, sanitising, and hygiene practices, including COVID-19-specific control measures.
In a food business, Good Manufacturing Practices (GMP) and Good Hygiene Practices (GHP) used to prevent pathogen contamination of food, and COVID-19-specific control and clinical measures, described in their COVID-Safe Plan, will reduce the risk of SARS-CoV-2 contamination of food. COVID-19-specific control measures refer to but are not limited to: social distancing; avoiding interpersonal physical interactions; using physical barriers, personal protective equipment (PPE) and personal hygiene etiquette, and providing up-to-date, accessible information on COVID-19-specific control and clinical measures to all staff in a language they can understand. Clinical measures include health checks for staff, and when necessary, isolation and/or quarantine of symptomatic or at-risk staff.
References
Refer to the Reference list on our COVID-19 page (under ‘Science Behind COVID-19’ tab)