Tomato brown rugose fruit virus: Survival of the virus and efficacy of disinfection approaches

Tomato brown rugose fruit virus (ToBRFV) is an emerging contact transmitted virus related to Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV). The virus was first described from tomato crops in Israel in 2014 and is now present in several European countries including the UK. Unlike TMV and ToMV, ToBRFV can overcome the Tm-22 resistance gene in tomatoes. The virus is thought to be robust (environmentally stable), and due to limited information current prophylactic hygiene and disinfection approaches are based on strategies to control and eradicate other contact transmissible pathogens. The aim was to gather data in support of current best practice for management of ToBRFV.

Key findings were:

• ToBRFV can survive on hands and gloves for at least 2 hours.
• Hand-washing is of limited use against ToBRFV but remains essential to prevent spread of other contact transmitted pathogens.
• ToBRFV survived on all glasshouse surfaces tested for at least 7 days, and in some cases for over 6 months.
• ToBRFV was destroyed on plastic trays soaked in hot water for 5 min at 90^o A soak in hot water at 70^oC for 5 min was insufficient alone to kill the virus but was effective when trays were sprayed with Virkon (1% ai, 1 min contact time) after the heat treatment.
• The thermal inactivation point for ToBRFV is 90^o This confirms the hot water treatment results and shows the inactivation is due to the heat treatment and not a washing effect of the water.
• Certain disinfectants were found to inactivate ToBRFV on a range of glasshouse surfaces (see report for details)

 Disclaimer

This project has been conducted for research and development purposes. The research evaluated a range of products used for general disinfection purposes (hand sanitisation; cleansing and disinfection of glasshouse surfaces).  No endorsement or recommendation of named products is intended nor is any criticism implied of alternative, untested products.

The products named in this report are not necessarily authorised as biocides across all UK cropping situations and mention of a product does not constitute a recommendation for its use against specific plant pathogens. Biocidal and plant protection products must only be used in accordance with the authorised conditions of use.

Any product marketed for use specifically against Tomato Brown Rugose Fruit Virus (ToBRFV) or any other plant pest/disease would require an authorisation under the Plant Protection Products Regulations/Regulation (EC) 1107/2009 before they are placed on the market for this use.

Regular changes occur in the authorisation status of biocides and plant protection products. For the most up to date information, please check with your professional supplier, BASIS registered adviser or the Chemical Regulation Division (CRD) of HSE (https://www.hse.gov.uk/crd/).

 Additional information:

Learn more about ToBRFV

The aims of this project were to investigate the following with specific reference to ToBRFV:

1. Survival of ToBRFV on skin and gloves
2. Handwashing to reduce the risk of contamination in the glasshouse
3. Survival of the virus on glasshouse surfaces and tools
4. Efficacy of disinfection approaches on glasshouse surfaces and tools
5. Ct values of swab samples taken from different surfaces after treatment with Unifect G and Virkon.
6. Hot water treatment of contaminated picking trays
7. Thermal inactivation of ToBRFV (funded under the Defra-Fera Long Term Service Agreement)