Analysis of the Spatial Dispersion of Tomato Brown Rugose Fruit Virus on Surfaces in a Commercial Tomato Production Site

Abstract

The tomato brown rugose fruit virus (ToBRFV) causes severe damage to tomato cultivars and has international economic importance. The harmful tobamovirus is easily mechanically transmissible and highly stable. An ongoing cultivation of infected tomato plants may lead to the spread of ToBRFV in and around the production area of the infested tomato farm. We conducted a study in which we collected a representative number of swab samples from various inanimate surfaces in greenhouses, packaging halls, and shared and private accommodations. In addition, numerous fabrics, such as outer clothing, bed linen, and items used by greenhouse workers, were tested. The infectivity of ToBRFV-contaminated surfaces was tested in bioassays using Nicotiana tabacum cv. Xanthi NN and confirmed using DAS-ELISA. The proportion of ToBRFV-contaminated surfaces varied among locations, from 48.7% in greenhouses to 0% in offices with limited access to staff. Samples from shared accommodation and private accommodation were 18.4% and 3.6% ToBRFV positive, respectively. Clothing and protective items were found to be highly contaminated with ToBRFV, and even around the sleeping area, infective ToBRFV was detected in a few apartments. This study provides evidence for the first time on how and where infectious ToBRFV can be spread by humans beyond the production area. To avoid further dissemination, strict hygiene protocols are required to interrupt transmission routes.