This could have implications for current trade restrictions between Europe and the US. EFSA's new Plant Health (PLH) panel, which started work in the summer 2006, was asked by the EC to evaluate a recent US study on citrus canker disease. The study, published by the US Agriculture Department's Animal and Plant Health Inspection Services (APHIS), covers an economically significant plant disease that is currently not present in Europe. The panel was asked to provide a scientific opinion on this study, in particular on its conclusion that citrus canker is not likely to spread by means of citrus fruit that show no signs of the disease. The PLH Panel concluded that key arguments in the study, and its conclusions, were not supported by scientifically sound evidence. Citrus canker is a disease of citrus trees caused by the bacterium Xanthomonas axonopodis pv. citri (Xac). Fruit affected by Xac is often of unacceptable quality for sale because of lesions on the fruits. However, affected fruit is not a food safety risk; there is no harm for human or animal consumption. Citrus canker is prevalent in many citrus growing regions and in recent years it has also spread across Florida. Xac is difficult to eradicate. Once established, various control methods including spraying of copper compounds must be combined to reduce the damage by Xac. For these reasons, Xac is considered a quarantine organism in many countries including the USA and the Member States of the European Union (EU), for which trade restrictions are in effect. The APHIS study identified five events as necessary for Xac to be introduced into a disease free area through the fruits. It concluded that fruit without visible signs of citrus canker disease, even if harvested in contaminated areas, is unlikely to spread Xac. Following a thorough evaluation of the study, the PLH Panel agreed with the method of analysis presented in the APHIS study but concluded that the key arguments did not provide a sufficient scientific justification for the reconsideration of the current phytosanitary measures.