Single torradovirus infections explain the mysterious cassava frogskin disease in the Americas

Cassava frogskin disease (CFSD) emerged in the Americas in the 1970s, but its causal agent has to date remained a mystery. The clonal propagation of cassava, high incidence of mixed infections, unknown alternative hosts, and root symptoms taking two or more crop cycles to develop, have made it difficult to identify the causal agent. Consequently, most studies on CFSD have produced a catalogue of pathogens occurring in affected plants. Using a sentinel approach, we captured single-pathogen infections in fields with high incidence of root symptoms. Eight months after being exposed to CFSD, we detected