Fig. 1

House fly mechanical transmission of SARS-CoV-2 study design. a Acquisition study: house flies were exposed to virus-spiked substrate or positive and negative controls on wicks for 4 and 24 h, following which the flies were collected. b Transmission study: house flies were exposed to the same set of substrates on wicks for 24 h and transferred to a second container containing virus-free substrate on wicks. At 4 and 24 h post-transfer, the flies, swabs and exposed substrate on wicks were collected. Sample analysis: the  flies, container inner surface swabs and substrate samples collected from the studies were processed and tested for SARS-CoV-2 nucleocapsid gene by quantitative reverse transcription-PCR (RT-qPCR) and for infectious virus by virus isolation