Transfer of Phi6 bacteriophage between human skin and surfaces common to consumer-facing environments

Aims: This study aimed to determine the extent of Phi6 (Φ6) transfer between skin and surfaces relevant to consumer-facing environments based on inoculum matrix, surface type and contact time.

Methods and results: Φ6 transfer rates were determined from skin-to-fomite and fomite-to-skin influenced by inoculum matrix (artificial saliva and tripartite), surface type (aluminium, plastic, stainless steel, touchscreen, vinyl and wood) and contact time (5 and 10 s). Significant differences in estimated means were observed based on surface type (both transfer directions), inoculum matrix (skin-to-fomite) and contact time (both transfer directions). During a sequential transfer experiment from fomite-to-skin, the maximum number of consecutive transfer events observed was 3.33 ± 1.19, 2.33 ± 1.20 and 1.67 ± 1.21 for plastic, touchscreen and vinyl, respectively.

Conclusions: Contact time significantly impacted Φ6 transfer rates, which may be attributed to skin absorption dynamics. Surface type should be considered for assessing Φ6 transfer rates.

Significance and impact of the study: Although the persistence of Φ6 on fomites has been characterized, limited data are available regarding the transfer of Φ6 among skin and fomites. Determining Φ6 transfer rates for surfaces in consumer-facing environments based on these factors is needed to better inform future virus transmission mitigation strategies.