Table 1.
WHO-recommended hand rub formulations.
Table 2.
Surface disinfectants.
Fig 1.
(A) Stability of YFV 17D. Nine parts YFV 17D were mixed with one-part interfering substance (BSA, 0.3 g/L final concentration) and incubated for the indicated time periods at either room temperature (21°C) or 4°C. Remaining infectious viral titers were recovered from the contaminated stainless steel discs at the indicated time points. Viral titers were determined by an end point dilution assay and calculated as TCID50/mL. A non-linear model based on a Weibull distribution was used to fit data. Dotted black line indicates the lower limit of detection. Colored area displays 95% confidence interval. (B and C) Inactivation of YFV 17D by WHO-recommended hand rub formulations and ethanol or 2-propanol. All four disinfectants were tested regarding their potential to inactivate YFV 17D in a quantitative suspension test according to EN14476. Ethanol and 2-propanol (B) as well as WHO formulation I and II (C) were diluted to 20, 30, 40, 60 and 80% final concentration and mixed with one-part interfering substance (BSA, 0.3 g/L final concentration) and one-part YFV 17D for 30 s. Remaining infectious viral titers were determined in an end-point dilution assay and are displayed as TCID50/mL. The untreated control (UTC) is displayed as the dark blue bar. The light grey bar shows viral titers recovered after exposure to the disinfectants. The cross (†) indicates a reduction of infectious viral titers to the lower limit of detection. Numbers above the grey bars indicate reduction factors (RFs) compared to the UTC. Each dot indicates one biological replicate. All experiments were performed three times. (D) Inactivation by WHO formulation I and II. Inactivation kinetics were compared to other viruses such as ZIKV (Zika virus), EBOV (Ebola virus), HCV (Hepatitis C virus), CHIKV (Chikungunya virus) as well as the reference virus MVA (Modified Vaccinia Ankara) using robust non-linear fitting.
Fig 2.
Inactivation of YFV 17D by surface disinfectants.
Five surface disinfectants based on alcohol, aldehyde, and hydrogen peroxide were tested according to EN16777 to evaluate their virucidal activity. All products were tested as suggested by the manufacturers. Nine parts YFV 17D mixed with one-part interfering substance (BSA, 0.3 g/L final concentration) were spiked and dried on sterile stainless steel discs. Subsequently the virus was inactivated with undiluted Bacillol AF, Antifect N liquid and Incidin OxyFoam for 30 s. Kohrsolin FF and Incidin Rapid were diluted to 0.5% working solutions and incubated for 5 min on contaminated stainless steel discs. Remaining infectious viral titers were determined in an end-point dilution assay and are displayed as TCID50/mL. The untreated control (UTC) is displayed as the dark blue bar. The light grey bar shows viral titers recovered after exposure to the surface disinfectants. Dotted black line indicates the lower limit of detection. Numbers above the grey bars indicate reduction factors (RFs) compared to the UTC. Each dot indicates one biological replicate. The experiment was performed in three independent replicates.