Survival of hepatitis A virus on human hands and its transfer on contact with animate and inanimate surfaces

Abstract

The survival of hepatitis A virus (HAV; strain HM175) on the hands of five volunteers was determined by depositing 10 ,ul of fecally suspended virus on each fingerpad and eluting the inoculum after 0, 20, 60, 120, 180, and 240 min. The amount of virus recovered from each fingerpad at 0 min was approximately 6.0 x 104 PFU. At the end of 4 h, 16 to 30%o of the initially recoverable virus remained detectable on the fingerpads. HAV inocula (10 ,ul; approximately 1.0 x 104 PFU) placed on fingerpads or 1-cm-diameter metal disks were used to determine virus transfer to clean surfaces upon a 10-s contact at a pressure of nearly 0.2 kg/cm2. When the inoculum was dried for 20 min, virus transfer from fingerpad to fingerpad, fingerpad to disk, and disk to fingerpad ranged from 2,667 to 3,484 PFU, while 0 to 50 PFU could be transferred after 4 h of drying. Elevation of the contact pressure alone from 0.2 to 1.0 kg/cm2 resulted in an approximately threefold increase in the amount of virus transferred. Incorporation of friction (10 half turns of the finger during 10 s of contact) with the low and high levels of pressure gave two-and threefold increases in the PFU of virus transferred, respectively. Pressure and friction were found to significantly affect HAV transfer (F = 33.98; P < 0.05), irrespective of the mode of transfer used. No statistically significant interaction was observed between mode of transfer and pressure or friction. The findings of this quantitative study suggest that human hands may play an important role in the direct as well as the indirect spread of HAV.

Virucidal activity of a new hand disinfectant with reduced ethanol content: comparison with other alcohol-based formulations

“…Many pathogenic viruses can remain viable on human hands for hours. 1,2 This gives hands the potential to spread such infectious agents directly or indirectly [3][4][5] in settings such as hospitals. 6,7 Recent studies with experimentally contaminated fingertips have further substantiated the potential of hands to spread viruses.…”

Environmentally Transmitted Pathogens

“…The survival of HAV on hands and its transfer to hands or inanimate surfaces were studied by Mbithi et al (1992). They found that approximately 20% of the initial HAV inoculated on hands remained infectious for at least 4 hours, and that HAV inoculated onto a stainless steel surface survived for 2 hours.…”

Achievement V – Methods for breaking the transmission of pathogens along the food chain

“…More recently, 1600 laboratory confirmed cases occurred in Czech Republic and 2800 in Latvia, during 2008 (Castkova & Benes, 2009;Perevoscikovs et al, 2009). HAV is also relatively resistant to many environmental conditions, physical and chemical agents (Mbithi, Springthorpe, Boulet, & Sattar, 1992), and may retain their infectivity for days to weeks in dried feces (McCaustland, Bond, Bradley, Ebert, & Maynard, 1982). Because of the absence of envelope the virus is very stable.…”