Sattar, S. A.,Ansari, Shamim Alam.2009-03-202009-03-2019911991Source: Dissertation Abstracts International, Volume: 54-01, Section: B, page: 0061.9780315750524http://hdl.handle.net/10393/5906http://dx.doi.org/10.20381/ruor-10990In this study, a simple protocol was developed to test the survival of a human rotavirus (HRV), rhinovirus type 14 (RV-14), and parainfluenzavirus type 3 (HPIV-3) as well as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) on human hands. HPIV-3 lost nearly all of its infectivity within the first 60 minutes on the fingerpads. In contrast to this, nearly 16% of infectious RV-14 could be recovered even after 3 hours. The poor survival of HPIV-3 on human hands prompted us to investigate its survival on stainless steel disks (1 cm in diam.) under ambient conditions. The ability of the two respiratory viruses to survive well on non-porous inanimate surfaces indicates that, once contaminated, these surfaces may act as a potential virus source. To study the patterns of virus transfer, the following three experimental models were developed and tested: finger-to-finger, finger-to-disk and disk-to-finger. The results suggest that human hands and environmental surfaces, singly or in combination, have the potential to spread rotaviral infections, particularly in institutional settings. The comparatively rapid loss of HPIV-3 infectivity on hands may reduce their potential as vehicles for transmission. These results also suggest a role for environmental surfaces in the contamination of hands with respiratory viruses. We compared the efficiency of paper-, cloth- and an electric blow dryer in further reducing the level of infectious rotavirus and E. coli remaining on fingerpads washed with either 70% isopropanol, Savlon in water (1:200), an unmedicated liquid soap, or tap water alone. Irrespective of the hand-washing agent used, warm air drying produced the greatest and the cloth the smallest reduction in the numbers of both test organisms. These findings indicate the importance of the proper drying of washed hands, particularly when less effective hand-washing agents are used. The results of this study show that HRV, RV-14 and S. aureus can survive on human hands long enough to permit their spread through hands. In contrast to this, parainfluenzaviruses and E. coli appeared to be limited in their capacity to survive on hands. The differences found in the efficacy of commonly used hand-washing agents against HRV and the bacteria tested point to the importance of testing such products by proper in vivo protocols using representative viruses. (Abstract shortened by UMI.)223 p.Biology, Microbiology.Thesis