Prevalence of Human Parainfluenza Viruses and Noroviruses Genomes on Office Fomites

The aim of this study was to evaluate the potential role of office fomites in respiratory (human parainfluenza virus 1-HPIV1, human parainfluenza virus 3-HPIV3) and enteric (norovirus GI-NoV GI, norovirus GII-NoV GII) viruses transmission by assessing the occurrence of these viruses on surfaces in office buildings. Between 2016 and 2017, a total of 130 surfaces from open-space and non-open-space rooms in office buildings located in one city were evaluated for HPIV1, HPIV3, NoV GI, and NoV GII viral RNA presence. Detection of viruses was performed by RT-qPCR method. Study revealed 27 positive samples, among them 59.3% were HPIV3-positive, 25.9% HPIV1-positive, and 14.8% NoV GII-positive. All tested surfaces were NoV GI-negative. Statistical analysis of obtained data showed that the surfaces of office equipment including computer keyboards and mice, telephones, and desktops were significantly more contaminated with respiratory viruses than the surfaces of building equipment elements such as door handles, light switches, or ventilation tracts (chi (2) p = 0.006; Fisher's Exact p = 0.004). All examined surfaces were significantly more contaminated with HPIVs than NoVs (chi (2) p = 0.002; Fisher's Exact p = 0.003). Office fomites in open-space rooms were more often contaminated with HPIVs than with NoVs (chi (2) p = 0.016; Fisher's Exact p = 0.013). The highest average concentration of HPIVs RNA copies was observed on telephones (1.66 x 10(2) copies/100 cm(2)), while NoVs on the light switches (1.40 x 10(2) copies/100 cm(2)). However, the Kruskal-Wallis test did not show statistically significant differences in concentration levels of viral RNA copies on surfaces between the all tested samples. This study unequivocally showed that individuals in office environment may have contact with both respiratory and enteric viral particles present on frequently touched surfaces.