The influence of risk perception on biosafety level-2 laboratory workers' hand-to-face contact behaviors

Pathogen transmission in the laboratory is thought to occur primarily through inhalation of infectious aerosols or by direct contact with mucous membranes on the face. While significant research has focused on controlling inhalation exposures, little has been written about hand contamination and subsequent hand-to-face contact (HFC) transmission. HFC may present a significant risk to workers in biosafety level-2 (BSL-2) laboratories where there is typically no barrier between the workers' hands and face. The purpose of this study was to measure the frequency and location of HFC among BSL-2 workers, and to identify psychosocial factors that influence the behavior. Research workers (N = 93) from 21 BSL-2 laboratories consented to participate in the study. Two study personnel measured workers' HFC behaviors by direct observation during activities related to cell culture maintenance, cell infection, virus harvesting, reagent and media preparation, and tissue processing. Following observations, a survey measuring 11 psychosocial predictors of HFC was administered to participants. Study personnel recorded 396 touches to the face over the course of the study (mean = 2.6 HFCs/hr). Of the 93 subjects, 67 (72%) touched their face at least once, ranging from 0.2-16.0 HFCs/hr. Among those who touched their face, contact with the nose was most common (44.9%), followed by contact with the forehead (36.9%), cheek/chin (12.5%), mouth (4.0%), and eye (1.7%). HFC rates were significantly different across laboratories F(20, 72) = 1.85, p = 0.03. Perceived severity of infection predicted lower rates of HFC (p = 0.03). For every one-point increase in the severity scale, workers had 0.41 fewer HFCs/hr (r = -.27, P < 0.05). This study suggests HFC is common among BSL-2 laboratory workers, but largely overlooked as a major route of exposure. Workers' risk perceptions had a modest impact on their HFC behaviors, but other factors not considered in this study, including social modeling and work intensity, may play a stronger role in predicting the behavior. Mucous membrane protection should be considered as part of the BSL-2 PPE ensemble to prevent HFC.