Vomiting Larry: a simulated vomiting system for assessing environmental contamination from projectile vomiting related to norovirus infection

Abstract

Infectious diseases such as norovirus can induce emesis (vomiting), which can be of a projectile nature. Although studies have been carried out on transmission, prevalence and decontamination of such micro-organisms within various environments, little is known about the extent to which the surrounding environment is contaminated when an individual vomits. This is an important consideration for infection control purposes. The aim of this study was to develop a simulated vomiting system (Vomiting Larry) to be used for assessing the extent to which projected fluid can contaminate the environment. Vomiting Larry was set up within a Controlled Atmosphere Chamber (CAC) facility at the Health and Safety Laboratory (HSL). Simulated vomiting was undertaken using water as a vomitus substitute containing a fluorescent marker enabling small splashes, ordinarily missed, to be visualised using UV lighting. Experiments revealed that splashes and droplets produced during an episode of projectile vomiting can travel great distances (>3 m forward spread and 2.6 m lateral spread). The research highlighted that small droplets can be hard to see and therefore cleaning all contaminated surfaces is difficult to achieve. Evidence from this study suggests that areas of at least 7.8 m2 should be decontaminated following an episode of projectile vomiting.

Prevalence of human norovirus and <em>Clostridium difficile</em> coinfections in adult hospitalized patients

“…Vomiting is a well-characterized symptom during HuNoV infection. 32 However, vomiting is not a feature of CDI and no association with vomiting was seen in C. difficile -infected patients in our study. Interestingly, no association between vomiting and coinfection was observed.…”

Vomiting as a Symptom and Transmission Risk in Norovirus Illness: Evidence from Human Challenge Studies

“…Simulated vomiting events have shown that a single vomiting event can contaminate a large area (7.8 m 2 ) and produce potentially infectious aerosols [ 29 , 30 ]. A recent study found that norovirus can survive in simulated emesis in suspension and on surfaces for up to 42 days [ 31 ].…”

Airborne or Fomite Transmission for Norovirus? A Case Study Revisited

“…Several studies [ 20 , 21 , 22 , 23 , 24 ] have assumed that the index patients’ vomiting episodes provided sufficient evidence of airborne transmission. Nevertheless, as Booth suggested experimentally [ 12 ], vomiting may contaminate a wide range of surfaces that are often difficult to clean sufficiently, thus increasing the likelihood of further transmission of surface contamination. Moreover, Marks et al [ 22 ] supported the possibility of airborne transmission because the time from exposure to illness decreased as the number of viral sources increased.…”

“…Although no evidence suggests that this virus is transmitted via the airborne route [ 9 ], the importance of this route has been suggested by several published reports [ 10 ]. In terms of biological plausibility, the potential of airborne transmission of norovirus exists [ 11 ], based on the findings of virus-containing aerosol droplets produced by vomiting [ 12 ] and toilet flushing [ 13 ], the detection of dispersed norovirus in the air [ 14 , 15 , 16 ], and the successful infection of mice via intranasal instillation [ 17 ]. In terms of outbreak investigations, a few studies [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ] have claimed to provide evidence for the airborne transmission.…”