Temporal-Spatial Analysis of Severe Acute Respiratory Syndrome among Hospital Inpatients

Abstract

The temporal-spatial spread of SARS in the ward was consistent with airborne transmission, as modeled by use of computational fluid dynamics. Infected health care workers likely acted as secondary sources in the latter phase of the outbreak.

SARS: clinical presentation, transmission, pathogenesis and treatment options

“…For instances, air samples obtained from a room occupied by a SARS patient, and swabs taken from frequently touched surfaces in rooms and at a nurse station, were positive for SARS-CoV by PCR [60]. The temporal-spatial spread of SARS among patients in a medical ward where there was a SARS outbreak, at the Prince of Wales Hospital in Hong Kong, was also consistent with airborne transmission [61].…”

“…The R 0 for SARS-CoV has been estimated to be between 2 and 3 [62,63]. These two analyses excluded superspreading events in their final value of R 0 , because the transmission route for these events were almost certainly atypical of the disease in most cases and may have been assisted in some way [57,61]. This value of R 0 puts SARS-CoV quite low down on the scale of transmissibility (Table 1) [64][65][66].…”

The Influence of Ward Ventilation on Hospital Cross Infection by Varying the Location of Supply and Exhaust Air Diffuser Using CFD

“…The Prince of Wales Hospital in Hong Kong, shown in Fig.1., was selected for our infection risk case analysis because the first patient in Hong Kong infected with SARS was hospitalized there, and the process of how the infection spread to nearby patients is well documented (Tomlinson and Cockram, 2003;Lee et al, 2003;Wong et al, 2003;Yu et al, 2005). This paper will analyze the infection path based on the hospital's reports and then compare that with the infection risk predicted by tracer gas density.…”

“…However, as can be seen in Table 3., there was a clear difference in the infection rate by location. Furthermore, according to the study by Yu et al (2005), doctors and nurses had specific locations that they were assigned to within the building and so they had almost no contact with patients in other parts of the hospital. In consideration of these facts, although we cannot rule out the possibility that the infection was passed through hospital staff such as doctors, nurses, or medical students, it is considered to be of low probability.…”

“…The second possibility is that the virus spreading through the air passed the infection from person to person. The results of a study by Yu et al (2005) show that the farther away from the index patient a person was, the lower the probability of SARS infection became, and so the spread of the SARS pathogen was deduced to have occurred through the movement of air currents through the ventilation and air conditioning system. Fig.2.…”