Rapid Awareness and Transmission of Severe Acute Respiratory Syndrome in Hanoi French Hospital, Vietnam

Abstract

A case-control study was conducted to examine the relationship between severe acute respiratory syndrome (SARS) and the time-dependent precautionary behaviors taken during an outbreak of SARS in Hanoi French Hospital (HFH), Vietnam. Masks (odds ratio [OR] = 0.3; 95% confidence interval [CI]: 0.1, 0.7) and gowns (OR = 0.2; 95% CI: 0.0, 0.8) appeared to prevent SARS transmission. The proportion of doctors and nurses who undertook each measure significantly improved (chi(2) = 9.8551, P = 0.043) after the onset of secondary cases. The impact of individual behaviors on an outbreak was investigated through mathematical approaches. The reproduction number decreased from 4.1 to 0.7 after notification. The basic reproduction number was estimated, and the use of masks alone was shown to be insufficient in containing an epidemic. Intuitive results obtained by means of stochastic individual-based simulations showed that rapid improvements in behavior and isolation would increase the probability of extinction.

The impact of illness and the impact of school closure on social contact patterns.

“…Two trials reported that repeated handwashing significantly reduced the incidence of colds by as much as 20% (Carabin 1999;Ladegaard 1999). One study found that in households in which interventions (handwashing with or without wearing a facemask) were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR-confirmed infection was reduced, an effect attributable to reductions in infection among participants using face masks plus hand hygiene (adjusted odds ratio, 0.33 (95% CI 0.13 to 0.87)) (Cowling 2009 (Nishiura 2005;Seto 2003). Another study from Hong Kong and Guangzhou hospitals wards reported that a minimum distance between beds of less than one meter was a risk factor for transmission (Yu 2007).…”

“…We classified four of the six case-control studies as having medium risk of bias (Lau 2004a;Seto 2003;Yin 2004) and two as at low risk of bias (Nishiura 2005;Teleman 2004), mostly because of inconsistencies in the text and lack of adequate description of controls.…”

Inactivation of influenza A viruses in the environment and modes of transmission: A critical review

“…Wearing simple face masks significantly reduced the risk of infection from SARS-CoV. 139,140 N95 masks are even more effective. 141 If these findings are relevant for influenza is unknown.…”

Association of human leukocyte antigen class II alleles with severe acute respiratory syndrome in the Vietnamese population

“…In the Vietnamese population, the frequency of HLA-DRB1*1202 mainly consisting of DRB1*12 is notably higher than in the Southern Chinese population [13] and therefore the HLA association with SARS might have been more obvious even in the smaller sample study like ours. In particular, our advantage is that the majority of cases and controls were exposed to SARS-CoV during a rather short period inside one hospital through a single spread from Hong Kong [14]. Such homogeneity of environmental and pathogenic factors might have provided a favorable situation to identify host genetic factors without detailed consideration of unknown confounders.…”