Environmental factors on the SARS epidemic: air temperature, passage of time and multiplicative effect of hospital infection

Abstract

The study sought to identify factors involved in the emergence, prevention and elimination of severe acute respiratory syndrome (SARS) in Hong Kong during 11 March to 22 May 2003. A structured multiphase regression analysis was used to estimate the potential effects of weather, time and interaction effect of hospital infection. In days with a lower air temperature during the epidemic, the risk of increased daily incidence of SARS was 18.18-fold (95% confidence interval 5.6-58.8) higher than in days with a higher temperature. The total daily new cases might naturally decrease by an average of 2.8 patients for every 10 days during the epidemic. The multiplicative effect of infected hospital staff with patients in an intensive care unit (ICU) and the proportion of SARS patients in ICUs might respectively increase the risk of a larger SARS epidemic in the community. The provision of protective gear in hospitals was also a very important factor for the prevention of SARS infection. SARS transmission appeared to be dependent on seasonal temperature changes and the multiplicative effect of hospital infection. SARS also appeared to retreat naturally over time.

Influence of meteorological factors and air pollution on the outbreak of severe acute respiratory syndrome

“…This finding is confirmed by the experimental study, 25,26 but is not consistent with other reports. 3,27 Further investigations are necessary to verify this finding.…”

Preliminary evidence that higher temperatures are associated with lower incidence of COVID-19, for cases reported globally up to 29th February 2020

“…This would also have implications for the risk of spread in temperate regions in the southern hemisphere at the onset of winter, and for tropical regions where the vast majority of LMICs are located. Higher temperatures were shown to have a protective effect against transmission of severe acute respiratory syndrome (SARS) in 2002-2003 [5], possibly due to the decreased survival of the SARS-CoV on surfaces at higher temperatures [6]. Decreased aerosol spread at higher temperatures is another possible mechanism, as observed for human influenza viruses [7].…”

Climate Variability and Population Health in China: Updated Knowledge, Challenges and Opportunities

“…Temperature, relative humidity, and wind velocity were identified as the three key meteorological determinants affecting the transmission of SARS in Guangdong (Yuan et al, 2006). A negative association between temperature and daily number of cases was reported (Lin et al, 2006, Bi et al, 2007a) and a certain range of temperature (14-28°C) was identified suitable for development and transmission of the SARS virus . The relationship between weather variables and other respiratory diseases, including asthma, pneumonia, influenza, chronic bronchitis, measles, scarlet fever and pulmonary tuberculosis (TB), were also analysed in some areas in China.…”