When the SARS outbreak happened in 2002-2003, SARS-CoV spread to approximately 30 countries only. However, the current outbreak of COVID-19 by SARS-CoV-2 has spread to 176 countries or territories which suggests the enhanced ability of viruses to be aerosolized. Environmental factors such as atmospheric temperature also can modulate the survival and spread of virus aerosols ―it is known that survival of influenza viral aerosols is reduced at higher temperature―.
COVID-19 primary mode of transmission is via respiratory droplets from coughs and sneezes.
Besides, the virus can remain viable for up to 3 days on plastic and stainless steel or in aerosols for upto 3 hours and is relatively more stable than the known human coronaviruses. Moreover, it is stable in faeces at room temperature for at least 1-2 days and can be stable in infected patients for up to 4 days. Nevertheless, heat at 56 degree Celsius kills the SARS coronavirus at around 10,000 units per 15 minutes. Thus, temperature could be an important factor in survival of COVID-19 virus and focus on understanding the relationship between temperature and COVID-19 transmission from the data available between January-March 2020.
In this way, authors analyzed data from 01/22/2020-03/16/2020 for COVID-19 confirmed positive, death and recovered cases and identified an increasing number of cases being recovered (~83%) especially in China, while Iran and Italy showed a slow recovery with 30% and 37% recovery rates respectively. China reported the highest percent deaths (~3.96%) in the world.
Although a strong correlation between cases confirmed with recovered, and cases confirmed with deaths was observed, changes in temperature showed no significant correlation with cases transmitted, deaths or recovered for the period 01/22/2020-03/16/2020. However, an interesting finding was observed wherein a drop in correlation was found between cases confirmed with recovered in Australia (average temperature ~16°C) and cases confirmed with deaths in Canada (average temperature ~-2°C).
Link to the paper: https://doi.org/10.1101/2020.03.29.20044461
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.