Role of Environmental Temperature on the Attack rate and Case fatality rate of Coronavirus Disease 2019 (COVID-19) Pandemic

ABSTRACT

SARS-CoV-2 is a zoonotic Betacoronavirus causing the devastating COVID-19 pandemic. More than twelve million COVID-19 cases and 500 thousand fatalities have been reported in 216 countries. Although SARS-CoV-2 originated in China, comparatively fewer people have been affected in other Asian countries than in Europe and the USA. This study examined the hypothesis that lower temperature may increase the spread of SARS-CoV-2 by comparing attack rate and case fatality rate (until 21 March 2020) to mean temperature in January–February 2020. The attack rate was highest in Luxembourg followed by Italy and Switzerland. There was a significant (p = 0.02) correlation between decreased attack rate and increased environmental temperature. The case fatality rate was highest in Italy followed by Iran and Spain. There was no significant correlation between the case fatality rate and temperature. This study indicates that lower temperature may increase SARS-CoV-2 transmission (measured as an increased attack rate), but there is no evidence that temperature affects the severity of the disease (measured as case fatality rate). However, there are clearly other factors that affect the transmission of SARS-CoV-2, and many of these may be sensitive to interventions, e.g. through increased public awareness and public health response.

KEYWORDS:

• SARS-CoV-2
• coronaviruses
• COVID-19
• environmental temperature
• pandemic
• attack rate
• case fatality rate

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Swedish Research Council (Vetenskapsrådet) [2016-02606].

Notes on contributors

Mohammad M. Hassan

Mohammad M. Hassan, PhD is a professor and epidemiologist, with research interests in Virology, Immunology, Microbiology, Therapeutic interventions, Epidemiology, Ecology of infectious diseases, Emerging zoonotic pathogens and One Health.

Mohamed E. El Zowalaty

Mohamed Ezzat El Zowalaty, PhD, is an associate professor affiliated to Zoonosis Science Center, Uppsala University, Sweden, an adjunct faculty at the Department of Clinical Sciences, College of Medicine, University of Sharjah, UAE, and an International Research Collaborator at Duke One Health, Duke University, North Carolina, USA. Dr. ME El Zowalaty is a virologist and microbiologist researching emerging infectious diseases, zoonotic viruses and bacteria, antimicrobial resistance at animal-human-environmental interface, and One Health.

Shahneaz A. Khan

Shahneaz A. Khan, PhD is an associate Professor and molecular biologists, with  research interests in Biochemistry, Molecular biology, Immunology, Microbiology,  Molecular epidemiology, and Emerging zoonotic pathogens.

Ariful Islam

Ariful Islam , DVM is a veterinary epidemiologist and disease ecologist, working as a senior scientist in Bangladesh field program in EcoHealth Alliance. His research focuses on understanding zoonotic disease emergence and the ecology and evolution of bats and their associated viruses such as Nipah and Ebola viruses, along with SARS, Midde East Respiratory Syndrome (MERS), and other pathogens at the animal, human, and ecosystem.

Md. Raihan K. Nayem

Md. Raihan K. Nayem,   is a postgraduate student at Faculty of Veterinary Medicine; Chattogram Veterinary and Animal Sciences University, Bangladesh, working on infectious disease epidemiology, AMR and One Health.

Josef D. Järhult

Josef Järhult, MD, PhD, is a Consultant, Associate Professor, and Senior Lecturer in Infectious Diseases at Uppsala University/University Hospital. His main research interests are zoonotic diseases and antimicrobial drug resistance in the human-animal-environment interface.