key: cord-0858364-6exmxw6r
authors: Kumar, Manish; Kuroda, Keisuke; Dhangar, Kiran
title: The most eagerly awaited summer of the Anthropocene: A perspective of SARS-CoV-2 decay and seasonal change
date: 2020-04-22
journal: Groundw Sustain Dev
DOI: 10.1016/j.gsd.2020.100400
sha: 3ccd1854942f5ee4133adf536e8962559831a58f
doc_id: 858364
cord_uid: 6exmxw6r

Abstract To date, the world perhaps has never waited for the summer so impatiently in the entire Anthropocene, owing to the debate whether increasing temperature and humidity will decrease the environmental endurance of SARS-CoV-2. We present the perspective on the seasonal change on SARS-CoV-2 decay and COVID-19 spread. Our arguments are based on: i) structural similarity of coronavirus with several enteric viruses, and its vulnerability; ii) reports related to decay of those similar transmissible gastroenteritis viruses (TGEV) like norovirus and iii) improvement in the human immunity during summer with respect to winter. We present reasons why we can be optimistic about the slowdown of corona in the upcoming summer.

To date, the world perhaps has never waited for the summer so impatiently in the 32 entire Anthropocene, owing to the debate whether increasing temperature and 33 humidity will decrease the environmental endurance of SARS-CoV-2. We present the 34 perspective on the seasonal change on SARS-CoV-2 decay and COVID-19 spread. Our 35 arguments are based on: i) structural similarity of coronavirus with several enteric 36 viruses, and its vulnerability; ii) reports related to decay of those similar transmissible 37 gastroenteritis viruses (TGEV) like norovirus and iii) improvement in the human 38 immunity during summer with respect to winter. We present reasons why we can be 39 optimistic about the slowdown of corona in the upcoming summer. 

Till date, the world perhaps has never waited for the summer so impatiently in the 45 entire Anthropocene, owing to the debate whether increasing temperature and 46 humidity decrease environmental endurance of SARS-CoV-2. It is firmly established that in the water environment, viruses become less prevalent in summer owing to high 48 temperature and solar radiation, leading to decline in flu patient numbers during 49 summer 1-5 . Thus, increase of both temperature and biological activities (both inside and 50 outside the human gut) in summer is likely to reduce COVID-19 prevalence.

As per the inactivation mechanism, environmental stressors disrupt the proteins and 53

lipids of viral envelope more easily than the genome and the protein capsid 6 . Thus, 54 under the similar adverse conditions, non-enveloped viruses, like norovirus, are 55 generally more resistant than enveloped viruses like SARS-CoV-2 (positive-stranded 56 RNA viruses with nucleocapsid and envelope) 2-3 . A decline in infections in summer has 57 been reported umpteen times for transmissible gastroenteritis viruses (TGEV) like 58 norovirus, which are antigenically and genetically related 1 to certain respiratory 59 coronavirus 1-3 . No wonder, current spread of COVID-19 along the equator and tropics 60 has been significantly less 7 . 61 62 Unlike TGEV, the main transmission pathway of SARS-CoV-2 is respiratory droplets, not 63 water 8 . Still we can remain optimistic about the endurance declination of COVID-19, as 64 human immunity increases in the summer owing to favourable seasonal variation in the 65 genetic activities, blood composition and adipose tissue 1-2,9-10 . Nevertheless, factors like 66 carrier prevalence, treatment efficacy of wastewater burden (virus source), and level of 67 spread, will remain critical variables [11] [12] [13] . Overall, at this juncture, we just intend to 68 point out that in this crisis we should not lose faith on scientific facts and principles 69 logics which strongly suggests COVID will not endure high temperature and humidity of 70 the (Indian/Tropical) summer. 

Emerging microbes & infections

SARS-CoV-2 106 titers in wastewater are higher than expected from clinically confirmed cases. medRxiv

Decline in infections in summer is reported for transmissible gastroenteritis viruses (TGEV)

Current spread of COVID-19 along the equator and tropics has been significantly less

SARS-CoV-2 is likely to have less endurance at high temperature and humidity

We declare to have no competing financial interest. We declare no conflict of interest.