1- Introduction
Coronaviruses are responsible for respiratory tract infections (RTIs).
In the December of 2019, cases of pneumonia with unknown origin were
reported in Wuhan, China 1-6. The disease started
spreading in the China first and then around world. Until March 20,
2020, this virus resulted in 234’073 confirmed cases and 9’840 deaths
worldwide; the statistics are 18’407 confirmed cases and 1’284 deaths in
Iran 7. This is while the number of studies on this
novel coronavirus is growing all around the world8-11.
Coronaviruses can infect the respiratory and intestinal epithelial cells
and generates a wide range of the clinical presentations in humans12. Coronaviruses are classified in Nidoviralesorder and Cornidoviridae suborder. Orthocoronavirinaesubfamily in Coronaviridae family is divided into four genera.
Severe acute respiratory syndrome-related coronavirus type 2
(SARS-CoV-2), and other SARS-like coronaviruses are classified inSarbecovirs subgenus in Betacoronaviruses genera10,13,14. Endemic coronaviruses, such as HCoV-NL63,
HCoV-229E, HCoV-OC43, and HKU1 can induce upper respiratory tract
infections (UTRI) with mild respiratory manifestation in immune
competent adults while infection with the epidemic coronaviruses, like
SARS-CoV and Middle East respiratory syndrome-related coronavirus
(MERS-CoV), could lead to the lower respiratory tract infections (LRTI)
as well as serious respiratory manifestations 15,16.
In endemic areas for coronaviruses, it is suggested that the HCoV-229E
and HCoV-OC43 are responsible for 15-29% of the common cold cases,
while during the epidemic coronaviruses, there is another scenario at
work 17. The SARS-CoV epidemic started from Guangdong,
China, in 2002-2003 and resulted in 8’089 infected cases and a 9.6%
mortality rate 7. Also, the MERS-CoV in 2012 firstly
started in Middle East and infected 2’465 cases demonstrating a high
mortality 18,19. All the mentioned pandemics as well
as the current pandemic condition with SARS-CoV-2 reflect the importance
of following coronaviruses in human population. The aim of the current
study was to investigate and track the SARS-CoV-2 in Iranian Coronavirus
Disease 2019 (COVID-19) patients using molecular and phylogenetic
methods.