Corona virus was first identified as the cause of the common cold in 1960. In one study carried out in Canada in 2001, more than 510 patients presented with flu-like symptoms. Virological analyses showed that 3.7% of these cases were positive for the HCoV-NL63 strain by polymerase chain reaction (PCR). Until 2002, the corona virus was considered a relatively simple, nonfatal virus; however, an outbreak in 2002–2003 in the Guangdong province in China, which resulted in spread to many other countries, encompassing Thailand, Vietnam, Taiwan, Hong Kong Singapore, and the United States of America, causes severe acute respiratory syndrome (SARS) and high mortality rates in over 1000 -1100 patients.

1. Corona Virus-Current Scenario-
Overview
BY DR.SREEREMYA

2. • INTRODUCTION
• Corona virus was first identified as the cause of the common cold in
1960. In one study carried out in Canada in 2001, more than 510
patients presented with flu-like symptoms. Virological analyses
showed that 3.7% of these cases were positive for the HCoV-NL63
strain by polymerase chain reaction (PCR). Until 2002, the corona
virus was considered a relatively simple, nonfatal virus; however, an
outbreak in 2002–2003 in the Guangdong province in China, which
resulted in spread to many other countries, encompassing Thailand,
Vietnam, Taiwan, Hong Kong Singapore, and the United States of
America, causes severe acute respiratory syndrome (SARS) and high
mortality rates in over 1000 -1100 patients.

3. • A total of 8097 individuals were infected with this virus,
resulting in 773 deaths; thus, in 2004, the Centers for
Disease Control and Prevention (CDC) and the World Health
Organization (WHO) declared a state of emergency . In
another report from Hong Kong, approximately 50 patients
presented with SARS, and more than 60% of these patients
were found positive for corona virus . The evolution of this
virus demonstrated that coronavirus is not quiet stable
virus and can adapt to become more virulent, even lethal,
to humans. Indeed, another outbreak in Saudi Arabia in the
year 2012 resulted in many deaths and spread first to other
countries in the Middle East and then worldwide, resulting
in the renewed interest in studies of this new form of
coronavirus(Reusken et al.,2014) .

4. • MICROBIOLOGY
• Corona virus is a single-stranded, enveloped RNA virus 1 that is of
shape spherical or pleomorphic in the shape with bear’s club-
shaped glycoprotein projections. There are subtypes of the corona
virus, alpha corona virus, beta corona virus, gamma corona virus,
and delta corona virus, and each subtype has many many
serotypes. For example, OC43-like and 229E–like have been shown
to mainly affect humans, whereas the other types mainly affect
animals . Corona viruses are transmitted via airborne zoonotic
droplets, and also viral replication occurs in the ciliated epithelium,
resulting in the cellular damage and inflammatory reactions at the
site of infection . In addition to humans, the corona viruses are also
found in bats, and also whales, pigs, birds, cats, dogs, and
mice(Perera et al.,2013) .

5. • Coronaviruses are allied with a wide variety of diseases of
man and other animals. The importance of this group of
viruses in both the medical and economic terms has
become aggrandizingly evident since the First International
Congress was held in Germany in the year 1980. The
application of modern molecular biology and immunology
has contributed to the new insights into understanding the
biology of the viruses and the pathogenesis of the diseases
they generate. The number of investigators has also
increased over the past few decades as evidenced by this
Congress which is thus far the largest and vastest ever
held(Nowotny et al.,2014). The significance and attraction
for veterinary, medical and basic scientists from the very

6. • Influence of relative humidity
• The relative humidity (RH) in the atmosphere plays a key role and
affects directly the amount of water on the metal surface. It was
assessed and reported that the atmospheric corrosion rate of
metals aggrandizes with the relative humidity during the
environmental atmosphere exposure. The presence of water is
quiet necessary for the atmospheric corrosion process and the
water layer acts as the medium for electrochemical reactions as
well as a solvent for atmospheric constituents. By the definition,
when relative humidity is 100%, the air is saturated with water. If
the water content in the air is aggrandized the air will be super-
saturated and the water condensation will occur on any surface
present, assuming that the surfaces are at the same temperature as
the air.

7. • The formation of the adsorbed layers of water on oxide covered and the
hydroxylated metal surfaces has been studied in several investigations.
Some researchers measured the water adsorption on the iron surface at
different temperatures and thus concluded that the amount of water on
the surface was only weakly dependent on the temperature. On the other
hand, few researchers showed that the amount of water on zinc decrease
3 times between 5 to80 °C. The presence of the hygroscopic salt particles
leads to absorption of water and formation of the bulk electrolyte layer on
the surface. This is usually accompanied with an abrupt aggrandize in the
corrosion rate of the metal (Syed, 2008). When the substance is dissolved
in a solvent, such as water, a decrease in the vapour pressure of the
solvent is mainly observed: Psolvent = asolventP0 solvent. The vapour
pressure of the solvent (Psolvent) is equal to vapour pressure of the pure
solvent (P0solvent) multiplied by activity of the solvent in the solution
(asolvent). The vapour pressure lowering has much significant
consequences for the formation of surface electrolyte layers on metal
surfaces.

9. •
• Journal of Research in Microbiology and
Immunology, Corona Virus-Current Scenario-
Overview, Dr.S.Sreeremya ,2020.Vol 2(1):1-18.