Coronavirus Omicron variant

The Omicron variant of COVID-19 has been called a variant of concern by WHO. Omicron is spreading faster than any previous variant, with a doubling time of 2-3 days.

The Omicron variant was first identified in Botswana and South Africa in November 2021 —although later reports showed earlier cases in the Netherlands. By late December, Omicron was the predominant strain in the U.S.

The Omicron variant causes more infections and spreads faster than the original SARS-CoV-2 strain of the virus that causes COVID-19.

The original Omicron strain has a relatively mild version of the virus, causing less severe disease and death than Delta, which preceded it. There is a reduced risk of hospitalization for Omicron compared to the Delta variant. But WHO warns that it should not be dismissed as “mild”. The analysis shows 4.4% of Omicron cases were long COVID, compared to 10.8% of Delta cases.

The BA.4 and BA.5 subvariants are spiking globally because they can spread faster than other circulating variants — mostly BA.2, which caused a surge in cases at the beginning of the year.
Coronavirus Omicron variant

Coronavirus disease

Coronaviruses are a group of viruses belonging to the family of Coronaviridae, which infect both animals and humans. Coronavirus (COVID-19) is an illness caused by a virus that can spread from person to person. The virus that causes COVID-19 is a new coronavirus that has spread throughout the world.

This pandemic (caused by the virus SARS-CoV-2) is the greatest threat not only to global health but also has far-reaching socio-economic impact on nearly all the countries in the world.

The first cases of coronaviruses in human found in 1965 by Tyrrell and Bynoe. They observed that they could passage a virus named B814. It was observed in human embryonic tracheal organ cultures obtained from the respiratory tract of an adult with a common cold symptom. The first 4 cases of COVID-19 were first reported on the 29th December 2019, all linked to Huanan (Southern China) seafood wholesale market. Many of the initial patients were either stall owners, market employees, or regular visitors to this market. Environmental samples taken from this market in December 2019 tested positive for SARS-CoV-2, further suggesting that the market in Wuhan City was the source of this outbreak or played a role in the initial amplification of the outbreak.

Another coronavirus, SARS-CoV-1, the cause of the Severe Acute Respiratory Syndrome (SARS) outbreak in 2003, was also closely related to other coronaviruses isolated from bats. These close genetic relations of SARS-CoV-1, SARSCoV-2 and other coronaviruses, suggest that they all have their ecological origin in bat populations.

Signs and symptoms include respiratory symptoms and include fever, cough and shortness of breath. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome and sometimes death.

Standard recommendations to prevent the spread of COVID-19 include frequent cleaning of hands using alcohol-based hand rub or soap and water; covering the nose and mouth with a flexed elbow or disposable tissue when coughing and sneezing; and avoiding close contact with anyone that has a fever and cough.
Coronavirus disease

Middle East respiratory syndrome (MERS)

Coronavirus are ubiquitous worldwide and were associated with relatively mild respiratory disease up to the emergence of the SARS-CoV in China in 2002.

Nearly 10 years later, another virulent coronavirus, MERS-CoV emerged. The index case of MERS-CoV occurred in Saudi Arabia in June 2012.

79% of the initial 40 cases of Middle East respiratory syndrome Coronavirus (MERS-CoV) infection were male.

Underlying chronic medical conditions are common, and most patients present with fever, cough, and shortness of breath. Renal failure, as well as pericarditis and adult respiratory distress syndrome have been part of the reported clinical picture.

Diarrhea, vomiting, myalgia, and elevated lactase dehydrogenase/aspartate aminotransferase are common.

Coronavirus are enveloped, single-stranded, positive-sense RNA viruses with relatively large genome. The spike(s) glycoprotein protrudes from the virions, giving the virus its characteristic crown-like.

The main infection control measures to prevent the transmission of MERS-CoV include contact isolation, standard precautions, droplet isolation and airborne infection isolation precautions especially when healthcare workers perform aerosol generating procedures.
Middle East respiratory syndrome (MERS)

Coronavirus

Coronaviruses comprise a large family of viruses infecting a broad range of vertebras, from a mammalian to avian species.

The viruses were initially named based on the disease syndrome they were isolated from and subsequently shown to cause following experimental inoculation. The word ‘coronavirus’ derives from the crown-like appearance of this type of virus in images generated by electron microscopes.

Coronaviruses are currently placed in the family Coronaviridae and together with the family Arteriviridae, comprise a new order: Nidovirales.

Coronaviruses are enveloped, positive-stranded RNA viruses that can infect a variety of vertebrates and are mainly associated with respiratory and enteric disease.

Coronaviruses are associated mainly with respiratory, enteric, hepatic and central nervous system disease

In humans, coronaviruses infections manifest usually as mild respiratory tract disease and only occasionally more severe symptoms, particularly on elderly or immune compromised individuals, are observed.

One type coronavirus is Middle East Respiratory Syndrome. It is a viral respiratory illness and it was first reported in Saudi Arabia in June 2012.

The virus which caused Middle East Respiratory Syndrome is caused by a beta coronaviruses. Most people who suffer from the MERS-CoV (Middle East Respiratory Syndrome Coronavirus) infection will develop severe acute respiratory illnesses, the symptoms of which include fever, coughing and shortness of breath.

MERS-CoV is closely related to SARS coronavirus, which was originated In China. It claimed 800 lives worldwide from 2002 to 2003.
Coronavirus

SARS

SARS is one of very dangerous disease of the twenty first century, which include avian flu and Ebola.

SARS or Severe acute respiratory syndrome is a respiratory illness that has been reported in Asia, North America and Europe and is caused by a special kind of virus called a coronavirus named SARS-Cov. It is very infectious which means it is easily spread from one person to another.

The virus remains active and is able to cease infection in both urine and feces for 24 to 48 hours. In the first week, the disease produce fever but few other symptoms. In the second week, pneumonia spread though the lungs.

In the third week, destruction of blood vessels occurred, which was fatal in many cases.

The overall mortality was 3%-6% of people infected, but mortality went up to 40% - 50% in certain area, when people older than 60 were infected.

The symptoms of SARS include high fever, headache, discomfort, body aches, dry cough and the development of pneumonia. SARS is spread by close contact involving respiratory droplets.

The first case of SARS was reported in Asia in February, 2003. In a few months, this disease spread in Europe, South and North America.

SARS