What is SARS Disease? Causes Symptoms and Treatment

What is SARS disease

SARS Disease Causes Symptoms and Treatment


What is SARS disease?

Severe acute respiratory syndrome (SARS) is an emerging zoonotic viral disease caused by infection with SARS-associated coronavirus (SARS-CoV), a positive single-stranded RNA virus belonging to a family of enveloped viruses that belong to the order Nidovirales in the subfamily Coronavirinae.

When SARS is present, symptoms are usually expressed in early stages, early symptoms include severe breathing difficulty (shortness of breath or dyspnea), pleural chest pain, malaise, dry, persistent cough, profuse sweating, fever over 100.4 F (38 C), shaking chills, confusion especially in adults age 65 and older, aching muscles and joints, diarrhea, muscle stiffness, loss of appetite, skin rash, headache, and other flu-like symptoms, like runny nose, nasal congestion, wheezing, sore throat, night sweats, etc.

If left untreated, SARS can lead to death. Symptoms tend to show up 2 to 14 days after infection.

When was SARS first discovered and what is the history of the SARS virus?

SARS (severe acute respiratory syndrome) was first identified in late 2002 in Guangdong Province, southern China. By February 2003, SARS had spread to Hong Kong, Guangxi, Guizhou, Hubei, Shaanxi, Yunnan, Shandong and other provinces across China. Within a few months, the infection spread rapidly through an unsuspecting population to other 28 countries including the USA and became pandemic. By July 2003, SARS took the lives of nearly 800 people in 29 countries. Moreover, more than 8000 cases of infection were reported in 29 countries during the 2003 SARS virus epidemic

The 2003 pandemic SARS outbreak lasted approximately six months as the disease spread to more than 29 countries in Europe, South America, North America, and Asia before it was stopped in July 2003.

The first case of atypical pneumonia occurred in Foshan City, Guangdong Province, China, on November 16th, 2002. However, the pathogenic agent was not identified until February 2003.

The first case of SARS infection involved a farmer from Foshan County.

Is SARS caused by a virus or bacteria?

Severe acute respiratory syndrome (SARS), also known as, atypical pneumonia, is a viral respiratory illness caused by a SARS-associated coronavirus (SARS-CoV).

Is the SARS virus DNA or RNA?

The SARS-associated coronavirus (SARS-CoV) is a positive single-stranded RNA virus belonging to the subfamily Coronavirinae

The Coronaviruses (CoVs) are a family of medium-sized, enveloped, positive-sense single stranded RNA viruses known to cause disease in birds, pigs, and humans.

The Coronaviridae family contains two subfamilies, Coronavirinae and Torovirinae

The genome of SARS coronavirus is about 29.7kb, making it one of the largest among RNA viruses. The SARS virus has 14 known proteins and 13 known genes.

Is SARS an emerging disease?

In February 2003, the outbreak of severe acute respiratory syndrome (SARS) took the lives of nearly 800 people in Asia. Building on these facts and observations, SARS remains an emerging pandemic threat to global health, especially with the current size, mobility, and international migration of human populations

Containing a zoonosis is a necessity in order to prevent the emergence of another SARS outbreak

What is an example of an emerging disease?

SARS, HIV/AIDS, influenza, West Nile fever, Lyme disease, drug resistant tuberculosis, MRSA (methicillin-resistant staphylococcus aureus), and swine flu (the 2009 pandemic H1N1 influenza) are only a few of many examples of emerging infectious diseases, each of these diseases has caused global economic and social impact related to unexpected illnesses and deaths

Is SARS an epidemic or pandemic?

The 2003 SARS virus epidemic in Asia took the lives of nearly 800 people.

A pandemic is a life-threatening global disease outbreak. The influenza pandemic of 1918-1919 (killing between 20 and 40 million people), plague pandemic in the 14th century (resulting in the deaths of an estimated 75 to 200 million people) and HIV/AIDS are examples of three of the most destructive global pandemics in history

The 2014 Ebola virus epidemic in Sierra Leone, Guinea, Liberia, Nigeria, and Mali (west Africa) took the lives of nearly 11,325 people. Moreover, more than 28,640 cases of EVD were reported during the Ebola outbreak in 2013–2016.

Eleven people were treated for travel-associated cases of EVD in the United States during the 2013-2016 epidemic.

Is SARS a zoonotic disease?

SARS is a zoonotic disease. The pandemic-causing SARS-CoV virus is believed to have originated from Chinese horseshoe bats (in the genus Rhinolophus). The virus was then transmitted to civets in the animal market. However, civets are unlikely the natural reservoir of SARS-CoV, as studies did not find SARS-CoV in wild-caught or farmed civets. Scientists believe that unhealthy commodities, health services, working conditions and other trading activities or other animal(s) were involved in SARS-CoV transmission in the animal market

Chinese horseshoe bats are recognized as the natural reservoirs of SARS-CoV viruses.

The two emerging coronaviruses that caused the outbreaks of SARS and MERS-CoV (Middle East respiratory syndrome coronavirus) in the 21st century were discovered in various species of chinese horseshoe bats (in the genus Rhinolophus). In fact, scientists believe that SARS-CoV virus evolved and adapted with accumulating mutations in chinese horseshoe bats

Before the SARS outbreak of 2003, coronaviruses rarely caused deadly outbreaks in humans; however, they had been known to cause severe diseases in animals.

Where did the SARS virus come from?

The SARS coronavirus (SARS-CoV) originated from animals; however, the first case of animal to human transmission occurred somewhere in the Guangdong province of China in late 2002.

How many people have been killed by SARS?

During the first outbreak of SARS (the 2002–04 outbreak), the SARS-CoV virus killed almost 800 people in Asia. According to the World Health Organization (WHO), almost 8,100 people worldwide became sick with SARS that was accompanied by either respiratory distress syndrome or pneumonia.

A total of 8099 people became sick with SARS during the 2003 outbreak (between November 2002 and July 2003)

Is SARS contagious and how?

A person with SARS is always contagious. SARS is caused by direct contact with an infected person or virus carrier.

How do you get SARS virus?

The source of infection:

In most cases, SARS is caught by direct contact with an infected animal or person

How can SARS be transmitted to humans?


In most cases, the virus spreads by respiration of contaminated airborne droplets when an infected person coughs or sneezes on you, or by close person-to-person contact with infected individuals, such as shaking hands, sexual contact, touching, kissing, contact with oral secretions, hugging, and poor personal hygiene (sharing equipment and utensils). Moreover, SARS-CoV virus can also be transmitted through direct or indirect contact with infected animals in markets, homes, or restaurants

Less commonly, SARS-CoV virus can spread by touching an object or surface contaminated with infectious droplets

Is SARS an airborne disease?

In most cases, SARS-CoV virus is transmitted by direct contact with infectious material, including dispersal of large respiratory droplets from coughing or sneezing.

SARS can be transmitted through the airborne route. Droplet transmission occurs by respiration of contaminated airborne droplets.

The pandemic-causing SARS-CoV was acquired through direct or indirect contact with infected civets in restaurants, or in wet markets where live animals were kept in Guangdong (Chinese: 广东). SARS originated from traded civets.

How long does it take for a person to get infected with SARS-CoV?

The incubation period for SARS ranges from 2 to 7 days. However, on rare occasions, the incubation period can last up to 14 days. SARS is characterized by an acute onset, symptoms usually develop suddenly and progresses quickly (acute disease).

The incubation period is the time between exposure to SARS-CoV and the onset of symptoms.

Is a person with SARS contagious before symptoms appear?

People who are infected with SARS-CoV can transmit the infection to other people beginning one day before they develop symptoms and realize that they are sick. They remain contagious thereafter. In fact, the closer a person with SARS is to death, the more infectious he is.

Is SARS virus fatal and how long does it take to die from untreated SARS?

Untreated cases of SARS carry a relatively high mortality rate. About 50% of untreated cases die of the disease. The overall median time from illness onset to death is 35 days

What happens when alveoli are damaged?

SARS is caused by a virus that damages the alveoli (air sacs of the lungs) leading to shortness of breath (dyspnea) and hypoxemia (lack of oxygen in the blood). This lack of oxygen in the blood causes hypoxia

The oxygen diffuses through the walls of the alveoli into the blood

What part of the body is affected by SARS?

The pathogenesis of SARS is complex, with multiple factors leading to severe acute lung injury and dissemination of the virus to other organs.

The SARS coronavirus (SARS-CoV) targets the airway epithelial cells (the respiratory epithelium), resulting in diffuse alveolar damage and alveolar collapse.

What does SARS do to the lungs and what causes the alveoli to collapse?

Without prompt antiviral treatment, the alveoli and lung tissue become inflamed, damaged and scarred. All of these changes can lead to alveolar damage, instability and collapse. With this damage, it becomes more difficult for the transfer of oxygen (o2) and carbon dioxide (co2) to take place in the alveolar sacs. This also causes the bronchioles to collapse and cause a blockage or obstruction, which traps air inside the lungs, leading to respiratory distress syndrome and pulmonary atelectasis

Patients infected with SARS usually develop acute lung injury (ALI), atypical pneumonia, acute respiratory distress syndrome (ARDS), and pulmonary fibrosis. Death may occur within a few days due to hypoxemic respiratory failure and other severe complications, such as heart and liver failure. The average time between admission to the hospital and death is 35 days

Dissemination of the SARS virus in the bloodstream to other organs results in multiple organ involvement and failure (MOF)

What is the mortality rate of SARS?

The overall fatality rate associated with SARS ranges from 14% among patients with atypical pneumonia only to 50% among patients aged 60‐64 yr, particularly among elderly patients with simultaneous impaired consciousness, atypical pneumonia, acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and pulmonary fibrosis.

During the Toronto SARS outbreak, about 10% of patients infected with SARS died from the disease.

is SARS and bird flu the same?

No, SARS and bird flu are not the same. Avian influenza or bird flu is a highly contagious viral illness caused by H5N1 virus, a subtype of the influenza A virus, that spreads to humans by birds, particularly ducks, geese and chickens. Bird flu is often fatal for humans. SARS is a viral disease caused by a coronavirus that originated from chinese horseshoe bats


How does SARS affect the human body?

Severe acute respiratory syndrome (SARS) affects mainly the human respiratory system; however, it may also affect other body systems. In most cases, the SARS coronavirus usually enters through the mouth or nose as you breathe and quickly invades the airway epithelial cells and begins to replicate in alveolar epithelial cells (ATII and ATI-like cells). Infection then progresses and may spread to other organs through the bloodstream.

How does SARS affect the human body

What are the signs and symptoms of SARS?

SARS causes high fever, flu-like symptoms and severe breathing problems.

When an infection is present, signs and symptoms are usually expressed in early stages, common symptoms include headache, malaise, fever over 100.4°F (37.8°C), body aches, loss of appetite, sore throat, confusion, runny nose, excessive sweating, shaking chills, red or pink eyes (conjunctivitis), and subsequent onset of respiratory symptoms including dry cough, shortness of breath (dyspnea), chest pain (especially when you cough or breathe), bilateral wheezing, or other problems breathing

During the early stage of the illness, SARS causes symptoms that are similar to those of a flu. SARS generally begins with a fever, headache, and malaise. After the onset of fever (after 2 to 7 days), SARS patients may develop a dry cough along with shortness of breath, wheezing, and chest pain

If left untreated, patients may also experience watery diarrhea and abdominal cramping usually at a later stage of the illness, suggesting that SARS may not be confined to the respiratory tract!

SARS often starts with mild symptoms similar to other common viral respiratory infections; However, the disease progresses rapidly and symptoms become severe in a relatively short period of time


What is the cause of SARS virus?

SARS is caused by the sars-coronavirus (SARS-CoV), a member of the Coronaviridae family of viruses.

The 2003 SARS virus epidemic started when the virus spread from small meat-eating mammals (civets) in China. Person to person transmission of SARS occurs when someone with SARS coughs or sneezes on you, or by close person-to-person contact with infected materials.

What animal causes SARS?

Scientists found that animals sold at street markets in Guangdong, China, carried a coronavirus nearly identical to the SARS coronavirus

The SARS coronavirus (SARS-CoV) was acquired through direct contact with infected animals in restaurants, or in wet markets where live animals were kept in Guangdong (Chinese: 广东). Marketplace himalayan palm civets (Paguma larvata), chinese muntjac deer, raccoon dogs (Nyctereutes procyonoides), beaver, chinese hare (Lepus sinensis), chinese ferret-badger (Melogale moschata), domestic cat, and the hog badger (Arctonyx collaris) harbored viruses highly similar to SARS-CoV.

The pandemic-causing SARS-CoV originated from traded civets.


How to diagnose SARS?

To decide whether SARS-CoV is present in your body, your doctor will obtain clinical specimens to examine them.

Clinical specimens such as saliva, sputum, nasopharyngeal aspirates, throat and nose swabs, endotracheal aspirates, feces, and urine, are used for SARS-CoV-specific RNA detection. Moreover, SARS-CoV-specific RNA can also be detected by inoculating cell cultures and growing the SARS coronavirus (SARS-CoV).

How soon can you get tested for SARS?

SARS-CoV-specific RNA can be detected in the first 5 days of illness in patients with Suspected SARS through RNA tests, serologic response, and viral culture.

Viral culture is not useful after week 3 of illness.

Detection rates of SARS-CoV-specific RNA peak at day 11 after onset of illness; however, SARS coronavirus specific RNA remains detectable in respiratory secretions, stool and urine specimens for more than 30 days after onset of illness

Nasopharyngeal aspirates, sputum samples, or throat swabs are the most useful clinical specimens in the first 5 days of illness; however, stool specimens can also be used to detect SARS-CoV-specific RNA later in the illness.

Serum specimens are collected to test for antibodies to SARS-CoV and to detect SARS-CoV in patients with SARS, respectively, whereas, fecal and throat swab specimens are collected and tested for SARS-CoV RNA

Paired serum samples are collected to detect antibody response to SARS-CoV

How do you get tested for SARS?

Specific laboratory tests are used to detect viral RNA and antibody responses and to establish a cause in patients suspected to have SARS

Tests include:

Reverse transcriptase polymerase chain reaction (RT-PCR) and indirect immunofluorescence (IFA) serological test for SARS-CoV

Reverse-transcriptase polymerase chain reaction (RT-PCR) is the gold standard test for detecting SARS CoV RNA.

The specificity and sensitivity of the Real-time PCR assays based on the LightCycler® technology have been confirmed. All PCR-positive stool specimens should be retested by the LightCycler PCR

SARS-CoV can also be detected using enzyme-linked immunoassays (EIA).

These tests are performed on respiratory (respiratory secretions) and serum specimens.

ELISA (enzyme-linked immunosorbent assay) can also be used to detect antibody to SARS CoV.


If diagnostic tests fail to detect monoclonal antibodies to SARS-associated coronavirus (SARS-CoV) after 21 days from onset of illness, this means that no infection with SARS-CoV took place

Can SARS virus be cured and how to treat SARS disease?

There is currently no cure for patients infected with SARS; However, the inactivated SARS-CoV vaccine is underway.

A person suspected of having SARS should be admitted to hospital immediately and kept in the isolation room under close observation until the patient is completely cured

Treatment of SARS may include: corticosteroids, human gamma globulin (human γ-Globulin) at a dosage of 5 g per day, interferon alpha, positive airway pressure (cpap) therapy and antiviral drugs, such as oral ribavirin, Oseltamivir phosphate (Tamiflu®), or Lopinavir-ritonavir co-formulation (Kaletra®), along with broad-spectrum antibiotics and supportive care.

Broad-spectrum antibiotics are often used for community-acquired or nosocomial pneumonia

The use of immunomodulatory therapy in SARS is highly effective. Early use of ribavirin and corticosteroids, such as pulsed methylprednisolone, can be beneficial to lower a fever and to sufficiently counterbalance the degree of hyperactive immune responses that the patient can mount a sufficient defense or adaptive immune response to eradicate the SARS virus without the development of irreversible lung damage

Treatment with gamma-interferon (IFN-γ) drugs, such as Actimmune®, is highly recommended to inhibit the replication of SARS-CoV (severe acute respiratory syndrome-associated coronavirus). Alternatively, Treatment with IFN-α (Interferon alpha) drugs, such as Infergen® (Interferon Alfacon-1), can effectively inhibit SARS-CoV replication

Non-invasive ventilation (NIV) via a face or nasal mask is often used for the management of SARS-related respiratory failure. Positive airway pressure (cpap) therapy is commonly employed to improve oxygenation and tachypnea, and to avoid intubation and invasive ventilation in up to two-thirds of patients infected with SARS. Alternatively, bilevel positive airway pressure therapy (BIPAP) with an inspiratory positive airway pressure (IPAP) of 10 cm H2O and an expiratory positive airway pressure (EPAP) of 5 cm H2O can also be used to improve oxygenation and tachypnea.

BIPAP at back up rate of 12 breaths per minute (BPM) can contribute to improving patient outcomes. BIPAP provides two pressure levels during respiration: a higher level during inspiration (IPAP) and a lower pressure during expiration (EPAP)

CPAP of 10 cmH2O can improve patient outcomes and will help you avoid using a higher dose of corticosteroids for respiratory failure

SARS Patients who continue to deteriorate while on NIV, or in whom NIV is contraindicated, should be immediately intubated and mechanically ventilated. Approximately, 5-10% of patients infected with SARS require intubation and mechanical ventilation.

Natural therapy

How to treat SARS disease naturally?

Glycyrrhizin, an extract from the root of the glycyrrhiza glabra plant (licorice root), is often used to inhibit the adsorption, penetration and replication of SARS-CoV. Glycyrrhizin is given orally at a daily dose of 200 – 800 mg

How do you prevent SARS?

Each patient with SARS should wear a procedure mask during close contact with uninfected persons to prevent airborne transmission. However, if it is not possible, a SARS patient should be advised to cover his nose and mouth with a facial tissue when coughing or sneezing.

Verified by: Dr.Diab (July 23, 2018)

Citation: Dr.Diab. (July 23, 2018). What is SARS Disease? Causes Symptoms and Treatment. Medcoi Journal of Medicine, 48(2). urn:medcoi:article20662.

, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

There are no comments yet

× You need to log in to enter the discussion
© 2024 Medcoi LLC, all rights reserved.
go to top