Severe acute respiratory syndrome (SARS)


Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the virus SARS-CoV-1, the first identified strain of the SARS-related coronavirus.

Symptoms include: Fever, persistent dry cough, headache, muscle pains, difficulty breathing.

Acute respiratory distress syndrome (ARDS) with other comorbidities can  eventually leads to death

Severe acute respiratory syndrome coronavirus (SARS-CoV-1).

Hand washing, cough etiquette, avoiding close contact with infected persons, avoiding travel to affected areas are preventative measures.

Prognosis- 9.5% chance of death.

No cases of SARS-CoV-1 have been reported worldwide since 2004.

In December 2019, another strain of SARS-CoV was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

This strain, which is related to SARS-CoV-1, caused coronavirus disease 2019 (COVID-19), a disease that brought about the COVID-19 pandemic.

SARS produces flu-like symptoms which may include fever, muscle pain, lethargy, cough, sore throat, and other nonspecific symptoms. 

Fever is the onlysymptom common to all patients. And appears to be a fever above 38 °C (100 °F). 

SARS often leads to shortness of breath and pneumonia, which may be direct viral pneumonia or secondary bacterial pneumonia.

The average incubation period for SARS is 4–6 days, although it is rarely as short as 1 day or as long as 14 days.

The primary route of transmission for SARS-CoV is contact of the mucous membranes with respiratory droplets or fomites. 

Diarrhea is common in people with SARS, the fecal–oral route is not appear to be a common mode of transmission.

For a case to be considered probable, a chest X-ray must be indicative for atypical pneumonia or acute respiratory distress syndrome.

Diagnosis: tested positive for SARS based on one of the approved tests (ELISA, immunofluorescence or PCR) with  chest X-ray findings show ing SARS-CoV infection with ground glass opacities, patchy consolidations unilaterally.

There is no approved vaccine for SARS.

Other prevention methods:

Hand-washing with soap and water, or use of alcohol-based hand sanitizer

Disinfection of surfaces of fomites to remove viruses

Avoiding contact with bodily fluids

Washing the personal items of someone with SARS in hot, soapy water,

Avoiding travel to affected areas.

Wearing masks and gloves

Keeping people with symptoms home from school

Simple hygiene measures

Distancing oneself at least 6 feet if possible to minimize the chances of transmission of the virus

It is mainly spread through respiratory droplets in the air, either inhaled or deposited on surfaces and subsequently transferred to a body’s mucous membranes. 

Other interventions include  earlier detection of the disease; isolation of people who are infected; droplet and contact precautions; and the use of personal protective equipment (PPE), including masks and isolation gowns.

A prior meta-analysis found that for medical professionals wearing N-95 masks could reduce the chances of getting sick up to 80% compared to no mask.

SARS-CoV is most infectious in severely ill patients, which usually occurs during the second week of illness. 

This delayed infectious period meant that quarantine was highly effective; people who were isolated before day five of their illness rarely transmitted the disease to others.

Antibiotics do not have direct effect on SARS, but may be used against bacterial secondary infection. 

Treatment of SARS is mainly supportive with antipyretics, supplemental oxygen and mechanical ventilation as needed. 

There is currently no proven antiviral therapy. 

People with SARS-CoV must be isolated, preferably in negative-pressure rooms, with complete barrier nursing precautions taken for any necessary contact with these patients, to limit the chances of medical personnel becoming infected.

Some of the more serious damage caused by SARS may be due to the body’s own immune system reacting, the cytokine storm.

No field-ready SARS vaccine had been completed because likely market-driven priorities had ended funding.

Recovered SARS patients showed severe long-time sequelae: pulmonary fibrosis, osteoporosis, and femoral necrosis, with some leading to impaired working ability or even self-care inabilities.

SARS is a relatively rare disease; at the end of the epidemic in June 2003, the incidence was 8,422 cases with a case fatality rate (CFR) of 11%.

The case fatality rate ranges from 0% to 50% depending on the age group of the patient.

Patients under 24 were least likely to die at less than 1%.

Those 65 and older were most likely to die at over 55%.

There were significantly more deaths of males than females, as with MERS and Covid-19.

The 2003 viral outbreak was subsequently genetically traced to a colony of cave-dwelling horseshoe bats in Yunnan.

There is a high probability that SARS coronavirus originated in bats and spread to humans either directly or through animals held in Chinese markets. 

The bats do not show any visible signs of disease, but are the likely natural reservoirs of SARS-like coronaviruses. 

While SARS-CoV-1 probably persists as a potential zoonotic threat in its original animal reservoir, human-to-human transmission of this virus may be considered eradicated because no human case has been documented since four minor, brief, subsequent outbreaks in 2004.

Very low risk of infection in patients without face-to-face exposure to a person with symptomatic disease.

Inoculation period of 1-11 days.

Virtually all infected persons are symptomatic with fewer than 1-2% of those infected experiencing mild or subclinical infection.

Treatment includes steroids and antiviral agents.

Disease is milder in children.

Chest x-ray findings can be initially normal, showing focal consolidation, multifocal or bilateral in extent.

Infiltrates tend to be peripheral and involve middle or lower lobes of the lung.

Pleural effusions are usually not seen on x-ray.

Atypical pneumonia associated with lymphopenia, elevated serum LDH, rapid clinical deterioration and lack of response to antibiotic therapy.

Elevations of LDH and CRP correlate with the severity of illness requiring ventilatory support.

Pulmonary function is mildly reduced at 6-8 months following the acute illness.

Leave a Reply

Your email address will not be published. Required fields are marked *