ABSTRACT

This study reviewed deadly Respiratory Tract Infections, Severe acute respiratory syndrome (SARS). The agent causing this illness has been identified as a novel coronavirus, SARS-coronavirus. Severe acute respiratory syndrome (SARS) emerged from China as an untreatable and rapidly spreading respiratory illness of unknown etiology. Following point source exposure in February 2003, more than a dozen guests infected at a Hong Kong hotel seeded multi-country outbreaks that persisted through the spring of 2003. The World Health Organization responded by invoking traditional public health measures and advanced technologies to control the illness and contain the cause. A novel coronavirus was implicated and its entire genome was sequenced by mid-April 2003. The urgency of responding to this threat focused scientific endeavor and stimulated global collaboration. Through real-time application of accumulating knowledge, the world proved capable of arresting the first pandemic threat of the twenty-first century, despite early respiratory-borne spread and global susceptibility. This review synthesizes lessons learned from this remarkable achievement. These lessons can be applied to re-emergence of SARS or to the next pandemic threat to arise.

TABLE OF CONTENTS

ABSTRACT

CHAPTER ONE: INTRODUCTION

1.1 Background of the study

1.2 History of SARS

1.3 Statement of the problem

1.4 Objectives of the study

CHAPTER TWO: LITERATURE REVIEW

2.1 The virus, its origins and evolution

2.2 Epidemiology

2.2.1 Incubation Period

2.2.2 Infectious Period

2.3 Etiology

2.4 Signs and symptoms

2.5 Complications

2.6 Treatment

2.6.1 Antiviral

2.6.2 Anti-Inflammatory

2.7 Anatomy of a coronavirus

CHAPTER THREE: CONCLUSION AND RECOMMENDATIONS

3.1 Conclusion

3.2 Recommendations

REFERENCES

CHAPTER ONE

INTRODUCTION

1.1 Background of the study

Severe acute respiratory syndrome (SARS) is a viral respiratory disease of zoonotic origin caused by the SARS coronavirus (SARS-CoV). Between November 2002 and July 2003, an outbreak of SARS in southern China caused an eventual 8,098 cases, resulting in 774 deaths reported in 17 countries (9.6% fatality rate), with the majority of cases in mainland China and Hong Kong.

It causes an often severe illness and marked initially by systemic symptoms of muscle pain, headache, and fever, followed in 2–14 days by the onset of respiratory symptoms, mainly cough, dyspnea, and pneumonia. Another common finding in SARS patients is a decrease in the number of lymphocytes circulating in the blood. In the SARS outbreak of 2003, about 9% of patients with confirmed SARS-CoV infection died. The mortality rate was much higher for those over 60 years old, with mortality rates approaching 50% for this subset of patients.

In late 2017, Chinese scientists traced the virus through the intermediary of civets to cave-dwelling horseshoe bats in Yunnan province. No cases of SARS have been reported worldwide since 2004. However, the related virus SARS-CoV-2 is the cause of the ongoing 2019–20 coronavirus pandemic.

In recent times, several life threatening viruses have emerged. They have been responsible for causing significant human mortality, in addition to raising serious public health concerns worldwide. Due to modern life, extensive travel of humans and goods, their outbreak anywhere in the world could potentially be a risk everywhere. Two novel viruses were implicated to be responsible for severe acute illness in recent times, i.e. Severe acute respiratory syndrome-corona-virus (SARS-CoV) (To et al., 2013, Meyer et al., 2015).

A newly discovered coronavirus (SARS-CoV) has been identified as the cause of SARS. SARS-CoV–like viruses have been detected in Himalayan palm civets and a raccoon-dog in a market in southern China, suggesting that the origin of SARSCoV may have been from these or other wild animals. Given the possibility that human or animal reservoirs of SARS-CoV may still exist and that SARS may have a seasonal predilection, there is concern that SARS may return in upcoming respiratory seasons. WHO guidelines emphasize the need for all countries to remain vigilant and to maintain their capacity to detect and respond to the potential reemergence of SARS.

The past 150 years saw the emergence of three pandemics from southern China: plague during the late nineteenth century and two influenza pandemics (Asian flu of 1957 and Hong Kong flu of 1968)1,2. In November 2002, a new ‘plague’ was emerging in Guangdong Province, China. On 21 February 2003 a physician from Guangdong spent a single day in hotel ‘M’ in Hong Kong, during which time he transmitted an infection to 16 other guests. These, in turn, seeded outbreaks of the disease in Hong Kong, Toronto, Singapore and Vietnam. Within weeks, SARS had spread to affect more than 8,000 people in 25 countries across 5 continents. By the end of the global outbreak (5 July 2003), it had killed 774 people—a small number in comparison with the fatalities during the previous pandemics of plague and influenza. But the rapidity of spread by air travel, immediate media coverage and today’s globalization of economic activity all contributed to the far more pronounced impact of SARS.

The speed of the scientific response in understanding this new viral disease was unparalleled. The clinical syndrome was described, the etiological agent identified, diagnostic tests devised and the genome completely sequenced within weeks of the virus’s emergence from mainland China. Just 1.5 years later, the first phase 1 vaccine trials are underway, and several other vaccine candidates are under evaluation in animal models. Previous reviews have addressed aspects of the clinical presentation, infection control, clinical management and public health. Here we emphasize aspects of pathogenesis and their correlation to clinical outcome, and discuss the progress that has been made towards antiviral treatment and vaccine development.