Understanding COVID-19: The Emerging Challenge to Human Survival
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By: Dr. Kumar Raka, Editor-ICN Group
VIJAYAWADA: In the past two decades, the world has seen at least three coronaviruses emergence and surge causing outbreaks that have caused considerable global health concerns. As per medical definition “Coronavirus is a common type of virus that infects humans, typically leading to an upper respiratory infection. Seven different types of human coronaviruses have been identified. Most people will be infected with at least one type of coronavirus in their lifetime. The viruses are spread through air by coughing and sneezing, close personal contacts, touching an object or surface contaminated with the contact and rarely by fecal contamination. The illness caused by most coronaviruses usually lasts a short time and is characterized by runny nose, sore throat, feeling unwell, cough and fever.”
The first severe acute respiratory syndrome (SARS) Coronavirus (SARS-Cov) infecting humans was identified in late 2002. As per World Health Organization SARS-Cov may be an animal virus from an uncertain animal reservoir (perhaps bats) that was transmitted to other animals (civet cats) and thereafter it infected humans. The SARS-CoV outbreak started in Guangdong, China, and spread to many countries in Southeast Asia, North America, Europe, and South Africa. Transmission was primarily person to person through droplets that occurred during coughing or sneezing, through personal contact (shaking hands), or by touching contaminated surfaces. Of note, health professionals were particularly at risk of acquiring the disease, as transmission also occurred if isolation precautions were not followed and during certain procedures. The last case of SARS-CoV occurred in September 2003, after having infected over 8,000 persons and causing 774 deaths with a case fatality rate calculated at 9.5% (Hsieh et al., 2005). Symptoms are influenza-like and include fever, malaise, myalgia, headache, diarrhoea, and shivering (rigors). No individual symptom or cluster of symptoms has proved to be specific for diagnosis of SARS. Transmission of SARS-CoV is primarily from person to person. As per WHO, currently no areas of the world are reporting transmission of SARS. Since the end of the global epidemic in July 2003, SARS has reappeared four times – three times from laboratory accidents (Singapore and Chinese Taipei), and once in southern China where the source of infection remains undetermined although there is circumstantial evidence of animal-to-human transmission.
Nine years later, a new coronavirus causing respiratory disease first identified in Saudi Arabia in 2012. It was named Middle East respiratory syndrome coronavirus (MERS-CoV). Since 2012, MERS-Cov has been reported in 27 countries, mainly middle eastern nations, and approximately 80% of human cases has been reported from Saudi Arabia. Cases identified outside Middle East and people who travelled and to Middle East or came into contact with infected persons from the Middle-East. In these patients, travel history is imperative, as all cases have been linked to persons in or near the Arabian Peninsula. As per WHO, MERS-CoV is a zoonotic virus transmitted between animals and people. Scientific evidence suggests that people are infected through direct or indirect contact with infected dromedary camels. MERS-CoV does not pass easily between people unless there is close contact, such as the provision of clinical care to an infected patient without strict hygiene measures. Similar to SARS-CoV, health professionals were at higher risk of acquiring the disease, as demonstrated in the outbreak in South Korea (S.Y. Cho et al., 2016). Symptoms of MERS-CoV are nonspecific, but many patients end up with severe acute respiratory distress. WHO records “A typical case of MERS includes fever, cough, and/or shortness of breath. Pneumonia is common, however some people infected with the MERS virus have been reported to be asymptomatic. Gastrointestinal symptoms, including diarrhoea, have also been reported. Severe cases of MERS can include respiratory failure that requires mechanical ventilation and support in an intensive-care unit.” However, in comparison with SARS-CoV, MERS-CoV is still circulating, data from WHO shows that almost 80% of the reported MERS-CoV cases have been in Saudi Arabia; a total of 1,983 cases, with 745 related deaths and a case-fatality rate of 37.5 (A. Altamimi, 2020)
In December 30, 2019, a cluster of patients with pneumonia of unknown etiology was observed in Wuhan, China, and reported to the World Health Organization (WHO) China bureau in Beijing. A week later, January 7, 2020, a new coronavirus (SARS-CoV-2) was isolated from these patients. This virus was initially referred to as novel coronavirus 2019 (2019-nCoV) but was given the official name of COVID-19 by the WHO on February 11, 2020. This new virus has infected more people than either of its two predecessors. he most common symptoms of COVID-19 are fever, tiredness, and dry cough. Some patients may have aches and pains, nasal congestion, runny nose, sore throat or diarrhea. These symptoms are usually mild and begin gradually. Some people become infected but don’t develop any symptoms and don’t feel unwell. Most people (about 80%) recover from the disease without needing special treatment. Around 1 out of every 6 people who gets COVID-19 becomes seriously ill and develops difficulty breathing. Older people, and those with underlying medical problems like high blood pressure, heart problems or diabetes, are more likely to develop serious illness. People with fever, cough and difficulty breathing should seek medical attention. People can catch COVID-19 from others who have the virus. The disease can spread from person to person through small droplets from the nose or mouth which are spread when a person with COVID-19 coughs or exhales. These droplets land on objects and surfaces around the person. Other people then catch COVID-19 by touching these objects or surfaces, then touching their eyes, nose or mouth. People can also catch COVID-19 if they breathe in droplets from a person with COVID-19 who coughs out or exhales droplets. This is why it is important to stay more than 1 meter (3 feet) away from a person who is sick. On March 12, 2020 outbreak of Covid-19 was announced by WHO a pandemic. Till now, the outbreak has spread to 203 countries infecting 10,26,688 humans and causing over 54,000 deaths. In summary, the story of Covid-19 continues to evolve. Because SARS-CoV and MERS-CoV have had different behaviors, Covid-19 will likely have unique features of its own that we will learn as the outbreak further progresses.
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