{"id":2472,"date":"2020-06-29T11:20:00","date_gmt":"2020-06-29T03:20:00","guid":{"rendered":"https:\/\/www.mdis.edu.sg\/blog\/?p=2472"},"modified":"2020-06-15T18:30:58","modified_gmt":"2020-06-15T10:30:58","slug":"pandemic-covid-19","status":"publish","type":"post","link":"https:\/\/www.mdis.edu.sg\/blog\/pandemic-covid-19\/","title":{"rendered":"Pandemic – COVID-19: The Coronavirus Disease Uncovered"},"content":{"rendered":"\n

The\nCoronavirus is a pathogen that has a direct impact on the respiratory system.\nIn the past, this type of virus had caused other outbreaks; namely the severe\nacute respiratory syndrome SARS and Middle East Respiratory Syndrome MERS.\nCOVID-19 is a potentially fatal disease caused by SARS-CoV2 (Novel Coronavirus)\n(Watts et. al, 2020). This strain is of great concern amongst health officials\ndue to its high R0<\/sub> value. The R0<\/sub> estimates ranged from\n2.06-2.52, which indicates the pathogen\u2019s great infectivity. <\/p>\n\n\n\n

\u2022          If R0 <\/sub>is less than 1, each\nexisting infection causes less than one new infection. In this case, the\ndisease will decline and eventually die out.<\/p>\n\n\n\n

\u2022          If R0<\/sub> equals 1, each\nexisting infection causes one new infection. The disease will stay alive and\nstable, but there will not be an outbreak or an epidemic.<\/p>\n\n\n\n

\u2022          If R0<\/sub> is more than 1, each\nexisting infection causes more than one new infection. The disease will spread\nbetween people, and there may be an outbreak or epidemic.<\/p>\n\n\n\n

Table 1. R0<\/sub> values and their implications.<\/strong><\/p>\n\n\n\n

The initial\ncluster of patients, identified in December 2019, upon admission to the\nhospitals were initially diagnosed with pneumonia of unknown aetiology. Based\non epidemiological evidence this cluster was linked to the Hua Nan seafood and\nlive animal market in Wuhan, Hubei Province, China (Watts et.al, 2020). <\/p>\n\n\n\n

The\npatients\u2019 preliminary symptoms included fever, cough, tiredness and dyspnoea\n(shortness of breath). The antecedent clinical manifestations of COVID-19 can\nbe classified into two categories; namely systemic and respiratory disorders.\nThe systemic disorders are sputum production, haemoptysis which involves instances\nof coughing up blood or blood-stained mucous, acute cardiac injury, hypoxemia\n(low oxygen levels in the blood mainly in the arteries), lymphopenia (reduced\nlymphocyte count) and diarrhoea. The respiratory disorders include sneezing,\nsore throat, rhinorrhea, pneumonia and acute respiratory distress syndrome.\n(Huang, et. al, 2020). <\/p>\n\n\n\n

The\npathogen\u2019s high infectivity made it imperative for early testing and diagnosis\nto be conducted. The preliminary testing methods used for diagnosis are body\ntemperature scans, chest CT scans, X-rays and blood work. Confirmatory tests\ninvolve specimen collection; nasopharyngeal (NP) swab are preferred although an\noropharyngeal swab is also acceptable. These specimens are then tested using\nserological methods, viral sequencing and most importantly nucleic acid\namplification tests (NAAT) for COVID-19. <\/p>\n\n\n\n

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Image Source: R & D Systems<\/figcaption><\/figure>\n\n\n\n

How exactly\ndoes the SARS-CoV2 manage to cause such life-threatening conditions? The virus\nmakes its way into your body via the droplets of an infected person. These\ndroplets are released by coughing, sneezing and even when breathing. The virus\ncould travel from the infected person through the air or land on surfaces and\nenter a healthy person via the mouth, nose or the eyes through touch. This\nprovides the virus with a pathway via the mucous membrane. Upon entry, the\nvirus will bind to the ACE2 receptors present on the lungs\u2019 epithelial cells,\nthus hijacking the healthy cells and eventually destroying them. (Hussin et.\nal, 2020) <\/p>\n\n\n\n

Patients\nwho test positive for COVID-19, exhibit abnormal respiratory symptoms along\nwith elevated pro-inflammatory cytokines (chemical messenger for immune cells).\nSome other laboratory findings include increased red blood cell sedimentation\nrate, leukopenia (decrease of white blood cells) of which 70% are neutrophils. (Huang\net. al, 2020). Neutrophils are significant as they are the front liners in our\nimmune systems response.  Additionally,\nthere are high levels of blood C-reactive protein which is an indicator that\nthe immune system is active and responding to inflammation. The cells in the\nimmune system will also secrete cytokines who act as chemical messengers e.g.  TNF\u03b1. When the patients\u2019 chest CT scans are\ntaken, they reveal pneumonia, RNAaemia (detection of cytomegalovirus RNA i.e\ngenetic material  in the serum) coupled\nwith ground-glass opacities (hazy opacities in CT scans that indicate filled\nair spaces in the lungs due to exudate accumulation).  <\/p>\n\n\n\n

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Image Source: Lancet<\/figcaption><\/figure>\n\n\n\n

At present,\nthere are no vaccines or antiviral therapies available for COVID-19. The\ncurrent treatment programme includes the use of broad-spectrum antiviral\nmedications such as oseltamivir, lopinavir and ritonavir. The National\nInstitute of Health is currently conducting trials to test hydroxychloroquine\nas a potential treatment option for COVID-19. (National Institute of Health,\n2020) Current research is now focused on understanding the biology of the\nvirus, potential treatment option and most importantly the psychological\neffects that a pandemic like situation has on the society along with the\nsocio-economic changes. <\/p>\n\n\n\n

During such\na pandemic, our best defence is to maintain good personal hygiene, practise\nsocial distancing and strictly follow the guidelines provided by government\nhealthcare officials.<\/p>\n\n\n\n

References <\/strong><\/p>\n\n\n\n