Covid 19: Transmission, case fatality rate, protective measures, laboratory diagnosis, and possible laboratory features

Abstract

Covid 19 is a coronavirus disease caused by Covid 19 virus or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) formerly referred to as novel coronavirus or Wuhan coronavirus or 2019-nCoV causes a deadly respiratory infection. It is an infectious viral agent and a positive-sense (+ssRNA), single-stranded RNA virus that causes acute respiratory disease which can be mild, moderate, or severe illness including death. It is a zoonotic infection and can also be transmitted from human to human. The virus enters the cell by binding with cell that has angiotensin I converting enzyme 2 (ACE2) receptor using the spike. ACE2 receptor is found on the cell membranes of cells in the lungs, arteries, heart, kidney, and intestines. The first outbreak was reported in Wuhan, China, on December 31, 2019, hence the initial name Wuhan coronavirus. Globally, it has a fatality rate of 6.7% with a fatality rate of 3.5% in Nigeria as at April 18, 2020. The infection is air borne through droplets from infected person during coughing, spiting or sneezing. It can also be contracted by touching eyes, nose, or mouth with contaminated hands. Covid 19 may elicit both inflammatory and acute phase immune responses while the mechanical innate immune defense can be overcome to cause severe pneumonia The virus enters the lung through ACE2 receptors on the cell membrane of the lung to destroy cilia resulting into the accumulation of dead tissues, cells/dirts/wastes, and fluids thereby displacing the normal air content of the lung which will eventually bring about dry cough, and difficulties in breathing. The infection can be prevented through basic protective measures which include regular washing of hands with soap and water followed by sanitizing hands with alcohol-based sanitizer, social distancing, avoidance of gathering, quarantine measure applicable to especially those from endemic areas, self-isolation for those who are positive or manifesting related signs and symptoms, use of personal protective equipment, early diagnosis, and adequate intervention. The use of soap and alcohol are effective as soap can break through the lipid layer of the virus to become smaller particles which are washed away by water while alcohol is capable of lysing the virus. Covid 19 is diagnosed in the laboratory by real-time reverse transcription polymerase chain reaction Panel. Covid 19 may result into abnormal liver function tests due to abnormal fat retention, elevated plasma creatinine and urea which may be due to kidney damage, elevated C02, and decreased oxygen, level due to severe pneumonia, decreased and elevated anti and pro-inflammatory cytokines respectively which may be manifested as fever, acute phase response, decreased erythropoietin due to possible kidney damage, prolong prothrombin time/activated partial thromboplastin time and depleted platelet count which may manifest as disseminated intravascular coagulation. This work reviewed the transmission, case fatality rate, basic protective measures, laboratory diagnosis, and possible laboratory features of Covid 19.