CHAPTER ONE
INTRODUCTION
1.1 Background to the study
Coronavirus (COVID-19) are positive-sense, single stranded RNA viruses and its diameters is 60 nm to140 nm with spike like projection on it’s around which giving it a crown like appearance. Their viral is RNA genomic and their ranges from 26 to 32 kilobases in length. COVID-19 belongs to the Nidovirales order which includes Roniviridae, Arteriviridae, and Coronaviridae families. The Coronviridae family is subdivided into Torovirinae and Coronavirinae subfamilies. Coronavirinae is further sub classified into alpha, beta, gamma, and delta. Phylogenetic clustering accounts from the classification of these subtypes of viruses. It can be isolated from different animal species. In 1960 first case of coronavirus was notified and Canadian study in 2001 was identified approximately 500 patients as Flu-like system in which 17 to 18 cases were confirmed as infected with Coronavirus by polymerase chain reaction. These include livestock, birds, and mammals such as bats, camels, masked palm civets, dogs, mice, and cats. In 2003, various reports were published the spreading of Coronavirus in many countries such as Hong Kong, United States America, Singapore, Vietnam, Thailand, Taiwan and their several case of severe acute respiratory syndrome which caused by Coronavirus and their mortally was more than 1000 patient. Another study report in Hong Kong was confirmed 50 patients are suffering from severe acute respiratory syndrome while 30 of them were confirmed as Coronavirus infected. In Wuhan (China) late December 2019 a case unidentified pneumonia was reported by Hubei Province, People’s Republic of China (PRC) their clinical characteristics were very similar to those of viral pneumonia. After analysis on respiratory samples the Centre for Disease Control expert declared that the pneumonia, later known as novel virus and officially named the disease COVID-19 was declared by World Health Organization (WHO). The initial cases had a common exposure to the Huanan wholesale seafood market that also traded live animals. On December 31st 2019, China notified the outbreak to the WHO and on 1st January the Huanan sea food market was closed. For identification of this disease different sample from Huanan sea food market also tested, signifying that the virus originated from there. The number of cases started increasing exponentially, some of which did not have exposure to the live animal market, suggestive of the fact that human-to-human transmission was occurring.
1.2 Statement of the Problem
Coronavirus disease spreads primarily through contact with an infected person when they cough or sneeze. It also spreads when a person touches a surface or object that has the virus on it, then touches their eyes, nose, or mouth.
Rural dwellers in West Africa are at risk of coronavirus because of proximity to animal reservoir, open construction of African villages, the practice of drying grains by road sides or outside homes and unprotected grain storage within homes. All these factors are known to facilitate increased rodent-man contact or contamination of food sources by infected rodent secretions.