INTRODUCTION

Coronavirus (COVID-19) is an enveloped RNA virus that is diversely found in humans and wildlife. A total of six species have been identified to cause disease in humans. This pandemic had spread to 209 countries and 1,455,519 are confirmed cases, which are including 83,664 deaths to date. It is about 3.4% worldwide. Similarly, Middle East respiratory syndrome coronavirus (MERS-CoV) had become a worldwide health concern. MERS-CoV originally reported in 2012¹. It has affected more than 2000 people in 27 countries and 4 sub-continents in the Middle East. While the epidemic of SARS, affected 26 countries and resulted in more than 8000 cases in 2003¹. Since then, a small number of cases have occurred as a result of laboratory accidents or possibly, through animal-to-human transmission (Guangdong, China)¹.

Coronaviruses cause illness in people and it can circulate among mammals and birds. Rarely animal coronaviruses can spread to human and then the human can spread to other humans. SARS-CoV-2 was first identified in Wuhan city, Hubei province, China, in December, 2019. Since then, it has spread to 209 countries all over the world when WHO declaring it a pandemic. The case fatality rate is approximately 2.3% based on initial information². It is spherical to pleomorphic enveloped particles. Its envelope is studded in glycoproteins associated with nucleoprotein. The virus enters into the host cell and its genome is translated and transcribed. The translation is usually done by airborne droplets to the nasal cavity. Virus divides into the epithelium cells and causes total inflammation.

To date, no specific antiviral treatment is proven effective, hence, infected people initially rely on symptomatic treatments that showed encouraging profile for blocking the new coronavirus in early clinical trials, but preventive measures are the best treatment at this stage. This review aimed to focus the epidemiology, infection transmission, clinical characteristics, prevention and management of the SARS-CoV-2, so that it can help readers to have the latest understanding and practical measures of COVID-19.

EPIDEMIOLOGY

On 31 December, 2019, the WHO was informed of a cluster of cases of pneumonia of unknown cause detected in Wuhan, China. On 12 January, 2020, it was announced that a novel coronavirus had been identified in samples obtained from these cases and that initial analysis of virus genetic sequences suggested that this was the cause of the outbreak. As of 8 April, 2020, more than 1,467,471 cases have been diagnosed globally, with over 85,382 fatalities (https://www.worldometers.info/coronavirus/).

TRANSMISSION

The main danger or source from human to human is direct contact or infectious respiratory droplets. According to the currently available evidence, transmission through smaller droplet nuclei (airborne transmission) that propagate through the air at distances longer than 1 m is limited to aerosol-generating procedures during clinical care of COVID-19 patients^3,4.

CLINICAL SYMPTOMS

The clinical manifestations which are seen till now are fever, coughing, sore throat, fatigue, headache, diarrhea, trouble breathing, blue lips or face, persistent pain or pressure in the chest, confusion and excessive drowsiness has been observed in a few cases. SARS-CoV-2 infection is more common in aged people between 60-80 years. These people are at high risk of primary infection with death rates, people from 20-59 years are at high risk of secondary infection and people are at least risk at the age of less than 20 years. Additionally, people with the weak immune system are the most prone to COVID-19^5-7.

PREVENTIVE MEASURES

WHO continues to recommend that everyone performs hand hygiene frequently, follows respiratory etiquette recommendations and regularly cleans and disinfects surfaces. Furthermore, people should take personal preventive equipment like gloves, gowns, masks and tissues (for sneezing and cough). In the severe condition, respirator (N95) is used along with disposal gowns, surgical gloves, goggles or face shields and wearing an isolated dress^6-8.