At the end of December 2019, a new respiratory virus infection was identified in Wuhan city, China, in the province of Hubei, after patients with acute severe respiratory infections showed clustering. The cases were thought that they could be related to exposure in the Huanan Seafood Market where wholesale fish and live animals are sold in this city. In January 2019, the causative agent was named 2019-nCoV (2019 novel coronavirus), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 2019 coronavirus disease (COVID-19) by the World Health Organization (WHO). Coronaviruses are enveloped and single-stranded RNA viruses of the Coronaviridae family and are known as 'crown viruses" due to their crown-like protrusions on their outer surfaces. They can infect various species. In addition to mild upper respiratory diseases, it is the causative agent of serious acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). 2019-nCoV shows 79% similarity to SARS-CoV and means that bats such as SARS-CoV may have been the original host of this virus. The route of transmission is by respiratory droplets and direct contact. In order to prevent the spread of infection, early diagnosis, proper isolation and personal protective measures are especially important in the hospital environment. The agent uses angiotensin converting enzyme 2 (ACE2) receptor to enter the cell. The incubation period is usually 3-7 days and can extend up to 14 days. While it is more severe in upper-middle aged people, those with advanced age and additional comorbidities pose risk factors for severe disease. Adult patients have high fever, weakness and dry cough, and some have headaches and muscle pain. As the disease period progresses, shortness of breath acute respiratory distress syndrome, septic shock, metabolic acidosis, clotting disorders, and multiple organ failure may occur. In particular, children can pose an unnoticed threat in spreading the outbreak. Children are less likely than adults to have the infection as an obvious clinical status. The clinical features of the disease are milder and death has not been reported under 10 years of age. Blood count and C-reactive protein values can usually be found normal or slightly increased. In the radiological evaluation of the lung, ground glass appearance and bronchial shadows may be evident. A nucleic acid test is performed from the nose or throat swab to determine the exact cause of the disease. Adequate calorie and fluid intake and the need for oxygen should be ensured in the treatment. An effective anti-virus treatment is not yet available. However, in severe cases, interferon-α nebulization and efficacy have not been proven, lopinavir / ritonavir and chloroquine are recommended. In certain cases, corticosteroids can be used. The virus can be inactivated with disinfectants containing ethanol and chlorine. People with close contacts and suspicious exposure should be advised of 14 days of observation and isolation, starting from the last contact day with the patient infected with 2019-nCoV. Vaccine development studies for 2019-nCoV are ongoing. [ABSTRACT FROM AUTHOR]