Epidemic vs. pandemic? Glossary of terms for virus outbreak

OUTBREAK: A sudden rise in cases of a disease in a particular place. | South Korean President Moon Jae-in (second from right) salutes during a special government meeting to discuss measures to prevent the further spread of COVID-19 at the Daegu City Hall in Daegu, South Korea.

EPIDEMIC: A large outbreak, one that spreads among a population or region. The current outbreak of a flu-like illness caused by a new virus in China is considered an epidemic. | Patients infected with the coronavirus take rest at a temporary hospital converted from Wuhan Sports Center in Wuhan in central China's Hubei Province.

PANDEMIC: Generally refers to an epidemic that has spread on a more global scale, affecting large numbers of people. While there are cases of illness outside China. Exactly when enough places have enough infections to declare one isn't a black-and-white decision. But generally, the WHO is looking for sustained outbreaks on different continents. | WHO warns of pandemic risk after virus peaks in China.

CORONAVIRUS: Term for a family of viruses. Some cause the common cold while others cause more severe illnesses like SARS, which stands for severe acute respiratory syndrome, and MERS, which stands for Middle East respiratory syndrome.

COVID-19: Name given to the illness caused by the new coronavirus first identified in China in late 2019. CO and VI are for coronavirus, D is for disease, and 19 for 2019. The virus itself is called SARS-cov-2. | Liang Wannian of China's National Health Commision attends a news conference of the World Health Organisation (WHO) - China Joint Mission on Covid-19 - about its investigation of the coronavirus outbreak in Beijing, China

INCUBATION PERIOD: Time between infection and the appearance of signs or symptoms of an illness. The incubation period for the new virus is thought to be up to two weeks. | Despite a quarantine imposed on the Diamond Princess, more than 600 people on board tested positive for the coronavirus, with several dozen in serious condition.

QUARANTINE: Restrict movement of healthy people who may have been exposed to an infection to see if they become ill. For example, the passengers on the Diamond Princess cruise ship in Japan were quarantined. | Buses carrying passengers who have been under quarantine on a coronavirus-stricken cruise ship off the coast of Japan, the Diamond Princess, leave RAF Boscombe Down in Amesbury, Britain

ISOLATION: Separate sick people from healthy people to prevent spread of disease. For example, people with the infection are put in isolation in hospitals. | A medical worker calls his colleague inside an isolated ward at Jinyintan Hospital in Wuhan, the epicentre of the novel coronavirus outbreak, in Hubei province, China