The coronavirus is currently classified as an epidemic and continues to spread. The virus appears to be spreading rapidly with new cases confirmed each day, including four in the UAE, and panic rising as medical suppliers are running out of face masks, but how much more it will grow, and whether it will reach the level of a pandemic, remains to be seen.
The virus, also known by many as corona, began in Wuhan, China and has infected nearly 6,000 people worldwide, killing over 130 people and reaching the level of an epidemic.
A new epidemic: coronavirus
An epidemic occurs when there is a sudden increase in the number of cases of a disease above what is normally expected. Further along the spectrum is a pandemic – an epidemic that has spread over an entire geographic area, whether a country, continent, or the entire world.
“The WHO [World Health Organization] has not classified this as a pandemic yet,” Joseph Eisenberg, chair of the department of epidemiology at the University of Michigan School of Public Health, said. “This is largely because even though there has been sporadic cases globally, most of the transmission and deaths has been focused in and around Wuhan.”
Eisenberg added that if things change and the number of transmissions and deaths increase worldwide, this classification will change.
How fast it can spread
How fast a disease spreads is determined by calculating a reproduction number, or R0. The WHO estimates the coronavirus R0 at somewhere between 1.4 and 2.5. WHO also reports that 12-21 percent of the people with the virus became critically ill, and 2-3 percent of those infected have died.
“If the R0 was higher than 2-3, we should have seen more cases globally by mid January, given Wuhan is a travel and trade hub of 11 million people,” wrote C Raina MacIntyre, a professor of global biosecurity at UNSW Sydney, for The Conversation.
The R0 refers to the average number of people a sick person will infect. So, if a virus has an R0 of 2, patient zero will likely infect two people, and then those two people will each infect two more people. The cycle repeats. If an RO is greater than 1, the infection will likely continue to spread. If it is below 1, it is unlikely to spread further.
Eisenberg said that a few factors have contributed to the rapid spread of corona virus, including the increased level of travel to and from China for the New Year holiday. The virus likely originated in a wild animal sold in the Wuhan markets.
“These animals harbor many viruses,” Eisenberg said. “Most of these viruses are unable to transmit from person to person. Once a virus emerges that can be transmitted person to person, it can often spread rapidly because everyone is susceptible; there is no prior immunity in the population.”
A WHO report said that since 1970, more than 1,500 new pathogens have been discovered, of which 70 percent were of animal origin. These include the well-known Ebola virus in 1976 and the human immunodeficiency virus (HIV) in 1983. However, not all these pathogens have had an impact on public health.
The coronavirus can spread through direct or indirect contact, meaning it can be transmitted via physical touch between humans, and it can also be contracted by touching a surface, like a door knob or table, that an infected person has contaminated with the virus.
It is too early to predict the further impact coronavirus will have on the global population, though it will likely continue to spread. But people should take the same protective measures that are taken against other respiratory viral diseases, such as influenza or the common cold.
On how likely a person is to catch the virus, Eisenberg said “At this point, unless you are in China you are much more at risk of being infected with influenza than with this new virus.”