Researchers are struggling to find an effective solution to flatten the curve and prevent the rapid spread of the novel virus that terrified the world.

Governments have issued many safety measures, and claim that if we are disciplined, we can dramatically contribute to the combat against the coronavirus.

The World Health Organization (WHO) has recently declared the Coronavirus (COVID-19) outbreak a pandemic. A pandemic is a disease that has spread over a large area of land, and there have been numerous pandemics throughout history.

Infectious diseases have spread just like humans have spread across the world. Outbreaks are almost constant even in modern times, but they rarely reach the pandemic level as the Novel Coronavirus (COVID-19) has.

People struggled with diseases and illnesses since the earliest days, but with the emergence of the agrarian communities and the establishment of trade relations, diseases increased, including smallpox, leprosy, malaria, tuberculosis, and influenza.

Yet, over time, the dead rates of diseases started to decrease, due to the numerous advancements in medicine and healthcare.

In ancient times, people linked everything to their gods, and believed that diseases were brought down by the supernatural powers of the Universe.

One of the earliest pandemics, Justinian’s plague, started from China or North-East India. Procopius of Caesarea, the Byzantine historian, blamed Emperor Justinian, maintaining that his actions brought upon God’s fury.

Yet, over time, people’s understanding of pandemics and diseases evolved, and they started relying on scientific explanations instead of superstitions.

The more civilized humans became, the more likely pandemics would occur. As trade relations boosted the spread of pandemics, quarantine was issued in the 14th century as a way to stop plaque from spreading in the coastal cities.

In Venice, ships that returned from a diseased port had to sit at the anchor for a month before they landed. In the 19th century, people used quarantine as the only way to survive the cholera outbreak in London.

To determine how infectious a disease is, scientists use a measure called the reproduction number, the R0 or “R naught”, which shows the number of people infected, and the number of those that can be susceptible to the disease on average.

For instance, measles is the most contagious, with an R0 range of 12-18.

The R0 of the COVID-19 is yet to be determined, as its outbreak is still ongoing and researchers are still learning about it.

The infographic can be used to compare the infectiousness of COVID-19 to the pandemics humans have experienced throughout history, from the Antonine Plague, of 165 to 180 AD, which killed an estimated 5 million people in the Roman Empire and accelerated its disintegration, to more recent pandemics, like Ebola and the swine flu.

The bubonic plague, also known as the Black Death, was the most lethal of all diseases, causing the death of nearly 200 million people in the 14th century.

Next is smallpox, which has killed over 56 million people in over four centuries, before it was finally eradicated in 1980.

The death rate of COVID-19 is fortunately significantly lower, but it is still in its early stages.

What remains the same in all pandemics in history is that the denser the neighborhood, the higher the risk of people being affected by pandemics. The driving forces behind pandemics remain to be the rising global connections and interactions.

Nowadays, the spread of diseases is additionally boosted by climate crisis and pollution.

What we can do in these “dark times” until scientists manage to find an effective medicine or, hopefully, a vaccine, is to be conscious and follow the recommendations of experts.