Quarantine was once the only tool in the fight against infectious disease. As countries across the globe move towards isolation to stop the spread of Coronavirus, the role of quarantine, even in today’s world of vaccines and antibiotics, is once again proving highly effective. 
To prevent the Black Death spreading in the 14th century, all ships thought to be infected were isolated for 40 days to prevent the spread of the disease. In fact, the word quarantine comes from the Italian quaranta giorni, meaning “40 days”.
Bubonic plague killed an estimated third of Europe’s population during the 14th century. Recurring outbreaks continued across the world until the 19th century, and ships’ crews were regularly inspected on arrival at ports and quarantined if necessary.
In the early years of the plague, Venice took the lead in establishing quarantine stations in the form of ships permanently at anchor, isolated islands, or segregated buildings. The stations became known as lazarettos, after the biblical Lazarus who rose from the dead.
The possessions of those who left the lazarettos were disinfected to prevent the risk of the infection spreading. Special kinds of apparatus, like the device pictured, were used to treat items like coins, letters and clothing.
While the word quarantine originated in the 14th century, the practice of isolating infected patients goes much further back. As long ago as biblical times, people affected with leprosy were segregated from others to protect the community.
Yellow fever is now known to be spread by mosquitoes, but in the 19th century it was believed immigrants were the cause because once bitten, the newcomers were less likely to be able to deal with the infection than locals, since they lacked any immunity from previous exposure.
On board ships and in ports flags were used to signal the presence of disease. The Yellow Jack, flown to denote yellow fever, also became a colloquial name for the disease itself. It is still used today to indicate a ship under quarantine measures.
Yellow fever wasn’t the only disease to be linked with a marginalised group. Many infectious diseases have been described as conditions from other places or have been blamed on specific demographics.
In the early 19th century diphtheria became one of the major causes of death. Its transmission was fuelled by increasingly crowded living conditions, which led to people being isolated in their homes or communities.
The widespread use of antibiotics and vaccination rendered isolation through official quarantining largely redundant in the 20th century. However, quarantine is still practised with infectious diseases like chicken pox or measles, where it is recommended that people stay at home.
Although the plague that led to the word ‘quarantine’ is no longer a threat, pandemics like Coronavirus continue to pose threats to human health on a large scale. In the absence of effective treatments, quarantine remains an important tool in preventing deaths.
While many might be experiencing anxiety about the thought of quarantine, it may be comforting to know that we’ve been practising it for centuries, and that it has been, and remains, an effective intervention in curtailing the spread of infectious disease.
