From a purely Malthusian perspective – in 1798 the Reverend Thomas Robert Malthus published his seminal work, An Essay on the Principle of Population, in which he observed that whilst population growth was exponential growth in food supply was arithmetical. Without checks populations would grow to a level where food supplies couldn’t sustain them. In the Malthusian view of the world there are two forms of check to the irresistible growth in humanity – preventive checks such as customs and moral restraints and positive checks such as disease, starvation and war – the spectre of plague that the current epidemic of Ebola generates can be seen as a corrective against the inexorable rise of human population.
Of course, the particular – the threat of and an actual outbreak of the disease in your vicinity – raises the age-old question of what to do about it. Our ancestors, heavily influenced by the writings and thinking of such legendary medical sages such as Hippocrates and Galen – thought that disease was caused and transmitted by miasmas. A miasma was a poisonous vapour or mist filled with particles of decomposed matter which caused illness. It was contaminated water, foul air and poor hygiene that caused disease. It was the proximity of humans to these miasmas that caused the epidemic, not the interaction between one infected individual with another.
That said, the idea of isolating the victim is an ancient one – Leviticus, the third book of the Pentateuch , recommends the practice for dealing with lepers. But it took a significant and cataclysmic medical emergency – the Black Death whose mortality rates put the World War carnage and the Spanish Flu epidemic into a cocked hat – before an organised and systematic approach to isolating victims was developed.
The city of Dubrovnik has the dubious privilege of introducing what is now known as quarantine. The city’s archives contain a letter dated 1377 in which it states that newcomers had to wait outside the city limits for a period of thirty days to see whether symptoms of the Black Death appeared. The period of isolation was extended to forty days, a practice that gave rise to the modern English appellation derived from the Italian quaranta giorni.
The city of Venice took the lead in introducing measures to stem the advance of the Black Death, appointing three guardians of public health in 1348 and the first lazaret or quarantine station for maritime travellers was opened in 1403 on a small island off its coast.
Quite why forty days was chosen as the appropriate period for isolation is not exactly clear. Of course, forty has biblical associations – Jesus, for example, was in the wilderness for forty days and forty nights. It may have owed its origins to a specific Hippocratic theory or it may have had a connection with the Pythagorean theory of numbers where four had a particular significance.
Anyway, whatever the reason the period was spent subjecting the poor travellers to a series of processes involving isolation, fumigation and disinfection. This was considered ample enough time to ensure the satisfactory and safe dispersal of the harmful miasmas in the air.
Next time we will look in more detail at the practice of quarantine in action.