In mid-September 1918, authorities in the populous American city of Philadelphia, Pennsylvania, underestimated the lethality of the infamous Spanish Flu.

The term "quarantine" today lacks the semantic connotation that identified it until a few decades ago. "She is now in quarantine", it used to be said of the woman who was taken in for the six-week rest (also called puerperium) indicated by her doctor after giving birth. The measure is still in force, but the word has fallen into disuse.

According to linguists, "quarantine" comes from the Italian words "quaranta giorni," meaning "40 days."
These, in turn, come from the Latin phrase "quadraginta," which means "four times 10."

Its practice began in the 14th century to protect cities on the coast of Europe from the Black Death. Venice was the first to close its ports to ships suspected of coming from infected sites and to set up the first isolation hospital in human history on an island.

"Starting in 1468, the Venetian authorities ordered that arriving ships stay there for 40 days. Passengers and crews were required to disembark, and even the products they carried were unloaded and taken to a huge hole in the centre of the island, where they were disinfected with steaming herbs, vinegar and boiling water," says the Pediatric Surgery website.

Clearly, there was already a strong suspicion that personal contact was conducive to infection. Giovanni Boccaccio, in El Decamerón, explained how the Black Death was spreading: "The fact that healthy people visited or communicated with those who had acquired the disease contributed to giving greater strength and vigour to this pestilence."

Nowadays, and in line with the meaning given to it by the Dictionary of the Royal Spanish Academy (DRAE), quarantine is the "preventive isolation to which people or animals are submitted during a period of time, for health reasons." This is the context in which some Cuban communities are to prevent the transmission of the dangerous COVID-19.

THE CONTRASTS OF A NAME

Scholars speculate that the 40-day cycle set for the preventive isolation of those infected with the Black Death may have been derived from the ancient Greek doctrine of the "critical day." It held that infectious diseases had their most dangerous phase in the 40 days following exposure, and that a shorter period was not enough to completely remove doubt.

Others attribute their origin to mystical factors, and give as an example the sacred books, where the number 40 becomes recurrent: 40 years Moses lived as a shepherd; 40 days lasted the fast of Jesus Christ in the desert; 40 days rained during the universal flood; 40 days calls for Lent to reach spiritual purification; and the prophet Mohammed had his revelation when he was 40 years old.

Galen and Hippocrates, famous Greek physicians of the medieval period, urged people to isolate themselves in the presence of contagious diseases. Galen is credited with the Latin phrase "Cito, Longe, Tarde," which translates into English as "go quickly, go far away and take your time coming back," an obvious health advice to avoid contamination.

Over the years, the word "quarantine" lost its quantitative lineage. But it persists in keeping that name, even though today its duration changes according to the pathology. In fact, medical records show that the longest quarantine in history was suffered in the United States by a humble cook named Mary Mallon, who in 1915 was imprisoned on North Brother Island for 23 years, accused of transmitting typhoid fever twice, although she never showed any symptoms.

WHEN PHILADELPHIA VIOLATED THE QUARANTINE

In mid-September 1918, authorities in the populous American city of Philadelphia, Pennsylvania, underestimated the lethality of the infamous Spanish Flu. In view of the progressive increase in cases of soldiers with acute respiratory problems, they irresponsibly declared that it was only a simple seasonal flu. "Our population has no reason to be concerned," they said, reassuringly.

But the virus began to spread at breakneck speed. The doctors warned that it was something more frightening than a harmless cold. However, no one heard them, for if they had, they would have had to cancel a big parade on the 28th of the month itself, which was to raise funds for the First World War.

That morning, some 200,000 Philadelphians ignored the quarantine dictated by the epidemiologists and crowded into the streets to witness the procession. By this time, 600 military personnel and 47 civilians had been admitted with the flu. The crowding spread the virus in the city so intensely that after three days, the dead totaled 2,600 and all the beds in its 31 hospitals were occupied.

During the following six weeks, 47,000 cases and 12,000 deaths were reported. Six months later, the number of fatalities rose to almost 16,000, and confirmed cases to over half a million. Telephone communications were disrupted, as most of their operators became ill or died. Funerals became a recurrence on the streets of the city, which looked like a death camp. According to the website of the Spanish newspaper Levante, "a mortality rate of 719 deaths per 100,000 was recorded."

By ignoring the recommended sanitary isolation and allowing massive gatherings, the Spanish Flu pandemic left Philadelphia with a sad toll of more than 17,500 victims. In contrast, the nearby city of San Luis, which canceled its parade and implemented social distancing measures, such as closing churches, libraries, theaters, playgrounds, schools, dance halls and banning popular parties, reduced the incidence of the pandemic by less than half compared to the populous city that took on the tragedy.

COVID-19 AND ITS FIGHT IN CUBA

Among the health provisions adopted by the Cuban authorities to prevent the spread of COVID-19 is quarantine, which is decreed depending on the behaviour of the disease in a community and by decision of the National Temporary Group, on the proposal of the presidents of the provincial defence councils.

In a document on the subject, the General Staff of the National Civil Defence indicates that this provision "includes the strict limitation and prohibition of the movement of the population to and from the areas affected by the disease, as well as the increase of active research for the detection, isolation and timely treatment of the sick, disinfection and other health measures."

Populations that are not infected, but which, even if they do not show symptoms of the disease, could be infected due to the risks they have faced, are subject to quarantine. Their asymptomatic inhabitants are restricted in their movements, as they may have been exposed to Covid-19 and do not know it. It can extend up to 28 days, i.e. two maximum incubation periods of the virus.

Isolation has other nuances. It is applied to travellers coming from abroad and lasts 14 days. It is also used to prevent those who test positive for SARS-CoV-2, those suspected of carrying the virus, or those who have had contact with sick people. Everyone is isolated and prevented from contacting healthy people.

Social distancing, on the other hand, makes it advisable to avoid crowds of people who are neither quarantined nor isolated. Those who take to the streets to carry out urgent actions must do everything possible to maintain a distance of no less than one meter from other inhabitants, who may be asymptomatic carriers of the disease.

Quarantine, isolation and social distancing play an important health role in the face of epidemics and pandemics that periodically scourge the health of humanity. Violating their postulates and overconfidence in situations such as those we face today could have very serious consequences. Discipline, common sense and responsibility are key in these cases.

We Cubans must fully comply with the provisions of our government and health authorities. To neutralize Covid-19 implies to proceed together in the fight and to convert the epidemiological forecast into a permanent surveillance quarantine. Only in this way, we will return to that normality that we so deserve and desire.