Pandemic

Epidemic, Endemic and Pandemic - Definitions

"The doctor of the plague", etching by Paulus Fürst 1656 (from J. Columbina). During the plague epidemic of 1656, in Rome, doctors believed that this clothing protected from infection. They wore a waxed cloak, a sort of protective goggles and gloves. Aromatic substances were found in the beak.

• Disease incidence : number of NEW cases of disease within a population during a specific period of time (weeks / month / year); it differs from the prevalence, which instead indicates the number of people within a population who suffer from that disease at a particular time or time span;
• sporadic infection : the infectious disease affects a negligible part of the population in an isolated and discontinuous manner, without relations with other cases;
• epidemic : the disease spreads rapidly in a limited population, affecting a much higher percentage of people than the average incidence of the disease in the population considered; consequently, the epidemic does not necessarily refer to a large number of people (as can be the spread of mumps in a school); for example, the occurrence of even a single case of smallpox would in itself represent an epidemic given that the virus has been eradicated worldwide;
• pandemic : when an epidemic spreads rapidly through vast territories and continents, affecting a vast number of individuals in different countries of the world, a pandemic is more correctly spoken of; Note well: the term pandemic applies only to diseases or contagious pathological conditions, therefore, many of the diseases that affect very large areas or the entire planet (for example cancer) are not to be considered pandemics
• endemia : continuous persistence of a disease in a particular population or locality (for example, dengue is endemic in the tropical and subtropical areas of the planet); it is subject to periodic recrudescence but the number of cases, more or less high, tends to remain constant. There are two types:
  1. dyscrasic endemics such as goiter, pellagra or beriberi, which derive from particular forms of feeding of the populations;
  2. infectious endemics - such as plague and cholera in India, yellow fever in America, sleeping sickness in Africa, malaria in wetlands, etc. - which are related to environmental conditions favorable to the conservation and spread of the germs responsible for these diseases.

Pandemic cases in history

A pandemic is not necessarily related to the severity or mortality of the infectious disease. However, in the past, some pandemics have led to very high numbers of patients, hospitalizations and deaths, with serious health, social and economic implications. Let's look at some examples:

• bubonic plague (or black plague), a pandemic that devastated Europe in the 14th century, killing over a third of the continent's total population.
• 1918-19, the Spanish epidemic [A (H1N1)] - so called because it seems to have developed from a death in the Spanish royal house - caused the highest number of deaths due to influenza, even if the data are very uncertain and range from 20 to 75-100 million people worldwide. Many deaths occurred within a few days of the infection, others due to subsequent complications. About half of the cases occurred between healthy young people and adults. The influenza A virus of subtype H1N1, after a period of absence of circulation in man (from 1958 to 1977), reappeared and continued to spread in the human population.
• 1957-58, Asian influence [A (H2N2)]. It caused seventy thousand deaths in the United States. The virus, identified for the first time in China in February 1957, spread in June of the same year in America and the rest of the world.
• 1968-69, Hong Kong influence [A (H3N2)]. Responsible for about 34, 000 deaths in the United States, the virus was first identified in Hong Kong in early 1968 and later spread to America. This subtype is still in circulation.

The fears of the health authorities are directed above all to the flu, given the punctual appearance of new pandemics at intervals of 20-40 years, correlated to the continuous antigenic reshuffling of animal flu viruses (pigs, aviaries) and humans; from this continuous genetic recombination can thus originate new strongly aggressive strains for humans, able to spread from person to person, finding fertile ground in an immune system that - having never met the virus - is scarcely active against him .. Another real danger of a pandemic could derive from the spread of multi-resistant bacterial strains to antibiotics, with the resurgence of diseases currently under control, such as tuberculosis.

Pandemic prevention

Although globalization, with its high level of mobility of goods and people on a global scale, can facilitate the spread of pandemics, compared to the past, health authorities are certainly more prepared to face a possible spread of an infection (stock of drugs antivirals, veterinary and animal surveillance protocols, continuous study of new drugs and vaccines etc.). The individual citizen, for his part, can contribute to avoiding the spread of pandemics by respecting the basic hygiene rules and the behavioral rules recommended from time to time by the health authorities; for example:

• adequate food storage and preventive cooking before use;
• purchase of food guaranteed by origin and origin;
• avoid cross-contamination with other foods during refrigeration or food handling (eg do not use for vegetables the same cutting board or the same knife used to cut raw meat);
• careful washing of the hands before and after going to the bathroom, before each meal and before or after handling raw food;
• thorough washing of utensils and kitchen surfaces;
• preventive vaccinations when going to countries at risk and adopting additional hygiene measures in the event of poor hygienic conditions (eg drinking only water from sealed bottles, also paying attention to ice cubes and water used to brush teeth, avoid the consumption of raw vegetables, protection from mosquitoes and other pests ...);
• adoption of all those useful behaviors to reinforce the body's immune defenses;
• avoid risky sexual relationships and use barrier contraceptive methods;
• to limit the development of drug resistance, avoid self-treatment with antibiotics and complete treatment according to medical indications; avoid therefore to stop the therapy at the first signs of healing;
• even in the absence of an ongoing flu pandemic, preventive influenza vaccination is strongly recommended for the older part of the population (people over the age of 65) and for individuals of all ages who, due to previous pathological conditions, could have serious consequences for their health if they contracted the flu. It should be pointed out, however, that, contrary to normal winter epidemics, an influenza pandemic would involve large segments of the population and could also occur in young and perfectly healthy individuals.