What are the odds of getting infected during a home party or while we are in a restaurant? Very high, even if the restaurant manager has to comply with all the rules – distance between the tables, maximum number of people inside the room and sanitation of the premises – provided for by the various decrees. This is what emerges from a simulation research conducted by some experts on behalf of the Spanish newspaper “El Pais”, which reproduced three of the most common everyday scenarios.
Dinner at home with friends: the possibilities of contagion
The first of the three scenarios described by “El Pais” concerns a lunch / party at home, with six friends, relatives or acquaintances (one of which is positive for Covid-19) who get together to spend some time together. If the six spent four hours without wearing a mask and without airing the room they are in, the other five people would inevitably be infected. If, however, the six had to wear the mask, the infections would be reduced to four.
To drastically reduce the chances of contagion it is necessary to halve the duration of the meeting (two hours instead of four), wear the mask all the time and, above all, favor air exchange by opening the windows or using ventilation systems in compliance with the law.
Dinner at a restaurant: the possibilities of contagion
The second of the three scenarios, on the other hand, concerns an evening spent in a restaurant (or place in general) where there are 15 customers and 3 waiters. In the simulation, the restaurant has closed doors and has no mechanical ventilation. In the case of a positive patient, without any concern, four hours of stay will be sufficient to infect all the other people present in the room.
If, on the other hand, the 14 not infected constantly wore the mask, even when they are at the table, the number of new infections would drop to 8. Ventilating and airing the room and shortening the time spent in the restaurant, the probability of contagion would be reduced to only 1 person.
Day at school: the possibilities of contagion
The third and final scenario concerns a school class with 24 pupils. The most dangerous situation would be in case the infected subject was the teacher: after two hours of lessons and without any precaution, the infected in class would be 12 (a figure that drops to 5 if everyone wears a mask during the lesson).
The risk of contagion is greatly reduced if, during the lesson, a ventilation system is active that allows the classroom to be aired. Even lower possibilities if the lessons are interrupted for an hour to allow the total exchange of air.
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