The coronavirus that causes covid-19 has already infected more than 100 million people and has killed more than 2.3 million worldwide. The prevention and control measures that different countries have put in place have yielded different results in terms of the scope of the pandemic and the changes it causes in society.
Control an outbreak in a residence hall: confinement by rooms, food in a tupperware and patience
In this context, researchers from the City University of Hong Kong (CityU), the Chinese Academy of Sciences and the Rensselaer Polytechnic Institute (USA) have developed a mathematical model to analyze the efficacy of different non-pharmaceutical interventions (NPI, in English), such as the closure of schools or social distancing in different areas (home, workplace, public spaces …) in New York City.
After running thousands of simulations, the results, published in the journal Chaos, show that the social distancing of the entire population next to the protection of the elderly in public spaces It is the most effective control measure to reduce serious coronavirus infections and deaths, and not so much the closure of schools, which hardly benefits.
“School only accounts for a small proportion of social contact. People are more likely to be exposed to the virus in public places, such as restaurants and shopping centers,” explains the co-author. Qingpeng Zhang from CityU, which insists: “Since we focus here on serious infections and fatalities, school closings contribute little if older citizens are not protected in public places and facilities.”
Zhang acknowledges to SINC that infected students could act as a bridge to the elderly or more vulnerable people, “but our results indicate that social contacts linked to schools are relatively lower than those of other sites. Therefore, the closure of schools it is not as effective as you would expect if those other public places do not have adequate social distancing measures. ”
To carry out their study, the authors have used a new model called A-SEIRD (assessing susceptible-exposed-infected-recovered-dead cases taking into account age) based on known models SEIR / SIR, highlighting the role of specific patterns that include age and location in epidemiological models.
“These patterns are unique to different cities: good practice in one city may not translate to another,” says Zhang, “although, in any case, ideal NPIs are those that can contain the epidemic with minimal disruption of social contacts, something especially important in cities like New York or Hong Kong, whose economies depend on international trade. In others, such as Madrid, I assume that it would be applicable because it is a relevant economic center in southern Europe, but it is not a scientific conclusion because I do not know the data. ”
In the case of New York, the numerical simulations of the model show that its control policies reduced the number of infections by 72% and the number of deaths by 76% at the end of 2020 (considering ranges in interquartiles statistics). The data also reflects that, being such a densely populated city, the effects of schools are significantly less than the general day-to-day interactions between the population.
The authors emphasize that while these findings have promising implications, the model still cannot capture the complexities and the subtle details of real life interactions offering a perfect measure. The inclusion of mobile phone data, censuses, transport and others big data they could help in the future to present results more adjusted to reality.