By pouring our hope into vaccines, we forget that we could stop the pandemic before achieving the desired herd immunity. To do this, in addition to improving the diagnostic system, we must change the paradigm that has permeated the strategies against covid-19. This implies assuming that, like the love in the song Love is in the air, the new coronavirus is also floating in the environment. For this reason, we must shift the axis of the measures to prevent them —disinfection of surfaces and standard physical distance— to coordinate efforts to ventilate the interiors.
Taiwan, which with 23.6 million inhabitants did not register a single domestic infection from April to December, is an example that the pandemic can be approached from another perspective. Your secret? First, an exemplary system of diagnosis and contact tracing. But even more important was that, thanks to the experience of East Asian countries with previous pandemics due to other coronaviruses that did not reach Europe – SARS, in 2003 and MERS, in 2012 – they soon understood that the new virus also spread. could spread through the air and generalized the use of masks From the beginning.
That form of contagion, called airborne transmission, is produced by aerosol sprays, microscopic particles that we expel when we breathe, speak or cough and that float loaded with viruses in closed places without ventilating where someone is infected. In non-ventilated interiors, the virus can be spread even if we maintain two meters of interpersonal distance.
Any outdoor space is less risky than eating with friends at home. Thus, it is sensible to close restaurant interiors and not their terraces, where getting infected is very unlikely unless they cough in our faces
That is why we detected numerous outbreaks in nursing homes, homes, restaurants, discos or offices; and none on beaches, where the coronavirus spreads as soon as the air runs. Any outdoor space is less risky than eating with friends at home. In fact, sharing air indoors is the most important risk factor for getting infected. Thus, it is sensible to close restaurant interiors and not their terraces, where getting infected is very unlikely unless they cough us in the face. Recall that in the US there were no notable outbreaks after the massive anti-racist demonstrations of 2020, but there were after family celebrations, such as Thanksgiving. In Spain, they soared after Christmas.
It is indoors where there is high risk
It is disheartening that we are still not clear that the risk of contagion occurs indoors, to which the partisan use of policies in the face of the pandemic and the wide Polarization in our society. Although it is shocking, and without addressing the issue of civility and the added risk of alcohol consumption, the celebrations of the end of the state of alarm in the streets of many cities or those of Genova street after the elections to the Community of Madrid involve a low risk of contagion because they occur in open spaces. What is serious, on the other hand, are the parties in houses with closed windows, the interiors of bars and entertainment venues, family gatherings in homes, and non-ventilated spaces.
The risk of contagion indoors grows if we crowd together and the more time we spend inside because it is necessary to inhale a certain amount of virus to become infected. It increases significantly after fifteen or thirty minutes, so going to buy bread for a moment has a very low risk. It also increases if indoors we sang, we scream or we are agitated because this way we exhale and inhale more quantity of virus. That is why it is common for dozens or hundreds of people to become infected in gymnastics classes, discos or choir rehearsals, as happened to the Zarzuela Theater Choir at the beginning of the pandemic.
Masks are the next key measure to prevent infection. Let’s be stricter indoors, where those with the highest filtering capacity —FPP2 or KN95— are more recommended.
A good ventilation It is the main measure to avoid contagion because it is what makes an interior look as much as possible to an exterior. A recent editorial in The BMJ also explains how this pandemic has redefined the concept of airborne transmission about the determinants of ventilation. The conceptual debate about the connotations of the term has become entrenched in the scientific community, such as whether it was the chicken or the egg before. Thus, although we have known the capital importance of ventilating interiors for more than half a year, the false idea persists that the key is to have everything like the jets of gold.
If an enclosed space, such as a school or business, does not have an adequate ventilation system, it should keep open doors or windows. Homes where someone has been infected must also be ventilated. It is enough to leave two openings on opposite sides for the air to flow, which we verify if the curtains are moved or with a portable CO2 meter, the gas that we exhale when we breathe.
The masks they are the next key measure to avoid infection. But we take them on the street, where almost no one is infected, while we can take them off inside a restaurant. Let’s be stricter indoors, where those with the highest filtering capacity —FPP2 or KN95— are more recommended than outdoors, where they only make sense in agglomerations. And remember to adhere it well to the face. Let’s not use excuses, if breathing with a mask made you sick, there would be no healthy surgeons left.
Mask, silence and ventilation
In this context, it is sad that many cinemas have closed: we do not know outbreaks in cinemas. In addition to its greater amplitude, those interiors where we are calm, in silence and with masks are safer because this way we exhale and inhale the minimum possible aerosols. The same occurs in other cultural environments, such as museums, theaters or libraries and in urban public transport. In fact, there are also no documented outbreaks since we wear a mask in subways, commuter trains or urban buses, which contributes to the fact that they are ventilated at each stop. In Catalonia or Valencia it is already recommended keep quiet or lower your voice on public transportation and in Japan yelling is not allowed on soccer fields. Let’s copy them.
All the money wasted on disinfecting could be used to improve ventilation and air filtration, which we do get infected.
Nor are there hardly any documented infections by touching surfaces or objects. What’s more, the probability of becoming infected every time we touch a contaminated surface is less than 1 in 10,000, according to a recent estimate by the US Centers for Disease Control and Prevention (CDC). Some studies early in the pandemic overestimated that risk, but we already know that it is almost non-existent for this virus. Thus, if we get infected at a dinner, it is not by passing the tureen, but by sharing the air.
Why, then, do we keep doing deep cleaning? asked a recent report in Nature. All the money wasted on disinfecting we could use it to improve ventilation and air filtration, which does infect us. Let’s maintain frequent hand washing as a precaution and because it prevents other infections, but thorough cleaning only makes sense where the sick are concentrated, such as in hospitals.
To prevent infections, colds, gastroenteritis or angina must also be considered as suspected covid-19 until proven otherwise. The coronavirus can produce all of these symptoms or those of a flu and there is no way to tell it apart without a test. Also, the infection may not give a fever or any symptoms at all.
As we do not get infected by being on the street, there is no justification for new confinements or indiscriminate perimeter closures. In uncontrolled outbreaks, let’s be drastic with non-essential interiors, but expand pedestrian spaces and terraces, promote the telecommuting and the outdoor activities, let us respect cultural spaces and parks, increase the use of public transport and promote outdoor exercise. Let’s listen to the song from the beginning, let’s remember that the coronavirus, like love, is in the air, and let’s act accordingly.
Aser Garcia Rada (@AserGRada) is a pediatrician, doctor of Medicine from the Complutense University of Madrid, actor and freelance journalist.