Artículos Gobierno

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Facing the blue Anthropocene in Patagonia by empowering indigenous peoples’ action networks
(2023) Araos, Francisco; Hidalgo, Carlos; Brañas, Francisco; Anbleyth-Evans, Jeremy; Diestre, Florencia; Yu Iwama, Allan
Chilean Patagonia is a globally significant ecosystem for biodiversity, and simultaneously a global center for the aquaculture industry. Environmental crises have accelerated over the last decades with the installation of salmon farms, increasing impacts on indigenous livelihoods and the habitats of marine species. Indigenous Marine Areas (IMA) have confronted the effects of the blue Anthropocene in Chilean Patagonia, causing diverse indigenous communities to evolve mechanisms to enhance ocean health and sustainability. Based on an analysis of the main socio-spatial trends of IMA in Patagonia and their action networks in the Los Lagos Region, this study demonstrates the importance of a multiple agent network to mobilize the implementation of IMA. The study shows how indigenous people face the challenges of the UN Ocean Decade, enhancing the sustainability pathways of blue Patagonia.
Imitation of Novel Intransitive Body Actions in a Beluga Whale (Delphinapterus leucas): A “Do as Other Does” Study
(2023) Zamorano-Abramson, José; Hernández-Lloreda, María Victoria
Cetaceans are well known for their unique behavioral habits, such as calls and tactics. The possibility that these are acquired through social learning continues to be explored. This study investigates the ability of a young beluga whale to imitate novel behaviors. Using a do-as-other does paradigm, the subject observed the performance of a conspecific demonstrator involving familiar and novel behaviors. The subject: (1) learned a specific ‘copy’ command; (2) copied 100% of the demonstrator’s familiar behaviors and accurately reproduced two out of three novel actions; (3) achieved full matches on the first trial for a subset of familiar behaviors; and (4) demonstrated proficiency in coping with each familiar behavior as well as the two novel behaviors. This study provides the first experimental evidence of a beluga whale’s ability to imitate novel intransitive (non-object-oriented) body movements on command. These results contribute to our understanding of the remarkable ability of cetaceans, including dolphins, orcas, and now beluga whales, to engage in multimodal imitation involving sounds and movements. This ability, rarely documented in non humananimals, has significant implications for the development of survival strategies, such as the acquisition of knowledge about natal philopatry, migration routes, and traditional feeding areas, among these marine mammals.
Another in need enhances prosociality and modulates frontal theta oscillations in young adults
(2023) Lavín, Claudio; Soto-Icaza, Patricia; López, Vladimir; Billeke, Pablo
Introduction: Decision-making is a process that can be strongly affected by social factors. Evidence has shown how people deviate from traditional rationalchoice predictions under different levels of social interactions. The emergence of prosocial decision-making, defined as any action that is addressed to benefit another individual even at the expense of personal benefits, has been reported as an example of such social influence. Furthermore, brain evidence has shown the involvement of structures such as the prefrontal cortex, anterior insula, and midcingulate cortex during decision settings in which a decision maker interacts with others under physical pain or distress or while being observed by others. Methods: Using a slightly modified version of the dictator game and EEG recordings, we tested the hypothesis that the inclusion of another person into the decision setting increases prosocial decisions in young adults and that this increase is higher when the other person is associated with others in need. At the brain level, we hypothesized that the increase in prosocial decisions correlates with frontal theta activity. Results and Discussion: The results showed that including another person in the decision, setting increased prosocial behavior only when this presence was associated with someone in need. This effect was associated with an increase in frontocentral theta-oscillatory activity. These results suggest that the presence of someone in need enhances empathy concerns and norm compliance, raising the participants’ prosocial decision-making.
Towards a comprehensive approach to mentalization-based treatment for children with autism: integrating attachment, neurosciences, and mentalizing
(2023) Costa-Cordella, Stefanella; Soto-Icaza, Patricia; Borgeaud, Karin; Grasso-Cladera, Aitana; Malberg, Norka T.
Autism spectrum disorder (ASD) is diagnosed based on socio-communicative difficulties, which are believed to result from deficits in mentalizing, mainly evidenced by alterations in recognizing and responding to the mental states of others. In recent years, efforts have been made to develop mentalization-based treatment (MBT) models for this population. These models focus on enhancing individuals’ ability to understand and reflect on their own mental states, as well as those of others. However, MBT approaches for people with ASD are limited by their existing theoretical background, which lacks a strong foundation grounded in neuroscience-based evidence properly integrated with attachment, and mentalizing. These are crucial aspects for understanding psychological processes in autism, and as such, they play a pivotal role in shaping the development of tailored and effective therapeutic strategies for this specific population. In this paper we review evidence related to the neurobiological, interpersonal, and psychological dimensions of autism and their implications for mentalizing processes. We also review previous mentalization-based frameworks on the psychosis continuum to provide a comprehensive understanding of attachment, neurobiology, and mentalization domains in therapeutic approaches for autism. After presenting a synthesis of the literature, we offer a set of clinical strategies for the work with children with autism. Finally, we provide recommendations to advance the field towards more robust models that can serve as a basis for evidence-based therapeutic strategies.
La despótica confortabilidad del consumidor: la identidad de cliente en el mercado personalizado
(2022) AEDO, ANDRES
Las interacciones entre consumidores y oferentes han dejado de ser intercambios libres y voluntarios basados en la mutua conveniencia, pues en las transacciones de mercado han emergido prácticas despóticas y violentas por parte de los clientes hacia los trabajadores. Esta forma patológica de ejercicio del consumo es resultado del condicionamiento de la nueva sociedad de mercado marcada por la personalización de productos y servicios, posibilitando la emergencia de una nueva forma de identidad de consumidor que tiene como rasgo característico la confortabilidad de los clientes. Esta condición de personalización/confortabilidad hace que se estructure una relación de autoridad situacional entre oferta y demanda, y posibilita los tratos despóticos cuando los deseos de los clientes son perturbados.
La ética de la confortabilidad personal: una nueva identidad económica
(2022) ; AEDO, ANDRES; Vargas, Francisca
Este artículo sostiene como hipótesis que una de las formas de comprender los comportamientos agresivos de los clientes hacia los trabajadores en el mercado contemporáneo puede sustentarse en la emergencia del derecho a la confortabilidad personal como característica de un nuevo espíritu del consumidor. Este derecho a la confortabilidad personal, derivado de una situación de autoridad y subordinación entre clientes y trabajadores, dada la personalización de los mercados contemporáneos, fue paradójicamente desplegado por las mismas empresas en sus procesos de atención a los clientes, tal como se aprecia en los manuales de atención al cliente analizados en este trabajo.
The influence of the Kemmerer’s Mission in the Constitution of 1925
(2022) Soto Velasco, Sebastián; Couyoumdjian, Juan Pablo
The Kemmerer Mission, which visited Chile between July and October 1925, was hired in order to implement a series of monetary and financial reforms intended to achieve monetary stability in the country. As part of this work, it was also consulted regarding some articles of the Constitution that was being drafted during this period. The participation of the Kemmerer mission in the discussion regarding the budgetary and fiscal norms of what would be the Constitution of 1925 is a matter that has not been sufficiently studied either by the constitutional or economic history in Chile. Some of the proposals of the Mission, such as the debates on the presidential initiative, came to ratify issues already agreed upon. Others, such as the reduction of the discussion period for the budget and the requirement to approve funded bills, were widely welcomed. And there are other matters where Kemmerer’s proposals were rejected. Based on this, we conclude that its influence on these matters was limited. But although the stricture in budgetary matters proposed by the Kemmerer Mission was considered excessive in the country, even in an admittedly presidential convention, this marks the beginning of a trend that laid the foundations for the concentration of financial power in the Executive.
COVID-19 aftermath: exploring the mental health emergency among students at a Northern Italian University
(2022) Patrono, Alessandra; Renzetti, Stefano; Manco, Angela; Brunelli, Paola; Moncada, Stefanny M.; Macgowan, Mark J.; Placidi, Donatella; Calza, Stefano; Cagna, Giuseppa; Rota, Matteo; Memo, Maurizio; Tira, Maurizio; Lucchini, Roberto G.
In this study, we investigated the symptoms of physical and mental health associated with lifestyle changes due to a lockdown among the students of a university in Northern Italy, one of the most affected areas in Europe during the first wave of COVID-19. We examined the psychopathological variations in relation to mental health problems in a young population. The goal was to develop interventions to resolve these new psychosocial problems. From June to July 2020, students participated in an anonymous survey asking about habits and symptoms that emerged during the lockdown and the COVID-19 pandemic. Five health outcomes were assessed: digestive disorders; headaches; fear of COVID-19; panic and anxiety crises; and depression/sadness. The conditions and duration of the social isolation, lifestyle, SARS-CoV-2 infection in the household, financial situation, and productivity were considered in the analysis. A total of 3533 students completed the survey. The participants experienced headaches, depression and sadness, digestive disorders, a fear of COVID-19, and anxiety/panic crises. The duration of isolation was associated with an increased risk of digestive disorders, headaches, and COVID-19 fear. The female gender, medium-intense telephone usage, sleep quality, memory difficulties, and performance reduction were associated with an increased risk of the health outcomes. Future interventions should focus on promoting and implementing different habits with the support of health and university organizations.
Multimodal imitative learning and synchrony in cetaceans: A model for speech and singing evolution
(2023) Zamorano-Abramson, José; Michon, Maëva; Hernández-Lloreda; Aboitiz, Francisco
Multimodal imitation of actions, gestures and vocal production is a hallmark of the evolution of human communication, as both, vocal learning and visual-gestural imitation, were crucial factors that facilitated the evolution of speech and singing. Comparative evidence has revealed that humans are an odd case in this respect, as the case for multimodal imitation is barely documented in non-human animals. While there is evidence of vocal learning in birds and in mammals like bats, elephants and marine mammals, evidence in both domains, vocal and gestural, exists for two Psittacine birds (budgerigars and grey parrots) and cetaceans only. Moreover, it draws attention to the apparent absence of vocal imitation (with just a few cases reported for vocal fold control in an orangutan and a gorilla and a prolonged development of vocal plasticity in marmosets) and even for imitation of intransitive actions (not object related) in monkeys and apes in the wild. Even after training, the evidence for productive or “true imitation” (copy of a novel behavior, i.e., not pre-existent in the observer’s behavioral repertoire) in both domains is scarce. Here we review the evidence of multimodal imitation in cetaceans, one of the few living mammalian species that have been reported to display multimodal imitative learning besides humans, and their role in sociality, communication and group cultures. We propose that cetacean multimodal imitation was acquired in parallel with the evolution and development of behavioral synchrony and multimodal organization of sensorimotor information, supporting volitional motor control of their vocal system and audio-echoic-visual voices, body posture and movement integration
When the agency wants too much: Experimental evidence on unfair audits and tax compliance
(2023) Lancee, Bora; Rossel, Lucía; Kasper, Matthias
This research investigates how unfairness in tax enforcement affects tax compliance. We study how unfair audits that overestimate a taxpayer’s true income affect the aggregate compliance level and the post-audit tax compliance of audited taxpayers. Using an online experiment with a representative sample of UK taxpayers, we find that introducing unfair audits has a positive effect on the aggregate compliance level. However, increasing the amount by which audits overestimate true income has no effect. Moreover, we find that the experience of unfairness in tax enforcement reduces post-audit tax compliance in the subsequent tax declaration by at least 7 percentage points. Our findings suggest that threatening taxpayers with unfair audits increases compliance in the aggregate, but behavioral responses to experiencing unfair audits undermine this effect.
The Ethics of Fractional-Reserve Banking System: A Private Property Rights Approach
(2023) Espinosa, Víctor I.; Alonso-Neira, Miguel A.; Huerta de Soto, Jesús
It is generally stated that the fractional-reserve banking system (FRBS) is consistent with sustainable economic growth and development. While it assumes that depositors will not be a joint demand who will claim all their money simultaneously, it supposes that a monetary aggregate greater than the monetary base will not harm economic performance. However, the FRBS’s call to central banks casts doubt on the sustainability argument and its ethical support. This article explores the FRBS from the ethics of private property, proving a radically different course to promote sustainable economic growth and development. After reviewing and discussing the ethics of private property for the FRBS and its call for central banks, the case of fiat inflation and business cycles clarifies the narrow relationship between ethics and sustainability. These findings are applied to some modern ethical dilemmas around the FRBS, proving novel avenues for policy reform and research opportunities.
Aportes epistemológicos para el análisis de la producción científica biomédica en torno a la niñez
(2019) Larraín-Valenzuela, Josefina
El siguiente artículo analiza, desde una perspectiva epistemológica, cuáles son los posibles mecanismos que operan en la producción de investigaciones científicas de carácter biomédico aplicadas a niños y niñas, y cómo influyen en la interpretación de los resultados, causando eventuales consecuencias que distan de los discursos emancipadores de la propia niñez. En el desarrollo del artículo se plantean tres posibles conflictos epistemológicos asociados a: la binariedad, la lógica de poder y la noción de realidad. La propuesta de hacer visibles estos conflictos permitiría explicar y comprender de manera crítica cómo se interpreta la producción científica del conocimiento. Cada hipótesis explicativa ofrece propuestas para incorporar, dentro de la producción científica, ciertas orientaciones provenientes de enfoques interdisciplinares como una forma de acercarse a la construcción del conocimiento desde una ética de la consecuencia que evite la vulneración de niños y niñas y se abran a mayores posibilidades de reconocimiento social.
A real-time fMRI neurofeedback system for the clinical alleviation of depression with a subject-independent classification of brain states: A proof of principle study
(2022) Pereira, Jaime A.; Ray, Andreas; Rana, Mohit; Silva, Claudio; Salinas, César; Zamorano, Francisco; Irani, Martín; Opazo, Patricia; Sitaram, Ranganatha; Ruíz, Sergio
Most clinical neurofeedback studies based on functional magnetic resonance imaging use the patient's own neural activity as feedback. The objective of this study was to create a subject-independent brain state classifier as part of a real-time fMRI neurofeedback (rt-fMRI NF) system that can guide patients with depression in achieving a healthy brain state, and then to examine subsequent clinical changes. In a first step, a brain classifier based on a support vector machine (SVM) was trained from the neural information of happy autobiographical imagery and motor imagery blocks received from a healthy female participant during an MRI session. In the second step, 7 right-handed female patients with mild or moderate depressive symptoms were trained to match their own neural activity with the neural activity corresponding to the “happiness emotional brain state” of the healthy participant. The training (4 training sessions over 2 weeks) was carried out using the rt-fMRI NF system guided by the brain-state classifier we had created. Thus, the informative voxels previously obtained in the first step, using SVM classification and Effect Mapping, were used to classify the Blood-Oxygen-Level Dependent (BOLD) activity of the patients and converted into real-time visual feedback during the neurofeedback training runs. Improvements in the classifier accuracy toward the end of the training were observed in all the patients [Session 4–1 Median = 6.563%; Range = 4.10–27.34; Wilcoxon Test (0), 2-tailed p = 0.031]. Clinical improvement also was observed in a blind standardized clinical evaluation [HDRS CE2-1 Median = 7; Range 2 to 15; Wilcoxon Test (0), 2-tailed p = 0.016], and in self-report assessments [BDI-II CE2-1 Median = 8; Range 1–15; Wilcoxon Test (0), 2-tailed p = 0.031]. In addition, the clinical improvement was still present 10 days after the intervention [BDI-II CE3-2_Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.50/ HDRS CE3-2 Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.625]. Although the number of participants needs to be increased and a control group included to confirm these findings, the results suggest a novel option for neural modulation and clinical alleviation in depression using noninvasive stimulation technologies.
Us versus them mentality in football fans: Significant social defeat engages the mentalization network and disengages cognitive control areas [version 1; peer review: awaiting peer review]
(2023) Zamorano, Francisco; Patricio Carvajal-Paredes; Soto-Icaza, Patricia; Stecher, Ximena; Salinas, César; Muñoz Reyes, José Antonio; López, Vladimir; Méndez, Waldemar; Barrera, Joel; Aragón-Caqueo, Gonzalo; Billeke, Pablo; Carvajal Paredes, Francisco
Background: Social affiliation is one of the building blocks that shapes cultures and communities. This motivation contributes to the development of social bonding among individuals within a group, enjoying rights, assuming obligations, and strengthening its identity. Evidence has shown that social affiliation has inspired different social phenomena, such as wars, political movements, social struggles, among others, based on two human motivations: the ingroup love and the outgroup hate. One contemporary group to study as a proxy of social affiliation, and ingroup and outgroup motivations is the sports competition. However, this affiliation model has been poorly considered in social neuroscience research. This research aimed to shed light on the neurobiological networks that are related to social affiliation in football fans of two of the most popular Chilean football teams. Methods: To this end, 43 male fans of two football rival teams watched videos of winning and losing goals of their favorite team while their brain activity was measured with functional magnetic resonance imaging (fMRI). Results: The results showed that while the activation of the reward system was observed in fans when their team scores goals against the rival, both the activation of the mentalization network and the inhibition of the dorsal anterior cingulate cortex were associated with the emotional correlates of defeat in football fans. Conclusions: Taking these findings together could contribute to a deeper understanding of social affiliation, and more importantly, of extreme affiliation phenomena, and fanaticism.
COVID-19 Aftermath : Exploring the Mental Health Emergency among Students at a Northern Italian University
(2022-07-14) Patrono,Alessandra; Renzetti,Stefano; Manco, Angela; Brunelli, Paola; Moncada, Stefanny M.; Macgowan, Mark J.; Placidi, Donatella; Calza, Stefano; Cagna, Giuseppa; Rota, Matteo; Memo, Maurizio; Tira, Maurizio; Lucchini, Roberto G.
In this study, we investigated the symptoms of physical and mental health associated with lifestyle changes due to a lockdown among the students of a university in Northern Italy, one of the most affected areas in Europe during the first wave of COVID-19. We examined the psychopathological variations in relation to mental health problems in a young population. The goal was to develop interventions to resolve these new psychosocial problems. From June to July 2020, students participated in an anonymous survey asking about habits and symptoms that emerged during the lockdown and the COVID-19 pandemic. Five health outcomes were assessed: digestive disorders; headaches; fear of COVID-19; panic and anxiety crises; and depression/sadness. The conditions and duration of the social isolation, lifestyle, SARS-CoV-2 infection in the household, financial situation, and productivity were considered in the analysis. A total of 3533 students completed the survey. The participants experienced headaches, depression and sadness, digestive disorders, a fear of COVID-19, and anxiety/panic crises. The duration of isolation was associated with an increased risk of digestive disorders, headaches, and COVID-19 fear. The female gender, medium-intense telephone usage, sleep quality, memory difficulties, and performance reduction were associated with an increased risk of the health outcomes. Future interventions should focus on promoting and implementing different habits with the support of health and university organizations.
Aportes históricos de la neurociencia cognitiva y su emergencia en Chile
(2022) Larraín-Valenzuela, Josefina; Mardones D., Francisca; Freire, Yerka; Kausel K., Leonie; Aboitiz, Francisco
Very little has been written about the national pioneer investigators and the formal institutions and channels of knowledge that have contributed to the consolidation of cognitive neuroscience in Chile. This article is a review based on scientific publications, magazine articles and interviews with neuroscientists that were key to the development of cognitive neuroscience in Chile. In particular, the review incorporates information about the different Chilean investigators, the universities where they completed their doctoral studies, and the institutions where they settled afterwards. The objective of this article is to describe the way in which neuroscientific knowledge extended in Chile and to give recognition to pioneering scientists. The information retrieved was processed through the reconstruction of an interaction network between local and foreign neuroscientists, as well as their universities and institutions of origin, that contributed to the development of cognitive neuroscience in Chile. A visual representation of these networks was elaborated. In addition, the scientists’ academic training in Chile and abroad is summarized in a table. This analysis allows for a deeper comprehension of the socio-historical context in which cognitive neuroscience emerges and encourages a critical perspective of its development in Chile.
A moral trade-off system produces intuitive judgments that are rational and coherent and strike a balance between conflicting moral values
(2022) Guzmán Price, Ricardo; Barbatoa, María Teresa; Daniel Sznycer, Daniel; Cosmides, Leda
How does the mind make moral judgments when the only way to satisfy one moral value is to neglect another? Moral dilemmas posed a recurrent adaptive problem for ancestral hominins, whose cooperative social life created multiple responsibilities to others. For many dilemmas, striking a balance between two conflicting values (a compromise judgment) would have promoted fitness better than neglecting one value to fully satisfy the other (an extreme judgment). We propose that natural selection favored the evolution of a cognitive system designed for making trade-offs between conflicting moral values. Its nonconscious computations respond to dilemmas by constructing “rightness functions”: temporary representations specific to the situation at hand. A rightness function represents, in compact form, an ordering of all the solutions that the mind can conceive of (whether feasible or not) in terms of moral rightness. An optimizing algorithm selects, among the feasible solutions, one with the highest level of rightness. The moral trade-off system hypothesis makes various novel predictions: People make compromise judgments, judgments respond to incentives, judgments respect the axioms of rational choice, and judgments respond coherently to morally relevant variables (such as willingness, fairness, and reciprocity). We successfully tested these predictions using a new trolley-like dilemma. This dilemma has two original features: It admits both extreme and compromise judgments, and it allows incentives—in this case, the human cost of saving lives—to be varied systematically. No other existing model predicts the experimental results, which contradict an influential dual-process model.
Immunization and SARS-CoV-2 Antibody Seroprevalence in a Country with High Vaccination Coverage: Lessons from Chile
(2022) Aguilera, Ximena; González, Claudia; Apablaza, Mauricio; Rubilar, Paola; Icaza, Gloria; Ramírez, Muriel; Pérez, Claudia; Cortes, Lina; Núñez, Loreto; Quezada, Rubén; Castillo, Carla; Correa, Juan; Said, Macarena; Hormazábal, Juan; Vial, Cecilia; Vial, Pablo
Chile is among the most successful nations worldwide in terms of its COVID-19 vaccine rollout. By 31 December 2021, 84.1% of the population was fully vaccinated, and 56.1% received booster doses using different COVID-19 vaccines. In this context, we aimed to estimate the prevalence of anti-SARS-CoV-2 antibodies following the infection and vaccination campaign. Using a three-stage stratified sampling, we performed a population-based cross-sectional serosurvey based on a representative sample of three Chilean cities. Selected participants were blood-sampled on-site and answered a short COVID-19 and vaccination history questionnaire using Wantai SARS-CoV-2 Ab ELISA to determine seroprevalence. We recruited 2198 individuals aged 7-93 between 5 October and 25 November 2021; 2132 individuals received COVID-19 vaccinations (97%), 67 (3.1%) received one dose, 2065 (93.9%) received two doses, and 936 received the booster jab (42.6%). Antibody seroprevalence reached 97.3%, ranging from 40.9% among those not vaccinated to 99.8% in those with booster doses (OR = 674.6, 154.8-2938.5). SARS-CoV-2 antibodies were associated with vaccination, previous COVID-19 diagnosis, age group, and city of residence. In contrast, we found no significant differences in the type of vaccine used, education, nationality, or type of health insurance. We found a seroprevalence close to 100%, primarily due to the successful vaccination program, which strongly emphasizes universal access.
SARS-CoV-2 Neutralizing Antibodies in Chile after a Vaccination Campaign with Five Different Schemes
(2022) Aguilera, Ximena; Hormazábal, Juan; Vial, Cecilia; Cortés, Lina Jimena; González, Claudia; Rubilar, Paola; Apablaza, Mauricio; Ramírez-Santana, Muriel; Icaza, Gloria; Núñez-Franz, Loreto; Castillo-Laborde, Carla; Ramírez-Riffo, Carolina; Pérez, Claudia; Quezada-Gate, Rubén; Said, Macarena; Vial, Pablo
Using levels of neutralizing antibodies (nAbs), we evaluate the successful Chilean SARS-CoV-2 vaccine campaign, which combines different vaccine technologies and heterologous boosters. From a population-based study performed in November 2021, we randomly selected 120 seropositive individuals, organized into six groups of positive samples (20 subjects each) according to natural infection history and the five most frequent vaccination schemes. We conclude that the booster dose, regardless of vaccine technology or natural infection, and mRNA vaccines significantly improve nAbs response.
First wave of SARS-CoV-2 in Santiago Chile: Seroprevalence, asymptomatic infection and infection fatality rate
(2022) Vial, Pablo; González, Claudia; Apablaza, Mauricio; Vial, Cecilia; Lavín, M. Estela; Araos, Rafael; Rubilar, Paola; Icaza, Gloria; Florea, Andrei; Pérez, Claudia; Concha, Paula; Bastías, Diego; Errázuriz, María Paz; Pérez, Ruth; Guzmán, Francisco; Olea, Andrea; Guzmán, Eugenio; Correa, Juan; Munita, José; Aguilera, Ximena
Background: The first wave of SARS-CoV-2 infection in Chile occurred during the cold season reaching a peak by the end of June 2020, with 80 % of the cases concentrated in its capital, Santiago. The main objective of this study was to estimate the attack rate during this first wave of SARS-CoV-2 in a large, densely populated city with more than seven million inhabitants. Since the number of confirmed cases provides biased information due to individuals’ potential self-selection, mostly related to asymptomatic patients and testing access, we measured antibodies against SARS-CoV-2 to assess infection prevalence during the first wave in the city, as well as estimate asymptomatic cases, and infection fatality ratio. To our knowledge this is one of the few population-based cross- sectional serosurvey during the first wave in a highly affected emerging country. The challenges of pandemic response in urban settings in a capital city like Santiago, with heterogeneous subpopulations and high mobility through public transportation, highlight the necessity of more accurate information regarding the first waves of new emerging diseases. Methods: From April 24 to June 21, 2020, 1326 individuals were sampled from a long-standing panel of household representatives of Santiago. Immunochromatographic assays were used to detect IgM and IgG anti-body isotypes. Results: Seroprevalence reached 6.79 % (95 %CI 5.58 %− 8.26 %) in the first 107 days of the pandemic, without significant differences among sex and age groups; this figure indicates an attack rate 2.8 times higher than the one calculated with registered cases. It also changes the fatality rate estimates, from a 2.33 % case fatality rate reported by MOH to an estimated crude 1.00 % (CI95 % 0.97–1.03) infection fatality rate (adjusted for test performance 1.66 % [CI95 % 1.61–1.71]). Most seropositive were symptomatic (81,1 %). Conclusions: Despite the high number of cases registered, mortality rates, and the stress produced over the health system, the vast majority of the people remained susceptible to potential new epidemic waves. We contribute to the understanding of the initial spread of emerging epidemic threats. Consequently, our results provide better information to design early strategies that counterattack new health challenges in urban contexts.

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