Showing papers by "Luis Hernandez published in 2021"
TL;DR: In this article, the authors implemented a COVID-19 sentinel surveillance study with 59,770 RT-PCR tests on mostly asymptomatic individuals and combined this data with administrative records on all detected cases to capture the spread and dynamics of the COVID19 pandemic in Bogota from June 2020 to early March 2021.
Abstract: Latin America has been severely affected by the COVID-19 pandemic but estimations of rates of infections are very limited and lack the level of detail required to guide policy decisions. We implemented a COVID-19 sentinel surveillance study with 59,770 RT-PCR tests on mostly asymptomatic individuals and combine this data with administrative records on all detected cases to capture the spread and dynamics of the COVID-19 pandemic in Bogota from June 2020 to early March 2021. We describe various features of the pandemic that appear to be specific to a middle income countries. We find that, by March 2021, slightly more than half of the population in Bogota has been infected, despite only a small fraction of this population being detected. The initial buildup of immunity contributed to the containment of the pandemic in the first and second waves. We also show that the share of the population infected by March 2021 varies widely by occupation, socio-economic stratum, and location. This, in turn, has affected the dynamics of the spread with different groups being infected in the two waves.
14 citations
TL;DR: In this article, the authors examined, for the first time in a low- or middle-income country, which mechanisms best explain the disproportionate impact of the SARS-CoV-2 pandemic on the poor.
Abstract: Across the world, the SARS-CoV-2 (COVID-19) pandemic has disproportionately affected economically disadvantaged groups. This differential impact has numerous possible explanations, each with significantly different policy implications. We examine, for the first time in a low- or middle-income country, which mechanisms best explain the disproportionate impact of the virus on the poor. Combining an epidemiological model with rich data from BogotAi, Colombia, we show that total infections and inequalities in infections are largely driven by inequalities in the inability to work remotely and in within-home secondary attack rates. Inequalities in isolation behavior are less important but non-negligible, while access to testing and contract-tracing plays practically no role. Interventions that mitigate transmission are often more effective when targeted on socioeconomically disadvantaged groups.
5 citations
TL;DR: In this paper, the authors evaluated the SARS-CoV-2 antibodies specific for the virus in individuals working at one university in Bogota-Colombia and identified three clusters of seropositive individuals.
Abstract: Most community-specific serological surveys for SARS-CoV-2 antibodies have been done in healthcare workers and institutions. In this study, IgG antibodies specific for the virus were evaluated in individuals working at one university in Bogota-Colombia. The aim of this work was to determine previous exposure to SARS-CoV-2 in those attending the campus during city lockdown. A total of 237 individuals including 93 women and 144 men were evaluated using chemiluminescent detection of IgG anti N-viral protein. There were 32 positives giving a seroprevalence of 13.5% (10 women and 22 men) and mostly asymptomatic (68.75%). Only 13 of the seropositive individuals had previous positive detection of SARS-CoV-2 RNA by RT-qPCR done in average 91 days before serological test. Seropositive individuals did not come from localities having higher percentages of SARS-CoV-2 cases in the city. Three cluster of seropositive individuals were identified. This survey was carried out after the first peak of SARS-CoV-2 transmission in the city, and before the preparedness to reopening the campus for students in 2021. These results will help to develop some of the strategies stablished to control virus spread in the campus.
2 citations
TL;DR: The CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bogota and low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.
2 citations
TL;DR: While the first wave of infections was driven by the lowest economic strata and highly-exposed occupations, the second peak affected the population more evenly, and the share of the population infected by February 2021 varies widely by occupation, socio-economic stratum, and location.
Abstract: In many developing countries, the COVID-19 pandemic has spread much faster and wider than the number of detected cases implies. By combining data from 59,770 RT-PCR tests on mostly asymptomatic individuals with administrative data on all detected cases, we capture the spread and dynamics of the COVID-19 pandemic in Bogota from June 2020 to early March 2021. Our data provide unusually broad and detailed information on mostly asymptomatic adults in Bogota, allowing to describe various features of the pandemic that appear to be specific to a developing country context. We find that, by the end of March 2021, slightly more than half of the population in Bogota has been infected, despite only a small fraction of this population being detected. In July 2020, after four months of generalized quarantine that mitigated the pandemic without curving it, the initial buildup of immunity contributed to the end of the first wave. We also show that the share of the population infected by February 2021 varies widely by occupation, socio-economic stratum, and location. This, in turn, has affected the dynamics of the spread: while the first wave of infections was driven by the lowest economic strata and highly-exposed occupations, the second peak affected the population more evenly. A better understanding of the spread and dynamics of the pandemic across different groups provides valuable guidance for efficient targeting of health policy measures and restrictions.
1 citations