ABSTRACT
Most community-specific serological surveys for SARS-CoV-2 antibodies have been performed in healthcare workers and institutions. In this study, IgG antibodies specific to the virus were evaluated in individuals working at a university campus in Bogotá, Colombia. Our aim 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 between November and December 2020. There were 32 positive individuals, i.e., a seroprevalence of 13.5% (10 women and 22 men) mostly asymptomatic (68.75%);we identified three clusters of seropositive individuals. Only 13 of the seropositive individuals had previous positive detection of SARS-CoV-2 RNA by RT-qPCR performed on average 91 days before the serological test. Seropositive individuals did not come from the boroughs with higher percentages of SARS-CoV-2 cases in the city. The survey was carried out after the first peak of SARS-CoV-2 transmission in the city and before the preparedness to reopen the campus for students in 2021, which demonstrates a low seroprevalence in a high percentage of asymptomatic individuals. These results will help to evaluate some of the strategies stablished to control virus spread on the campus or other similar communities. © 2022 Colombian Academy of Exact, Physical and Natural Sciences. All rights reserved.
ABSTRACT
Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model’s performance were based on international experiences and scientific literature. Two screening centers were implemented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bogotá. 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.