Introduction: The 2019 coronavirus pandemic (COVID-19) has caused around 25 million cases worldwide . Asymptomatic patients have been described as potential sources of transmission . However, there are difficulties to detect them and to establish their role in the dynamics of virus transmission, which hinders the implementation of prevention strategies .
Objective: To describe the behavior of asymptomatic SARS-CoV-2 virus infection in a cohort of workers at the El Dorado``Luis Carlos Galán Sarmiento"International Airport in Bogotá, Colombia . Materials and methods: A prospective cohort of 212 workers from the El Dorado airport was designed . The follow-up began in June , 2020 . A survey was used to characterize health and work conditions . Every 21 day, a nasopharyngeal swab was taken to identify the presence of SARS-CoV-2 using RT-PCR . We analyzed the behavior of the cycle threshold (ORF1ab and N genes) according to the day of follow-up .
Results: In the first three follow-ups of the cohort, we found an incidence of SARS-CoV-2 infection of 16.51% . The proportion of positive contacts was 14.08% . The median threshold for cycle threshold was 33.53 . Conclusion: We characterized the asymptomatic SARS-CoV-2 infection in a cohort of workers . The identification of asymptomatic infected persons continues to be a challenge for epidemiological surveillance systems.