Abstract
Objective: To assess the magnitude of active and recovering COVID-19 patients among at-risk communities and to identify the factors associated with positive serology.
Methods: Four hundred and eighty-three close contacts of COVID-19 patients residing in Ho Chi Minh City, Vietnam, during the fourth wave of the COVID-19 epidemic (September and October 2021) were included. Five weeks after exposure to a COVID-19 patient, they underwent a serology test using the BIOSYNEX COVID-19 BSS kit.
Results: The median age of participants was 37 years. A total of 34.6% individuals presented at least one clinical symptom between the time of contact with the COVID-19 patient and inclusion in study. A total of 1.7% unvaccinated individuals tested positive for SARS-CoV-2 using real-time PCR, and 9.5% had evidence of recent infection (positive PCR and/or IgM). A further 26.7% unvaccinated individuals presented evidence of a past infection (positive IgG only). Socio-demographic characteristics, vaccination status and clinical symptoms were not associated with a positive IgM test.
Conclusion: This is the first serosurvey conducted during the fourth wave of the epidemic in Vietnam. It revealed a seropositivity rate higher than in previous studies and confirmed the hyperendemicity of SARS-CoV-2. Testing using rapid serological tests proved to be a reliable, easy-to-use method and enabled a rapid estimation of the burden of COVID-19.
Keywords: COVID-19; SARS-CoV-2; Vietnam; high-density communities; seroprevalence.
【저자키워드】 COVID-19, SARS-CoV-2, Vietnam, seroprevalence., high-density communities, 【초록키워드】 IgG, IgM, vaccination, Infection, Testing, Characteristics, Serosurvey, Real-time PCR, Community, serology test, Evidence, COVID-19 epidemic, close contact, Contact, COVID-19 patient, Ho Chi Minh, Factor, clinical symptom, city, median age, individual, IgM test, participant, previous study, positive, positive PCR, positive serology, high-density, Inclusion, rapid serological test, the epidemic, tested, identify, conducted, magnitude, BSS, 【제목키워드】 Seroprevalence, Community, high-density,