COVID-19 seroprevalence among hospital staff and preprocedural patients in Thai community hospitals: a cross-sectional study

Abstract

ObjectivesWe aimed to explore the seroprevalence of hospital staff comparing to preprocedural patients in Thai community hospitals to shed light on the situation of COVID-19 infection of frontline healthcare workers in low infection rate countries where mass screening was not readily available.DesignCross-sectional study.Setting52 community hospitals in 35 provinces covered all regions of Thailand.Participants857 participants consisted of 675 hospital staff and 182 preprocedural patients.Outcome measureCOVID-19 seroprevalence using a locally developed rapid IgM/IgG test kitResultsOverall, 5.5% of the participants (47 of 857) had positive IgM, 0.2% (2 of 857) had positive IgG which both of them also had positive IgM. Hospitals located in the central part of Thailand had the highest IgM seroprevalence (11.9%). Preprocedural patients had a higher rate of positive IgM than the hospital staff (12.1% vs 3.7%). Participants with present upper respiratory tract symptoms had a higher rate of positive IgM than those without (9.6% vs 4.5%). Three quarters (80.5%, 690 of 857) of the participants were asymptomatic, of which, 31 had positive IgM (4.5%) which consisted of 20 of 566 healthcare workers (3.5%) and 11 of 124 preprocedural patients (8.9%).ConclusionsCOVID-19 antibody test could detect a substantial number of potential silent spreaders in Thai community hospitals where the nasopharyngeal PCR was not readily available, and the antigen test was prohibited. Antibody testing should be encouraged for mass screening in a limited resource setting, especially in asymptomatic individuals.Trial registrationTCTR20200426002.

SARS-CoV-2 Seroprevalence in Unvaccinated Adults in Thailand in November 2021

“…We found a seroprevalence of 1.4% in the studies. This prevalence increases from the beginning of the fourth wave (April 2021) with 0.2% seropositive results [11,16].…”

Prevalences of SARS-CoV-2 RNA and anti-SARS-CoV-2 among at-risk populations in Chiang Mai and Lamphun provinces, Thailand, during November 2020–January 2021

“…However, a study conducted among hospitalized patients in Siriraj hospital, Bangkok province reported a SARS-CoV-2 prevalence of 7.5% during the February–April 2020 outbreak [ 20 ]. In addition, anti-SARS-CoV-2 IgM seroprevalence among asymptomatic staff working in community hospitals throughout the country and having close contact with infected patients during the outbreak was found 0.8–5.5% and IgG seroprevalence was 0.0–5.0% [ 21 – 23 ]. These IgM or IgG seroprevalence tend to be slightly higher than our results which mat reflect the higher exposure risk of health care workers in contact of COVID-19 patients.…”

“…Data on SARS-CoV-2 prevalence and seroprevalence in Thailand originated from infected individuals (hospitalized and recovered COVID-19 patients), close contacts with recovered COVID-19 patients and healthcare workers is available [ 20 – 23 ]. Data among asymptomatic/mild symptomatic and high exposure risk populations is still scarce, in particular Chiang Mai and Lamphun provinces, Thailand.…”

Exploring the Role of Serology Testing to Strengthen Vaccination Initiatives and Policies for COVID-19 in Asia Pacific Countries and Territories: A Discussion Paper

“…A general agreement exists regarding the use of serology tests to support individual and outbreak management. Australia, India, Indonesia, Thailand, and Taiwan recognize the benefit of serology testing to [237,[256][257][258][263][264][265][266][267][268]:…”

“…The Thai Department of Medical Science advises against antibody testing after receiving a COVID-19 vaccine [259]; • Members of the academic community have recommended using serology testing for preliminary screening to reduce the number of patients who visit the hospital, help predict the extent of infection in the future, detect hot spots, identify plasma donors [264][265][266], and detect asymptomatic individuals through mass screenings [267].…”