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Hoang VT, Pham TD, Nguyen QT, Nguyen DC, Nguyen DT, Nguyen TB, Tran TKT, Phan TL, Vo PLN, Dao TL, Fenollar F, Gautret P. Seroprevalence of SARS-CoV-2 among high-density communities and hyper-endemicity of COVID-19 in Vietnam. Trop Med Int Health 2022; 27:515-521. [PMID: 35303386 PMCID: PMC9115418 DOI: 10.1111/tmi.13744] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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.
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Affiliation(s)
- Van Thuan Hoang
- Thai Binh University of Medicine and PharmacyThai BinhVietnam
| | - Thi Dung Pham
- Thai Binh University of Medicine and PharmacyThai BinhVietnam
| | | | | | | | | | | | - Trong Lan Phan
- General Department of Preventive MedicineMinistry of HealthHa NoiVietnam
| | | | - Thi Loi Dao
- Thai Binh University of Medicine and PharmacyThai BinhVietnam
| | - Florence Fenollar
- Aix Marseille UnivIRDAP‐HMSSA, VITROMEMarseilleFrance
- IHU‐Méditerranée InfectionMarseilleFrance
| | - Philippe Gautret
- Aix Marseille UnivIRDAP‐HMSSA, VITROMEMarseilleFrance
- IHU‐Méditerranée InfectionMarseilleFrance
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2
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Hasan T, Thach PN, Anh NT, Hien LTT, An NTM, Thuy DT, Van Duyet L, Dung NT, Diep TT, Van Huynh H, Toelle BG, Marks GB, Fox GJ. The prevalence of SARS-CoV-2 antibodies in quarantine workers and high-risk communities in Vietnam. IJID REGIONS 2022; 2:137-140. [PMID: 35721423 PMCID: PMC8665841 DOI: 10.1016/j.ijregi.2021.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/04/2022]
Abstract
A low prevalence (2%) of SARS-CoV-2 antibodies was found among quarantine workers. A low prevalence of SARS-CoV-2 antibodies was found in communities with COVID-19. Vietnam had controlled the COVID-19 pandemic until mid-2021. This study preceded the widespread outbreak in Vietnam in mid-2021.
Objective The aim of this study was to determine the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in high-risk communities and quarantine workers in Vietnam. Methods The prevalence of SARS-CoV-2 antibodies was measured in household contacts, close contacts, community members, and migrant workers from two sub-communes in which COVID-19 outbreaks occurred in early 2021: Bac Ma 1 and Tien. The prevalence of SARS-CoV-2 antibodies was also evaluated among quarantine workers at two facilities responsible for quarantining of contacts of COVID-19 cases. Results Among 2069 participants from the two sub-communes, six individuals (0.3%) had detectable SARS-CoV-2 antibodies despite no history of COVID-19. This included one Vietnamese migrant worker, two community members, two household contacts, and one close contact of known COVID-19 cases. Among 50 workers at two COVID-19 quarantine facilities, including 15 health care workers (HCWs), one of the HCWs tested positive for SARS-CoV-2 antibodies (1/50, 2.0%) despite no known disease. Conclusion The prevalence of SARS-CoV-2 antibodies was low in Vietnamese ‘hotspots’, suggesting limited community transmission.
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3
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Nguyen HHH, Nguyen QH, Truong DTT, Dao MH, Le TN, Nguyen HT, Nguyen AH, Nguyen TV, Hoang DTN, Hoang LK, Tran TT, Cao TM, Luong QC, Phan LT, Huynh LTK, Nguyen TV, Pham QD. Seroprevalence of SARS-CoV-2 Neutralizing Antibodies among Blood Donors in Ho Chi Minh City, Vietnam, August-November 2020. Am J Trop Med Hyg 2022; 106:891-895. [PMID: 35081510 PMCID: PMC8922498 DOI: 10.4269/ajtmh.21-0259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 01/05/2022] [Indexed: 12/27/2022] Open
Abstract
Relatively little is known about the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibodies and COVID-19-related behaviors in the general population in Vietnam, where the first case of COVID-19 was detected on January 22, 2020. We surveyed a group of 885 blood donors at community blood donation sessions in Ho Chi Minh City from August 27 to November 7, 2020. Blood was collected to test for SARS-CoV-2 IgG antibodies using the plaque reduction neutralization test. We adjusted the seroprevalence by weight for ages 18 to 59 years old obtained from the 2019 population census. The weighted seroprevalence estimate for SARS-CoV-2 neutralizing IgG antibodies was 0.20% (95% CI, 0.05-0.81). Reports of usually or always using a mask in public places were observed at high levels of 28.6% and 67.5%, respectively. The percentages of usually or always washing hands with soap or disinfecting with hand sanitizer after touching items in public places were 48.0% and 37.6%, respectively. Although our findings suggest undocumented exposure to the virus, the seroprevalence of SARS-CoV-2 IgG antibodies among blood donors was low in this city.
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Affiliation(s)
- Hanh Hong Ho Nguyen
- Training Center, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam;,School of Medicine, Vietnam National University, Ho Chi Minh City, Vietnam;,Viet-Anh Department, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Quan Hoang Nguyen
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Dung Thi Thuy Truong
- Department for Disease Control and Prevention, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Manh Huy Dao
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Tu Ngoc Le
- Department for Disease Control and Prevention, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Hieu Trung Nguyen
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Anh Hoang Nguyen
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Thinh Viet Nguyen
- Department for Disease Control and Prevention, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | | | - Loan Kim Hoang
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Tham Thi Tran
- Blood Donation Centre of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Thang Minh Cao
- Microbiology and Immunology Department, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Quang Chan Luong
- Department for Disease Control and Prevention, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Lan Trong Phan
- Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | | | - Thuong Vu Nguyen
- Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Quang Duy Pham
- Training Center, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam;,Planning Division, Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City, Vietnam,Address correspondence to Quang D. Pham, Training Center– Planning Division, Pasteur Institute of Ho Chi Minh City, 167 Pasteur St., District 3, Ho Chi Minh City, Vietnam. E-mail:
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4
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Chau NVV, Nguyet LA, Truong NT, Toan LM, Dung NT, Hung LM, Nhan MT, Man DNH, Ngoc NM, Thao HP, Tu TNH, Mai HK, Hung DT, Ny NTH, Thanh LK, Anh NT, Hong NTT, Nhu LNT, Yen LM, Choisy M, Thanh TT, Thwaites G, Tan LV. Immunogenicity of Oxford-AstraZeneca COVID-19 Vaccine in Vietnamese Health-Care Workers. Am J Trop Med Hyg 2022; 106:556-561. [PMID: 34996048 PMCID: PMC8832887 DOI: 10.4269/ajtmh.21-0849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/29/2021] [Indexed: 11/07/2022] Open
Abstract
We studied the immunogenicity of the Oxford-AstraZeneca vaccine in health-care workers of a major infectious diseases hospital in Vietnam. We measured neutralizing antibodies before and 14 days after each dose, and at day 28 and month 3 after dose 1. A total of 554 workers (136 men and 418 women; age range, 22-71 years; median age, 36 years) participated with the study. Of the 144 participants selected for follow-up after dose 1, 104 and 94 gave blood for antibody measurement at weeks 6 and 8, and at month 3 after dose 1, respectively. The window time between the two doses was 6 weeks. At baseline, none had detectable neutralizing antibodies. After dose 1, the proportion of participants with detectable neutralizing antibodies increased from 27.3% (151 of 554) at day 14 to 78.0% (432 of 554) at day 28. Age correlated negatively with the development and the levels of neutralizing antibodies. However, at day 28, these differences were less profound, and women had a greater seroconversion rate and greater levels of neutralizing antibodies than men. After dose 2, these age and gender associations were not observable. In addition, the proportion of study participants with detectable neutralizing antibodies increased from 70.2% (73 of 104) before dose 2 (week 6, after dose 1) to 98.1% (102 of 104) 14 days later. At month 3, neutralizing antibodies decreased and 94.7% (89 of 94) of the study participants remained seropositive. The Oxford-AstraZeneca COVID-19 vaccine is immunogenic in Vietnamese health-care workers. These data are critical to informing the deployment of the COVID-19 vaccine in Vietnam and in Southeast Asia, where vaccination coverage remains inadequate.
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Affiliation(s)
| | - Lam Anh Nguyet
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Le Mau Toan
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Le Manh Hung
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Mai Thanh Nhan
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | - Nghiem My Ngoc
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | | | | | | | | | | | - Le Kim Thanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nguyen To Anh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | | | - Lam Minh Yen
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Marc Choisy
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Tran Tan Thanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Guy Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Institute of Pasteur, Nha Trang City, Vietnam
| | - Le Van Tan
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
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Chau NVV, Ngoc NM, Nguyet LA, Quang VM, Ny NTH, Khoa DB, Phong NT, Toan LM, Hong NTT, Tuyen NTK, Phat VV, Nhu LNT, Truc NHT, That BTT, Thao HP, Thao TNP, Vuong VT, Tam TTT, Tai NT, Bao HT, Nhung HTK, Minh NTN, Tien NTM, Huy NC, Choisy M, Man DNH, Ty DTB, Anh NT, Uyen LTT, Tu TNH, Yen LM, Dung NT, Hung LM, Truong NT, Thanh TT, Thwaites G, Tan LV. An observational study of breakthrough SARS-CoV-2 Delta variant infections among vaccinated healthcare workers in Vietnam. EClinicalMedicine 2021; 41:101143. [PMID: 34608454 PMCID: PMC8481205 DOI: 10.1016/j.eclinm.2021.101143] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals are limited. METHODS We studied breakthrough infections among Oxford-AstraZeneca vaccinated healthcare workers in an infectious diseases hospital in Vietnam. We collected demographic and clinical data alongside serial PCR testing, measurement of SARS-CoV-2 antibodies, and viral whole-genome sequencing. FINDINGS Between 11th-25th June 2021 (7-8 weeks after the second dose), 69 staff tested positive for SARS-CoV-2. 62 participated in the study. Most were asymptomatic or mildly symptomatic and all recovered. Twenty-two complete-genome sequences were obtained; all were Delta variant and were phylogenetically distinct from contemporary viruses obtained from the community or from hospital patients admitted prior to the outbreak. Viral loads inferred from Ct values were 251 times higher than in cases infected with the original strain in March/April 2020. Median time from diagnosis to negative PCR was 21 days (range 8-33). Neutralizing antibodies (expressed as percentage of inhibition) measured after the second vaccine dose, or at diagnosis, were lower in cases than in uninfected, fully vaccinated controls (median (IQR): 69.4 (50.7-89.1) vs. 91.3 (79.6-94.9), p=0.005 and 59.4 (32.5-73.1) vs. 91.1 (77.3-94.2), p=0.002). There was no correlation between vaccine-induced neutralizing antibody levels and peak viral loads or the development of symptoms. INTERPRETATION Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies. Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals. FUNDING Wellcome and NIH/NIAID.
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Affiliation(s)
| | - Nghiem My Ngoc
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | - Lam Anh Nguyet
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vo Minh Quang
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | - Dao Bach Khoa
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | - Le Mau Toan
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | | | - Voong Vinh Phat
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | | | | | | | | | - Vo Trong Vuong
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | - Ngo Tan Tai
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | - Ho The Bao
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | | | | | - Nguy Cam Huy
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | - Marc Choisy
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | | | - Nguyen To Anh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | | | - Lam Minh Yen
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | | | - Le Manh Hung
- Hospital for Tropical Diseaes, Ho Chi Minh City, Vietnam
| | | | - Tran Tan Thanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Guy Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Le Van Tan
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
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6
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He S, Hecimovic A, Matijasevic V, Mai HT, Heslop L, Foster J, Alexander KE, Pal N, Alexandrou E, Davidson PM, Frost SA. Prevalence of SARS-CoV-2 antibodies among nurses: A systematic review and meta-analysis. J Clin Nurs 2021; 31:1557-1569. [PMID: 34570947 PMCID: PMC8661824 DOI: 10.1111/jocn.16009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/10/2021] [Accepted: 08/05/2021] [Indexed: 12/12/2022]
Abstract
Aims and Objectives This systematic review and meta‐analysis reports the seroprevalence of SARS‐CoV‐2 antibodies among nurses. Background With a growing body of literature reporting the positive serology for SARS‐CoV‐2 antibodies among healthcare workers, it remains unclear whether staff at the point of direct patient care are more prone to developing and transmitting the virus. Given nurses make up the majority of the global health workforce, outbreaks among these workers could severely undermine a health system’s capability to manage the pandemic. We aimed to summarise and report the seroprevalence of SARS‐CoV‐2 antibodies among nurses globally. Design Systematic review and meta‐analyses. Methods This systematic review was developed, undertaken and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guideline. We searched the electronic medical literature databases: MEDLINE; CINAHL; and EMBASE for studies reporting the seroprevalence of SARS‐CoV‐2 antibodies among nursing staff. Studies that reported nursing specific data were included in this review. Study quality was evaluated using the Joanna Briggs Institute checklist for studies reporting prevalence data. Studies were stratified according to the World Health Organisation region classifications, and results were presented using forest plots and summary prevalence and variance was estimated using a random effects model. Results Our electronic search identified 1687 potential studies, of which 1148 were screened for eligibility after duplicates were removed, and 51 of the studies were included in our meta‐analysis. The overall seroprevalence of SARS‐CoV‐2 antibodies among nurses was estimated to be 8.1% (95% CI 6.9%–9.4%) among the 60,571 participants included in the studies. Seropositivity was highest in the African region (48.2%, 95% CI 39.2%–57.3%), followed by the European region (10.3%, 95% CI 8.0%–12.5%), the Region of the Americas (8.4%, 95% CI 6.0%–10.7%), the South‐East Asia region (3.0%, 95% CI 0.00%–6.5%) and the Western Pacific region (0.5%, 95% CI 0.0%–1.0%). Pooled estimates were unable to be calculated in the Eastern Mediterranean region due to insufficient studies. Conclusion The seroprevalence of SARS‐CoV‐2 antibodies among nurses is comparable to other healthcare workers, and possibly similar to the general population. Early adoption and adherence to personal protective equipment and social distancing measures could explain these similarities, meaning the majority of staff contracted the virus through community transmission and not in a healthcare setting. Relevance to clinical practice Fear and uncertainty have been features of this pandemic, including among nurses. This meta‐analysis should provide some comfort to nurses that risks are similar to community exposure when adequate PPE is available and there is an adherence to infection control measures.
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Affiliation(s)
- Steven He
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,Western Sydney University, Sydney, New South Wales, Australia
| | - Anthony Hecimovic
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,South Western Sydney Local Health District Primary and Community Health, Sydney, New South Wales, Australia
| | - Vesna Matijasevic
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,South Western Sydney Local Health District Primary and Community Health, Sydney, New South Wales, Australia
| | - Ha Thi Mai
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,Western Sydney University, Sydney, New South Wales, Australia
| | - Linda Heslop
- Ken Merten Library, Liverpool Hospital, Sydney, New South Wales, Australia
| | - Jann Foster
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,Western Sydney University, Sydney, New South Wales, Australia.,NSW Centre for Evidence Based Health Care: A JBI Affiliated Group, Sydney, New South Wales, Australia
| | - Kate E Alexander
- South Western Sydney Local Health District Public Health Unit, Sydney, New South Wales, Australia
| | - Naru Pal
- South Western Sydney Local Health District Public Health Unit, Sydney, New South Wales, Australia
| | - Evan Alexandrou
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,Western Sydney University, Sydney, New South Wales, Australia.,Department of Intensive Care, Liverpool Hospital, Sydney, New South Wales, Australia.,Griffith University, Brisbane, Queensland, Australia
| | | | - Steven A Frost
- South Western Sydney Nursing and Midwifery Research, Ingham Institute of Applied Medical Research, Sydney, New South Wales, Australia.,Western Sydney University, Sydney, New South Wales, Australia.,Department of Intensive Care, Liverpool Hospital, Sydney, New South Wales, Australia
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7
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Flower B, Marks M. Did Laos really control the transmission of SARS-CoV-2 in 2020? LANCET REGIONAL HEALTH-WESTERN PACIFIC 2021; 13:100202. [PMID: 34308399 PMCID: PMC8290237 DOI: 10.1016/j.lanwpc.2021.100202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 06/14/2021] [Indexed: 11/26/2022]
Affiliation(s)
- Barnaby Flower
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Michael Marks
- Clinical Research Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London.,Hospital for Tropical Diseases, London, United Kingdom
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Sero-Prevalence of SARS-CoV-2 Antibodies in High-Risk Populations in Vietnam. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18126353. [PMID: 34208212 PMCID: PMC8296183 DOI: 10.3390/ijerph18126353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/07/2021] [Accepted: 06/07/2021] [Indexed: 12/23/2022]
Abstract
As a response to the coronavirus disease 2019 (COVID-19) pandemic, Vietnam enforced strict quarantine, contact tracing and physical distancing policies resulting in one of the lowest numbers of individuals infected with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) globally. This study aimed to determine the prevalence of SARS-CoV-2 antibody positivity among high-risk populations in Vietnam. A prevalence survey was undertaken within four communities in Vietnam, where at least two COVID-19 cases had been confirmed. Participants were classified according to the location of exposure: household contacts, close contacts, community members, and healthcare workers (HCWs) responsible for treating COVID-19 cases. Participants completed a baseline questionnaire and SARS-CoV-2 IgG antibodies were quantified using a commercial assay. A total of 3049 community members and 149 health care workers consented to the study. Among 13 individuals who were seropositive (0.4%), five household contacts (5/27, 18.5%), one close contact (1/53, 1.9%), and seven community members (7/2954, 0.2%) had detectable SARS-CoV-2 antibodies. All HCWs were negative for SARS-CoV-2 antibodies. Participants were tested a median of 15.1 (interquartile range from 14.9 to 15.2) weeks after exposure. Our study found a low prevalence of SARS-CoV-2 antibodies in high-risk communities and healthcare workers in communities in Vietnam with known COVID-19 cases.
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9
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Seroprevalence of hospital staff in a province with zero COVID-19 cases. PLoS One 2021; 16:e0238088. [PMID: 33793556 PMCID: PMC8016267 DOI: 10.1371/journal.pone.0238088] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 03/04/2021] [Indexed: 12/31/2022] Open
Abstract
Background COVID-19 seroprevalence data, particularly in less developed countries with a relatively low incidence, has been scant. We aimed to explore the seroprevalence of hospital staff in the area with zero confirmed COVID-19 case to shed light on the situation of COVID-19 infection in zero or low infection rate countries where mass screening was not readily available. Methods A locally developed rapid immunoglobulin M (IgM)/immunoglobulin G (IgG) test kit was used for hospital staff screening of Ranong hospital which is located in a province with zero COVID-19 prevalence in Thailand from 17th April to 17th May 2020. All staff was tested, 100 of which were randomly invited to have a repeating antibody test in one month. (Thai Clinical Trials Registry: TCTR20200426002) Results Of 844 hospital staff, 82 were tested twice one month apart (response rate for repeating antibody test 82%). Overall, 0.8% of the participants (7 of 844) had positive IgM, none had positive IgG. Female staff had 1.0% positive IgM (95% CI: 0.5–2.1%) while male had 0.5% positive IgM (95% CI: 0.1–2.6%). No participants with a history of travel to the high-risk area or close contact with PCR-confirmed COVID-19 case developed SARS-CoV-2 antibodies. Among 844 staff, 811 had no symptoms and six of them developed IgM seropositive (0.7%) while 33 had minor symptoms and only one of them developed IgM seropositive (3.0%). No association between SARS-CoV-2 IgM status and gender, history of travel to a high-risk area, close contact with PCR-confirmed or suspected COVID-19 case, presence of symptoms within 14 days, or previous PCR status was found. None of the hospital staff developed SARS-CoV-2 IgG. Conclusions COVID-19 antibody test could detect a considerable number of hospital staff who could be potential silent spreaders in a province with zero COVID-19 cases. Accurate antibody testing is a valuable screening tool, particularly in asymptomatic healthcare workers. Trial registration: This study was approved by the Institutional Review Board of Chulalongkorn University (IRB No.236/63) and the Institutional Review Board of Ranong Hospital. (Thai Clinical Trials Registry: TCTR20200426002).
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