|Year : 2022 | Volume
| Issue : 2 | Page : 113-117
A cross-sectional anti-SARS coV-2 seroprevalence study among healthcare workers in a tertiary care hospital of eastern India
Samatirtha Chandra, Roumi Ghosh, Md Khalid Rashid
Department of Microbiology, ESI-PGIMSR ESIC Medical College Hospital, Joka, Kolkata, West Bengal, India
|Date of Submission||05-Jul-2021|
|Date of Decision||08-Jan-2022|
|Date of Acceptance||21-Jan-2022|
|Date of Web Publication||3-Aug-2022|
Dr. Roumi Ghosh
Present working Address: Assistant Professor, Department of Microbiology, ESI-PGIMSR & ESIC Medical College Joka, Diamond Harbour Road, P.O. Joka, Kolkata, West Bengal - 700 104
Source of Support: None, Conflict of Interest: None
Purpose: Seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a cohort of health care workers (HCWs) in our tertiary health care set-up and determine the association of seroconversion with demographic characteristics, level of exposure, job responsibilities, and clinical symptoms of HCWs exposed to COVID-19 patients.
Method: An observational cross-sectional epidemiological study was conducted in the Department of Microbiology, ESI-Postgraduate Institute of Medical Science and Research (PGIMSR), Kolkata. The study population was hospital staff who deliver care and services to patients
Result: A total of 242 HCWs participated in this cross-sectional study. Among the study population, 161 (66.5%) were male, and 81 (33.5%) were females, and the median age was 43 years. Of all, 22.7% were physicians, 22.3% nurses, 15.7% lab technician. A total of 16 HCWs had reported having diabetes mellitus, 7 chronic lung diseases, and 4 cardiac diseases. Out of 242 participants, 30 (12.4%) HCWs were found to be anti-SARS-CoV-2 IgG antibody positive after 4 months of duty in COVID hospital. Seropositivity rate was more among the age group 18–44 years (76.7%) and doctors (33.3%) than other disciplines. Around 31.4% (76/242) of them had high-risk exposure with either COVID patients or samples, and 18.4% became seropositive. A total of 59.1% HCWs gave the history of known or suspected contact with COVID patients in the household, and 14.7% turned seropositive. A total of 84.8% of those participants, who attended in-house training on infection control practices, remained seronegative.
Conclusion: In conclusion, the cross-sectional serology study in a tertiary care hospital in Kolkata revealed 30 (12.4%) HCWs had positive serology responses to SARS-CoV-2 out of 242 participants. Though there was an infection control policy and practice in the hospital to prevent the disease transmission, high-risk exposure and presence of comorbidities were definite risk factors for acquiring disease in our study.
Keywords: Anti SARS-CoV-2 antibody, COVID-19, health care worker, seroprevalence
|How to cite this article:|
Chandra S, Ghosh R, Rashid MK. A cross-sectional anti-SARS coV-2 seroprevalence study among healthcare workers in a tertiary care hospital of eastern India. J NTR Univ Health Sci 2022;11:113-7
|How to cite this URL:|
Chandra S, Ghosh R, Rashid MK. A cross-sectional anti-SARS coV-2 seroprevalence study among healthcare workers in a tertiary care hospital of eastern India. J NTR Univ Health Sci [serial online] 2022 [cited 2022 Dec 10];11:113-7. Available from: https://www.jdrntruhs.org/text.asp?2022/11/2/113/353225
| Introduction|| |
It has been more than a year since COVID-19 (Coronavirus disease 2019) was declared a pandemic illness on 11th March 2020, which has posed a huge challenge to health care settings and health care workers (HCWs). More than 114 million cases of SARS CoV-2 have been reported globally to date with India at the second leading position amounting to nearly 12 million cases. As per the World Health Organization (WHO), health workers are at a higher risk of being infected with SARS-CoV-2 than the general population, and it was estimated that approximately 14% of COVID-19 cases reported to WHO were among health workers. Direct and repeated contact with infected cases and performing aerosol-generating procedures impose this higher risk on them. HCWs play a role in transmission in health care settings as well as in household or community settings. Though a majority of SARS-CoV-2 infected HCWs were symptomatic and presented with cough, fever, and sore throat, a considerable percentage was asymptomatic. One of the main challenges in containing the spread of SARS-CoV-2 is the diagnosis of infected asymptomatic individuals. The majority of the asymptomatic cases may remain undetected and continue to transmit unknowingly.
The infection with the SARS-CoV-2 usually leads to the production of IgG antibodies 11–14 days after the first symptoms, once the individual has recovered after infection and lasts for several months. Though the IgG test is not useful for case detection, serological assay detecting IgG antibodies against SARS-CoV-2 helps us to determine the actual burden of infection and its spread.
The mainstay of diagnosis of COVID-19 as per recommendation, periodic screening by a serological test is an easy to use and cost-effective tool for assessing the level of exposure among hospital personnel and identifying high-risk departments in resource-limited settings., Likewise, the knowledge of past infection among HCW could be useful for avoiding unnecessary quarantines and for health care human resource planning.
| Objectives|| |
Our study aimed to find out the seroprevalence of SARS-CoV-2 in a cohort of HCWs in our tertiary health care set-up and determine the association of seroconversion with demographiccharacteristics, level of exposure, job responsibilities, clinical symptoms of HCWs exposed to COVID-19 patients.
| Materials and Methods|| |
A cross-sectional observational study was conducted in the Department of Microbiology, ESI-Postgraduate Institute of Medical Science and Research (PGIMSR), Kolkata. The study population was hospital staff who deliver care and services to patients, either directly as physicians or nurses, pharmacists, assistants, technicians, nursing orderly conservancy staff, or other support staff (administrative officers, cleaning, kitchen, laundry, maintenance, etc.). All consenting individuals working in our facilities were included in the study. Staff positive for COVID-19 PCR within the last 17 days were excluded from the study.
The participants were interviewed using a web-based questionnaire to collect information on socio-demographic details, history of symptoms suggestive of COVID-19 (e.g., fever, cough, shortness of breath, sore throat, the new loss of taste or smell, fatigue), contact with laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. HCWs were divided according to department and additional duty in COVID wards. We had used a surveillance questionnaire for SARS-CoV-2 infection among health workers formulated by WHO for data collection. A total of 242 HCWs satisfying our inclusion and exclusion criteria were included in this study. Clotted/EDTA blood samples were collected from subjects.
Blood samples were tested for anti-SARS-CoV-2 IgG antibody using Indian council of medical research (ICMR) validated SARS-CoV-2 DetectTM IgG enzyme-linked immunosorbent assay (ELISA) kit (InBios, Washington, USA) following manufacturers instruction. Recommended safety precautions were followed. Biomedical waste disposal was be done following national guidelines.
The study population was divided into two categories. High-risk exposure: frontline HCWs and COVID-19 RT-PCR laboratory workers, including medical doctors, nurses, and laboratory technical persons. Low-risk exposure: administrative staff of the hospital, paramedics, and others who may have minimal chance of exposure. The participants were also asked for contact history with known COVID-19 cases out of the hospital (e.g. household, transport). Ethical approval for this study ( An anti-SARS coV-2 sero-prevalence study among healthcare workers in a tertiary care hospital of eastern India) was provided by the Institutional Ethics Committee (IEC) of ESI-PGIMSR & ESIC Medical College, Joka, Kolkata on 22.12.2020 (Letter no.: No. 412 (DEAN-JOKA)/IEC/2014-15/VolI).
| Results|| |
A total of 242 HCWs of our health facility participated in this cross-sectional study. [Table 1] shows the age and sex distribution of our study population. The median age of participants was 43 years, and 161 (66.5%) were male and 81 (33.5%) female, and. Of all, 19.4% were physicians, 20.7% nurses, 11% lab technicians, 4.2% clerks, and 23% nursing orderly, and the rest others. A total of 73% (177/242) HCWs had not reported any underlying comorbidity, whereas 16 participants reported having diabetes mellitus, 4 asthma, 2 chronic renal disease, and 2 cardiac diseases.
Around 33% (81/242) of them had direct interaction with either COVID patients or samples, including 75 working at the COVID-19 ward and 34 at laboratories handling samples from COVID patients. Ninety-five of the participants had reported having COVID-19 exposure by direct contact (95/242, 39.0%). Forty of the participants had ever had possible COVID-19 symptoms in the past 3 months (40/242, 16.5%). Twenty-eight of them had a sore throat, headache, fatigue, and twelve of them had a fever ≥38°C [Table 2].
|Table 2: Sero-Prevalance OF COVID-19 IGG and ITS distribution among different demographic, occupational, risk of exposure, and contact history|
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Though 77% of the participants attended a training session on Infection Prevention & Control including personal protective equipment (PPE) donning-doffing, 11% failed to practice the recommended steps [Table 3].
|Table 3: Association OF COVID- 19 IGG Sero-Prevalance with exposure, contact, and infection control practices|
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We detected 12.4% (30 out of 242) of randomly selected health care workers to be positive for anti-SARS-CoV-2 IgG antibody after 4 months of duty in the COVID hospital.
As among the 30 persons positive for COVID-19 IgG, 8 were previously reverse transcription polymerase chain reaction (RT-PCR) POSITIVE (26.6% of seropositive were RT PCR positive) so only 22 positives out of 236 (only 9.32%) were asymptomatic or mildly symptomatic.
| Discussion|| |
A considerable proportion of the SARS-CoV-2-infected individuals (around 80%) did not have any noticeable symptoms and yet were able to transmit the infection. Such unique transmission potentials of SARS-CoV-2 and lack of definitive antiviral therapy were the reasons behind its wide-scale spread. HCWs are particularly at risk of acquiring SARS-CoV-2 infection due to repeated occupational exposure. A total of 10 out 16 having occupational exposure showed seropositivity. Seropositives with comorbidities was almost twice that when compared seronegative with co-morbidities, so comorbidity was a definite risk factor. Understanding the risk factors of SARS-CoV-2 infection in a hospital setting is urgently needed, which not only provides the HCWs with essential guidance of self-protection but also helps infection control committee to formulate appropriate training for HCW to control infection in a hospital setting.
A study conducted on health care workers of a tertiary care hospital in Mumbai showed an overall seroprevalence of 11% inclusive of 7.2% past RT PCR positive individuals.
The seroprevalence in HCW in a private tertiary-care hospital in Kolkata was at 11.94%.
A sero prevalence study done in Kolkata in a tertiary care private hospital detected a prevalence rate of 11.94%, which included 19.85% in COVID units, 11.09% in non-COVID units, and 8% in administrative workers.
HCW from a large Spanish referral hospital found the seroprevalence of 9.3% (95% CI: 7.2–12.0)
In a similar study from the USA, the prevalence of antibodies among HCW was similar to what has been reported for the general population of New York State (14%) and another New York HCW cohort (13.7).
SARS-CoV-2 and COVID-19 have significant diagnostic issues, and serological tests aim to identify previous SARS-CoV-2 infections by detecting the presence of SARS-CoV-2 antibodies. It is known that SARS-CoV-2 antibody tests are accurate to detect previous SARS-CoV-2 infection if performed >14 days after the onset of symptoms, but they have very low sensitivity in the first week after symptom onset.
The overall seroprevalence was 8.7%, ranging from 0% to 45.3% between studies in meta-analysis among HCW.
In a serosurvey conducted among HCWs at a private hospital in Mumbai treating COVID patients, the prevalence of infection was 4.3% in asymptomatic HCW.
| Conclusion|| |
In conclusion, the cross-sectional serology study in a tertiary care hospital in Kolkata revealed 12.4% HCWs had positive serology responses to SARS-CoV-2.
Technical staffs of Department of Microbiology.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]