|Year : 2021 | Volume
| Issue : 3 | Page : 93-98
Risk of SARS-CoV-2 infection among healthcare workers in a tertiary care center
Mysore K Yashaswini, Banur R Archana, Kirtilaxmi Benachinmardi, Lakshminarayana S Anjanappa, Sangeetha Sampath
Department of Microbiology, Rajarajeswari Medical College and Hospital, Bangalore, Karnataka 560074, India
|Date of Submission||17-Aug-2021|
|Date of Acceptance||11-Oct-2021|
|Date of Web Publication||11-May-2022|
Department of Microbiology, Rajarajeswari Medical College and Hospital, Bangalore, Karnataka 560074
Source of Support: None, Conflict of Interest: None
Purpose: Healthcare workers (HCWs) are at higher risk of acquiring SARS-CoV-2, the causative agent of current pandemic COVID-19. Being frontline workers and most essential resource of healthcare systems, it is important to identify infection in them early. Hence, this study was conducted to assess the risk of HCWs in acquiring SARS-CoV-2 infection. Materials and Methods: This prospective study was conducted at a tertiary healthcare center for a duration of 6 months. All the HCWs, involved in Covid-19 patient care, were enrolled in the study. A total number of 792 HCWs were screened for COVID-19 by using real-time reverse transcriptase–polymerase chain reaction (rRT–PCR). Data on age, sex, and occupational categories were also analyzed. Results: There were a total of 792 HCWs involved in Covid-19 patient care. Doctors were 350 (44%), nursing staff 230 (29%), cleaning staff 130 (17%), and supporting staff 82 (10%). Female staff (66%) outnumbered male staff (34%). Among 792 HCWs, 35 (4.42%) were positive for SARS-CoV-2 by RT–PCR. The highest positivity rate was seen in supporting staff (18.30%), followed by cleaning staff (3.84%), doctors (3.14%), and lowest in nurses (1.74%). Out of the 35 positive cases, clinical symptoms were seen in only 18 patients. Majority of the patients (53%) were asymptomatic. Conclusion: Although HCWs are at a higher risk of acquiring SARS-CoV-2 infection as an occupational hazard, the chances of acquiring infection in the community cannot be ruled out. All the HCWs in the hospital setting should be screened periodically, even if they are asymptomatic.
Keywords: COVID-19, healthcare workers, real time RT-PCR, risk of infection, SARS-CoV-2
|How to cite this article:|
Yashaswini MK, Archana BR, Benachinmardi K, S Anjanappa L, Sampath S. Risk of SARS-CoV-2 infection among healthcare workers in a tertiary care center. D Y Patil J Health Sci 2021;9:93-8
|How to cite this URL:|
Yashaswini MK, Archana BR, Benachinmardi K, S Anjanappa L, Sampath S. Risk of SARS-CoV-2 infection among healthcare workers in a tertiary care center. D Y Patil J Health Sci [serial online] 2021 [cited 2022 May 27];9:93-8. Available from: http://www.dypatiljhs.com/text.asp?2021/9/3/93/345106
| Introduction|| |
The current coronavirus disease-19 (COVID-19) pandemic caused by novel severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) has affected more than 89,000,000 people and caused over 1,51,000 deaths worldwide. The first case of SARS CoV-2 was reported in Wuhan, China in December 2019, soon it spread globally and was declared as pandemic by the World Health Organization (WHO) on March 11, 2020.
The disease commonly spreads by respiratory droplets of infected person via coughing, sneezing, speaking and also by self-inoculation of virus by touching nose, mouth, and eyes with contaminated hands after contact with SARS-CoV-2-contaminated surfaces. In healthcare settings, in addition to droplet and contact transmission, aerosol transmission can also occur through the aerosol-generating procedures. Thus healthcare workers (HCWs) are at a greater risk of acquiring and transmitting disease to family members. WHO defines HCWs as “all people engaged in actions whose primary intent is to enhance health.” This includes doctors, nurses, midwives, paramedical staff, hospital administrative staff, supporting staff, and community workers. As most of the patients with COVID-19 remain asymptomatic, it is important to identify them early and isolate to reduce unnecessary occupational exposure.
Hence, this study was conducted to assess the risk of HCWs in acquiring SARS-CoV-2 infection.
| Materials and Methods|| |
This prospective study was conducted at a tertiary healthcare center for a duration of 6 months during Covid-19 pandemic, after obtaining approval from Institutional Ethics Review Board. All HCWs, involved in Covid-19 patient care, i.e., treatment and diagnostics, were included in the study. Inclusion criteria were all HCWs including physicians, nurses, cleaning staff, and other supporting personnel (technicians, radiographers, pharmacy staff, and administrative staff) who were assigned to deal with COVID-19 patients between July 2020 and December 2020. The doctor/patient ratio was 1:20, whereas the nurse/patient ratio was 1:5–10. A total number of 792 HCWs were screened for COVID-19 by nasopharyngeal swabs. Sample collection was done by a trained team, and the swabs were tested for COVID-19 RNA using real-time reverse transcriptase–polymerase chain reaction (rRT–PCR). Nasopharyngeal swabs (NPs) were placed in 3 mL of viral transport medium and transported to laboratory in ice packs after collection. RNA was extracted using a Favorogen RNA extraction kit. RT–PCR was performed on QuantStudio 7 (Applied Biosystems), using an ICMR-approved Mylab RT–PCR kit for SARS-CoV-2 (RNAse P, E & RdRp). Ct values lower than 40 cycles for both E & RdRp gene indicate a diagnostic qualitative positive result for SARS-CoV-2.
Data on age, sex, and occupational categories were also analyzed. HCWs with comorbidities (diabetes, hypertension, respiratory diseases, and other chronic medical illnesses) and pregnant staff were not included because they were already excluded from work during this period. This study was conducted according to the STROCSS 2019 guidelines.
Descriptive statistics were used to summarize the characteristics of the study population. Hypothesis tests for differences between groups were performed using non-parametric Wilcoxon–Mann–Whitney and Kruskal–Wallis tests for continuous variables and Fisher’s exact tests for categorical variables. All P-values were calculated and P < 0.05 was considered to indicate significance.
| Results|| |
There were a total of 792 HCWs involved in Covid-19 patient care. Doctors were 350 (44%), nursing staff 230 (29%), cleaning staff 130 (17%), and supporting staff 82 (10%). Female staff outnumbered male staff with male-to-female ratio of 0.51. Details are shown in [Table 1].
HCWs belonged to the age group of 25–50 years with the mean age of 32.8 years. Details are shown in [Figure 1]. Among doctors and nurses, maximum belonged to the age group of 25–30, whereas among cleaning staff and supporting staff, maximum were in the age group of 31–40.
|Figure 1: Age-wise distribution of HCWs involved in COVID-19 patient care|
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Among 792 HCWs, 35 (4.42%) were positive for SARS-CoV-2 by RT–PCR. Details of these positive HCWs are shown in [Table 2]. Positivity rate among HCWs is shown in [Figure 2]. The highest positivity rate was seen in supporting staff (18.30%), followed by cleaning staff (3.84%), doctors (3.14%), and lowest in nurses (1.74%). Among these positive HCWs, 83% were males and 17% were females overall. Positivity rate with respect to males and females is shown in [Figure 3]. Out of the 35 positive cases, clinical symptoms were seen in only 18 subjects. Majority of the participants (53%) were asymptomatic. No deaths were recorded. Details are shown in [Table 3]. P-value was calculated for different variables of SARS-CoV-2-positive HCWs, as shown in [Table 4]. For male and female, Z-score value is 5.438, stating that males are prone for infection.
| Discussion|| |
Throughout the progression of the COVID-19 pandemic, high levels of exposure have been experienced by HCWs to SARS-CoV-2, with the risk of infection increasing with each time point of exposure. HCWs are at greatest risk of SARS-CoV-2 infection, representing a large percentage of new infections. This has resulted in a great deal of anxiety and distress among HCWs due to concern about self-infection with COVID-19 and probable family exposure.
At our institute, preparedness for pandemic started well before the admission of first suspected/diagnosed case of SARS-CoV-2, in the form of selecting HCWs to be posted to COVID-19 ward by excluding HCWs aged more than 50 years, pregnant HCWs, and HCWs with other underlying comorbidities such as diabetes, hypertension, respiratory diseases, and other chronic medical illnesses in concern with safety of HCWs. All the HCWs were trained in hospital infection prevention and control practices (IPC) like proper use of personal protective equipment (PPE) including donning and doffing, hand hygiene, and biomedical waste management.
Our HCWs were team members with varying degrees of patient care involvement from all departments across different shifts, who were tested after a regular 7-day quarantine period after 10 days of 8 h shift duty. All HCWs irrespective of their clinical presentation were screened by RT–PCR even if they were asymptomatic. This policy of our institute aided in point of care management, identifying asymptomatic carriers, and preventing further spread and contact tracing.
In spite of all necessary precautions, 35 (4.42%) out of 792 got infected with SARS-CoV-2. Among them 31% were doctors, 11% were nurses, 15% were cleaning staff, and 43% were supporting staff. Details are shown in [Figure 2].
In Wuhan, the origin of current SARS-CoV-2 pandemic itself, HCWs accounted for 5.1% of the total patients. The prevalence of SARS-CoV-2 among HCWs ranges from 0% to 18% in different studies. In the Turkish study, according to the data collected from 30 countries by the International Council of Nurses, an average of 6% (range between 0% and 18%) and in the Netherlands 4.1% of the confirmed COVID-19 cases were HCWs.,, In a study by Çelebi et al., 7.1% were HCWs, out of which physicians were 6.3%, nurses 8%, cleaning staff 9.1%, and other staff 2.6%. The infection rate varied from 2% to 12.6% in different studies. HCWs in direct contact with patients had lower risk of acquiring SARS-CoV-2 probably due to good compliance with PPE. The same has been potentiated by the present study also. The highest positivity rate was seen in supporting staff, that is, 12 were pharmacy staff, 2 covid testing laboratory technicians, and 1 radiology technician. Even though there was extensive and regular training conducted for HCWs, two pharmacy staff failed to attend and follow IPC and they visited the emergency/triage area and intensive care unit without proper PPE to remove extra medicines and acquired the disease. They also spread the disease to 10 other colleagues. Among the technicians who acquired SARS-CoV-2, one had history of family members being positive, and later he/she developed symptoms and tested positive. One of his colleagues also tested positive later.
Among 11 doctors, 3 acquired infection from family members. One developed symptoms just on the second day of the duty, relating to unknown exposure in a crowded public place (shopping mall). Another doctor in contact with this doctor also turned positive. On the contrary, a study from China reported working in high-risk department as a major risk factor. According to Nguyen et al., frontline HCWs had at least a three-fold increased risk of reporting as positive Covid-19 when compared with the general community.
After analyzing the various risk factors, majority (48%) were hospital-acquired, i.e., acquired the infection from a co-worker, where they share common break room and cafeteria without wearing medical mask and are in contact for more than 15 min and do not maintain safe distance from each other. Breach in PPE was seen in 34%, of which 58% were supporting staff and 42% were cleaning staff. Acquisition of infection from family members (household acquisition) and community-acquired were 9% each. Hence, community acquisition of infection in HCWs cannot be ruled out. Similar risk factors were found in another study by Çelebi et al. Other risk factors found in other studies are working in high-risk department, suboptimal hand washing before and after patient contact, longer working hours, and improper use of PPE.
In the present study, although female HCWs were 66% of the total HCWs involved in patient care, infectivity rate was more in males (83%) when compared with females (17%). On the contrary, in a systematic review by Bandyopadhyay et al., high infection was seen in women (71.6%) and nurses (70.8%) but death was common in males (70.8%) and doctors (51.4%). Fortunately, there was no mortality among our HCWs.
The majority of HCWs tested positive for SARS-CoV-2 were asymptomatic (49%), followed by fever (26%), anosmia/ageusia (23%), nasal symptoms (23%), sore throat (17%), cough (11%), and headache (6%). Similar to this finding, Martin et al. reported that 75% of asymptomatic HCWs are positive for SARS-CoV-2 by RT–PCR. This suggests that if screening was based solely on clinical features, then we could have missed many cases, resulting in nosocomial and community spread, as reported earlier. In another study by Moynan et al., 44% were asymptomatic. Therefore, periodic regular screening of all HCWs irrespective of symptoms is recommended for early detection, isolation, and prevention of spread of infection.
| Conclusion|| |
Even though HCWs are at higher risk of acquiring SARS-CoV-2 infection as an occupational hazard, the chances of acquiring infection in the community cannot be ruled out.
Therefore, following strict infection control practices including proper use of N-95/medical mask, maintaining distance of 6 feet, avoiding close contact plays a vital role in the prevention of spread of SARS-CoV-2 infection, and also all the HCWs in the hospital setting should be screened periodically for Covid-19 even if they are asymptomatic to reduce hospital and community spread through asymptomatic carriers.
All healthcare workers participated in the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]