|
 
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| REVIEW ARTICLE |
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| Year : 2020 | Volume
: 22
| Issue : 3 | Page : 36-45 |
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COVID-19 in healthcare workers: A review of existing literature
Vineet Behera1, Pramod Kumar Srivastava1, Jayakrishnan Jayaramachandran1, Sougat Ray2, Vivek Hande3, Sheila Samanta Mathai4
1 Department of Medicine, INHS Asvini, Mumbai, Maharashtra, India
2 SSO (Health), Western Naval Command, Mumbai, Maharashtra, India
3 Senior Registrar, INHS Asvini, Mumbai, Maharashtra, India
4 Commanding Officer INHS Asvini, Mumbai, Maharashtra, India
| Date of Submission | 11-Sep-2020 |
| Date of Decision | 29-Sep-2020 |
| Date of Acceptance | 05-Oct-2020 |
| Date of Web Publication | 07-Nov-2020 |
Correspondence Address:
Surg Cmde (Dr) Vivek Hande
Senior Registrar, INHS Asvini, Colaba, Mumbai, Maharashtra
India
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jmms.jmms_133_20
Background: Healthcare workers (HCWs) are particularly at a risk of acquiring COVID-19 infection. The pattern of disease and outcome in HCWs has not been studied adequately. This review was done to determine the prevalence of COVID-19 in HCWs and to find out the clinical profile and mortality of COVID-19 in HCWs. Materials and Methods: A systematic search of all published or in press studies from January 1, 2020, to July 15, 2020, with confirmed COVID-19 HCWs was done in PubMed, Scopus, and Google Scholar and in other key journals using terms such as “2019-nCoV,” “novel coronavirus 2019,” “COVID-19,” “SARS-CoV-2,” “Wuhan coronavirus,” “health care worker,” “health care professional,” “physician,” and “medical staff.” Results: We analyzed 43 research articles, mostly cross-sectional studies with 20 studies from China, and included 13,725 COVID-19–positive HCWs. Proportion of COVID-19–positive HCWs (n = 8405) among all HCWs (n = 276,392) were 3.04% (95% confidence interval [CI]: 0.62–9.76), while the proportion of positive HCWs (n = 9458) among all COVID-19–positive patients (n = 230,626) were 4.1% (95% CI: 1.44–12.46). The mean age of HCWs was 42.78 ± 6.82 years, 34.47% were males, and 51.04% were nurses. Most COVID-19–positive HCWs were asymptomatic (64.41%), while severe disease occurred in 4.08% with a mortality of 0.80% (47/5823). The incidence of severe disease and mortality among HCWs (n = 9458) and general population (n = 230,626) was extracted from nine studies, and it was seen that severe disease (1.7%) or mortality (0.04%) in HCWs was significantly less as compared to non-HCWs population (8.26% and 1.23%, respectively) (P < 0.001). Conclusion: There is a considerable risk of contracting COVID-19 infection among HCWs which re-emphasizes the strong need of personal protective measures. However, the incidence of severe disease and deaths is significantly low among HCWs, which may somewhat reduce apprehension and be morale boosting for HCWs all across the world.
Keywords: Coronavirus, COVID-19, healthcare professional, healthcare worker, mortality, SARS-CoV-2
How to cite this article:
Behera V, Srivastava PK, Jayaramachandran J, Ray S, Hande V, Mathai S. COVID-19 in healthcare workers: A review of existing literature. J Mar Med Soc 2020;22, Suppl S1:36-45 |
| Introduction | |  |
SARS-CoV-2 is a RNA virus which is responsible for the novel coronavirus disease (COVID-19) that originated in December 2019 in China and has evolved into a global pandemic involving over 200 countries.[1] Healthcare workers (HCWs) are particularly at a risk of acquiring COVID-19 infection due to repeated occupational exposure while working in COVID-19 facilities or while looking after asymptomatic COVID-19 cases in other areas.[2],[3]
COVID-19 in HCWs increases the risk of nosocomial transmission of SARS-CoV-2 and increases the overall disease burden.[4] A study from the United States (US) and the United Kingdom (UK) showed that HCWs were at a 12-fold increased risk of COVID-19 compared to general population and comprised 4.8% of the total COVID-19–positive cases.[5] The recent spread of SARS-CoV-2 has led to considerable anxiety and concern among HCWs all over the world.[6] HCWs may accept increased risk of SARS-CoV-2 infection, as part of their chosen profession, but they often show concern about transmission of COVID-19 to their families and friends, especially those who are elderly, are immunocompromised, or have chronic medical conditions.[2]
Despite numerous studies on COVID-19, the pattern of disease and outcome in HCWs has not been studied, with only a few cross-sectional studies available, of which most have a small sample size. Therefore, this review was done to determine the prevalence of COVID-19 in HCWs, i.e., the proportion of HCWs who were COVID-19 positive among all COVID-19 patients, to find out the clinical profile of COVID-19 in HCWs, and to evaluate the incidence of severe disease and deaths among HCWs.
| Materials and Methods | | |
Data sources and search strategy
This review was performed by conducting a systematic search of all articles published from January 1, 2020, to July 15, 2020, in the following databases: PubMed, Scopus, and Google Scholar.[7] The databases were searched using terms such as “2019-nCoV,” “novel coronavirus 2019,” “COVID-19,” “SARS-CoV-2,” “Wuhan coronavirus,” “health care worker,” “health care professional,” “physician,” and “medical staff.” We also searched for studies into the research domains of NEJM, JAMA, Lancet, BMJ, Nature, and Chest that included the above terms. There were no restrictions in terms of country or language of publication. Reference lists of all relevant articles and “related citation” search tool of PubMed were checked for any additional publications.
Selection criteria
We included published or in press peer-reviewed articles reporting cases of HCWs with confirmed COVID-19. We accepted the following types of studies: randomized trials, case–control or cohort studies, cross-sectional studies, case series, and letters to editors that incorporated clinical, epidemiological, laboratory, imaging, and hospital course of HCWs with COVID-19. Duplicate publications, reviews, and family-based studies were excluded.
The HCWs included in the study included doctors, nurses, paramedical staff, medical technicians, support staff, and other staff who were exposed while working in hospital or looking after COVID-19 patients. Patients were included if SARS-CoV-2 was detected by real-time reverse transcriptase polymerase chain reaction in nasopharyngeal, throat swab samples at any point of their clinical evaluation. Our outcomes of interest included the incidence of COVID-19, baseline characteristics of HCWs, and clinical profile and mortality in HCWs.
Data collection and quality assessment
Screening by title and abstract was conducted independently by two investigators of which one extracted the data and the second verified the data independently. A third investigator was consulted to resolve any differences of opinion. Subsequent full-text review and data extraction were conducted by all investigators using a standardized online form shared among the authors. Data retrieved from each article were verified for consistency by an independent investigator. Data collected included the details of authors, type of article, country of origin, number of cases among HCWs, total COVID-19 cases or total HCWs, demographic details of HCWs, clinical profile, laboratory and imaging characteristics, number of asymptomatic or severe cases, cases on ventilator, and number of deaths among HCWs.
Statistical analysis
The total number of HCWs infected with COVID-19 and the total number of COVID-19–positive patients or total HCWs were extracted for calculation of proportion. The data were presented as percentage of total or mean with standard deviation. To compare the incidence of severe disease/deaths in HCWs versus all patients, the Chi-square test was used. P < 0.05 was considered statistically significant. Statistical analysis was done with SPSS software version 22 (SPSS for Windows software; SPSS Inc., Chicago, IL, USA).
| Results | | |
Search results and study characteristics
The literature search yielded 1769 studies from a database of PubMed, Scopus, and Google Scholar, and a parallel search from NEJM, Lancet, JAMA, BMJ, Nature, and Chest yielded 156 studies. After removing 1203 duplicates, 722 articles were reviewed by abstract and title. Initial screening was done, and 411 articles were excluded that were retracted or consisted of editorials, reviews, reports, or commentaries. Thereafter, 311 full-text articles met inclusion criteria and underwent full text evaluation, of which 268 articles which did not meet our criteria were removed, generating a final list of 43 articles that were included in the review [Figure 1].
Studies published or accepted for publication up to July 15, 2020, were included in this review. Among the 43 research articles included in the analysis, 36 were original articles while seven were published as letters to editor. There were no randomized trials, three were case–control studies, 34 were cross-sectional studies, and six were case series, with 28 being retrospective and 15 being prospective studies. Most of the articles were from China (n = 20, 46.51%),[4],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26] four (9.3%) each were from Italy,[27],[28],[29],[30] UK,[31],[32],[33],[34] and US;[5],[35],[36],[37] two (4.65%) each were from India,[38],[39] France,[40],[41] and the Netherlands;[42],[43] while one (2.3%) each was from Poland,[44] Belgium,[45] Spain,[46] Germany,[47] and Australia.[48] Most of the publications (n = 39, 90.6%) were in English while four studies (9.3%) were in Chinese [Table 1]. Most of the papers were focused on HCWs (n = 33, 76.74%) while ten articles (23.25%) were primarily on general population but also provided data about HCWs. | Table 1: Summary of key studies of coronavirus disease-19 in healthcare workers
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Prevalence of healthcare workers affected in included studies
The 43 studies included 13,725 COVID-19–positive HCWs with the sample size of HCWs in studies ranging between 3 and 5545 laboratory-confirmed COVID-19 HCWs. Twenty-four of these studies evaluated COVID-19 positivity among HCWs, as given in [Figure 2]a. The overall proportion of HCWs who were COVID-19 positive (n = 8405) among all HCWs (n = 276,392) was 3.04% (95% confidence interval [CI]: 0.62–9.76). This proportion varied according to the country of the study: China (6 studies) –2.09%, Italy (4 studies) –6.35%, UK (4 studies) –4.72%, India (2 studies) –4.69%, and US (2 studies) –5.22%. Nine studies provided data of COVID-19–positive HCWs among COVID-19–positive general population, as given in [Figure 2]b. The proportion of HCWs who were COVID-19 positive (n = 9458) among all COVID-19–positive patients (n = 230,626) were 4.1% (95% CI: 1.44–12.46). Ten studies were just case series of COVID-19–positive HCWs and did not have any baseline population as denominator. | Figure 2: Incidence of COVID-19 in HCWs. (a) COVID-19–positive HCWs among the total HCWs studied. (b) COVID-19–positive HCWs among the total COVID-positive patients. HCWs: Healthcare workers
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Characteristics of COVID-19–positive healthcare workers
The baseline characteristics of COVID-19–positive HCWs were analyzed by extracting data from the available studies which analyzed that parameter, as given in [Table 2]. The mean age of the HCWs was 42.78 ± 6.82 years, 34.47% were males, and 16.12% of the HCWs had underlying comorbidities such as hypertension, diabetes, cardiac disease, and hypothyroidism. Nurses were the most frequent type of HCWs affected (51.04%) followed by doctors (31.17%). | Table 2: Baseline characters of healthcare workers with coronavirus disease-19 (from all studies)
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[Table 3] summarizes the clinical features and disease outcomes of COVID-19–positive HCWs. Most of the HCWs were asymptomatic (64.41%), while in the symptomatic patients, fever was seen in 65.68% cases, cough in 50.80%, and dyspnea in 21.58% cases, as given in [Table 3]. The other symptoms seen were malaise, fatigue, headache, diarrhea, and anosmia, as given in [Table 1]. Severe disease (characterized by features of sepsis, respiratory failure, acute respiratory distress syndrome, multiorgan dysfunction, shock, ventilator support, or others) was seen in 178 of 4353 HCWs (4.08%). Mortality of COVID-19–positive HCWs was provided in 30 studies in which a total of 47 of the 5823 HCWs died, with a mortality rate of 0.80%. | Table 3: Clinical profile and disease outcomes in healthcare workers (from all studies)
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The common laboratory abnormalities of COVID-19–positive HCWs included lymphopenia, leukopenia, transaminitis, raised LDH, and elevated CRP and IL-6, as given in [Table 4]. The most common and characteristic radiological features seen in most studies included bilateral ground glass opacities, patchy consolidation, or other features of interstitial pneumonia on CT scan of chest. | Table 4: Radiological and laboratory manifestations in healthcare workers with corona virus disease-19
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The incidence of severe disease and mortality among HCWs (n = 9458) and general population (n = 230,626) affected with COVID-19 was extracted from nine studies and compared. It was found that the incidence of severe disease (1.7%) and death seen in HCWs with COVID-19 (37/9458, 0.04%) [Figure 3]a was significantly lower than the incidence of severe disease (7.9%) and deaths (2767/230,626, 1.19%) in general population with COVID-19 [Figure 3]b. | Figure 3: Severe disease and deaths in HCWs and other COVID cases. (a) Severe disease and deaths in COVID-positive HCWs. (b) Severe disease and deaths in COVID-positive general population. HCWs: Healthcare workers
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The same was analyzed statistically and it was observed that severe disease was less common in HCW (1.7%) as compared to non-HCW population (8.26%), which was statistically significant (by Chi-square test, P < 0.001), as given in [Table 5]. Similarly, it was also observed that mortality was less common in HCWs (0.04%) than non-HCW population (1.23%), which was statistically significant (by Chi-square test, P < 0.001). | Table 5: Comparison of severe cases and deaths between healthcare workers with coronavirus disease-19 and others with coronavirus disease-19
Click here to view |
| Discussion | | |
Most studies of COVID-19 have focused on general population and specific subsets of patients. However, very few studies have studied COVID-19 in HCWs, who are one of the most vulnerable subsets of population.[1] Majority of existing reports of COVID-19 in HCWs are from data shared by various agencies and surveys and by media reports. Identification of clinical and laboratory characteristics in the HCWs population is essential to guide clinical care, predict disease severity, and determine prognosis. In this context, we performed a review of published studies involving HCWs with known COVID-19.
Our review showed that the overall proportion of HCWs who were COVID-19 positive were 4.1% among all COVID-19 patients and were 3% among all HCWs, which is high compared to the average number of COVID cases in general population (<1%). However, the SARS-CoV-2 has been less infectious compared to previous SARS-CoV which infected HCWs in the range of 21%–26.31%.[49] The country-wise distribution of COVID–positive HCWs also showed variation ranging from 2.09% in China, 4.6% in India, and 6.35% in Italy. This might be explained due to lack of adequate preparation in the West to meet the surge of patients, which led to the acute shortage in the personal protective equipment (PPE) and higher exposure of HCWs.[50],[51]
The COVID-19–positive HCWs were predominantly females and relatively younger with a mean age of 42 years. Most of the HCWs were healthy without any comorbidities, stressing the role of occupational exposure in acquiring COVID-19 infection. Nurses comprise the predominant affected HCWs followed by doctors. This is likely due to persistent and longer exposure of nurses while working in COVID-19 facilities. The predominance of nurses affected may explain the female preponderance among HCWs.
It is good to note that 64.4% of HCWs are asymptomatic and many have mild symptoms, with low incidence of severe disease and mortality among HCWs, compared to general population. However, on the contrary, asymptomatic HCWs pose a greater risk of transmission of SARS-CoV-2 infection to other HCWs and individuals, because they are often unaware of their infection. One reason for the rapid spread of COVID-19 worldwide could be asymptomatic patients in the early stage.[52] The viral load detected in asymptomatic patients was similar to that detected in symptomatic patients, indicating the transmission potential of asymptomatic carriers of SARS-CoV-2.[53] Therefore, identification of asymptomatic carriers among HCWs would be important, and asymptomatic carriers should be isolated from family, colleagues, and workplace to avoid cross-infection.[54] Our review showed that the clinical symptoms, laboratory findings, and radiological findings are similar to those of COVID-19 in general population.
We analyzed the incidence of severe disease and deaths among the affected HCWs. Severe disease was four times lower in HCWs compared to all positive COVID-19 patients (1.7% vs. 7.9%), and the mortality among HCWs was significantly lower compared to all positive COVID-19 patients (0.04% vs. 1.3%). These facts might be explained by the younger age of HCWs, lesser prevalence of comorbidities as compared to non-HCWs,[52] early accessibility of HCWs to the healthcare system, and their better understanding of the disease process. It is also possible that the use of PPE and N95 masks by HCWs may reduce the viral load or exposure and thus may result in less severe disease. However, there is no evidence to back these assumptions. This finding is important to clarify that the HCWs have a lower incidence of severe disease or deaths, and most HCWs have an asymptomatic or mild course. This may somewhat reduce anxiety and fear of COVID-19 among HCWs working in COVID-19 facilities. However, at the same time, the HCWs should not be complacent in taking all precautions and using appropriate PPE, as they are more vulnerable and have higher risk of COVID-19 than general population.
Our review supports the findings by a systematic review by Sahu et al. on the COVID-19–positive healthcare workers, which included 11 studies and found the overall proportion of HCWs who were SARS-CoV-2 positive among all COVID-19 patients was 10.1% (95% CI: 5.3–14.9).[55],[56] The incidence of severe or critical disease in HCWs (9.9% vs. 29.4%) and the mortality among HCWs (0.3% vs. 2.3%) was significantly lower than the other COVID-19–positive patients.
Our study has several advantages. We summarized 43 studies that included 13,725 COVID-19–positive HCWs from 12 different countries and objectively defined the incidence of COVID-19 among other HCWs or other COVID-19 population and the incidence of severe disease or deaths caused by COVID-19. However, there are few limitations in our study. The studies included in our analysis were only from 12 countries, while more than 200 countries have been affected by COVID-19. Most studies were observational studies, had small sample size, and had low level of evidence, and significant statistical heterogeneity was observed among the included studies. There were differences in the definition of severe disease across the included studies. Finally, it is possible that new studies were published between the completion of the literature review and when this article was completed. Moreover, a significant amount of data is available in reports and surveys of various government and other agencies, which was not considered in the study. We hope that the findings presented here will encourage a more comprehensive assessment of SARS-CoV-2 infection in HCWs.
There is considerable risk of contracting COVID-19 infection among HCWs, but the incidence of severe disease and deaths was significantly low. These data may somewhat reduce apprehension of having severe or life-threatening COVID-19 among HCWs but, at the same time, emphasize the strong need of personal protective measures among HCWs, as they are more vulnerable to infection. Early recognition, identification, isolation, and implementation of appropriate infection prevention and control measures are imperative, for successful management of COVID-19 in HCWs.
Financial support and sponsorship
Nil.
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], [Table 5]
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