As of 30 April 2021, a total of 6,364 COVID-19 admissions (2.7% of all hospital admissions) were reported amongst HCWs across South Africa. Compared to other countries, South Africa reached its first wave and second wave a few months later (19–21). The implementation of the four week hard lockdown period following identification of the first case in the country likely slowed transmission of COVID-19 infection in the general population (21). Early studies on COVID-19 reported that a large proportion of early cases were HCWs (21, 22). In this study, a high number of HCW admissions were seen in pre-wave one, wave one and post-wave one period compared to the second wave. The decrease in admissions in HCWs in the second wave may been due to proper safety protocols being put into place in facilities for managing the transmission of the virus, such as use of appropriate PPE and improved knowledge in handling admitted patients. In pre-wave one, the spread of the virus was new in the country, facilities and the frontline line workers were not prepared to handle rising COVID-19 cases. Work overload, lack of PPE, poor infection control, which resulted in outbreaks in hospitalsand limited training on handling the new infection, among other factors were reported risk factors of HCWs infections in the first wave (7). Improved competency of handling infected patients as well as better preparedness in facilities may have resulted in decrease of admissions in HCWs (18, 19). In addition, COVID-19 exposure in the first wave among HCWs may have increased antibody levels, thus subsequent improved immunity against the infection in the second wave (23, 24). It was expected that hospital admissions among non-HCWs would decrease in the second wave due to the introduction of several intervensions and therapeutic agents administered to admitted patients such as the use of high flow oxygen (HFNO)(25), remdesivir (26), dexamethasone (27), and thromboprophylaxis (28).
The majority of HCW and non-HCW admissions were females (71.9% for HCWs and 55.4% for non-HCWs) in the age group 50–59 years (33.1% and 30.6%). HCWs in this study were less likely to males, more likely to be in the age group 30–59 years in the private sector. In addition, we found that HCWs were less likely to have mortality as an outcome [aOR 0.6; 95%CI (0.5–0.7)]. A study comparing COVID-19 infections among HCWs and non-HCWs, reported that being a HCW was not associated with increased risk of mortality (22). Furthermore, the risk of mortality in HCWs was high in the older age group (≥ 60 years) (22).
We assessed COVID-19 hospital mortality among HCWs. After restricting the age to that of working population, the multivariable analysis showed that risk of mortality increased with age, with older age agoup (60–65 years) having higher risk of mortality compared to the young age group (20–29 years). In many countries, COVID-19 mortality were seen among the older age group, especially those aged ≥ 60 years (28, 29). Previous studies have shown that males were twice as likely to be at high risk of mortality than females across age groups (30–33), however our study did not find association of male sex with mortality.
Comorbidities have been identified as a significant factor for mortality in both older and young COVID-19 patients (34–36). A meta-analysis of 55 independent studies reporting clinical data of patients with COVID-19 reported that pre-exisiting hypertension, diabetes, respiratory diseases, malignancy and severe chronic kidney diseases were risk factors for severe COVID-19 infection and mortality (10). Our study showed that HCWs who had hypertension, diabetes, chronic renal diseases, malignancy and current and past TB history were more lileky to die compared to those without these comorbidities (10, 35, 37). Even though obesity has been shown to increase COVID-19 mortality as independent risk factor for comorbidities such as diabetes and hypertension (38, 39), this study did not find obesity to be a significant factor of HCW mortality. In addition, as previously reported by Jassat et al. (2002) that HIV and TB increased the risk of hospital mortality in the general population (40), we found that HIV infection in HCWs was not associated with COVID-19 mortality in HCWs. Antiretroviral (ART) drugs such as tenofovir (TDF) and lopinavir-ritonavir have been found to reduce the risk of severe COVID-19 in people living with HIV (35, 41). The lack of association in this study could be that HIV infected HCW may be receiving ART. A study conducted in the Western cape in South Africa on the risk of HIV on COVIID-19 death found an increased risk of COVID-19 mortality among people living with HIV, where those who reveived TDF as ART treatment had a lower risk of COVID- 19 mortality. A study by Boulle et al. (2020) conducted in the Western Cape in South Africa reported that patients with HIV and TB are at an increased risk of COVID-19 mortality (33). In a poor resourced county such as South Africa, TB infection prevention and control (IPC) measures are frequently poorly implemented. There have been reports that shows that HCWs who care care directly and indirectly for TB patients irregularly use appropriate respiratory protection, resulting in high prevalence of TB among HCWs (42). In this study, we found that current and past TB history was associated with HCW mortality.
This study shows that HCWs who were admitted for COVID-19 were more likely to white, nonetheless white and coloured HCWs were less likely to have mortality as an outcome. HCWs were more likely to be admitted to the private sector compared to the public sector and public sector had decreased odds of hospital mortality among HCWs compared to the private sector. This may be expected as most HCWs would access private health care sectors to seek medication attention. Differences in the povinces level may indicate differences in health systems and testing, health seeking behaviour and clinical practice (18).
Strengths And Limitations
The main strengths of this paper is that we used real time data from an ongoing hospital surveillance system that covers a large number of public and private health sectors across provinces in South Africa, thus maximizing generalizability of the data. Nonetheless, there are limitation in the use of this data to access mortality, such as the under-reporting of risk factors such comorbidities, race, obesity and specific job categories of HCWs, which may indicate which job cateogy of HCWs had increased mortality.