A study conducted at a major UK medical centre shows the risk of hospital staff contracting COVID-19 at the height of the coronavirus pandemic was lowest among intensive care staff.
The occupational risk of exposure to SARS-CoV-2 has caused great concern since the beginning of the SARS-CoV-2 pandemic. Due to the nature of their work, healthcare clinicians are at risk of infection from SARS-CoV-2, and studies have shown that infection rates are higher in healthcare workers than the general population. Infection rates of up to 14% in symptomatic and 7.1% in asymptomatic hospital staff identify that they face an increased occupational risk of COVID-19.
One of the largest hospital trusts in the UK – University Hospitals Birmingham NHS Foundation Trust (UHBFT) decided to carry out a cross-sectional study of 554 staff within the trust. The aim was to determine the point prevalence of infection and seroprevalence of SARS-CoV-2 antibodies in healthcare workers. Also, it investigated the study participant’s relationship to prior symptoms of COVID-19 and the hospital departments in which they worked. By trying to understand the relationship between infection, symptoms, and the subsequent serological responses, it gives researchers vital information to understand herd immunity, vaccine development, and how to safeguard workforces.
The study recruited 545 asymptomatic healthcare workers who were invited to participate through UHBFT social media. Exclusion criteria included current symptoms consistent with COVID-19. A nasopharyngeal swab and venous blood sample were tested from each participant for SARS-CoV-2 RNA and anti-SARS-CoV-2 spike glycoprotein antibodies, respectively.
Published in the journal Thorax, results showed that the risk of COVID-19 infection among clinicians at the height of the pandemic was lowest among intensive care staff. Found to be at the highest risk of infection were cleaners, acute and general medicine clinicians, and those of Black, Asian, and Minority Ethnic (BAME) backgrounds.
Nearly 2.5% of healthcare staff, who showed no symptoms, tested positive for SARS-CoV-2, and 38% went on to develop COVID-19 symptoms. 26% said they had previously had symptoms consistent with COVID-19 infection, and those with previous symptoms were found significantly more likely to have antibodies than those who hadn’t had symptoms. The overall seroprevalence (prevalence of antibody positivity) was 24%, which compared with 6% generally in the Midlands area at the time.
Researchers discuss that fewer intensive care clinicians contracted SARS-CoV-2 due to having the use of enhanced personal protective equipment (PPE), which included a mandatory filtered face piece (class 3) respirator. In other clinical areas, fluid-resistant surgical masks were used. The use of enhanced PPE in protecting staff from infection with SARS-CoV-2 should be studied further. These studies also need to look at the availability of training, space, and supervision to use PPE appropriately and effectively.
The data collected from this study is useful for future planning as to how best to protect healthcare workers in case of a further spike in cases, or in future pandemics. Lessons can also be learned and applied with regards to the impact influenza has on the health service and health care workers each winter.
Written by Helen Massy, BSc
References:
EurekAlert!. 2020. Hospital COVID-19 Risk Lowest Among Intensive Care Staff. [online] Available at: <https://www.eurekalert.org/pub_releases/2020-09/b-hcr090920.php> [Accessed 16 September 2020].
Shields, A., Faustini, S., Perez-Toledo, M., Jossi, S., Aldera, E., Allen, J., Al-Taei, S., Backhouse, C., Bosworth, A., Dunbar, L., Ebanks, D., Emmanuel, B., Garvey, M., Gray, J., Kidd, I., McGinnell, G., McLoughlin, D., Morley, G., O’Neill, J., Papakonstantinou, D., Pickles, O., Poxon, C., Richter, M., Walker, E., Wanigasooriya, K., Watanabe, Y., Whalley, C., Zielinska, A., Crispin, M., Wraith, D., Beggs, A., Cunningham, A., Drayson, M. and Richter, A., 2020. SARS-CoV-2 seroprevalence and asymptomatic viral carriage in healthcare workers: a cross-sectional study. Thorax, pp.thoraxjnl-2020-215414.
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