Occupational risk factors for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection among healthcare personnel: A 6-month prospective analysis of the COVID-19 Prevention in Emory Healthcare Personnel (COPE) Study

SARS-CoV-2 seropositivity among healthcare professionals in a rural state

Objectives

We evaluated SARS-CoV-2 anti-nucleocapsid (anti-N) seroconversion and seroreversion rates, risk factors associated with SARS-CoV-2 seroconversion, and COVID-19 risk perceptions among academic healthcare center employees in a rural state.

Methods

Among employees aged ≥18 years who completed a screening survey (n = 1,377), we invited all respondents reporting previous COVID-19 (n = 85; 82 accepted) and a random selection of respondents not reporting previous COVID-19 (n = 370; 220 accepted) to participate. Participants completed surveys and provided blood samples at 3-month intervals (T0, T3, T6, T9). We used logistic regression to identify risk factors for seropositivity at T0.

Results

The cohort was primarily direct patient caregivers (205/302; 67.9%), white (278/302; 92.1%), and female (212/302; 70.2%). At T0, 86/302 (28.4%) participants were seropositive. Of the seronegative participants, 6/198 (3.0%), 6/183 (3.3%), and 14/180 (7.8%) had seroconverted at T3, T6, and T9, respectively. The overall seroreversion rate was 6.98% at T9. At T0, nursing staff (odds ratio [OR], 2.37; 95% confidence interval [CI], 1.08, 5.19) and being within six feet of a non-household member outside of work (OR, 2.91; 95% CI, 1.02, 8.33) had significantly higher odds of seropositivity. Vaccination (OR, 0.05; 95% CI, 0.02, 0.12) and face mask use (OR, 0.36; 95% CI, 0.17, 0.78) were protective.

Conclusions

The seroconversion and seroreversion rates were low among participants. Public health and infection prevention measures implemented early in the COVID-19 pandemic - vaccination, face mask use, and social distancing - were associated with significantly lower odds of SARS-CoV-2 seropositivity among participants.

Post-Omicron SARS-CoV-2 serostatus in Sierra Leone: A cross-sectional study in a maternity hospital setting in Freetown, November/December 2022

BACKGROUND

Spread of SARS-CoV-2 in Sub-Saharan African countries has been poorly investigated, especially in the later pandemic stages. We aimed to assess the post-Omicron situation in Sierra Leone in November/December 2022 considering SARS-CoV-2 serostatus, vaccinations, and behavioral factors.

METHODS

In a cross-sectional study conducted in a maternity hospital in Freetown, Sierra Leone, both patients and staff provided dried blood spot samples for analysis of anti-S and anti-N IgG prevalence using Anti-SARS-CoV-2-ELISA. Additionally, we collected sociodemographic and infection-related information through questionnaires. Outcome parameters included seropositivity, infection-related seroprevalence, and self-reported vaccination status. We used logistic regression to identify associations with prior infection and with vaccination status.

RESULTS

Out of 791 participants (389 patients, 402 staff), 670 (84.7 %) displayed a positive SARS-CoV-2 serostatus resulting from either infection or vaccination. Among a sub-sample of 514 participants within which determination of prior natural infection was possible, 441individuals (85.8 %) were affected. Prior infection was associated with female sex and tertiary education level. Overall, 60.3 % reported having been vaccinated. Staff as opposed to patients, and individuals with higher socioeconomic status were more likely to report vaccination. Individuals who assessed their risk of COVID-19 as either higher or lower compared to a medium-level risk were more likely to have contracted the virus and less likely to have received vaccination.

CONCLUSION

Our findings suggest that since the Omicron wave in 2022, the Sierra Leonean population has almost universally been exposed to SARS-CoV-2. While this is encouraging in the light of relatively low excess mortality in the country, future investigations on the long-term effect of high viral exposure on epidemic resilience and public health impact will be crucial.

Effectiveness of face masks for reducing transmission of SARS-CoV-2: a rapid systematic review

This rapid systematic review of evidence asks whether (i) wearing a face mask, (ii) one type of mask over another and (iii) mandatory mask policies can reduce the transmission of SARS-CoV-2 infection, either in community-based or healthcare settings. A search of studies published 1 January 2020-27 January 2023 yielded 5185 unique records. Due to a paucity of randomized controlled trials (RCTs), observational studies were included in the analysis. We analysed 35 studies in community settings (three RCTs and 32 observational) and 40 in healthcare settings (one RCT and 39 observational). Ninety-five per cent of studies included were conducted before highly transmissible Omicron variants emerged. Ninety-one per cent of observational studies were at 'critical' risk of bias (ROB) in at least one domain, often failing to separate the effects of masks from concurrent interventions. More studies found that masks (n = 39/47; 83%) and mask mandates (n = 16/18; 89%) reduced infection than found no effect (n = 8/65; 12%) or favoured controls (n = 1/65; 2%). Seven observational studies found that respirators were more protective than surgical masks, while five found no statistically significant difference between the two mask types. Despite the ROB, and allowing for uncertain and variable efficacy, we conclude that wearing masks, wearing higher quality masks (respirators), and mask mandates generally reduced SARS-CoV-2 transmission in these study populations. This article is part of the theme issue 'The effectiveness of non-pharmaceutical interventions on the COVID-19 pandemic: the evidence'.

Major Update: Masks for Prevention of SARS-CoV-2 in Health Care and Community Settings-Final Update of a Living, Rapid Review

BACKGROUND

Optimal use of masks for preventing COVID-19 is unclear.

PURPOSE

To update an evidence synthesis on N95, surgical, and cloth mask effectiveness in community and health care settings for preventing SARS-CoV-2 infection.

DATA SOURCES

MEDLINE, EMBASE, medRxiv (3 June 2022 to 2 January 2023), and reference lists.

STUDY SELECTION

Randomized trials of interventions to increase mask use and risk for SARS-CoV-2 infection and observational studies of mask use that controlled for potential confounders.

DATA EXTRACTION

Two investigators sequentially abstracted study data and rated quality.

DATA SYNTHESIS

Three randomized trials and 21 observational studies were included. In community settings, mask use may be associated with a small reduced risk for SARS-CoV-2 infection versus no mask use, on the basis of 2 randomized trials and 7 observational studies. In routine patient care settings, surgical masks and N95 respirators may be associated with similar risk for SARS-CoV-2 infection, on the basis of 1 new randomized trial with some imprecision and 4 observational studies. Evidence from observational studies was insufficient to evaluate other mask comparisons due to methodological limitations and inconsistency.

LIMITATION

Few randomized trials, studies had methodological limitations and some imprecision, suboptimal adherence and pragmatic aspects of randomized trials potentially attenuated benefits, very limited evidence on harms, uncertain applicability to Omicron variant predominant era, meta-analysis not done due to heterogeneity, unable to formally assess for publication bias, and restricted to English-language articles.

CONCLUSION

Updated evidence suggests that masks may be associated with a small reduction in risk for SARS-CoV-2 infection in community settings. Surgical masks and N95 respirators may be associated with similar infection risk in routine patient care settings, but a beneficial effect of N95 respirators cannot be ruled out.

PRIMARY FUNDING SOURCE

None.