Epidemiology of SARS-CoV-2 antibodies among firefighters/paramedics of a US fire department: a cross-sectional study

SARS-CoV-2 infection among Colorado adults working outside the home: Occupation, race and ethnicity and mask use

OBJECTIVES

The workplace is an important setting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure and transmission. Using data from a large case-control study in Colorado during 2021 and 2022, we aimed to evaluate working outside the home and SARS-CoV-2 infection, the racial and ethnic distribution of workers in occupations associated with infection, and workplace face mask use.

METHODS

Cases were Colorado adults with a positive SARS-CoV-2 test by reverse transcription-polymerase chain reaction (RT-PCR) reported to Colorado's COVID-19 surveillance system selected from surveillance data ≤12 days after their specimen collection date. Control participants were randomly selected adult Coloradans with a RT-PCR-confirmed negative SARS-CoV-2 test result reported to the same surveillance system.

RESULTS

Working outside the home was associated with infection (odds ratio [OR] = 1.46, 95% confidence interval [CI]: 1.39-1.54). Among participants working outside the home, "Food Preparation and Serving Related" (aOR = 2.35, 95% CI: 1.80-3.06), "Transportation and Material Moving" (aOR = 2.09, 95% CI: 1.62-2.69), "Construction and Extraction" (aOR = 1.88, 95% CI: 1.36-2.59), "Protective Service" (aOR = 1.60, 95% CI: 1.15-2.24), and "Sales and Related" (aOR = 1.44, 95% CI: 1.22-1.69) were occupational categories most strongly associated with infection. American Indian/Alaskan Native, Black, and Hispanic/Latino participants were more likely than others to work in occupational categories with the highest odds of infection (p < 0.05). Cases were less likely than controls to report always wearing a mask (31.9% vs. 41.5%) and wearing a KN95/N95/KF94 mask (16.8% vs. 27.2%) at work.

CONCLUSIONS

These findings emphasize the importance of occupation and workplace mask use in the COVID-19 pandemic and its disproportionate racial/ethnic impact on workers.

Gender and sex differences in occupation-specific infectious diseases: a systematic review

Occupational infectious disease risks between men and women have often been attributed to the gendered distribution of the labour force, with limited comparative research on occupation-specific infectious disease risks. The objective of this study was to compare infectious disease risks within the same occupations by gender. A systematic review of peer-reviewed studies published between 2016 and 2021 was undertaken. To be included, studies were required to report infectious disease risks for men, women or non-binary people within the same occupation. The included studies were appraised for methodological quality. A post hoc power calculation was also conducted. 63 studies were included in the systematic review. Among high-quality studies with statistical power (9/63), there was evidence of a higher hepatitis risk for men than for women among patient-facing healthcare workers (HCWs) and a higher parasitic infection risk for men than for women among farmers (one study each). The rest of the high-quality studies (7/63) reported no difference between men and women, including for COVID-19 risk among patient-facing HCWs and physicians, hepatitis risk among swine workers, influenza risk among poultry workers, tuberculosis risk among livestock workers and toxoplasmosis risk among abattoir workers. The findings suggest that occupational infectious disease risks are similarly experienced for men and women within the same occupation with a few exceptions showing a higher risk for men. Future studies examining gender/sex differences in occupational infectious diseases need to ensure adequate sampling by gender.

Vaccination against influenza viruses reduces infection, not hospitalization or death, from respiratory COVID-19: A systematic review and meta-analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes COVID-19 and has brought a huge burden in terms of human lives. Strict social distance and influenza vaccination have been recommended to avoid co-infections between influenza viruses and SARS-CoV-2. Scattered reports suggested a protective effect of influenza vaccine on COVID-19 development and severity. We analyzed 51 studies on the capacity of influenza vaccination to affect infection with SARS-CoV-2, hospitalization, admission to Intensive Care Units (ICU), and mortality. All subjects taken into consideration did not receive any anti-SARS-CoV-2 vaccine, although their status with respect to previous infections with SARS-CoV-2 is not known. Comparison between vaccinated and not-vaccinated subjects for each of the four endpoints was expressed as odds ratio (OR), with 95% confidence intervals (CIs); all analyses were performed by DerSimonian and Laird model, and Hartung-Knapp model when studies were less than 10. In a total of 61 029 936 subjects from 33 studies, influenza vaccination reduced frequency of SARS-CoV-2 infection [OR plus 95% CI = 0.70 (0.65-0.77)]. The effect was significant in all studies together, in health care workers and in the general population; distance from influenza vaccination and the type of vaccine were also of importance. In 98 174 subjects from 11 studies, frequency of ICU admission was reduced with influenza vaccination [OR (95% CI) = 0.71 (0.54-0.94)]; the effect was significant in all studies together, in pregnant women and in hospitalized subjects. In contrast, in 4 737 328 subjects from 14 studies hospitalization was not modified [OR (95% CI) = 1.05 (0.82-1.35)], and in 4 139 660 subjects from 19 studies, mortality was not modified [OR (95% CI) = 0.76 (0.26-2.20)]. Our study emphasizes the importance of influenza vaccination in the protection against SARS-CoV-2 infection.

Exploring First Responder Beliefs and Decisions to Vaccinate Against SARS-COV-2

As frontline providers, first responders are not always thought of as patients with unique health beliefs. During early and continued distribution, many first responders in the United States chose to refuse vaccination. Guided by the health belief model and emerging research related to SARS-COV-2, the aim of this study was to further explore the complex message conditions that contributed to first responders' early vaccination decisions. An online survey was conducted between March 1 and March 31 2021, among first responders in the state of Kentucky, which has lagged behind most states in the percentage of the population who are fully vaccinated. The first responder sample included Firefighters, Emergency Medical Technicians (EMTs), and paramedics who completed a Qualtrics survey that included measures aimed at assessing health beliefs about SARS-COV-2, beliefs about SARS-COV-2 vaccines, source trustworthiness, and vaccine motivation. First responders were also asked to rank the importance of various information sources about SARS-COV-2 and its vaccines. Findings suggest significant differences exist among first responders who have chosen to receive SARS-COV-2 vaccines and those who have refused, including source preference, conspiracy beliefs, and perceived risk. Future directions, including the exploration of institutional mistrust as a health belief are discussed. These findings offer practical insights that may improve continuing approaches to discover and use preferred communication sources to reach the vaccine-hesitant.

Demographic, social, and behavioral correlates of SARS-CoV-2 seropositivity in a representative, population-based study of Minnesota residents

BACKGROUND

Monitoring COVID-19 infection risk in the general population is a public health priority. Few studies have measured seropositivity using representative, probability samples. The present study measured seropositivity in a representative population of Minnesota residents prior to vaccines and assess the characteristics, behaviors, and beliefs of the population at the outset of the pandemic and their association with subsequent infection.

METHODS

Participants in the Minnesota COVID-19 Antibody Study (MCAS) were recruited from residents of Minnesota who participated in the COVID-19 Household Impact Survey (CIS), a population-based survey that collected data on physical health, mental health, and economic security information between April 20 and June 8 of 2020. This was followed by collection of antibody test results between December 29, 2020 and February 26, 2021. Demographic, behavioral, and attitudinal exposures were assessed for association with the outcome of interest, SARS-CoV-2 seroprevalence, using univariate and multivariate logistic regression.

RESULTS

Of the 907 potential participants from the CIS, 585 respondents then consented to participate in the antibody testing (64.4% consent rate). Of these, results from 537 test kits were included in the final analytic sample, and 51 participants (9.5%) were seropositive. The overall weighted seroprevalence was calculated to be 11.81% (95% CI, 7.30%-16.32%) at of the time of test collection. In adjusted multivariate logistic regression models, significant associations between seroprevalence and the following were observed; being from 23-64 and 65+ age groups were both associated with higher odds of COVID-19 seropositivity compared to the 18-22 age group (17.8 [1.2-260.1] and 24.7 [1.5-404.4] respectively). When compared to a less than $30k annual income reference group, all higher income groups had significantly lower odds of seropositivity. Reporting practicing a number of 10 (median reported value in sample) or more of 19 potential COVID-19 mitigation factors (e.g. handwashing and mask wearing) was associated with lower odds of seropositivity (0.4 [0.1-0.99]) Finally, the presence of at least one household member in the age range of 6 to 17 years old was associated with higher odds of seropositivity (8.3 [1.2-57.0]).

CONCLUSIONS

The adjusted odds ratio of SARS-CoV-2 seroprevalence was significantly positively associated with increasing age and having household member(s) in the 6-17 year age group, while increasing income levels and a mitigation score at or above the median were shown to be significantly protective factors.

Factors affecting health-related quality of life among firefighters during the COVID-19 pandemic: A single-center study

During the coronavirus disease 2019 (COVID-19) outbreak, firefighters have been working in an environment that is both physically and mentally taxing. This study aimed to investigate factors affecting health-related quality of life (HRQOL) among firefighters in Japan during the COVID-19 pandemic. A total of 227 firefighters from a single firefighting organization were surveyed in June 2021, during the fourth infection spread period of COVID-19 in Japan. Regression analysis was performed to examine factors affecting HRQOL of firefighters measured with the SF-8. In the present study, factors affecting HRQOL among firefighters during the COVID-19 pandemic were lack of sleep, physical abnormalities due to infection control measures, exercise habits, living with family members, and history of suspected COVID-19 infection. The present findings may help develop support services for first responders, including firefighters during the COVID-19 pandemic.

A review of infectious disease epidemiology in emergency medical service clinicians

BACKGROUND

The emergency medical service (EMS) workforce is at high risk of occupationally-acquired infections. This review synthesized existing literature on the prevalence, incidence, and severity of infections in the EMS workforce.

METHODS

We searched PubMed, Embase, CINAHL, and SCOPUS from January 1, 2006 to March 15, 2022 for studies in the US that involved EMS clinician or firefighter populations and reported 1 or more health outcomes related to occupationally-acquired infections.

RESULTS

Of the 25 studies that met the inclusion criteria, most focused on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, with prevalence rates ranging from 1.1% to 36.2% (median 6.7%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in 4 studies ranged from 1.9% to 6.4%, and the prevalence of Hepatitis C in 1 study was 1.3%. Few studies reported incidence rates. The prevalence or incidence of these infections generally did not differ by age or gender, but 4 studies reported differences by race or ethnicity. In the 4 studies that compared infection rates between EMS clinicians and firefighters, EMS clinicians had a higher chance of hospitalization or death from SAR-CoV-2 (odds ratio 4.23), a higher prevalence of Hepatitis C in another study (odds ratio 1.74), and no significant difference in MRSA colonization in a separate study.

CONCLUSIONS

More research is needed to better characterize the incidence and severity of occupationally-acquired infections in the EMS workforce.

Influenza and Pneumococcal Vaccination and the Risk of COVID-19: A Systematic Review and Meta-Analysis

A number of studies have investigated the potential on-specific effects of some routinely administered vaccines (e.g., influenza, pneumococcal) on COVID-19 related outcomes, with contrasting results. In order to elucidate this discrepancy, we conducted a systematic review and meta-analysis to assess the association between seasonal influenza vaccination and pneumococcal vaccination with SARS-CoV-2 infection and its clinical outcomes. PubMed and medRxiv databases were searched up to April 2022. A random effects model was used in the meta-analysis to pool odds ratio (OR) and adjusted estimates with 95% confidence intervals (CIs). Heterogeneity was quantitatively assessed using the Cochran's Q and the I2 index. Subgroup analysis, sensitivity analysis and assessment of publication bias were performed for all outcomes. In total, 38 observational studies were included in the meta-analysis and there was substantial heterogeneity. Influenza and pneumococcal vaccination were associated with lower risk of SARS-CoV-2 infection (OR: 0.80, 95% CI: 0.75-0.86 and OR: 0.70, 95% CI: 0.57-0.88, respectively). Regarding influenza vaccination, it seems that the majority of studies did not properly adjust for all potential confounders, so when the analysis was limited to studies that adjusted for age, gender, comorbidities and socioeconomic indices, the association diminished. This is not the case regarding pneumococcal vaccination, for which even after adjustment for such factors the association persisted. Regarding harder endpoints such as ICU admission and death, current data do not support the association. Possible explanations are discussed, including trained immunity, inadequate matching for socioeconomic indices and possible coinfection.

SARS-CoV-2 Seroprevalence Among First Responders in Northeastern Ohio, 2020

Objectives:

First responders, including firefighters, emergency medical technicians (EMTs), paramedics, and law enforcement officers, are working on the front lines to fight the COVID-19 pandemic and facing an increased risk of infection. This study assessed the seroprevalence of SARS-CoV-2 infection among first responders in northeastern Ohio.

Methods:

A survey and immunoglobulin G antibody test against SARS-CoV-2 nucleocapsid protein were offered to University Hospitals Health System–affiliated first-responder departments during May to September 2020. The survey contained questions about demographic characteristics and history of SARS-CoV-2 infection. A total of 3080 first responders with diverse job assignments from more than 400 fire and police departments participated in the study.

Results:

Of 3080 participants, 73 (2.4%) were seropositive and 26 (0.8%) had previously positive real-time polymerase chain reaction results. Asymptomatic infection accounted for 46.6% (34 of 73) of seropositivity. By occupation, rates of seropositivity were highest among administration/support staff (3.8%), followed by paramedics (3.0%), EMTs (2.6%), firefighters (2.2%), and law enforcement officers (0.8%). Work-associated exposure rates to COVID-19 patients were: paramedics (48.2%), firefighters (37.1%), EMTs (32.3%), law enforcement officers (7.7%), and administration/support staff (4.4%). Self-reported community exposure was positively correlated with self-reported work-associated exposure rate (correlation coefficient = 0.99). Neither self-reported community nor work-associated exposure was correlated with SARS-CoV-2 seroprevalence. We found no significant difference in seroprevalence among sex/gender or age groups; however, Black participants had a higher positivity rate than participants of other racial groups despite reporting lower exposure.

Conclusions:

Despite the high work-associated exposure rate to SARS-CoV-2 infection, first responders with various roles demonstrated seroprevalence no higher than their administrative/supportive colleagues, which suggests infection control measures are effective in preventing work-related infection.

SARS-CoV-2 seroprevalence around the world: an updated systematic review and meta-analysis

BACKGROUND

Covid-19 has been one of the major concerns around the world in the last 2 years. One of the challenges of this disease has been to determine its prevalence. Conflicting results of the serology test in Covid explored the need for an updated meta-analysis on this issue. Thus, this systematic review aimed to estimate the prevalence of global SARS-CoV-2 serology in different populations and geographical areas.

METHODS

To identify studies evaluating the seroprevalence of SARS-CoV-2, a comprehensive literature search was performed from international databases, including Medline (PubMed), Web of Sciences, Scopus, EMBASE, and CINHAL.

RESULTS

In this meta-analysis, the results showed that SARS-CoV-2 seroprevalence is between 3 and 15% worldwide. In Eastern Mediterranean, the pooled estimate of seroprevalence SARS-CoV-2 was 15% (CI 95% 5-29%), and in Africa, the pooled estimate was 6% (CI 95% 1-13%). In America, the pooled estimate was 8% (CI 95% 6-11%), and in Europe, the pooled estimate was 5% (CI 95% 4-6%). Also the last region, Western Pacific, the pooled estimate was 3% (CI 95% 2-4%). Besides, we analyzed three of these areas separately. This analysis estimated the prevalence in subgroups such as study population, diagnostic methods, sampling methods, time, perspective, and type of the study.

CONCLUSION

The present meta-analysis showed that the seroprevalence of SARS-CoV-2 has been between 3 and 15% worldwide. Even considering the low estimate of this rate and the increasing vaccination in the world, many people are still susceptible to SARS-CoV-2.

Differences in Motivating Factors for SARS-CoV-2 Vaccination and Perceptions of Infection Risk among Healthcare and EMS Personnel in South Carolina

OBJECTIVES

Although medical workers were prioritized to receive the coronavirus disease 2019 (COVID-19) vaccination, many have declined. Even though studies have investigated differences in COVID-19-related attitudes and vaccination for workers in hospitals and long-term care facilities, none have included emergency medical services (EMS) personnel. We investigated the association between type of medical worker (EMS vs healthcare worker [HCW]) and COVID-19 vaccination, vaccine beliefs, vaccine motivators, personal protection behaviors, and risk perceptions.

METHODS

The data for self-identified HCWs came from surveys distributed to randomly selected residents of South Carolina and EMS personnel recruited at a targeted surveillance testing event during the South Carolina EMS Symposium. Pearson χ2 and Fisher exact tests analyzed differences in the distribution of demographic characteristics and self-reported COVID-19 vaccination attitudes by medical workers. Multivariable logistic regression assessed the association between COVID-19 vaccination and type of medical worker, adjusting for age, sex, race, and frontline status, and assessed the associations among vaccine beliefs, vaccine motivators, personal protection behaviors, and risk perceptions by type of medical worker, adjusting for age, sex, race, frontline status, and vaccination status.

RESULTS

Of the 126 respondents 57.9% were EMS, 42.1% were HCWs, and 73.6% of the cohort were self-reported frontline medical workers. Approximately two-thirds of respondents received a vaccine for COVID-19, with no significant differences between EMS and HCWs; however, EMS workers were significantly less likely to receive the vaccination out of concern about exposures at work/school (adjusted odds ratio [aOR] 0.22, 95% confidence interval [CI] 0.08-0.57), concern about exposures within the community (aOR 0.18, 95% CI 0.07-0.48), or to do their part to control the pandemic (aOR 0.20, 95% CI 0.06-0.69). EMS workers also were significantly less likely to wear a mask all/most of the time when outside the home (aOR 0.04, 95% CI 0.0-0.21) and less concerned about the spread of COVID-19 in their community as compared with HCWs (aOR 0.19, 95% CI 0.06-0.56).

CONCLUSIONS

EMS personnel were significantly less concerned about the spread of COVID-19 in their community and significantly less likely to wear a mask all/most of the time while outside the home as compared with HCWs. Differences in the COVID-19-related attitudes and personal protection behaviors of EMS personnel should be used to develop targeted interventions to increase vaccine motivation and adherence to personal protection protocols.

Returning to Work after the COVID-19 Pandemic Earthquake: A Systematic Review

Background: The ongoing SARS-CoV-2 pandemic has disrupted life and work habits and has produced landmark changes worldwide. This systematic review aimed to analyse the management of Return to Work (RTW) by work organisations following the virus spread. Methods: A selection of 2477 papers, using string research on PubMed, Embase, Web of Science and Scopus from January 2020 to October 2021, were analysed. Results: Fifty-one articles were finally included, and the results obtained were discussed from three different points of view. Twenty articles concerning ‘Remodelling of Work Organization’ proposed some model strategies for resumption to work. Twenty-one papers, including ‘Clinical Evaluation of Workers’, mostly explored the psychosocial impact of returned workers. Finally, twelve articles explored the best ‘Testing Strategies related to RTW’. Despite the heterogeneity of included articles, several interesting approaches have emerged in managing RTW. Conclusions: The reported experiences could help to develop an RTW model for COVID-19 and future pandemics.

COVID-19: Vaccination Side Effects and Sick Leave in Frontline Healthcare-Workers-A Web-Based Survey in Germany

(1) Background: The COVID-19 vaccination has caused uncertainty among employees and employers regarding vaccination reactions and incapacitation. At the time of our study, three vaccines are licensed in Germany to combat the COVID-19 pandemic (BioNTech/Pfizer (Comirnaty), AstraZeneca (Vaxzevria), and Moderna (Spikevax). We aim to assess how often and to what extent frontline healthcare workers had vaccination reactions after the first and second vaccination. The main focus is on the amount of sick leave after the vaccinations. (2) Methods: We create a web-based online questionnaire and deliver it to 270 medical directors in emergency medical services all over Germany. They are asked to make the questionnaire public to employees in their area of responsibility. To assess the association between independent variables and adverse effects of vaccination, we use log-binomial regression to estimate prevalence ratios (PR) with 95% confidence intervals (95%CI) for dichotomous outcomes (sick leave). (3) Results: A total of 3909 individuals participate in the survey for the first vaccination, of whom 3657 (94%) also provide data on the second vaccination. Compared to the first vaccination, mRNA-related vaccine reactions are more intense after the second vaccination, while vaccination reactions are less intense for vector vaccines. (4) Conclusion: Most vaccination reactions are physiological (local or systemic). Our results can help to anticipate the extent to which personnel will be unable to work after vaccination. Even among vaccinated HCWs, there seems to be some skepticism about future vaccinations. Therefore, continuous education and training should be provided to all professionals, especially regarding vaccination boosters. Our results contribute to a better understanding and can therefore support the control of the pandemic.

Seroprevalence of SARS-CoV-2 Among Workers in Northern Italy

BACKGROUND

The spread of severe acute respiratory coronavirus 2 (SARS-CoV-2) among active workers is poor known. The aim of our study was to evaluate the seroprevalence of immunoglobulin G (IgG) among a convenience sample of workers and to identify high-risk job sectors during the first pandemic way.

METHODS

We conducted a cross-sectional study among workers tested for SARS-CoV-2 between 28 March and 7 August 2020, recorded by a private healthcare center located in North-West Italy. Association among seroprevalence and demographic and occupational variables was evaluated using chi square test and the seroprevalence and 95% confidence intervals (CI) were calculated.

RESULTS

We collected the results for 23568 serological tests from a sample of 22708 workers from about 1000 companies. Median age was 45 years and about 60% of subjects were male. The overall seroprevalence was 4.97% [95%CI 4.69-5.25]. No statistical difference was found among gender while seroprevalence was associated with subjects' age, geographical location, and occupational sector. Significantly higher values of positivity were observed for the logistics sector (31.3%), weaving factory (12.6%), nursing homes (9.8%), and chemical industry (6.9%) workers. However, we observed some clusters of cases in single companies independently from the sector.Then, a detailed focus on 940 food workers shown a seroprevalence of 5.21% [95%CI 3.79-6.63] and subjects who self-reported COVID-19 symptoms and who worked during lockdown had a higher probability of being infected (p < 0.001).

CONCLUSIONS

Data obtained might be useful for future public health decision; more than occupation sector, it seems that failure on prevention system in single companies increase the SARS-CoV-2 transmission.

SARS-CoV-2 seroprevalence among firefighters in Los Angeles, California

Objective

We estimate the seroprevalence of SARS-CoV-2 antibodies among a sample of firefighters in the Los Angeles (LA), California fire department in October 2020 and compare demographic and contextual factors for seropositivity.

Methods

We conducted a serological survey of firefighters in LA, California, USA, in October 2020. Individuals were classified as seropositive for SARS-CoV-2 if they tested positive for IgG, IgM or both. We compared demographic and contextual factors for seropositivity.

Results

All firefighters in LA, California, USA were invited to participate in our study, but only roughly 21% participated. Of 713 participants with valid serological data, 8.8% tested positive for SARS-CoV-2 antibodies, and among the 686 with complete survey data 8.9% tested positive for antibodies. Seropositivity was not associated with gender, age or race/ethnicity. Seropositivity was highest among firefighters who reported working in the vicinity of LA International Airport, which had a known outbreak in July 2020.

Conclusions

Seroprevalence among firefighters in our sample was 8.8%, however, we lack a full workplace seroprevalence estimate to compare the relative magnitude against general population seroprevalence (15%). Workplace safety protocols, such as access to personal protective equipment and testing, can mitigate increased risk of infection at work, and may have eliminated differences in disease burden by geography and race/ethnicity in our sample.

Underascertainment of COVID-19 cases among first responders: a seroepidemiological study

Background

Providing frontline support places first responders at a high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Aims

This study was aimed to determine the anti-SARS-CoV-2 seroprevalence in a cohort of first responders (i.e. firefighters/paramedics), to detect the underascertainment rate and to assess risk factors associated with seropositivity.

Methods

We conducted a serological survey among 745 first responders in Germany during 27 November and 4 December 2020 to determine the anti-SARS-CoV-2 seroprevalence using Elecsys® Anti-SARS-CoV-2 immunoassay (Roche Diagnostics, Mannheim, Germany). As part of the examination, participants were asked to provide information on coronavirus disease 2019 (COVID-19)-like-symptoms, information on sociodemographic characteristics and workplace risk factors for a SARS-CoV-2 infection and any prior COVID-19 infection. Descriptive statistics and logistic regression analysis were performed and seroprevalence estimates were adjusted for test sensitivity and specificity.

Results

The test-adjusted seroprevalence was 4% (95% CI 3.1–6.2) and the underascertainment rate was 2.3. Of those tested SARS-CoV-2 antibody positive, 41% were aware that they had been infected in the past. Seropositivity was elevated among paramedics who worked in the emergency rescue team providing first level of pre-hospital emergency care (6% [95% CI 3.4–8.6]) and those directly exposed to a COVID-19 case (5% [95% CI 3.5–8.1]). Overall, the seroprevalence and the underascertainment rate were higher among first responders than among the general population.

Conclusions

The high seroprevalence and underascertainment rate highlight the need to mitigate potential transmission within and between first responders and patients. Workplace control measures such as increased and regular COVID-19-testing and the prompt vaccination of all personnel are necessary.

The Effect of Influenza Vaccination on COVID-19 Morbidity, Severity and Mortality: Systematic Review and Meta-Analysis

Coronavirus disease 2019 (COVID-19) pandemic is rapidly developing worldwide with a high mortality rate. In this meta-analysis study, the effect of influenza vaccination on the prevention of COVID-19 and its consequences in patients were investigated. The systematic search for this study was performed from November 2019 to 25 November 2020, in the databases of Medline, PubMed, Scopus, Web of Science, Embase, Ebsco, Cochrane and medRxiv. Search terms used included COVID-19, coronavirus, SARS-CoV-2, covid, influenza, flu, grippe and vaccine. The present study examined the association between influenza vaccination and COVID-19 including COVID-19 infection, mortality, hospitalisation and intensive care unit (ICU) admission. Finally, the pooled estimates for different outcomes were calculated by the software for statistics and data science (STATA) version 15 and I2 was used to determine the heterogeneity. By analysing the data of articles, the pooled estimates of these data indicated that influenza vaccination could lower probability of COVID-19 infection up to 24% (OR = 0.77; 95% CI: 0.65, 0.91), of death up to 32% (OR = 0.68; 95% CI: 0.42, 1.11), of the hospitalisation up to 25% (OR = 0.75; 95% CI: 0.46; 1.23) and of admission to ICU up to 29% (OR = 0.71; 95% CI: 0.40, 1.27). Influenza vaccination can help decrease the COVID-19 infection and reduce hospitalisation and the need for ICU and mortality rates.

COVID-19 seroconversion in the aircrew from Turkey

Background

Pneumonia due to Severe Acute Respiratory Syndrome 2 (SARS-CoV-2) is spreading rapidly all over the world and air travel is the leading transmission route of the virus among countries. The aim of the study is to determine the frequency of SARS-CoV-2 Immunoglobulin G (IgG) antibodies in aircrew, to determine occupational exposure, and to understand the spread of immunity in social groups.

Method

The study was designed as a cross-sectional retrospective study. SARS-CoV-2 IgG levels were measured in patients who applied to between December 1, 2020 and January 13, 2021. Coronavirus disease-2019 (COVID-19) Reverse transcription polymerase chain reaction (RT-PCR) positivity was investigated before December 1, 2020.

Results

The patients were divided into three groups according to their jobs such as 313 aircrew; 451 healthcare workers; 4258 other patients. The PCR positivity rate was found to be 39% in the aircrew group, 32% in the healthcare workers and %20 other patient group (p < 0.001). The IgG antibody positivity rate was 46% in the aircrew, 41% in healthcare workers, and 35.3% in the other patient group (p < 0.001).The group with the highest IgG antibody titer is in the aircrew; there was a significant difference between the groups (p < 0.001).

Conclusions

In our study, it was observed that aircrew, similar to healthcare workers, are at serious risk against SARS-CoV-2. In this process, it is suggested that the vaccination processes included repeated doses of aircrew should be accelerated and protective measures and equipment should be increased in terms of reinfection.

Seroprevalence of SARS-CoV-2 Among Firefighters/Paramedics in San Francisco, CA

OBJECTIVES

Despite having close contact with the general public, members of the San Francisco Fire Department (SFFD) reported relatively few cases of COVID-19 during the first half of 2020. Our objective was to explore evidence for prior undetected infections by conducting a seroprevalence survey, and to document both risk and protective factors for prior COVID-19 infection.

METHODS

This cross-sectional study assessed workplace practices and exposures of SFFD personnel during the first 6 months of 2020 via questionnaire and documented prior COVID-19 infections by serologic antibody testing using an orthogonal testing protocol.

RESULTS

Of 1231 participating emergency responders, three (0.25%) had confirmed positive COVID-19 antibody results.

CONCLUSIONS

Safe workplace practices, community public health intervention, and low community infection rates appear to have been protective factors for emergency responders in San Francisco during our study period.

COVID-19 seroprevalence among hospital staff and preprocedural patients in Thai community hospitals: a cross-sectional study

OBJECTIVES

We aimed to explore the seroprevalence of hospital staff comparing to preprocedural patients in Thai community hospitals to shed light on the situation of COVID-19 infection of frontline healthcare workers in low infection rate countries where mass screening was not readily available.

DESIGN

Cross-sectional study.

SETTING

52 community hospitals in 35 provinces covered all regions of Thailand.

PARTICIPANTS

857 participants consisted of 675 hospital staff and 182 preprocedural patients.

OUTCOME MEASURE

COVID-19 seroprevalence using a locally developed rapid IgM/IgG test kit RESULTS: Overall, 5.5% of the participants (47 of 857) had positive IgM, 0.2% (2 of 857) had positive IgG which both of them also had positive IgM. Hospitals located in the central part of Thailand had the highest IgM seroprevalence (11.9%). Preprocedural patients had a higher rate of positive IgM than the hospital staff (12.1% vs 3.7%). Participants with present upper respiratory tract symptoms had a higher rate of positive IgM than those without (9.6% vs 4.5%). Three quarters (80.5%, 690 of 857) of the participants were asymptomatic, of which, 31 had positive IgM (4.5%) which consisted of 20 of 566 healthcare workers (3.5%) and 11 of 124 preprocedural patients (8.9%).

CONCLUSIONS

COVID-19 antibody test could detect a substantial number of potential silent spreaders in Thai community hospitals where the nasopharyngeal PCR was not readily available, and the antigen test was prohibited. Antibody testing should be encouraged for mass screening in a limited resource setting, especially in asymptomatic individuals.

TRIAL REGISTRATION

TCTR20200426002.

SARS-CoV-2 antibody seroprevalence among firefighters in Orange County, California

OBJECTIVES

We conducted serological SARS-CoV-2 antibody testing from October to November 2020 to estimate the SARS-CoV-2 seroprevalence among firefighters/paramedics in Orange County (OC), California.

METHODS

OC firefighters employed at the time of the surveillance activity were invited to participate in a voluntary survey that collected demographic, occupational and previous COVID-19 testing data, and a SARS-CoV-2 immunoglobulin (Ig)G antibody blood test. We collected venous blood samples using mobile phlebotomy teams that travelled to individual fire stations, in coordination with an annual tuberculosis testing campaign for firefighters employed by OC Fire Authority (OCFA), and independently for firefighters employed by cities. We estimated seroprevalence and assessed several potential predictors of seropositivity.

RESULTS

The seroprevalence was 5.3% among 923 OCFA personnel tested, with 92.2% participating. Among firefighters self-reporting a previous positive COVID-19 antibody or PCR test result, twenty-one (37%) did not have positive IgG tests in the current serosurvey. There were no statistically significant differences in demographic characteristics between cases and non-cases. Work city was a significant predictor of case status (p=0.015). Seroprevalence (4.8%) was similar when aggregated across seven city fire departments (42%-65% participation). In total, 1486°C fire personnel were tested.

CONCLUSION

Using a strong serosurvey design and large firefighter cohort, we observed a SARS-CoV-2 IgG seroprevalence of 5.3%. The seroprevalence among OC firefighters in October 2020 was lower than the general county population estimated seroprevalence (11.5%) in August. The difference may be due in part to safety measures taken by OC fire departments at the start of the pandemic, as well as differences in antibody test methods and/or duration of antibody response.

Estimated SARS-CoV-2 Infection and Seroprevalence in Firefighters from a Northeastern Brazilian State: A Cross-Sectional Study

The new coronavirus has been affecting health worldwide and essential service workers are continually exposed to this infectious agent, increasing the chance of infection and the development of the disease. Thus, this study aimed to estimate the frequency of infection and seroprevalence for SARS-CoV-2 in military firefighters in a city in Northeastern Brazil in January 2021. An observational cross-sectional study was carried out with 123 firefighters who answered a brief questionnaire to collect socio-epidemiological data and underwent RT-PCR and immunofluorescence test (IgM and IgG). The results found reveal a positive seroprevalence, with a high rate of infection in this class of workers, since they are essential service professionals who are exposed to risk due to their working hours, in addition to sharing some spaces and work materials. Besides, there were significant associations between positivity for IgG and IgM, as well as for positive RT-PCR prior to the study and the presence of IgG, with odd ratios of 3.04 and 4.9, respectively. These findings reinforce the need for immunization in this category, whose line of service hinders the adoption of distancing measures, since in many situations physical contact is inevitable.

SARS-CoV-2 IgG Seropositivity and Acute Asymptomatic Infection Rate among Firefighter First Responders in an Early Outbreak County in California

Objective: Firefighter first responders and other emergency medical services (EMS) personnel have been among the highest risk healthcare workers for illness during the SARS-CoV-2 pandemic. We sought to determine the rate of seropositivity for SARS-CoV-2 IgG antibodies and of acute asymptomatic infection among firefighter first responders in a single county with early exposure in the pandemic. Methods: We conducted a cross-sectional study of clinically active firefighters cross-trained as paramedics or EMTs in the fire departments of Santa Clara County, California. Firefighters without current symptoms were tested between June and August 2020. Our primary outcomes were rates of SARS-CoV-2 IgG antibody seropositivity and SARS-CoV-2 RT-PCR swab positivity for acute infection. We report cumulative incidence, participant characteristics with frequencies and proportions, and proportion positive and associated relative risk (with 95% confidence intervals). Results: We enrolled 983 out of 1339 eligible participants (response rate: 73.4%). Twenty-five participants (2.54%, 95% CI 1.65-3.73) tested positive for IgG antibodies and 9 (0.92%, 95% CI 0.42-1.73) tested positive for SARS-CoV-2 by RT-PCR. Our cumulative incidence, inclusive of self-reported prior positive PCR tests, was 34 (3.46%, 95% CI 2.41-4.80). Conclusion: In a county with one of the earliest outbreaks in the United States, the seroprevalence among firefighter first responders was lower than that reported by other studies of frontline health care workers, while the cumulative incidence remained higher than that seen in the surrounding community.

Acceptance of COVID-19 Vaccination among Front-Line Health Care Workers: A Nationwide Survey of Emergency Medical Services Personnel from Germany

INTRODUCTION

The aim of this study was to evaluate the COVID-19 vaccination acceptance of emergency medical services (EMS) personnel as front-line health care workers (HCW) in Germany. Several studies have shown low willingness for vaccination (e.g., seasonal influenza) among HCWs and EMS personnel.

METHODS

We created a web-based survey. The questions were closed and standardized. Demographic data were collected (age, sex, federal state, profession). Experience with own COVID-19 infection, or infection in personal environment (family, friends) as well as willingness to vaccinate was queried.

RESULTS

The sample includes n = 1296 participants. A willingness to be vaccinated exists in 57%, 27.6% participants were undecided. Our results show a higher propensity to vaccinate among the following groups: male gender, higher medical education level, older age, own burden caused by the pandemic (p < 0.001).

CONCLUSIONS

Due to the low overall acceptance of vaccination by HCWs, we recommend that the groups with vaccination hesitancy, in particular, be recruited for vaccination through interventions such as continuing education and awareness campaigns.

Risk Factors of SARS-CoV-2 Antibodies in Arapahoe County First Responders-The COVID-19 Arapahoe SErosurveillance Study (CASES) Project

OBJECTIVES

Define the seroprevalence and risk factors for SARS-CoV-2 antibodies in Arapahoe County, Colorado first responders (eg, law enforcement, human services, fire departments).

METHODS

Two hundred sixty four first responders were enrolled June to July 2020. SARS-CoV-2 seropositivity was defined as detection of immunoglobulin G (IgG) antibodies to both spike receptor binding domain and nucleocapsid in venous blood by validated enzyme-linked immunosorbent assay. We compared risk factors for being seropositive versus seronegative.

RESULTS

4% (11/264) were SARS-CoV-2 seropositive. Seropositive participants were significantly more likely to have lung disease (% seropositive, % seronegative; P-value) (36%, 8%; P = 0.01), prior SARS-CoV-2/COVID-19 testing (36%, 8%; P ≤ 0.01), a prior positive result (18%, less than 1%), and to believe they previously had COVID-19 (64%, 15%; P < 0.01). Only 15% of those believing they had COVID-19 had anti-SARS-CoV-2 antibodies.

CONCLUSIONS

Human services employees and individuals with lung disease are at SARS-CoV-2 exposure risk. Few individuals believed they had COVID-19 had prior exposure.

A Case-Control Study of the 2019 Influenza Vaccine and Incidence of COVID-19 Among Healthcare Workers

PURPOSE

The influenza vaccine is essential in reducing the influenza burden, especially among healthcare workers (HCW). Experimental studies suggest both coronaviruses and influenza viruses engage with the angiotensin-converting enzyme 2 (ACE 2) and tetraspanin antibodies, and that ACE 2 tetraspanin antibodies in turn may inhibit both coronavirus and low-pathogenicity influenza A viruses (LP IAV) infections. This study aims to investigate the potential clinical association between receiving the 2019 influenza vaccine and the incidence of COVID-19 among HCW.

METHODS

We designed a case-control study within a hospital setting in Iran when it became a center for treating COVID-19 patients. We collected data and calculated relevant incidence and associative measures among HCW who had received the 2019 influenza vaccine as compared to HCW who had not received the vaccine.

RESULTS

Our total sample size was 261 HCW. Of 80 COVID-19 incident cases, three cases had received the influenza vaccine, while 87 of 181 controls had received the vaccine. The odds ratio (OR) and confidence interval (CI) of being vaccinated were 0.04 (95% CI: 0.01 to 0.14) among COVID-19 cases as compared to controls.

CONCLUSIONS

Significant findings suggest that the 2019 influenza vaccine may have a protective association against COVID-19 among HCW.

The Association between Influenza Vaccination and the Risk of SARS-CoV-2 Infection, Severe Illness, and Death: A Systematic Review of the Literature

We reviewed the association between seasonal influenza vaccination and the risk of SARS-CoV-2 infection or complicated illness or poor outcome (e.g., severe disease, need for hospitalization or ventilatory support, or death) among COVID-19 patients. None of the studies that were reviewed (n = 12) found a significant increase in the risk of infection or in the illness severity or lethality, and some reported significantly inverse associations. Our findings support measures aimed at raising influenza vaccination coverage in the coming months.

Influenza Vaccination and Risk of SARS-CoV-2 Infection in a Cohort of Health Workers

Vaccines may induce positive non-specific immune responses to other pathogens. This study aims to evaluate if influenza vaccination in the 2019-2020 season had any effect on the risk of SARS-CoV-2 confirmed infection in a cohort of health workers. During the first SARS-CoV-2 epidemic wave in Spain, between March and May 2020, a cohort of 11,201 health workers was highly tested by RT-qPCR and/or rapid antibody test when the infection was suspected. Later in June, 8665 of them were tested for total antibodies in serum. A total of 890 (7.9%) health workers were laboratory-confirmed for SARS-CoV-2 infection by any type of test, while no case of influenza was detected. The adjusted odds ratio between 2019-2020 influenza vaccination and SARS-CoV-2 confirmed infection was the same (1.07; 95% CI, 0.92-1.24) in both comparisons of positive testers with all others (cohort design) and with negative testers (test-negative design). Among symptomatic patients tested by RT-qPCR, the comparison of positive cases and negative controls showed an adjusted odds ratio of 0.86 (95% CI, 0.68-1.08). These results suggest that influenza vaccination does not significantly modify the risk of SARS-CoV-2 infection. The development of specific vaccines against SARS-CoV-2 is urgent.