Adherence of healthcare workers to COVID-19 infection prevention practices and its relationship with SARS-CoV-2 seropositivity

Background Infection prevention and control (IPC) practices against COVID-19 should be adopted by healthcare workers (HCWs) at their workplaces to protect themselves, their patients, and their families from infection. Purpose This study aimed to describe the relationship between the healthcare-related COVID-19 infection prevention measures adopted by HCWs and their SARS-CoV-2 seropositivity. Research Design This cross-sectional study was conducted during the second and third COVID-19 waves in Egypt. Study Sample The study included 416 unvaccinated HCWs from 39 hospitals in Egypt. Data Collection Sociodemographic data, as well as COVID-19 IPC measures done at work, and protective measures performed by their healthcare facilities were collected. SARS-CoV-2 spike protein antibodies were measured by ELISA. Results 58.2% of participants were seropositive for SARS-CoV-2. Among the previously undiagnosed HCWs, 125/271 (46.1%) were seropositive. Predictors of seropositivity were rural residence (aOR = 5.096;95% CI: 1.583–16.403, p = 0.006), previous COVID-19 infection (aOR = 4.848, 95% CI: 2.933–8.015, p = 0.000), and examining 10–20 suspected COVID-19 patients daily (aOR = 2.329;95% CI: 1.331–4.077, p = 0.003. Reporting low satisfaction (25–50%) with infection control implementation, working more than 40 h per week, reporting to "sometimes abiding by hand hygiene” compared to those who reported to "always” adhere to hand hygiene and shorter duration of hand washing (<20 s) were associated with significantly higher odds of seropositivity. Conclusions Poor infection control measures and the high workload of HCWs (longer working hours and examining more patients) were modifiable risk factors for SARS-CoV-2 seropositivity among HCWs. Hand hygiene was better among HCWs working in urban versus rural areas.

Adherence of healthcare workers to COVID-19 infection prevention practices and its relationship with SARS-CoV-2 seropositivity.

Background: Infection prevention and control (IPC) practices against COVID-19 should be adopted by healthcare workers (HCWs) at their workplaces to protect themselves, their patients, and their families from infection. Purpose: This study aimed to describe the relationship between the healthcare-related COVID-19 infection prevention measures adopted by HCWs and their SARS-CoV-2 seropositivity. Research Design: This cross-sectional study was conducted during the second and third COVID-19 waves in Egypt. Study Sample: The study included 416 unvaccinated HCWs from 39 hospitals in Egypt. Data Collection: Sociodemographic data, as well as COVID-19 IPC measures done at work, and protective measures performed by their healthcare facilities were collected. SARS-CoV-2 spike protein antibodies were measured by ELISA. Results: 58.2% of participants were seropositive for SARS-CoV-2. Among the previously undiagnosed HCWs, 125/271 (46.1%) were seropositive. Predictors of seropositivity were rural residence (aOR = 5.096; 95% CI: 1.583-16.403, p = 0.006), previous COVID-19 infection (aOR = 4.848, 95% CI: 2.933-8.015, p = 0.000), and examining 10-20 suspected COVID-19 patients daily (aOR = 2.329; 95% CI: 1.331-4.077, p = 0.003. Reporting low satisfaction (25-50%) with infection control implementation, working more than 40 h per week, reporting to "sometimes abiding by hand hygiene" compared to those who reported to "always" adhere to hand hygiene and shorter duration of hand washing (<20 s) were associated with significantly higher odds of seropositivity. Conclusions: Poor infection control measures and the high workload of HCWs (longer working hours and examining more patients) were modifiable risk factors for SARS-CoV-2 seropositivity among HCWs. Hand hygiene was better among HCWs working in urban versus rural areas.

Prevalence of severe acute respiratory syndrome coronavirus 2 spike antibodies in some healthcare settings in Egypt.

BACKGROUND: Healthcare workers (HCWs) are at the front line in battling infection transmission, such as that in coronavirus disease 19 (COVID-19). Additionally, they may act as potential carriers passing the virus on to others. Anti-spike (anti-S) antibodies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are formed either as a result of infection or vaccination with both indicating immunity against future COVID-19 infection. AIM: This study aimed to identify the prevalence of COVID-19 seropositivity among HCWs. METHODS: This cross-sectional study included 559 HCWs from 39 hospitals with variable degrees of COVID-19 exposure risk (depending on the occupation, department, and hospital type). Demographic data were recorded as well as history of COVID-19 infection and vaccination. Serum samples were collected and tested for SARS-CoV-2 spike antibodies. RESULTS: Anti-S positivity was found in 59.0% of the participating 559 HCWs, indicating a high level of seroprotection. Of the 559 HCWs, 34.1% had reported previous infection with COVID-19. Following infection, only 46 (24.0%) of those affected received vaccination. Anti-S seropositivity was found in 39.1% of participants who were unvaccinated and had no history of infection. Physicians had the highest median anti-S titers (58.0 relative units (RU)/mL), whereas pharmacists and office staff had the lowest (25.7 and 38.2 RU/mL, respectively). CONCLUSIONS: Overall, 59.0% of the 559 HCWs were anti-S positive, indicating a relatively high seroprotective status. Among those who were unvaccinated and had no history of infection, 39.1% were seropositive for anti-S, denoting a high rate of silent/asymptomatic infections. Screening of HCWs for SARS-CoV-2 anti-S is recommended, along with the vaccination of seronegative individuals.

Delayed seropositivity is associated with lower levels of SARS-CoV-2 antibody levels in patients with mild to moderate COVID-19.

BACKGROUND: Patients with COVID-19 can develop a range of immune responses, including variations in the onset and magnitude of antibody formation. The aim of this study was to investigate whether SARS-CoV-2 antibody levels vary in patients with mild to moderate COVID-19 in relation to the onset (days) of their post-symptom seropositivity and to explore host factors that may affect antibody production METHODS: This was a prospective, multiple measurements study involving 92 PCR-confirmed patients with mild to moderate COVID-19. Antibody testing for anti-nucleocapsid (anti-NP) and spike proteins (anti-S) was performed using ELISA tests. Serum samples were collected over a period of 55 days from symptom onset of COVID-19 infection, and repeated as necessary until they turned positive. RESULTS: No significant differences were found between the positivity rates of anti-S or anti-NP regarding any clinical symptom (p > 0.05). The majority of patients who tested positive for anti-NP and anti-S showed early seropositivity (within 15 days of symptom onset) (75.9% for anti-NP and 82.6% for anti-S). Younger patients, those without chronic diseases, and non-healthcare workers had the highest percentage of seroconversion after day 35 post-symptom onset (p = 0.002, 0.028, and 0.036, respectively), while older patients and those with chronic diseases had earlier seropositivity and higher anti-NP levels (p = 0.003 and 0.06, respectively). Significantly higher anti-S ratios were found among older (p = 0.004), male (p = 0.015), and anemic patients (p = 0.02). A significant correlation was found between both antibodies (p = 0.001). At the end of the study, the cumulative seroconversion rate for both antibodies was almost 99%. CONCLUSIONS: Some COVID-19 patients may exhibit delayed and weak immune responses, while elderly, anemic patients and those with chronic diseases may show earlier and higher antibody responses.

Asymptomatic versus symptomatic SARS-CoV-2 infection: a cross-sectional seroprevalence study.

BACKGROUND: Although symptomatic SARS-CoV-2 infection predisposes patients to develop complications, the asymptomatic SARS-CoV-2 infection state is of public health importance being a hidden source of infection. Moreover, the asymptomatic state may camouflage the actual burden of the disease. METHODS: Data of 1434 seropositive participants for SARS-CoV-2 spike (anti-S) and/or nucleocapsid antibodies (anti-N) were retrieved from a larger cross-sectional survey on COVID-19. Relevant data were retrieved from records including socio-demographic, medical, and behavioral characteristics of seropositive participants as well as history of COVID-19 symptoms during the last 6 months. Symptomatic/asymptomatic SARS-CoV-2 infection was categorized based on the history of the presence or absence of COVID-19 symptoms. RESULTS: The rate of asymptomatic SARS-CoV-2 infection was 34.9%. There was a statistically significant difference between symptomatic and asymptomatic participants regarding age, residence, medical conditions, habits, and infection control measures. The number of symptoms was positively correlated with anti-S titer and both were positively correlated with adult body mass index. Slum areas residence, client-facing occupation or being a healthcare worker, having lung disease, having blood group type A, never practicing exercise or social distancing, never using soap for hand washing, and minimal engagement in online working/studying were independent factors associated with the symptomatic state. Patients having less than three symptoms were less likely to be diagnosed by any means. CONCLUSIONS: One-third of SARS-CoV-2 infections in our study were asymptomatic. This mandates applying proper measures to prevent transmission even from apparently healthy individuals. Modifiable factors associated with symptomatic infection should be controlled to reduce the risk of COVID-19 complications.

"Day 25": a temporal indicator of stabilization of mortality risk among COVID-19 patients with high viral load.

INTRODUCTION: The relationship between SARS-CoV-2 viral load and hospitalization and mortality among COVID-19 patients has been established. However, the estimation of the duration of time after which the risk of mortality of these patients stops escalating was not extensively discussed earlier. Stratifying patients according to their risk of mortality would optimize healthcare services and costs and reduce mortality. METHODOLOGY: In this retrospective observational study, hospital records were used to collect data of 519 COVID-19 patients from May through November 2020. Data included the clinical condition of patients, their viral loads, their admission chest computed tomography results (CO-RAD scale), and the duration of their hospitalization. A Kaplan-Meier analysis was constructed to estimate mortality risk concerning viral load. RESULTS: By the end of the study, 20.42% of patients were deceased. The cumulative mortality was: 36.1% (75/208) among patients with high viral load, 12.6% (28/222) in those with moderate viral load, and 3.4% (3/89) among those with low viral load. Predictors of mortality were: older age [adjusted hazard ratio (aHR) = 1.02, 95% CI: [1.00-1.03], (p = 0.05)], "being female" [aHR = 1.53 with 95% CI: [1.03-2.26], (p = 0.031), "high CO-RAD scale" [aHR = 1.32 (1.06-1.64), p = 0.013], "high viral load" [aHR = 4.59 (2.38-20.92), p = 0.017, ICU admission [aHR = 15.95; 95%CI:7.22-35.20, p < 0.001] and lymphocytosis [aHR = 1.89 45;95%CI:1.04-3.45, p = 0.036]. In the ICU-admitted patients, the median survival was 19 days and mortality stabilized at "day 25". For patients with high viral load, mortality rates stabilized at "day 25 post-admission" after which the risks of mortality did not change until day 40, while patients with low and moderate viral loads reached the peak and stabilized at day "20 post-admission". CONCLUSIONS: Initial high SARS-CoV-2 viral load might be used as an indicator of a delayed stabilization of mortality risk among COVID-19 patients.

COVID-19 vaccine acceptance rates and predictors among the Egyptian general population and Healthcare workers, the intersectionality of age and other factors.

The promise of COVID-19 vaccines in ending the pandemic can only be achieved by overcoming the challenge of vaccine refusal. Healthcare workers (HCWs) are the trusted advisors of vaccination decisions. Recommendations for vaccinating children against COVID-19 are recently gaining more public health attention due to the role of children in disease transmission and associated morbidities. Vaccination is one of the first medical decisions parents or guardians make on behalf of their children. To investigate the determinants associated with vaccine acceptability among the general population through a direct interview questionnaire and assess guardians' views towards childhood COVID-19 vaccinations. This cross-sectional study included 2919 participants A pre-designed structured questionnaire about COVID-19 vaccination acceptability was completed by trained interviewers and interviewing the participants or their guardians (for those below 18 years old). Nearly two-thirds of participants (66.5%) accepted vaccination, 20.2% were refusing and 13.3% were hesitant. Most participants who were guardians of children below 12 years and from 13 to 17 years reported that they would accept vaccination of their children (72.5% and 70.5%, respectively). The acceptance rate among HCWs was 58.2%. The main reasons beyond vaccine refusal were mistrust of vaccine efficacy (39.5%) and having concerns regarding vaccine safety (38.8%). In a multivariable regression model, being male (OR 1.362, 95% CI 1.082-1.714, p = 0.008) resident in rural area (OR 1.796, 95% CI 1.435-2.247, p = 0.000), and lower education (OR 1.245, 95% CI 1.018-1.523, p = 0.033) were associated with an increased acceptance to be vaccinated. The acceptance rate for vaccinating children reported among their guardians was higher than adults for themselves. Extremes of age showed higher vaccine acceptance compared to young adults. Upper Egypt governorates (Faiyum and Giza) were outpacing Lower Egypt governorates in vaccination acceptance rates.

Determining the SARS-CoV-2 Anti-Spike Cutoff Level Denoting Neutralizing Activity Using Two Commercial Kits.

BACKGROUND: The viral neutralization assay is the gold standard to estimate the level of immunity against SARS-CoV-2. This study analyzes the correlation between the quantitative Anti-SARS-CoV-2 QuantiVac ELISA (IgG) and the NeutraLISA neutralization assay. METHODS: 650 serum samples were tested for both SARS-CoV-2 anti-spike (anti-S) immunoglobulin G (IgG) and neutralizing antibodies (nAbs) using kits by EUROIMMUN, Germany. RESULTS: There was a significant correlation between levels of anti-S and nAbs (Spearman's rho = 0.913). Among the positive samples for anti-S, 77.0% (n = 345) were positive for nAbs. There was a substantial agreement between anti-S and nAbs (Cohen's kappa coefficient = 0.658; agreement of 83.38%). Considering NeutraLISA as a gold standard, anti-S had a sensitivity of 98.57%, specificity of 65.66%, NPV of 97.5%, and PPV of 77.0%. When the anti-S titer was greater than 18.1 RU/mL (57.9 BAU/mL), nAbs were positive, with a sensitivity of 90.0% and specificity of 91%. CONCLUSIONS: A titer of SARS-CoV-2 anti-S IgG can be correlated with levels of nAbs.

A pre-vaccine exploratory survey of SARS-CoV-2 humoral immunity among Egyptian general population.

BACKGROUND: Population-based studies on COVID-19 have important implications for modeling the pandemic and determining vaccination policies. Limited data are available from such surveys in Egypt. METHODS: This cross-sectional was conducted throughout the period between January and June 2021, which coincided with the second and third waves of the COVID-19 pandemic in Egypt. At that time, vaccines against COVID-19 were not available to the general population. The study was carried out in eight Egyptian governorates and included 2360 participants, who were recruited through a multistage stratified cluster sample technique, based on gender, age, and district followed by a random sample within each district. Socio-demographic data were recorded and serum samples were collected and tested for SARS-Co-V2 spike (S) antibodies. RESULTS: The overall adjusted prevalence of anti-S was 46.3% (95% CI 44.2-48.3%), with significant differences between governorates. Factors associated with anti-S seropositivity were: being female (p = 0.001), living in a rural area (p = 0.008), and reporting a history of COVID-19 infection (p = 0.001). Higher medians of anti-S titers were significantly associated with: extremes of age (p < 0.001), living in urban areas, having primary education (p = 0.009), and reporting a history of COVID-19 infection, especially if based on chest CT or PCR (p < 0.001). CONCLUSIONS: High seroprevalence rates indicate increased COVID-19 infection and immune response among a considerable percentage of the community. Age, gender, residence, educational level, and previous PCR-confirmed COVID-19 infections were all determinants of the immune response.

Anti-Spike and Neutralizing Antibodies after Two Doses of COVID-19 Sinopharm/BIBP Vaccine.

Host response to COVID-19 vaccines is partially evaluated through the estimation of antibody response, specifically the binding anti-spike (anti-S) and the neutralizing antibodies (nAbs) against SARS-CoV-2. Vaccine-induced humoral response affects decisions on the choice of vaccine type, vaccine acceptance, and the need for boosting. Identification of risk factors for poor antibody response helps to stratify individuals who might potentially require booster doses. The primary objective of this cross-sectional study was to investigate the antibody response after receiving two Sinopharm vaccine doses. Factors affecting antibody response were additionally studied. Moreover, a predictive cutoff for anti-S was generated to predict positivity of nAbs. Blood samples were collected from 92 adults and relevant data were recorded. Antibody levels (anti-S and nAbs) against SARS-CoV-2 were tested one month following the second dose of Sinopharm vaccine using two commercial ELISA tests. Among the 92 participants, 88 tested positive for anti-S (95.7%), with a median level of 52.15 RU/mL (equivalent to 166.88 BAU/mL). Fewer participants (67.4%) were positive for nAbs, with a median percentage of inhibition (%IH) of 50.62% (24.05-84.36). A significant positive correlation existed between the titers of both antibodies (correlation coefficient = 0.875, p < 0.001). When the anti-S titer was greater than 40 RU/mL (128 BAU/mL), nAbs were also positive with a sensitivity of 80.6% and a specificity of 90%. Positive nAbs results were associated with a higher anti-S titers (62.1 RU/mL) compared to negative nAbs (mean anti-S titer of 18.6 RU/mL). History of COVID-19 infection was significantly associated with higher titers of anti-S (p = 0.043) and higher IH% of nAbs (p = 0.048). Hypertensive participants were found to have significantly higher median titers of anti-S (101.18 RU/mL) compared with non-hypertensive ones (42.15 RU/mL), p = 0.034. Post-vaccination headache was significantly higher among those with higher anti-S than those with relatively lower titers (98.82 versus 43.69 RU/mL, p = 0.048). It can be concluded that the Sinopharm vaccine produced high levels of binding antibodies but with low neutralizing abilities. Also, levels of anti-S titer greater than 40 RU/mL could adequately predict positivity of nAbs without need for their testing.

Predictors of Anti-SARS-CoV-2 Seropositivity: An Egyptian Population- based Study

Background Population-based studies on the determinants of COVID-19 seroprevalence constitute a cornerstone in guiding appropriate preventive measures. Such studies are scarce in Egypt, thus we conducted this study to explore risk factors for SARS-CoV-2 seropositivity. Methods This survey included 2919 participants from 10 Egyptian governorates. Sera were tested for SARS-CoV-2 spike (S) and nucleocapsid (N) antibodies. Univariate and multivariate analyses were performed to identify associated factors and predictors of seropositivity regarding socio-demographic factors, clinical data and personal practices of participants. A sub-group analysis was performed to investigate the occupational risks of seropositivity. Results Seropositivity was recorded in 1564 participants (53.6%). Independent predictors of seropositivity included non-smokers (aOR= 1.817;95%CI: 1.407–2.346, p= 0.000), having blood group A (aOR= 1.231;95%CI: 1.016–1.493, p=0.034), a history of COVID-19 infection (aOR=2.997;95%CI: 2.176–4.127, p=0.000), COVID-19 vaccination (aOR=4.349;95%CI: 2.798–6.759, p=0.000), higher crowding index (aOR=1.229;95%CI: 1.041–1.451, p=0.015), anosmia and/or ageusia (aOR= 3.453;95%CI: 2.661–4.481, p = 0.000) and history of fever (aOR=1.269;95%CI: 1.033–1.560, p =0.023). Healthcare worker and Obesity/overweight were additional significant predictors of seropositivity among the working participants (aOR= 1.760;95%CI: 1.301–2.381, p=0.000 and aOR= 1.384;95%CI:1.059–1.808, p= 0.019, respectively). Additional factors showing association with seropositivity in the univariate analysis were: female gender, age group (15–39 years), higher educational level (preparatory and above), lack of environmental disinfection and having roommates at the workplace. There was a positive correlation between the titres of both antibodies. Age was weakly correlated with anti-S titre, while anti-N was significantly correlated with the number of protective measures applied by the participants. Both antibodies were significantly correlated with adult BMI, while both were significantly negatively correlated with the smoking index. Conclusions SARS-CoV-2 seropositivity was associated with some personal and behavioral and occupation-related factors. Fever and anosmia and/or ageusia were the symptoms mostly associated with seropositivity.

Prevalence of severe acute respiratory syndrome coronavirus 2 spike antibodies in some healthcare settings in Egypt

BackgroundHealthcare workers (HCWs) are at the front line in battling infection transmission, such as that in coronavirus disease 19 (COVID-19). Additionally, they may act as potential carriers passing the virus on to others. Anti-spike (anti-S) antibodies for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are formed either as a result of infection or vaccination with both indicating immunity against future COVID-19 infection.AimThis study aimed to identify the prevalence of COVID-19 seropositivity among HCWs.MethodsThis cross-sectional study included 559 HCWs from 39 hospitals with variable degrees of COVID-19 exposure risk (depending on the occupation, department, and hospital type). Demographic data were recorded as well as history of COVID-19 infection and vaccination. Serum samples were collected and tested for SARS-CoV-2 spike antibodies.ResultsAnti-S positivity was found in 59.0% of the participating 559 HCWs, indicating a high level of seroprotection. Of the 559 HCWs, 34.1% had reported previous infection with COVID-19. Following infection, only 46 (24.0%) of those affected received vaccination. Anti-S seropositivity was found in 39.1% of participants who were unvaccinated and had no history of infection. Physicians had the highest median anti-S titers (58.0 relative units (RU)/mL), whereas pharmacists and office staff had the lowest (25.7 and 38.2 RU/mL, respectively).ConclusionsOverall, 59.0% of the 559 HCWs were anti-S positive, indicating a relatively high seroprotective status. Among those who were unvaccinated and had no history of infection, 39.1% were seropositive for anti-S, denoting a high rate of silent/asymptomatic infections. Screening of HCWs for SARS-CoV-2 anti-S is recommended, along with the vaccination of seronegative individuals.

Determinants of the Development of SARS-CoV-2 Anti-Spike Immune-Response after Vaccination among Healthcare Workers in Egypt.

BACKGROUND: Understanding the factors affecting humoral immune response to COVID-19 vaccines among healthcare workers (HCWs) is essential to predict their level of protection. Vaccination elicits antibodies against SARS-CoV-2 spike protein (anti-S). AIM: To investigate the factors associated with the presence of SARS-CoV-2 anti-S antibodies among vaccinated HCWs. METHODS: This cross-sectional study included 143 vaccinated HCWs, with or without a history of previous COVID-19 infection (clinically, radiologically, or by laboratory results) from different departments. Socio-demographic, clinical, as well as vaccine-related data, were recorded. Serum samples were collected and tested for SARS-CoV-2 spike antibodies. RESULTS: Vaccination provoked an immunogenic response, where the overall anti-S positivity was 83.9% (95% CI: 77.8-90.0%). The response was not affected either by the age or gender of HCWs. Out of the 143 HCWs, 46 (32.1%; 95% CI: 24.4-39.9%) reported a previous history of COVID-19 infection, and seropositivity was significantly higher among them (p = 0.002), and it was associated with the frequency of infection (p = 0.044) and duration since diagnosis of COVID-19 infection (p = 0.065). They had higher median anti-S titers (111.8 RU/mL) than those without infection (39.8 RU/mL). Higher seropositivity was observed with Oxford/AstraZeneca vaccine (AZD1222) (88.9%; 95% CI: 83.1-95.0%) than Sinopharm (BBIBP-CorV) (67.7%; 95% CI: 50.3-85.2%), and with receiving two doses of vaccine (92.3%; 95% CI: 87.1-97.5%). CONCLUSIONS: Antibody positivity was significantly affected by the previous history of COVID-19 infection, type of vaccine, the number of doses received, and duration since vaccination.