Sero-Prevalence and Sero-Incidence of Antibodies to SARS-CoV-2 in Health Care Workers in Israel, Prior to Mass COVID-19 Vaccination

Polymerase chain reaction-positivity and predictors for SARS-CoV-2 infection among diagnosed cases' in North West Ethiopia

Background

The lack of sophisticated diagnosing equipment for polymerase chain reaction (PCR) during the incidence of variant types of COVID-19 underestimates the morbidity and mortality patterns of this pandemic. Thus, this study aimed to estimate seropositive and confirmatory predictors for COVID-19 suspected and tested cases through polymerase chain reaction (RT-PCR) in two diagnosing.

Methods

A facility-based descriptive cross-sectional study was employed among COVID-19 suspected cases from January 2, 2022, to June 9, 2022. The data were collected both using a structured interviewees and nasopharyngeal (NP) swabs. The nasal swab (NS) was analyzed in the laboratory for RNA detection of the virus using PCR. The collected data were entered into Epi Data version 4.2 and then exported to STATA (SE) version R-14 software for further analysis. multivariable logistic regression was used to assess the associated risk.

Results

A total of 285 suspected cases have participated in this study. The overall mean (±SD) age of the participants was 37.5 (±18.5) years. The majority, 174 (61.1%) of the tested groups were symptomatic when diagnosed. The positivity of RT-PCR for suspected and COVID-19 diagnosed cases were confirmed in 62/285 (21.75%). In multivariable analysis, they were aged 26-50 years (adjusted odds ratio [AOR] = 4.2, 95% confidence interval [CI] = 1.5-10.75), had comorbidity (AOR = 5.8; 95% CI = 2.1-12.2), and cigarette smokers (AOR = 13.5; 95% CI = 5.3-36.6) were significantly associated with developing COVID-19 infection.

Conclusion

More than two in every nine suspected cases were positive RT-PCR tests, and the infectivity of COVID-19 was significantly associated with age 25-50 years, comorbidities, and cigarette smoking. The deployment of high-quality diagnostic kits like RT-PCR is crucial for the early detection and risk stratification of suspected cases.

SARS-CoV-2 infection rate in Antananarivo frontline health care workers, Madagascar

BACKGROUND

Health care workers (HCWs) represent a vulnerable population during epidemic periods. Our cohort study aimed to estimate the risk of infection and associated factors among HCWs during the first wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Madagascar.

METHODS

A prospective cohort study was carried out in three hospitals that oversaw the first cases of COVID-19. Monthly ELISA-based serological tests were conducted, and nasopharyngeal swabs were collected in the case of symptoms linked to COVID-19 for RT-PCR analysis. Survival analyses were used to determine factors associated with SARS-CoV-2 infection.

RESULTS

The study lasted 7 months from May 2020. We included 122 HCWs, 61.5% of whom were women. The median age was 31.9 years (IQR: 26.4-42.3). In total, 42 (34.4%) had SARS-CoV-2 infections, of which 20 were asymptomatic (47.6%). The incidence of SARS-CoV-2 infection was 9.3% (95% CI [6.5-13.2]) person-months. Sixty-five HCWs presented symptoms, of which 19 were positive by RT-PCR. When adjusted for exposure to deceased cases, infection was more frequent in HCWs younger than 30 years of age (RR = 4.9, 95% CI [1.4-17.2]).

CONCLUSION

Our results indicate a high incidence of infection with SARS-CoV-2 among HCWs, with a high proportion of asymptomatic cases. Young HCWs are more likely to be at risk than others. Greater awareness among young people is necessary to reduce the threat of infection among HCWs.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ) IgG-antibody seroprevalence among quarantined population, during the first wave of COVID-19 pandemic, In North West Ethiopia (from 30 April to 30 May 2020)

Objective:

The spread of Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) in Ethiopia is below par understood and to date has been poorly characterized by a lower number of confirmed cases and deaths as compared with other regions of the Sub-Saharan African (SSA) countries. We aimed to investigate the seroprevalence of SARS-CoV-2 specific IgG antibodies, using the Abbott anti-nucleocapsid IgG chemiluminescent microparticle immunoassay, in two COVID-19 diagnosed and treatment centers of quarantined population during the first wave of the COVID-19 pandemic (since 30 April–30 May 2020).

Methods:

We analyzed data of 446 quarantined individuals during the first wave of COVID-19 pandemic. The data were collected using both interviewed and blood sample collection. Participants asked about demographic characteristics, COVID-19 infection symptoms, and its practice of preventive measures. Seroprevalence was determined using the severe acute respiratory syndrome coronavirus 2 IgG test.

Results:

The mean (± standard deviation) age of the respondent was 37.5 (±18.5) years. The estimated SARS-CoV-2 infection seroprevalence was found 4.7% (95% confidence interval: 3.1–6.2) with no significant difference on age and gender of participants. Severe acute respiratory syndrome coronavirus 2 antibody seroprevalence was significantly associated with individuals who have been worked by moving from home to work area (adjusted odds ratio = 7.8, 95% confidence interval: 4.2–14.3, p < 0.019), not wearing masks (adjusted odds ratio = 2.4, 95% confidence interval: 1.9–3.8, p < 0.02), and baseline comorbidity (adjusted odds ratio = 6.3, 95% confidence interval: 2.3–17.1, p < 0.01) as compared to their counter groups, respectively.

Conclusion:

Our study concluded that lower coronavirus disease 2019 seroprevalence, yet the large population in the community to be infected and insignificant proportion of seroprevalence, was observed between age and sex of respondents. Protective measures like contact tracing, face covering, and social distancing are therefore vital to demote the risk of community—strengthening factors should be continued as effect modification of anticipation for severe course of coronavirus disease 2019.

Factors Associated with Pre-Vaccination SARS-CoV-2 Infection Risk among Hospital Nurses Facing COVID-19 Outbreak

The objective of this work was to evaluate the magnitude of COVID-19 spread and the related risk factors among hospital nurses employed in a COVID hospital in Rome, before the beginning of the vaccination programmes commenced in 2021. Participants periodically underwent (every 15–30 days) nasopharyngeal swab and/or blood sample for SARS-CoV-2 IgG examination. From 1 March 2020 to 31 December 2020, we found 162 cases of COVID-19 infection (n = 143 nasopharyngeal swab and n = 19 IgG-positive) in a total of 918 hospital nurses (17.6%). Most SARS-CoV-2-infected hospital nurses were night shift workers (NSWs), smokers, with higher BMI and lower mean age than that of individuals who tested negative. After adjusting for covariates, age (OR = 0.923, 95% C.I. 0.895–0.952), night shift work (OR = 2.056, 95% C.I. 1.320–2.300), smoking status (OR = 1.603, 95% C.I. 1.080–2.378) and working in high-risk settings (OR = 1.607, 95% C.I. 1.036–2.593) were significantly associated with SARS-CoV-2 hospital infection, whereas BMI was not significantly related. In conclusion, we found a high prevalence of SARS-CoV-2 infection among hospital nurses at a Rome COVID hospital in the pre-vaccination period. Smoking, young age, night shift work and high-risk hospital settings are relevant risk factors for hospital SARS-CoV-2 infection; therefore, a close health surveillance should be necessary among hospital nurses exposed to SARS-CoV-2.

Changes in COVID-19 IgM and IgG antibodies in emergency medical technicians (EMTs)

Introduction

Serologic testing can provide a safe and fast approach for assessing SARS-CoV-2 antibodies. These tests can be utilized as a complementary method in diagnosis and patients' follow-up, and can also be helpful in epidemiological studies. This study aimed to describe temporal changes in the incidence of COVID-19 IgM and IgG antibodies in emergency medical technicians (EMTs) within a specified time period.

Methods

All EMTs working for Tehran Emergency Medical Service (EMS) center during May to September 2020 were eligible for this study. Those EMTs who were suspected/probable/confirmed cases of COVID-19, based on WHO defined criteria and were willing to participate, entered the study. The EMTs underwent serology testing four weeks after the occurrence of exposure (in suspected cases) or onset of their symptoms (in probable/confirmed cases). Cases were further confirmed by RT-PCR and/or lung CT, and antibody testing was performed for the second and third time with 12-week intervals. Finger-stick blood sampling was utilized for the specimen collection in three different phases. Samples were then analyzed by a commercial immunochromatography-based kit for qualitative measurement of serum IgM and IgG antibodies against the COVID-19 S-protein antigen.

Results

Two hundred eighty-four participants met the inclusion criteria; their mean age was 35.9 (SD = 7.6) years and consisted of 244 (85.9%) males. COVID-19 was confirmed in 169 out of 284 participants. Subsequently, 142 and 122 participants were included in phases 2 and 3 of the study, respectively. The number of seronegative patients exceeded seropositive ones in all three phases. At baseline, 162 (57%) patients were seronegative, 27 (9.5%) were only positive for IgG, 3 (1.1%) were only positive for IgM, and 92 (32.4%) were positive for both antibodies; Seventy-eight (54.9%) were seronegative, and 31 (21.8%) were positive for both antibodies in the second phase; These values were 85 (69.6%) and 8 (6.6%) for the third phase, respectively. Among the people who were positive IgG in the first phase (80 people), 56.3% were still positive in the second phase and 27.5% in both subsequent phases.

Conclusion

The results of our study show that there is a significant reduction in COVID-19 antibody seropositivity over time.