Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 1.548
Filter
1.
MMWR Morb Mortal Wkly Rep ; 72(22): 601-605, 2023 Jun 02.
Article in English | MEDLINE | ID: covidwho-20237470

ABSTRACT

Changes in testing behaviors and reporting requirements have hampered the ability to estimate the U.S. SARS-CoV-2 incidence (1). Hybrid immunity (immunity derived from both previous infection and vaccination) has been reported to provide better protection than that from infection or vaccination alone (2). To estimate the incidence of infection and the prevalence of infection- or vaccination-induced antibodies (or both), data from a nationwide, longitudinal cohort of blood donors were analyzed. During the second quarter of 2021 (April-June), an estimated 68.4% of persons aged ≥16 years had infection- or vaccination-induced SARS-CoV-2 antibodies, including 47.5% from vaccination alone, 12.0% from infection alone, and 8.9% from both. By the third quarter of 2022 (July-September), 96.4% had SARS-CoV-2 antibodies from previous infection or vaccination, including 22.6% from infection alone and 26.1% from vaccination alone; 47.7% had hybrid immunity. Prevalence of hybrid immunity was lowest among persons aged ≥65 years (36.9%), the group with the highest risk for severe disease if infected, and was highest among those aged 16-29 years (59.6%). Low prevalence of infection-induced and hybrid immunity among older adults reflects the success of public health infection prevention efforts while also highlighting the importance of older adults staying up to date with recommended COVID-19 vaccination, including at least 1 bivalent dose.*,†.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Aged , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Blood Donors , Incidence , Seroepidemiologic Studies , Antibodies, Viral , Vaccination
2.
Trop Med Int Health ; 28(7): 508-516, 2023 07.
Article in English | MEDLINE | ID: covidwho-20236947

ABSTRACT

BACKGROUND: Many SARS-CoV-2 seroprevalence surveys since the end of 2020 have disqualified the first misconception that Africa had been spared by the pandemic. Through the analysis of three SARS-CoV-2 seroprevalence surveys carried out in Benin as part of the ARIACOV project, we argue that the integration of epidemiological serosurveillance of the SARS-CoV-2 infection in the national surveillance packages would be of great use to refine the understanding of the COVID-19 pandemic in Africa. METHODS: We carried out three repeated cross-sectional surveys in Benin: two in Cotonou, the economic capital in March and May 2021, and one in Natitingou, a semi-rural city in the north of the country in August 2021. Total and weighted-by-age-group seroprevalences were estimated and the risk factors for SARS-CoV-2 infection were assessed by multivariate logistic regression. RESULTS: In Cotonou, a slight increase in overall age-standardised SARS-CoV-2 seroprevalence from 29.77% (95% CI: 23.12%-37.41%) at the first survey to 34.86% (95% CI: 31.57%-38.30%) at the second survey was observed. In Natitingou, the globally adjusted seroprevalence was 33.34% (95% CI: 27.75%-39.44%). A trend of high risk for SARS-CoV 2 seropositivity was observed in adults over 40 versus the young (less than 18 years old) during the first survey in Cotonou but no longer in the second survey. CONCLUSIONS: Our results show that, however, rapid organisation of preventive measures aimed at breaking the chains of transmission, they were ultimately unable to prevent a wide spread of the virus in the population. Routine serological surveillance on strategic sentinel sites and/or populations could constitute a cost-effective compromise to better anticipate the onset of new waves and define public health strategies.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Adolescent , Benin/epidemiology , COVID-19/epidemiology , Pandemics , Cross-Sectional Studies , Seroepidemiologic Studies , Antibodies, Viral
3.
Actas Dermosifiliogr ; 114(7): T580-T586, 2023.
Article in English, Spanish | MEDLINE | ID: covidwho-20236178

ABSTRACT

BACKGROUND AND OBJECTIVE: SARS-CoV-2 is more easily spread by close contact, which is inherent to sexual intercourse. People with, or at risk for, sexually transmitted infections (STIs) may therefore have higher rates of COVID-19. The aim of this study was to estimate SARS-CoV-2 antibody seroprevalence in people seen at a dedicated STI clinic, compare our findings to the estimated seroprevalence in the local general population, and study factors associated with SARS-CoV-2 infection in this setting. MATERIAL AND METHODS: Cross-sectional observational study including consecutive patients older than 18 years of age who had not yet been vaccinated against COVID-19 and who underwent examination or screening at a dedicated municipal STI clinic in March and April 2021. We ordered rapid SARS-CoV-2 serology and collected information on demographic, social, and sexual variables, STI diagnoses, and history of symptoms compatible with SARS-CoV-2 infection. RESULTS: We studied 512 patients (37% women). Fourteen (24.2%) had a positive SARS-CoV-2 test. Variables associated with positivity were use of FFP2 masks (odds ratio 0.50) and a higher-than-average number of sexual partners (odds ratio 1.80). Use of FFP2 masks was not randomly distributed in this sample. CONCLUSIONS: Sexually active members of the population in this study had a higher incidence of SARS-CoV-2 infection than the general population. The main route of infection in this group appears to be respiratory, linked to close contact during sexual encounters; sexual transmission of the virus is probably limited.


Subject(s)
COVID-19 , Sexual Health , Sexually Transmitted Diseases , Humans , Female , Male , COVID-19/epidemiology , SARS-CoV-2 , Incidence , Cross-Sectional Studies , Seroepidemiologic Studies , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/prevention & control
4.
Clinics (Sao Paulo) ; 78: 100233, 2023.
Article in English | MEDLINE | ID: covidwho-20235535

ABSTRACT

OBJECTIVES: To summarize the data on SARS-CoV-2 seroprevalence surveys conducted in Brazil before the introduction of vaccines METHODS: The authors conducted a systematic review and meta-analysis on the seroprevalence of SARS-CoV-2 infection in Brazil. The present review followed the PRISMA guidelines. The authors searched Medline, Embase, and LILACS databases for serologic surveys conducted in the Brazilian population, in the period from 01/10/2019 to 07/11/2021, without language restrictions. The authors included studies that presented data concerning SARS-CoV-2 antibodies seroprevalence in Brazil and had a sample size ≥50 individuals. Considering the expected heterogeneity between studies, all analyses were performed using the random effects model, and heterogeneity was assessed using the I2 statistic RESULTS: Of 586 publications identified in the initial searches, 54 were included in the review and meta-analysis, which contained the results of 135 surveys, with 336,620 participants. The estimated seroprevalence was 11.0%, ranging from 1.0% to 83.0%, with a substantial heterogeneity (I2 = 99.55%). In subgroup analyses, the authors observed that the prevalence of SARS-CoV-2 antibodies was 13.0% in blood donors, 9.0% in the population-based surveys, 13% in schoolchildren, and 11.0% in healthcare workers. CONCLUSIONS: Seroprevalence increases over time. Large differences were observed among the regions of the country. It was higher in the Northern region, decreasing towards the South. The present results may contribute to the analysis of the spread of SARS-CoV-2 infection in the Brazilian population before vaccination, one of the factors that may be influencing the clinical presentation of COVID-19 cases related to the new variants, as well as the effectiveness of the vaccination program.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Child , COVID-19/epidemiology , Brazil/epidemiology , Seroepidemiologic Studies , Antibodies, Viral
5.
Emerg Infect Dis ; 29(7): 1479-1481, 2023 07.
Article in English | MEDLINE | ID: covidwho-20235506

ABSTRACT

We evaluated SARS-CoV-2 antibody response in voluntary blood donors in Italy at different timepoints. Immediately after lockdown easing, 908/25,657 donors (3.5%) had low IgG titers against nucleocapsid. In the next 2 years, titers increased despite few COVID-19 symptoms. On multivariate analysis, allergic rhinitis was associated with reduced risk for symptomatic COVID-19.


Subject(s)
Blood Donors , COVID-19 , Humans , SARS-CoV-2 , Seroepidemiologic Studies , COVID-19/epidemiology , Communicable Disease Control , Italy/epidemiology , Antibodies, Viral
6.
BMJ Open ; 13(5): e070291, 2023 05 31.
Article in English | MEDLINE | ID: covidwho-20234967

ABSTRACT

OBJECTIVES: This study aims to quantify the degree to which an underserved, Hispanic population in Los Angeles is impacted by SARS-CoV-2, and determine factors associated with paediatric seropositivity. DESIGN: Cross-sectional. SETTING: AltaMed, a Federally Qualified Health Center in Los Angeles. PARTICIPANTS: A random sample of households who had received healthcare at AltaMed Medical Group was invited to participate. Households with at least one adult and one paediatric participant between 5 and 17 years of age were eligible to participate. Consented participants completed a survey on social determinants of health and were tested for antibodies using Abbott Architect SARS-CoV-2-IgG and SARS-CoV-2-IgM tests. PRIMARY OUTCOME MEASURE: Seropositive status. RESULTS: We analysed 390 adults (mean age in years, 38.98 (SD 12.11)) and 332 paediatric participants (11.26 (SD 3.51)) from 196 households. Estimated seropositivity was 52.11% (95% CI 49.61% to 55.19%) in paediatric participants and 63.58% (95% CI 60.39% to 65.24%) in adults. Seropositivity was 11.47% (95% CI 6.82% to 14.09%) lower in paediatric participants, but high relative to other populations. A household member with type 2 diabetes (OR 2.94 (95% CI 1.68 to 5.14)), receipt of food stamps (OR 1.66 (95% CI 1.08 to 2.56)) and lower head-of-household education (OR 1.73 (95% CI 1.06 to 2.84)) were associated with paediatric seropositivity. CONCLUSIONS: SARS-CoV-2 seropositivity is high in Hispanic children and adolescents in Los Angeles. Food insecure households with low head-of-household education, and at least one household member with type 2 diabetes, had the highest risk. These factors may inform paediatrician COVID-19 mitigation recommendations. TRIAL REGISTRATION NUMBER: NCT04901624.


Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Adolescent , Adult , Humans , Child , SARS-CoV-2 , Los Angeles/epidemiology , COVID-19/epidemiology , Cross-Sectional Studies , Antibodies, Viral , Seroepidemiologic Studies
7.
J Med Virol ; 95(6): e28864, 2023 06.
Article in English | MEDLINE | ID: covidwho-20234964

ABSTRACT

Accumulating evidence shows that SARS-CoV-2 can potentially trigger autoimmune processes, which can be responsible for the long-term consequences of COVID-19. Therefore, this paper aims to review the autoantibodies reported in COVID-19 convalescents. Six main groups were distinguished: (i) autoantibodies against components of the immune system, (ii) autoantibodies against components of the cardiovascular system, (iii) thyroid autoantibodies, (iv) autoantibodies specific for rheumatoid diseases, (v) antibodies against G-protein coupled receptors, and (vi) other autoantibodies. The evidence reviewed here clearly highlights that SARS-CoV-2 infection may induce humoral autoimmune responses. However, the available studies share number of limitations, such as: (1) the sole presence of autoantibodies does not necessarily implicate the clinically-relevant risks, (2) functional investigations were rarely performed and it is often unknown whether observed autoantibodies are pathogenic, (3) the control seroprevalence, in healthy, noninfected individuals was often not reported; thus it is sometimes unknown whether the detected autoantibodies are the result of SARS-CoV-2 infection or the accidental post-COVID-19 detection, (4) the presence of autoantibodies was rarely correlated with symptoms of the post-COVID-19 syndrome, (5) the size of the studied groups were often small, (6) the studies focused predominantly on adult populations, (7) age- and sex-related differences in seroprevalence of autoantibodies were rarely explored, (8) genetic predispositions that may be involved in generation of autoantibodies during SARS-CoV-2 infections were not investigated, and (9) the autoimmune reactions following infection with SARS-CoV-2 variants that vary in the clinical course of infection remain unexplored. Further longitudinal studies are advocated to assess the link between identified autoantibodies and particular clinical outcomes in COVID-19 convalescents.


Subject(s)
Blood Group Antigens , COVID-19 , Adult , Humans , Autoantibodies , SARS-CoV-2 , Post-Acute COVID-19 Syndrome , Seroepidemiologic Studies
8.
BMC Vet Res ; 19(1): 74, 2023 Jun 01.
Article in English | MEDLINE | ID: covidwho-20234911

ABSTRACT

BACKGROUND: The European bison (Bison bonasus) is a near threatened species and requires health monitoring. The aim of the present study was to determine the prevalence of antibodies to pathogens known to cause respiratory and digestive illness in ruminants. RESULTS: In the studied 328 European bison, the highest seroprevalence was observed for Bovine herpesvirus-1 (BoHV-1) (50.27%), Bovine Coronavirus (BCoV) (26.36%), and Bluetongue Virus (BTV) (12.83%). For Mycoplasma bovis strains and Bovine Viral Diarrhea Virus (BVDV), positive results were rare. Interestingly, a higher prevalence of BTV antibodies was noted in the northeastern populations and older animals. CONCLUSIONS: Our findings indicate that the Polish European bison population appears to have considerable contact with BoHV-1; however, this does not appear to be of great significance, as clinical symptoms and post-mortem lesions are rarely noted in Polish European bison population. The high seroprevalence of BTV in the north-east of Poland is an ongoing trend, also noted in previous studies. It is possible that European bison may perpetuate the virus in this region. This is the first report of antibodies for BCoV in European bison.


Subject(s)
Bison , Herpesvirus 1, Bovine , Animals , Poland/epidemiology , Seroepidemiologic Studies , Antibodies, Viral , Digestive System
9.
BMJ Open ; 13(6): e068988, 2023 06 06.
Article in English | MEDLINE | ID: covidwho-20234714

ABSTRACT

INTRODUCTION: As COVID-19 continues to spread globally and within Mozambique, its impact among immunosuppressed persons, specifically persons living with HIV (PLHIV), and on the health system is unknown in the country. The 'COVid and hIV' (COVIV) study aims to investigate: (1) the seroprevalence and seroincidence of SARS-CoV-2 among PLHIV and healthcare workers providing HIV services; (2) knowledge, attitudes, practices and perceptions regarding SARS-CoV-2 infection; (3) the pandemic's impact on HIV care continuum outcomes and (4) facility level compliance with national COVID-19 guidelines. METHODS AND ANALYSIS: A multimethod study will be conducted in a maximum of 11 health facilities across Mozambique, comprising four components: (1) a cohort study among PLHIV and healthcare workers providing HIV services to determine the seroprevalence and seroincidence of SARS-CoV-2, (2) a structured survey to assess knowledge, attitudes, perceptions and practices regarding COVID-19 disease, (3) analysis of aggregated patient data to evaluate retention in HIV services among PLHIV, (4) an assessment of facility implementation of infection prevention and control measures. ETHICS AND DISSEMINATION: Ethical approval was obtained from the National Health Bioethics Committee, and institutional review boards of implementing partners. Study findings will be discussed with local and national health authorities and key stakeholders and will be disseminated in clinical and scientific forums. TRIAL REGISTRATION NUMBER: NCT05022407.


Subject(s)
COVID-19 , HIV Infections , Humans , Cohort Studies , COVID-19/epidemiology , Health Personnel , HIV Infections/epidemiology , HIV Infections/drug therapy , Mozambique/epidemiology , Prospective Studies , SARS-CoV-2 , Seroepidemiologic Studies
10.
Transfusion ; 63(7): 1354-1365, 2023 07.
Article in English | MEDLINE | ID: covidwho-20233322

ABSTRACT

BACKGROUND: The true burden of COVID-19 in low- and middle-income countries remains poorly characterized, especially in Africa. Even prior to the availability of SARS-CoV-2 vaccines, countries in Africa had lower numbers of reported COVID-19 related hospitalizations and deaths than other regions globally. METHODS: Ugandan blood donors were evaluated between October 2019 and April 2022 for IgG antibodies to SARS-CoV-2 nucleocapsid (N), spike (S), and five variants of the S protein using multiplexed electrochemiluminescence immunoassays (MesoScale Diagnostics, Rockville, MD). Seropositivity for N and S was assigned using manufacturer-provided cutoffs and trends in seroprevalence were estimated by quarter. Statistically significant associations between N and S antibody seropositivity and donor characteristics in November-December 2021 were assessed by chi-square tests. RESULTS: A total of 5393 blood unit samples from donors were evaluated. N and S seropositivity increased throughout the pandemic to 82.6% in January-April 2022. Among seropositive individuals, N and S antibody levels increased ≥9-fold over the study period. In November-December 2021, seropositivity to N and S antibody was higher among repeat donors (61.3%) compared with new donors (55.1%; p = .043) and among donors from Kampala (capital city of Uganda) compared with rural regions (p = .007). Seropositivity to S antibody was significantly lower among HIV-seropositive individuals (58.8% vs. 84.9%; p = .009). CONCLUSIONS: Despite previously reported low numbers of COVID-19 cases and related deaths in Uganda, high SARS-CoV-2 seroprevalence and increasing antibody levels among blood donors indicated that the country experienced high levels of infection over the course of the pandemic.


Subject(s)
Blood Donors , COVID-19 , Humans , Uganda/epidemiology , SARS-CoV-2 , COVID-19 Vaccines , Seroepidemiologic Studies , COVID-19/epidemiology , Antibodies, Viral
11.
BMJ Open ; 13(6): e071228, 2023 06 12.
Article in English | MEDLINE | ID: covidwho-20244540

ABSTRACT

OBJECTIVE: To determine the SARS-CoV-2 seroprevalence among school workers within the Greater Vancouver area, British Columbia, Canada, after the first Omicron wave. DESIGN: Cross-sectional study by online questionnaire, with blood serology testing. SETTING: Three main school districts (Vancouver, Richmond and Delta) in the Vancouver metropolitan area. PARTICIPANTS: Active school staff enrolled from January to April 2022, with serology testing between 27 January and 8 April 2022. Seroprevalence estimates were compared with data obtained from Canadian blood donors weighted over the same sampling period, age, sex and postal code distribution. PRIMARY AND SECONDARY OUTCOMES: SARS-CoV-2 nucleocapsid antibody testing results adjusted for test sensitivity and specificity, and regional variation across school districts using Bayesian models. RESULTS: Of 1850 school staff enrolled, 65.8% (1214/1845) reported close contact with a COVID-19 case outside the household. Of those close contacts, 51.5% (625/1214) were a student and 54.9% (666/1214) were a coworker. Cumulative incidence of COVID-19 positive testing by self-reported nucleic acid or rapid antigen testing since the beginning of the pandemic was 15.8% (291/1845). In a representative sample of 1620 school staff who completed serology testing (87.6%), the adjusted seroprevalence was 26.5% (95% CrI 23.9% to 29.3%), compared with 32.4% (95% CrI 30.6% to 34.5%) among 7164 blood donors. CONCLUSION: Despite frequent COVID-19 exposures reported, SARS-CoV-2 seroprevalence among school staff in this setting remained no greater than the community reference group. Results are consistent with the premise that many infections were acquired outside the school setting, even with Omicron.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , British Columbia , Cross-Sectional Studies , Bayes Theorem , Seroepidemiologic Studies , Antibodies, Viral
12.
Emerg Microbes Infect ; 12(2): 2222849, 2023 Dec.
Article in English | MEDLINE | ID: covidwho-20243126

ABSTRACT

Studying the prevalence of SARS-CoV-2 specific antibodies (seroprevalence) allows for assessing the impact of epidemic containment measures and vaccinations and estimating the number of infections regardless of viral testing. We assessed antibody-mediated immunity to SARS-CoV-2 induced by infections and vaccinations from April 2020 to December 2022 in Finland by measuring serum IgG to SARS-CoV-2 nucleoprotein (N-IgG) and spike glycoprotein from randomly selected 18-85-year-old subjects (n = 9794). N-IgG seroprevalence remained at <7% until the last quartile (Q) of 2021. After the emergence of the Omicron variant, N-IgG seroprevalence increased rapidly and was 31% in Q1/2022 and 54% in Q4/2022. Seroprevalence was highest in the youngest age groups from Q2/2022 onwards. We did not observe regional differences in seroprevalence in 2022. We estimated that 51% of the Finnish 18-85-year-old population had antibody-mediated hybrid immunity induced by a combination of vaccinations and infections by the end of 2022. In conclusion, major shifts in the COVID-19 pandemic and resulting population immunity could be observed by serological testing.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Adolescent , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , COVID-19/epidemiology , Finland/epidemiology , Pandemics , Seroepidemiologic Studies , Antibodies, Viral , Immunoglobulin G
13.
Int J Environ Res Public Health ; 20(11)2023 May 25.
Article in English | MEDLINE | ID: covidwho-20241952

ABSTRACT

Infection of SARS-CoV-2 among health workers (HWs) in contact with cancer patients has been a major issue since the beginning of the pandemic. We aimed to assess the serological immune status of SARS-CoV-2 infection among these HWs. A prospective cohort study was initiated in the comprehensive cancer center of the Nouvelle-Aquitaine region (NA, France). Volunteer HWs working on March 2020 without active infection or symptoms of COVID-19 completed a self-questionnaire and had a blood test at inclusion, at 3 and 12 months. Positive serological status of SARS-CoV-2 infection was defined by anti-nucleocapsid antibodies and/or IgG anti-spike antibodies, except at 12 months due to vaccine. Half of the HWs were included (N = 517) and 89% were followed for three months (N = 500) and one year (N = 462). Seroprevalence of SARS-CoV-2 infection was 3.5% (95% CI: 1.9-5.1), 6.2% (95% CI: 4.1-8.3), and 10% (95% CI: 7.2-12.7) on June-September 2020, September 2020-January 2021, and June-October 2021, respectively. At 12 months, 93.3% had detectable antibodies with 80% vaccinated in the first three months of vaccine availability. The COVID-19-free policy of the institution, respect for barrier gestures, high and early vaccination of HWs, and low prevalence of SARS-CoV-2 in NA may explain the low rate of seropositivity among the HWs of the Institut Bergonié.


Subject(s)
COVID-19 , Neoplasms , Humans , Seroepidemiologic Studies , Follow-Up Studies , Prospective Studies , COVID-19/epidemiology , SARS-CoV-2 , Anxiety/epidemiology , Health Personnel , Immunoglobulin G , Antibodies, Viral , Neoplasms/epidemiology
14.
Res Synth Methods ; 14(4): 608-621, 2023 Jul.
Article in English | MEDLINE | ID: covidwho-20241233

ABSTRACT

The laborious and time-consuming nature of systematic review production hinders the dissemination of up-to-date evidence synthesis. Well-performing natural language processing (NLP) tools for systematic reviews have been developed, showing promise to improve efficiency. However, the feasibility and value of these technologies have not been comprehensively demonstrated in a real-world review. We developed an NLP-assisted abstract screening tool that provides text inclusion recommendations, keyword highlights, and visual context cues. We evaluated this tool in a living systematic review on SARS-CoV-2 seroprevalence, conducting a quality improvement assessment of screening with and without the tool. We evaluated changes to abstract screening speed, screening accuracy, characteristics of included texts, and user satisfaction. The tool improved efficiency, reducing screening time per abstract by 45.9% and decreasing inter-reviewer conflict rates. The tool conserved precision of article inclusion (positive predictive value; 0.92 with tool vs. 0.88 without) and recall (sensitivity; 0.90 vs. 0.81). The summary statistics of included studies were similar with and without the tool. Users were satisfied with the tool (mean satisfaction score of 4.2/5). We evaluated an abstract screening process where one human reviewer was replaced with the tool's votes, finding that this maintained recall (0.92 one-person, one-tool vs. 0.90 two tool-assisted humans) and precision (0.91 vs. 0.92) while reducing screening time by 70%. Implementing an NLP tool in this living systematic review improved efficiency, maintained accuracy, and was well-received by researchers, demonstrating the real-world effectiveness of NLP in expediting evidence synthesis.


Subject(s)
COVID-19 , Natural Language Processing , Humans , Seroepidemiologic Studies , SARS-CoV-2 , Systematic Reviews as Topic
15.
PLoS One ; 18(5): e0285879, 2023.
Article in English | MEDLINE | ID: covidwho-20240854

ABSTRACT

Chikungunya is an arboviral disease causing arthralgia which may develop into a debilitating chronic arthritis. In Mayotte, a French overseas department in the Indian Ocean, a chikungunya outbreak was reported in 2006, affecting a third of the population. We aimed at assessing the chikungunya seroprevalence in this population, after over a decade from that epidemic. A multi-stage cross sectional household-based study exploring socio-demographic factors, and knowledge and attitude towards mosquito-borne disease prevention was carried out in 2019. Blood samples from participants aged 15-69 years were taken for chikungunya IgG serological testing. We analyzed associations between chikungunya serological status and selected factors using Poisson regression models, and estimated weighted and adjusted prevalence ratios (w/a PR). The weighted seroprevalence of chikungunya was 34.75% (n = 2853). Seropositivity for IgG anti-chikungunya virus was found associated with living in Mamoudzou (w/a PR = 1.49, 95%CI: 1.21-1.83) and North (w/a PR = 1.41, 95%CI: 1.08-1.84) sectors, being born in the Comoros islands (w/a PR = 1.30, 95%CI: 1.03-1.61), being a student or unpaid trainee (w/a PR = 1.35, 95%CI: 1.01-1.81), living in precarious housing (w/a PR = 1.30, 95%CI: 1.02-1.67), accessing water streams for bathing (w/a PR = 1.72, 95%CI: 1.1-2.7) and knowing that malaria is a mosquito-borne disease (w/a PR = 1.42, 95%CI: 1.21-1.83). Seropositivity was found inversely associated with high education level (w/a PR = 0.50, 95%CI: 0.29-0.86) and living in households with access to running water and toilets (w/a PR = 0.64, 95%CI: 0.51-0.80) (n = 1438). Our results indicate a long-lasting immunity from chikungunya exposure. However, the current population seroprevalence is not enough to protect from future outbreaks. Individuals naïve to chikungunya and living in precarious socio-economic conditions are likely to be at high risk of infection in future outbreaks. To prevent and prepare for future chikungunya epidemics, it is essential to address socio-economic inequalities as a priority, and to strengthen chikungunya surveillance in Mayotte.


Subject(s)
Antibodies, Viral , Chikungunya Fever , Female , Animals , Humans , Comoros/epidemiology , Seroepidemiologic Studies , Cross-Sectional Studies , Disease Outbreaks
16.
J Infect Public Health ; 16(8): 1256-1261, 2023 Aug.
Article in English | MEDLINE | ID: covidwho-20231291

ABSTRACT

AIM: This study aimed to assess the seroprevalence of SARS-CoV-2 and disease symptoms in Malakand, Pakistan. MATERIALS & METHOD: 623 samples with suspected SARS-CoV-2 were collected from different regions of Malakand and analyzed to detect SARS-CoV-2 IgG antibodies using ELISA. RESULTS: 306 (49.1%) 0 f 623 patients were anti-SARS-CoV-2 IgG reactive, with a higher prevalence in males (75%) than females (25%). In this study, we enrolled two groups, subjects working in a non-medical setting and subjects working in a medical setting. Clinical symptoms were statistically linked with SARS-CoV-2. Four weeks of follow-up analysis of IgG titers in health care workers showed an increase in IgG antibodies titer. CONCLUSION: This study gives insights into the community-based spread of SARS-CoV-2 infection, associated immunity, and herd immunity in the studied population. This study can provide insights to the government about early vaccination of this population as most of the population is not yet vaccinated.


Subject(s)
COVID-19 , SARS-CoV-2 , Female , Male , Humans , Pandemics , Seroepidemiologic Studies , COVID-19/epidemiology , Antibodies, Viral , Immunoglobulin G
17.
East. Mediterr. health j ; 29(4): 254-261, 2023-04.
Article in English | WHOIRIS | ID: gwh-368518

ABSTRACT

Background: This is one of the first studies exploring immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among blue-collar workers in Abu Dhabi. Aims: This study estimated the seroprevalence of SARS-CoV-2 infection among workers living in a closed setting using qualitative analysis of the total SARS-CoV-2 antibody immune response. Methods: We conducted this monocentric, prospective, observational study in a labor compound for a cohort of workers between 28 March and 6 July 2020. We tested for SARS-CoV-2 (nasopharyngeal) (RT-PCR) and anti-SARS-CoV-2 T-Ab. Results: Out of a total of 1600 workers, 1206 (75.0%) participated in the study – all were males, median age 35 years (19–63 years). We found 51% of the participants to be positive for SARS-CoV-2; the 49.0% who tested negative were considered as contacts. Anti-SARS-CoV-2 T-Ab was detected among 864 participants, showing an overall point prevalence of 71.6%. A relatively higher response was found among cases (89.0%) than among contacts (53.2%). Conclusion: This study highlights the need to prioritize public health interventions in closed settings where disease transmission is higher due to greater overall exposure. A high seroprevalence of anti-SARS-CoV-2 T-Ab was found among the residents. A serial quantitative study applying time series and regression models is recommended to further evaluate the sustainability of the immune response among this and similar population groups.


Subject(s)
Antibodies, Viral , COVID-19 , Betacoronavirus , Disease Outbreaks , Health Personnel , Prospective Studies , SARS-CoV-2 , Seroepidemiologic Studies , United Arab Emirates
18.
Front Immunol ; 13: 1028246, 2022.
Article in English | MEDLINE | ID: covidwho-2326410

ABSTRACT

Background: The aim of this study was to explore the short-term safety and immunogenicity of inactivated and peptide-based SARS-CoV-2 vaccines in patients with endocrine-related cancer (ER). Methods: Eighty-eight patients with ER cancer and 82 healthy controls who had completed a full course of inactivated or peptide-based SARS-CoV-2 vaccines were recruited. Adverse events (AEs) were recorded. Responses to receptor-binding domain IgG antibody (anti-RBD-IgG), neutralizing antibodies (NAbs) and RBD+ memory B cells (MBCs) were evaluated. Results: Approximately 26.14% (23/88) of patients with ER cancer reported AEs within 7 days, which was comparable to that reported by healthy controls (24.39%, 20/82). Both the overall seroprevalence of anti-RBD-IgG and NAbs was obviously lower in the cancer group (70.45% vs. 86.59%, P < 0.05; 69.32% vs. 82.93%, P < 0.05, respectively). Anti-RBD-IgG and NAbs titers exhibited similar results, and dropped gradually over time. Patients with ongoing treatment had an attenuated immune response, especially in patients receiving active chemotherapy. The frequency of overall RBD+ MBCs was similar between the two groups, but the percentage of active MBCs was remarkably reduced in patients with ER cancer. Unlike antibody titers, MBCs responses were relatively constant over time. Conclusion: Inactivated and peptide-based COVID-19 vaccines were well tolerated, but with lower immunogenicity for ER cancer patients. More intensive antibody monitoring and timely booster immunization is recommended for patients with ER cancer presenting disordered subpopulations of RBD+ MBCs.


Subject(s)
COVID-19 Vaccines , COVID-19 , Neoplasms , Humans , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Immunoglobulin G , Neoplasms/chemically induced , Peptides , SARS-CoV-2 , Seroepidemiologic Studies , Viral Vaccines
19.
Int J Public Health ; 67: 1604548, 2022.
Article in English | MEDLINE | ID: covidwho-2324885

ABSTRACT

Objective: We aimed to quantify SARS-CoV-2 specific antibodies' seroprevalence among university students in Porto. Methods: A rapid point of care testing for SARS-CoV-2 specific immunoglobulin (Ig) M and IgG antibodies was performed, and a questionnaire was applied to 6512 voluntary students from September to December 2020. We computed the apparent IgM, IgG, and IgM or IgG prevalence, and the true prevalence and 95% credible intervals (95% CI) using Bayesian inference. Results: We found an apparent prevalence (IgM or IgG) of 9.7%, the true prevalence being 7.9% (95% CI 4.9-11.1). Prevalence was significantly higher among males (10.9% vs. 9.2%), international students (18.1% vs. 10.4% local vs. 8.8% nationally displaced), and increased with age. Those with a known risk contact, that experienced quarantine, had symptoms, or a previous negative molecular test had a higher seroprevalence. Of the 91 (1.4%) students who reported a molecular diagnosis, 86.8% were reactive for IgM or IgG. Conclusion: Based on immunological evidence infection was 5.6-fold the reported molecular diagnosis. The higher seroprevalence among male, older, and international students emphasizes the importance of identifying particular groups.


Subject(s)
COVID-19 , Male , Humans , COVID-19/epidemiology , Seroepidemiologic Studies , SARS-CoV-2 , Cross-Sectional Studies , Immunoglobulin M , Bayes Theorem , Antibodies, Viral , Immunoglobulin G , Students
20.
J Med Virol ; 95(5): e28797, 2023 05.
Article in English | MEDLINE | ID: covidwho-2327342

ABSTRACT

The immunogenicity induced by the third dose of inactivated coronavirus disease 2019 (COVID-19) vaccines in people living with HIV (PLWH) is unclear, and relevant literature is extremely scarce. It is important to add evidence on the humoral immune response induced by the third dose of inactivated COVID-19 vaccine in PLWH. We collected peripheral venous blood for spike receptor binding domain-protein specific immunoglobulin G (S-RBD-IgG) antibody tests at 28 days after the second dose (T1 ), 180 days after the second dose (T2 ) and 35 days after the third dose (T3 ) of inactivated COVID-19 vaccines in PLWH. The differences in S-RBD-IgG antibody levels and specific seroprevalence among T1 , T2 , and T3 time periods were analyzed, and the effects of age, vaccine brand, and CD4+ T cell count on the levels and specific seroprevalence of S-RBD-IgG antibody induced by the third dose in PLWH were examined. The third dose of inactivated COVID-19 vaccines induced strong S-RBD-IgG antibody responses in PLWH. The levels and specific seroprevalence of S-RBD-IgG antibody were significantly higher than those at 28 and 180 days after the second dose and were not affected by vaccine brand or CD4+ T cell count. Younger PLWH produced higher levels of S-RBD-IgG antibody. The third dose of inactivated COVID-19 vaccine showed good immunogenicity in PLWH. It is necessary to popularize the third dose in the PLWH population, especially PLWH who do not respond to two doses of inactivated COVID-19 vaccines. Meanwhile, the durability of the protection provided by the third dose in PLWH must be continuously monitored.


Subject(s)
Antibody Formation , COVID-19 , Humans , COVID-19 Vaccines , Seroepidemiologic Studies , COVID-19/prevention & control , Immunoglobulin G , Antibodies, Viral , Antibodies, Neutralizing
SELECTION OF CITATIONS
SEARCH DETAIL