Herd immunity to SARS-CoV-2 in the Novosibirsk Region population amid the COVID-19 pandemic

Aim. To determine the level of SARS-CoV-2 seroprevalence among the Novosibirsk Region population against the background of the COVID-19 pandemic.Material and methods. The work was carried out in 2 phases: 1) a cross-sectional cohort study performed 28.06– 15.07.2020; 2) longitudinal cohort 3-stage seromonitoring: 1st stage 28.06–15.07.2020; 2nd 14.09–04.10.2020; 3rd 10–30.12.2020 The work was carried out according to a unified methodology developed by Rospotrebnadzor with the participation of St-Petersburg Pasteur Institute, taking into account the recommendations of the WHO. IgG antibodies to the SARS-CoV-2 nucleocapsid protein were detected by ELISA using a kit of reagents produced by the SRCMSB (Obolensk) according to the manufacturer’s instructions. Statistical analysis was performed using Microsoft Excel 2010 and other programs.Results. The seroprevalence in the region’s population was 9.1% (95% CI 8.0–10.2): maximum in children 14–17 years old (17.6%, 95% CI 12.3–23.9) and persons over 75 years (14.8%, 95% CI 11.4–18.8), minimum among persons 30–39 years old (4.9%, 95% CI 3.0–8.0). Increased rate was noted among the unemployed (15.4%, 95% CI 9.9–17.1) and other individuals (13.0%, 95% CI 8.6–18.5). Seroprevalence was 33.3% (95% CI 16.3–59.0) in COVID-19 convalescents and 19.0% (95% CI 13.9-25.0) in contact persons. More than 94.7% (95% CI 91.2–97.2) of seropositive individuals were asymptomatic. During the serological monitoring, seroprevalence increased from 7.4% (95% CI 6.2–8.9) at 1st stage 1 to 12.4% (95% CI 10.6–14.3) at 2nd , and 31% (95% CI 28.8–33.3) at 3rd stage.Conclusion. SARS-CoV-2 herd immunity has not reached the threshold level, this does not exclude exacerbation of the epidemic process.

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SARS-CoV-2 Herd Immunity of the Kyrgyz Population in 2021

10.21203/rs.3.rs-1138128/v1 ◽

2021 ◽

Author(s):

Anna Y. Popova ◽

Omor T. Kasymov ◽

Vyacheslav Y. Smolenski ◽

Вячеслав Смирнов ◽

Svetlana A. Egorova ◽

...

Keyword(s):

Randomized Study ◽

Herd Immunity ◽

Statistical Processing ◽

Cloud Service ◽

Asymptomatic Infection ◽

Enzyme Linked Immunosorbent Assay ◽

Pasteur Institute ◽

Cross Sectional ◽

Saint Petersburg ◽

Kyrgyz Population

Abstract Background. In the fight against coronavirus infection, an important direction is control of herd immunity to the pathogen. SARS-CoV-2 herd immunity is formed naturally as a result of manifest or asymptomatic infection, or artificially as a result of vaccination Aim: To assess the SARS-CoV-2 herd immunity status of the Kyrgyz population. Materials and methods. A cross-sectional, randomized study of SARS-CoV-2 herd immunity was carried out according to a program developed by Rospotrebnadzor, with the participation of the Saint Petersburg Pasteur Institute, taking into account WHO recommendations. In all study stages cloud service (internet) technologies were used. The ethics committees of the Preventive Medicine Association (Kyrgyzstan) and the Saint Petersburg Pasteur Institute (Russia) approved the study. A total of 9,471 volunteers were selected, representing 0.15% (95% CI 0.14-0.15) of the total population. They were randomized according to age and region. Antibodies (Abs) to the nucleocapsid antigen (Nag) were determined by enzyme-linked immunosorbent assay (ELISA) of volunteer blood plasma. For vaccinated individuals, Abs to the SARS-CoV-2 receptor-binding domain antigen (RBDag) were determined. Statistical processing of the results was carried out using Excel 2010 and other programs. Differences were designated as statistically significant at p<0.05. Results. The seroprevalence of the general population was 48.7% (95% CI 47.7-49.7), with a maximum in the group of '60-69 year old' (59.2% (56.6-61.7)) and a minimum in the group '1-17 y.o.' (32.7% (95 CI 29.4-36.1)). The largest proportion seropositive was found in the Chui region (51.3% (95% CI 47.9-54.8)). The lowest was in Osh city (38.1% (95 CI 32.6-43.9)). The maximum seropositivity was detected among healthcare workers (57.1% (95% CI 55.4-58.8); the minimum was noted among artists (38.6% (95% CI 26.0-52.4)). Asymptomatic SARS-CoV-2 positivity was 79.1% (96% CI 77.9-80.3). Vaccination with Sputnik V, EpiVacCorona, or Sinopharm formed comparable levels of immunity. Conclusions. The herd immunity to SARS-CoV-2 Nag is 48.75% (95% CI 47.7-49.7), and the overall immunity (Nag + RBDag) is 57%.

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Herd immunity to SARS-COV-2 in the population of the Southern regions of the Far East of Russia

Acta biomedica scientifica ◽

10.29413/abs.2021-6.5.25 ◽

2021 ◽

Vol 6 (5) ◽

pp. 253-273

Author(s):

A. Yu. Popova ◽

V. S. Smirnov ◽

E. B. Ezhlova ◽

A. A. Melnikova ◽

O. E. Trotsenko ◽

...

Keyword(s):

Statistical Significance ◽

Herd Immunity ◽

Far East ◽

Amur Region ◽

Reproductive Number ◽

Pasteur Institute ◽

Scientific Center ◽

Cross Sectional ◽

Population Immunity ◽

The Far East

The aim: to study the structure and dynamics of population immunity to SARSCoV-2 of the population of the Southern Regions of the Far East (SRFE): Khabarovsk, Primorsky Krai and Amur Region during the COVID-19 epidemic in 2020.Materials and methods. The work was carried out according to the program for assessing population immunity to SARS -CoV-2 of the population of the Russian Federation according to the methodology developed by the Rospotrebnadzor with the participation of the St. Petersburg Pasteur Institute. The study was approved by the ethical committee of the St. Petersburg Pasteur Institute. The selection of participants was carried out by a questionnaire method using cloud technologies. The volunteers were randomized by age by stratification into 7 age groups: 1–17, 18–29, 30–39, 40–49, 50–59, 60–69, 70+ years old. Territorial randomization consisted in limiting the engaging of volunteers – no more than 30 people from one enterprise. After the initial cross-sectional study, a 3-stage seromonitoring was carried out, in which the same volunteers participated. Antibodies to the SARS-CoV-2 nucleocapsid were determined in peripheral blood serum by the enzyme immunoassay using an appropriate set of reagents produced by the State Scientific Center for Medical and Biological Sciences of the Rospotrebnadzor (Obolensk). Statistical analysis was performed using the Excel package. The confidence interval for the proportion was calculated using the A. Wald, J. Wolfowitz method with A. Agresti, B.A. Coull’s correction. The statistical significance of the differences was calculated online using a specialized calculator. The statistical significance of the differences was assessed with a probability of p˂ 0.05, unless otherwise indicated.Results. In a comparative analysis, the highest morbidity was observed in the Khabarovsk Territory, the lowest – in the Primorsky Territory. The level of seroprevalence among the population of the region was 19.6 % (95 % CI: 18.2–21.1) in the Khabarovsk Territory, 19.6 % (95 % CI: 18.1–21.2) in the Primorsky Territory19,6 % and 45,5 % (95 % CI: 43.7–47.3) in the Amur region. The highest seroprevalence was noted among 1–17 years old children, mainly due to the subgroup of 14–17-years-olds. The smallest proportion of seropositive was found among 40–49-year-olds in the Khabarovsk Territory (14.7 %, 95 % CI: 11.2–18.6), 18–28-yearolds in the Primorsky Territory (13.3 %, 95 % CI: 10.0–17.1) and 30–39-year-olds in the Amur Region (36.3 %, 95% CI: 31.7–41.6). No statistically significant dependence of seroprevalence on territorial and occupational factors has been established, with the exception of an increase in the proportion of seropositive medical workers in Primorsky Territory. In the process of 3-stage seromonitoring, a regular increase in the proportion of seropositive people was revealed in all SRFE. The resulting tendency is correctly described by a second-order polynomial. A relationship was revealed between the number of convalescents and persons in contact with them, which made it possible to calculate the base reproductive number (R0) in the range from 1.4 (Primorsky Territory) to 2.4 (Amur Region). Analysis of seroprevalent volunteers showed that the number of asymptomatic individuals varied from 94.1 % (95 % CI: 92.8–95.3) to 98.3 % (95 % CI: 98.8–99.2). This indicates that most of the volunteers had COVID-19 asymptomatically.Conclusions. A comparative study showed the prevalence of seroprevalence in the Amur Region compared with the Khabarovsk and Primorsky Territories. The relationship between the number of convalescents and persons in contact with them was noted. The value of the base R0 is calculated. It has been shown that more than 90 % of seropositive individuals in the COVID-10 SRFE were asymptomatic.

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High Community SARS-CoV-2 Antibody Seroprevalence in a Ski Resort Community, Blaine County, Idaho, US. Preliminary Results

10.1101/2020.07.19.20157198 ◽

2020 ◽

Cited By ~ 4

Author(s):

Colleen McLaughlin ◽

Margaret K. Doll ◽

Kathryn T Morrison ◽

William L McLaughlin ◽

Terry OConnor ◽

...

Keyword(s):

Disease Surveillance ◽

Population Distribution ◽

A Priori ◽

Herd Immunity ◽

Sensitivity Analyses ◽

Igg Antibodies ◽

Cross Sectional ◽

Diagnostic Uncertainty ◽

Ski Resort ◽

Zip Code

Community-level seroprevalence surveys are needed to determine the proportion of the population with previous SARS-CoV-2 infection, a necessary component of COVID-19 disease surveillance. In May, 2020, we conducted a cross-sectional seroprevalence study of IgG antibodies for nucleocapsid of SARS-CoV-2 among the residents of Blaine County, Idaho, a ski resort community with high COVID-19 attack rates in late March and Early April (2.9% for ages 18 and older). Participants were selected from volunteers who registered via a secure web link, using prestratification weighting to the population distribution by age and gender within each ZIP Code. Participants completed a survey reporting their demographics and symptoms; 88% of volunteers who were invited to participate completed data collection survey and had 10 ml of blood drawn. Serology was completed via the Abbott Architect SARS-CoV-2 IgG immunoassay. Primary analyses estimated seroprevalence and 95% credible intervals (CI) using a hierarchical Bayesian framework to account for diagnostic uncertainty. Stratified models were run by age, sex, ZIP Code, ethnicity, employment status, and a priori participant-reported COVID-19 status. Sensitivity analyses to estimate seroprevalence included base models with post-stratification for ethnicity, age, and sex, with or without adjustment for multi-participant households. IgG antibodies to the virus that causes COVID-19 were found among 22.7% (95% CI: 20.1%, 25.5%) of residents of Blaine County. Higher levels of antibodies were found among residents of the City of Ketchum 34.8% (95% CI 29.3%, 40.5%), compared to Hailey 16.8% (95%CI 13.7%, 20.3%) and Sun Valley 19.4% (95% 11.8%, 28.4%). People who self-identified as not believing they had COVID-19 had the lowest prevalence 4.8% (95% CI 2.3%, 8.2%). The range of seroprevalence after correction for potential selection bias was 21.9% to 24.2%. This study suggests more than 80% of SARS-CoV-2 infections were not reported. Although Blaine County had high levels of SARS-CoV-2 infection, the community is not yet near the herd immunity threshold.

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Impact of the Second Epidemic Wave of SARS-CoV-2: Increased Exposure of Young People

Frontiers in Public Health ◽

10.3389/fpubh.2021.715192 ◽

2021 ◽

Vol 9 ◽

Author(s):

Lisandru Capai ◽

Shirley Masse ◽

Toscane Fourié ◽

Dorine Decarreaux ◽

Jean Canarelli ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Herd Immunity ◽

Wave Period ◽

Quantitative Detection ◽

Igg Antibodies ◽

Cross Sectional ◽

Clinical Laboratories ◽

Serological Surveillance ◽

Second Wave ◽

Neutralization Antibody Titer

We aimed to use serological surveillance based on serial cross-sectional sampling of residual sera obtained from clinical laboratories to compare the differences in age and sex profiles of infected persons in the first and second waves of SARS-CoV-2 in Corsica, France. Residual sera were obtained, including samples from individuals of all ages collected for routine screening or clinical management by clinical laboratories. All the sera collected were tested for the presence of anti-SARS-CoV-2 IgG using a kit for semi-quantitative detection of IgG antibodies against the S1 domain of the viral spike protein (ELISA-S). Samples that were borderline and positive in ELISA-S were tested with an in-house virus neutralization test. During the second-wave period, we collected between 6 November, 2020 and 12 February, 2021, 4,505 sera from patients aged 0–101 years (60.4% women). The overall weighted seroprevalence of residual sera collected during the second-wave period [8.04% (7.87–9.61)] was significantly higher than the overall weighted seroprevalence estimated at the end of the first wave between 16 April and 15 June, 2020 [5.46% (4.37–7.00)] (p-value = 0.00025). Ninety-eight (30.1%) of the 326 samples tested in the VNT assay had a positive neutralization antibody titer. Estimated seroprevalence increased significantly for men [odds ratio (OR) OR = 1.80 (1.30–2.54); p-value = 0.00026] and for people under 30 years of age [OR = 2.17 (1.46–3.28); p-value = 0.000032]. This increase was observed in young adults aged 20–29 years among whom antibody frequencies were around four-fold higher than those observed at the end of the first wave. In conclusion, our seroprevalence estimates, including the proportion of the participants who had produced neutralizing antibodies, indicate that in February, 2021 the population of Corsica was still far from being protected against SARS-Cov-2 by “herd immunity.”

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Prevalence and associated characteristics of anti-SARS-CoV-2 antibodies in Mexico 5 months after pandemic arrival

BMC Infectious Diseases ◽

10.1186/s12879-021-06550-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Cristina Díaz-Salazar ◽

Adriana Sánchez-García ◽

René Rodríguez-Gutiérrez ◽

Adrián Camacho-Ortiz ◽

Donato Saldívar-Rodríguez ◽

...

Keyword(s):

Clinical Characteristics ◽

Statistical Significance ◽

Herd Immunity ◽

Epidemiological Data ◽

City Government ◽

Epidemiological Surveillance ◽

Continuous Variables ◽

Igg Antibodies ◽

Government Employees ◽

Cross Sectional

Abstract Background Seroprevalence of anti-SARS-CoV-2 antibodies is now available in several world regions to better estimate transmission dynamics. However, to date, there is no epidemiological data regarding anti-SARS-CoV-2 prevalence in Mexico. Therefore, we aimed to determine the prevalence of anti-SARS-CoV-2 antibodies and define the clinical and demographic characteristics associated with seroprevalence. Methods We conducted a cross-sectional serological survey in Ciudad Guadalupe, NL, Mexico. City government employees voluntarily participated during July 2020. Demographic and clinical characteristics were collected at the time of blood sampling to analyze the associated characteristics. IgM/IgG antibodies were determined using a qualitative chemiluminescent immunoassay. Descriptive statistics were used for categorical and continuous variables. Statistical significance was tested using the Chi-squared test, Student’s t-test and the Mann–Whitney. Logistic regression models and the odds ratios (adjusted and unadjusted) were used to estimate the association of demographic and clinical characteristics. Results Of the 3,268 participants included, 193 (5.9%, 95% CI 5.1–6.8) tested positive for IgM/IgG against SARS-CoV-2. Sex, city of residence, and comorbidities did not show any association with having IgM/IgG antibodies. A total of 114 out of 193 (59.1%) subjects with a positive test were asymptomatic, and the odds of being positive were higher in those who reported symptoms of COVID-19 in the previous four weeks to the survey (OR 4.1, 95% CI 2.9–5.5). Conclusions There is a low rate of SARS-CoV-2 infection among government employees that have continuously been working during the pandemic. Six in ten infections were asymptomatic, and seroprevalence is low and still far from herd immunity. Epidemiological surveillance and preventive measures should be mandatory.

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Seroprevalence of IgG antibodies against SARS coronavirus 2 in Belgium – a prospective cross-sectional study of residual samples

10.1101/2020.06.08.20125179 ◽

2020 ◽

Cited By ~ 20

Author(s):

Herzog Sereina ◽

De Bie Jessie ◽

Abrams Steven ◽

Wouters Ine ◽

Ekinci Esra ◽

...

Keyword(s):

Herd Immunity ◽

World Health Organisation ◽

Added Value ◽

World Health ◽

Igg Antibodies ◽

Cross Sectional ◽

Horizon 2020 ◽

Age Related ◽

The World ◽

Belgian Population

AbstractBackgroundIn the first weeks of the COVID-19 epidemic in Belgium, a repetitive national serum collection was set up to monitor age-related exposure through emerging SARS-CoV-2 antibodies. First objective was to estimate the baseline seroprevalence and seroincidence using serial survey data that covered the start of a national lock-down period installed soon after the epidemic was recognized.MethodsA prospective serial cross-sectional seroprevalence study, stratified by age, sex and region, started with two collections in April 2020. In residual sera taken outside hospitals and collected by diagnostic laboratories, IgG antibodies against S1 proteins of SARS-CoV-2 were measured with a semi-quantitative commercial ELISA. Seropositivity (cumulative, by age category and sex) and seroincidence over a 3 weeks period were estimated for the Belgian population.FindingsIn the first collection, IgG antibodies were detected in 100 out of 3910 samples, whereas in the second collection 193 out of 3391 samples were IgG positive. The weighted overall seroprevalence increased from 2·9% (95% CI 2·3 to 3·6) to 6·0% (95% CI 5·1 to 7·1), reflected in a seroincidence estimate of 3·1% (95% CI 1·9 to 4·3). Age-specific seroprevalence significantly increased in the age categories 20-30, 80-90 and ≥90. No significant sex effect was observed.InterpretationDuring the start of epidemic mitigation by lockdown, a small but increasing fraction of the Belgian population showed serologically detectable signs of exposure to SARS-CoV-2.FundingThis independent researcher-initiated study acknowledges financial support from the Antwerp University Fund, the Flemish Research Fund, and European Horizon 2020.Research in contextEvidence before this studyThis is the first study reporting seroprevalence and seroincidence of IgG against SARS-CoV-2 in the Belgian population. Worldwide, PCR tests are being performed to identify mainly sick people suffering from COVID-19. However, seroprevalence studies are important and feasible to study the proportion of the population that has already been in contact with the virus, which helps to understand the likelihood of asymptomatic infections or infections with mild symptoms.From 11 March to 11 May, updates on the COVID-19 pandemic by the World Health Organisation as well as bulletins from the Belgian Scientific Institute for Public Health, Sciensano, were consulted daily. Press releases from all over the world were monitored during that period. Google, PubMed as well as the pre-print server medrxiv were consulted by searching the terms “seroprevalence SARS-CoV-2” and “COVID-19”,Added value of this studyThis study reports that seroprevalence increased in Belgium from 2·9% (95% CI 2·3 to 3·6) to 6·0% (95% CI 5·1 to 7·1) over a period of 3 weeks during lockdown (30 March-5 April 2020 & 20-26 April 2020) with seroincidence estimate of 3·1% (95% CI 1·9 to 4·3). Moreover, a significant increase in seroprevalence in the age categories 20-30 and ≥80 and within each sex were reported.Implications of all the available evidenceSeroprevalences worldwide indicate that an increasing fraction of the population has already been exposed to SARS-CoV-2. The continuous monitoring of seroprevalences is valuable to calibrate the response to the epidemic and to guide policy makers to control the epidemic wave and potential future waves and to avoid a deconfinement strategy leading to a rebound. However, it seems likely that natural exposure during this pandemic might not soon deliver the required level of herd immunity and there will be a substantial need for mass vaccination programmes to save time and lives.

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Herd immunity to SARS-CoV-2 among the population of the Republic of Belarus amid the COVID-19 pandemic

Russian Journal of Infection and Immunity ◽

10.15789/2220-7619-hit-1798 ◽

2021 ◽

Vol 11 (5) ◽

pp. 887-904

Author(s):

A. Yu. Popova ◽

A. A. Tarasenko ◽

V. Yu. Smolensky ◽

S. A. Egorova ◽

V. S. Smirnov ◽

...

Keyword(s):

Herd Immunity ◽

Age Groups ◽

Statistical Processing ◽

Threshold Level ◽

Test System ◽

Elisa Test ◽

Surface Glycoprotein ◽

Pasteur Institute ◽

The Republic ◽

Questionnaire Method

Objective was to investigate the SARS-CoV-2 collective immunity status of the population of Belarus within the context of the COVID-19 pandemic. Materials and methods. The work was carried out according to the methodology for assessing SARS-CoV-2 population immunity, developed by Rospotrebnadzor Russia and the Ministry of Health of Belarus with the participation of the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The Bioethics Committee of Belarus and the local ethics committee of the St. Petersburg Pasteur Institute approved the study. Selection of participants was carried out using a questionnaire method and online technology (internet, cloud server). Volunteers were randomized into seven age groups (years of age): 1–17; 18–29; 30–39; 40–49; 50–59; 60–69; and 70+. Regional randomization ensured proportional representation of volunteers from each region, and no more than 30 people were included from one enterprise. In accordance with manufacturer instructions, blood plasma samples were analyzed for: IgG antibodies (Abs) to the SARS-CoV-2 nucleocapsid (Nc) using a quantitative ELISA test system; and IgG Abs to the receptor binding domain (RBD) of the SARS-CoV-2 S (spike) surface glycoprotein using a qualitative ELISA test system. Statistical processing was carried out using Excel 2010 and other software. Statistical differences were designated as significant when p < 0.05, unless otherwise indicated. Results. The level of seroprevalence, in terms of Abs to Nc among the Belarusian population, was 38.4% (95% CI 37.6–45.4). The highest Ab levels were found among individuals in older age groups (50-70+ years old). The lowest were found in children 1–17 years old and in young people 18–39 years old The distribution of seroprevalence across Belarusian regions was relatively homogeneous, with the exception of the Minsk Region, where a statistically significant decrease in the indicator was noted. In terms of profession, the largest share of seropositive individuals was found among transportation workers; the smallest was found in business. The moderate COVID-19 incidence has not led to a dramatic increase in the number of contacts. The base reproduction number (R0) was 1.3. In the Republic of Belarus, there was a moderate level of asymptomatic COVID-19 among seropositive individuals (45.3% [95% CI 44.0–46.7]). This form of infection was observed most often among children aged 1–17 years old (65.0% [95% CI 61.3–68.6]). In parallel with seroprevalence assessment, SARS-CoV-2 vaccination was carried out. We used two vaccines: Gam-COVID-Vac (also known as Sputnik V, developed by Gamaleya National Center for Epidemiology and Microbiology, Russia); and BBIBP-CorV (Sinopharm, PRC). Vaccination against SARS-CoV-2 was accompanied by an increase in the level of anti-RBD Abs (95% [95% CI 94.7–96.7]). Taking into account the vaccination of a subset of the population with BBIBP-CorV, the overall herd immunity, inferred from the analyzed indicators (presence of anti-Nc or anti-RBD Abs), was 47.1% (95% CI 46.3–48.0). Conclusion. COVID-19 in Belarus was characterized by a moderately pronounced course of the epidemic process. The threshold level of herd immunity to SARS-CoV-2 has not yet been reached, as a result of which the conditions for progression of the epidemic remain.

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Seroprevalence of IgG antibodies against SARS-CoV-2 among the general population and healthcare workers in India, June–July 2021: A population-based cross-sectional study

PLoS Medicine ◽

10.1371/journal.pmed.1003877 ◽

2021 ◽

Vol 18 (12) ◽

pp. e1003877

Author(s):

Manoj V. Murhekar ◽

Tarun Bhatnagar ◽

Jeromie Wesley Vivian Thangaraj ◽

V. Saravanakumar ◽

Muthusamy Santhosh Kumar ◽

...

Keyword(s):

General Population ◽

Rural Areas ◽

Urban Areas ◽

Nucleocapsid Protein ◽

Healthcare Workers ◽

National Level ◽

Cross Sectional Study ◽

Igg Antibodies ◽

Cross Sectional ◽

June July

Background India began COVID-19 vaccination in January 2021, initially targeting healthcare and frontline workers. The vaccination strategy was expanded in a phased manner and currently covers all individuals aged 18 years and above. India experienced a severe second wave of COVID-19 during March–June 2021. We conducted a fourth nationwide serosurvey to estimate prevalence of SARS-CoV-2 antibodies in the general population aged ≥6 years and healthcare workers (HCWs). Methods and findings We did a cross-sectional study between 14 June and 6 July 2021 in the same 70 districts across 20 states and 1 union territory where 3 previous rounds of serosurveys were conducted. From each district, 10 clusters (villages in rural areas and wards in urban areas) were selected by the probability proportional to population size method. From each district, a minimum of 400 individuals aged ≥6 years from the general population (40 individuals from each cluster) and 100 HCWs from the district public health facilities were included. The serum samples were tested for the presence of IgG antibodies against S1-RBD and nucleocapsid protein of SARS-CoV-2 using chemiluminescence immunoassay. We estimated the weighted and test-adjusted seroprevalence of IgG antibodies against SARS-CoV-2, along with 95% CIs, based on the presence of antibodies to S1-RBD and/or nucleocapsid protein. Of the 28,975 individuals who participated in the survey, 2,892 (10%) were aged 6–9 years, 5,798 (20%) were aged 10–17 years, and 20,285 (70%) were aged ≥18 years; 15,160 (52.3%) participants were female, and 21,794 (75.2%) resided in rural areas. The weighted and test-adjusted prevalence of IgG antibodies against S1-RBD and/or nucleocapsid protein among the general population aged ≥6 years was 67.6% (95% CI 66.4% to 68.7%). Seroprevalence increased with age (p < 0.001) and was not different in rural and urban areas (p = 0.822). Compared to unvaccinated adults (62.3%, 95% CI 60.9% to 63.7%), seroprevalence was significantly higher among individuals who had received 1 vaccine dose (81.0%, 95% CI 79.6% to 82.3%, p < 0.001) and 2 vaccine doses (89.8%, 95% CI 88.4% to 91.1%, p < 0.001). The seroprevalence of IgG antibodies among 7,252 HCWs was 85.2% (95% CI 83.5% to 86.7%). Important limitations of the study include the survey design, which was aimed to estimate seroprevalence at the national level and not at a sub-national level, and the non-participation of 19% of eligible individuals in the survey. Conclusions Nearly two-thirds of individuals aged ≥6 years from the general population and 85% of HCWs had antibodies against SARS-CoV-2 by June–July 2021 in India. As one-third of the population is still seronegative, it is necessary to accelerate the coverage of COVID-19 vaccination among adults and continue adherence to non-pharmaceutical interventions.

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Prevalence of hypertension among the rural population of Mehsana district of North Gujarat region, India

International Journal of Community Medicine and Public Health ◽

10.18203/2394-6040.ijcmph20214577 ◽

2021 ◽

Vol 8 (12) ◽

pp. 5847

Author(s):

Nilesh Thakor ◽

Pankaj B. Nimbalkar ◽

Maulik D. Joshi

Keyword(s):

Blood Pressure ◽

Rural Areas ◽

Rural Population ◽

Cross Sectional Study ◽

Microsoft Excel ◽

Cross Sectional ◽

The Social ◽

And Gender ◽

Stage 1 ◽

North Gujarat

Background:High blood pressure is considered both a disease and a risk factor, especially for cardiovascular diseases, and is one of the most serious public health problems. To find out the prevalence of hypertension among the rural population of Mehsana district of North Gujarat region, India.Methods:This was cross sectional study and conducted in rural areas of Mehsana district of Gujarat during January 2019 to June 2019. People living rural areas were selected by stratified random sampling. They were screened for hypertension by JNC VII criteria using sphygmomanometer after written and informed consent. Data was entered in Microsoft excel and analysis was done using statistical package for the social sciences (SPSS) statistical package.Results: Out of total 602, majority 293 (48.7%) subjects had normal blood pressure with mean age of 25.28±16.62 years, 271 subjects (45.0%) had pre hypertension with mean age of 40.30±14.32 years. Out of total, 25 (4.2%) subjects had hypertension stage 1 with mean age of 45.82±11.48 years and 13 (2.2%) subjects had hypertension stage 2 with mean age of 53.77±16.02 years. Out of total 271 subjects who had pre hypertension, 150 (55.3%) were males. Hypertension stage 1 and 2 were almost equally distributed among both gender. A blood pressure category and gender difference was statically significant. Out of total 38 hypertensive subjects, 19 (50%) subjects were in the age group of 40-59 years.Conclusions: Prevalence of hypertension among rural population was 6.4%.

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Changes in Cytomegalovirus Seroprevalence Among U.S. Children Aged 1–5 Years: The National Health and Nutrition Examination Surveys

Clinical Infectious Diseases ◽

10.1093/cid/ciaa1168 ◽

2020 ◽

Author(s):

Molly R Petersen ◽

Eshan U Patel ◽

Alison G Abraham ◽

Thomas C Quinn ◽

Aaron A R Tobian

Keyword(s):

Confidence Interval ◽

National Health ◽

Immunoglobulin G ◽

Igg Antibodies ◽

Cross Sectional ◽

Health And Nutrition ◽

Prevalence Difference ◽

The Cross ◽

Us Children

Abstract Data from the cross-sectional National Health and Nutrition Examination Surveys (NHANES) indicate that the seroprevalence of cytomegalovirus immunoglobulin G (IgG) antibodies among US children aged 1–5 years was 20.7% (95% confidence interval [CI]: 14.0, 29.0) in 2011–2012 and 28.2% (95% CI: 23.1–34.0) in 2017–2018 (adjusted prevalence difference, +7.6% [95% CI: −.4, +15.6]).

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