Seroprevalence of anti-SARS-CoV-2 antibodies in residents of Karachi—challenges in acquiring herd immunity for COVID 19 (original) (raw)
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American Journal of Health, Medicine and Nursing Practice, 2021
Introduction: Coronavirus emerged as a pandemic in 2019 with the SARS COV 2 virus infecting people worldwide. Although PCR successfully detected symptomatic patients, asymptomatic patients remained undetected due to limitation of resources. The objective of the study was to determine the prevalence of IgM and IgG antibodies in the faculty, staff, and MBBS students in Medical school and tertiary care hospital, Pakistan. Material and Methods: A cross-sectional study was conducted on 500 asymptomatic healthy subjects, from September to December 2020 in Biochemistry department Shalamar Medical and Dental College (SMDC). Rapid antibody test was used to determine the presence of IgM and IgG antibodies in the subjects. Those found IgM positive were validated by COVID 19 detection by Polymerase Chain Reaction. Results: Anti-SARS-COV 2 antibodies was observed in 19.6 % of 500 asymptomatic subjects. Significant reactive cases were identified in hospital staff (27.5%) compared to hospital fa...
SARS-CoV-2: big seroprevalence data from Pakistan—is herd immunity at hand?
Infection, 2021
Purpose Seroprevalence surveys from diferent countries have reported SARS CoV-2 antibodies below 20% even in the most adversely afected areas and herd immunity cannot be predicted till more than half of the population gets the disease. The purpose of this survey was to estimate the magnitude of community-based spread of the infection, associated immunity, and the future prospects and proximity to a ‘herd community’. Methods The study was undertaken as a cluster randomized, cross-sectional countrywide survey. This largest communitybased seroprevalence data of SARS-CoV-2 were collected between 15th and 31st July, 2020 from seven randomly selected cities belonging to the three most populous provinces of Pakistan. The FDA approved kit of ROCHE was used for detection of SARS-CoV-2 antibodies. Results Serum samples of 15,390 participants were tested for SARS CoV-2 antibodies with an overall seroprevalence of 42.4%. The seroprevalence ranged from 31.1% to 48.1% in diferent cities with the ...
2021
Introduction One million cases of COVID-19 have been reported in Pakistan until August 1, 2021. However, SARS-CoV-2 PCR testing capacity is limited, and the true level of SARS-CoV-2 infections is unknown. Most individuals have asymptomatic or mild COVID-19 and remain undiagnosed. Volunteer healthy blood donors can be a control population for assessment of SARS-CoV-2 exposure. We determined COVID-19 seroprevalence during the second pandemic wave in Karachi. Materials and Methods We enrolled 558 healthy blood donors at the Aga Khan University Hospital blood bank between December 2020 and February 2021. Serum IgG reactivity were measured to spike and receptor binding domain (RBD) proteins. Clinical history was taken from individuals with a positive IgG result. Results Of the 558 study subjects, 553 (99.1%) were males and 5 (0.9%) were females with a mean (± SD) age of 29.0 ± 7.4 years (range 17–53 years). Positive IgG responses to spike were detected in 298/558 blood donors (53.4%). Of...
Cureus
Background The number of confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is vastly underestimated. In this context, seroprevalence surveys are of utmost importance to assess the proportion of the population that has already developed antibodies against the virus and might potentially be protected against subsequent infection. Health care workers (HCWs) face a greater risk of developing SARS-CoV-2. Therefore, the present retrospective study was undertaken to estimate the prevalence of antibodies against SARS-CoV-2 among healthcare workers at a tertiary care institute in Uttarakhand, India. Material and methods Data were gathered from hospital records of 704 healthcare workers admitted to the coronavirus disease 2019 (COVID-19) unit and attended the COVID OPD of the tertiary care institute between July 15 to Aug 14, 2020. Result Out of the 704 recruited participants, 14 (1.99%) were seropositive for immunoglobulin G (IgG) antibodies against SARS-CoV-2. The cumulative prevalence of SARS-CoV-2 infection (presence of antibodies or past or current positive reverse transcription-polymerase chain reaction (RT-PCR)) was 4.40%. Conclusion The present study shows a low prevalence of SARS-CoV-2 IgG antibodies among health care workers. In addition, posting in COVID-19-positive areas was not associated with increased seropositivity. More studies are warranted to assess IgG/IgM antibodies against SARS-CoV-2 among those HCWs who are exposed to COVID-19 patients.
Seroprevalence of SARS-COV-2 Antibodies in Medical Staff, South-West of Iran
International Journal of Basic Science in Medicine, 2021
Introduction: Serological assay has critical role in defining immunity based on seroprevalence. Identifying the extend of seropositivity would determine the truly infected cases. Method: We conducted serologic testing for SARS-COV-2 antibodies in 492 health care workers (HCWs) before vaccination program in Shiraz, Iran (30 April 2020). Results: Based on job position, cases were divided into two categories: frontline staff (169, 34.34%) and non-front-line staff (323, 65.65%). Of all cases 40.65 were female and the rest of them were male. Mean age was estimated 47.97 ± 109.20 and 38.98 ± 8.76 in high risk and low risk population respectively (P = 0.1). In total 367 (74.59%) subjects reported to suffered at least one of the COVID-19 symptoms. More than half of cases (73.57) had history of COVID-19 disease within six months before this survey. No relation was seen between blood type and immunoglobulin positivity. Seropositivity prevalence in low risk and high-risk populations were estim...
Seroprevalence of anti-SARS-CoV-2 total Antibodies in the rural population of Udaipur district
International journal of scientific research, 2021
Purpose Frequently the infection with coronavirus 2 (SARS-CoV-2) can be asymptomatic or provoke only mild symptoms. These cases often remain unnoticed, so it is difficult to estimate the actual numbers of infections. Aim of this study was to determine the seroprevalence of anti-SARS-CoV-2 total antibody in Austrian blood donors. Methods 20,228 blood donors aged between 18 and 72 years resident in four Austrian federal states were screened for anti-SARS-CoV-2 total antibody between 5th of June and 4th of December 2020. To evaluate the impact of sex, age, AB0-blood group and donation period on the anti-SARS-CoV-2 seroprevalence, multiple logistic regression was done. Results Our data reveal an anti-SARS-CoV-2 seroprevalence of 2.5% overall, significantly depending on the time point of blood donation: after the first Austrian lockdown the seroprevalence was lower compared to the following months, when the rate was constantly rising. While younger blood donors showed significantly higher seroprevalence, no differences were found concerning sex or AB0 blood group. Conclusion Broad testing strategies are required to better determine the number of SARS-CoV-2 infections. Screening blood donors as a representative group for the adult population could be a valid tool to determine the number of recorded and unrecorded cases of SARS-CoV-2 infection.
https://www.ijhsr.org/IJHSR\_Vol.11\_Issue.7\_July2021/IJHSR-Abstract.014.html, 2021
Background-COVID-19 is the latest raging pandemic that the world is facing at the moment. Frontline workers have been highly exposed to this disease and majority of them have suffered from this deadly disease too. Studying the prevalence of antibodies among frontline workers in different areas is crucial for understanding the potential risk of transmission, the prevalence of herd immunity, vaccine deployment and risk stratification in different areas of work. Materials and Methods-A prospective study was conducted in a tertiary care hospital of Navi Mumbai on 200 essential service providers, 100 HCWs and 100 police personnel, of which 2 police personnel dropped out of the study. This study was conducted over a period of 2 days, i.e., 20 th and 21 st May 2021 and it included answering a questionnaire and drawing blood to detect SARS COV-2 antibodies. Results-Out of the total 198 participants, there were 130 males and 68 females. Most of the participants were in the 30-39 years age group and 41% participants had suffered from COVID-19 in the past one year. 60.10% participants had developed IgG antibodies against COVID-19. The highest titre of antibodies found was between 1-10 amongst both groups followed by antibody levels more than 100 among HCWs. Subsequently, it was found that there was a 72% seropositivity rate amongst frontline workers whereas only a 48% positivity rate in HCWs. Conclusion-Measuring antibody titres allows determination of prevalence of COVID-19 infection amongst heavily exposed individuals, who have been badly affected by the 2 waves of this pandemic. This serosurvey also helped us confirm that there is a declining trend of antibodies during convalescence phase and that even though the infectivity rate is high amongst essential service providers, not all developed a sustained antibody response. These findings uphold the need for strict precautionary measures and that laxity must not be observed while following the same to contain the pandemic.
International Journal of Environmental Research and Public Health, 2021
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread globally, causing unprecedented effects on global health and economies. Community-based serological data are essential for understanding the true prevalence of infections, specifically the subclinical infections, as COVID-19 asymptomatic infections are common. Such data would also be important for decision making around choosing appropriate epidemiological control measures, as well as for the true estimation of mortality rates in the population. Further, determining the seroprevalence of anti-SARS-CoV-2 antibodies in the population would provide important information on herd immunity. In this study, we conducted a population-based age-stratified serological study to understand the prevalence of SARS-CoV-2 in Jazan Province, Saudi Arabia. Out of 594 participants who were recruited from 29 August to 30 December 2020, just before the vaccination rollout program in Saudi Arabia, about 157 were seropositive ...