ABSTRACT
Repeated serological testing tells about the change in the overall infection in a community. This study aimed to evaluate changes in antibody prevalence and kinetics in a closed cohort over six months in different sub-populations in India. The study included 10,000 participants from rural and urban areas in five states and measured SARS-CoV-2 antibodies in serum in three follow-up rounds. The overall seroprevalence increased from 73.9% in round one to 90.7% in round two and 92.9% in round three. Among seropositive rural participants in round one, 98.2% remained positive in round two, and this percentage remained stable in urban and tribal areas in round three. The results showed high antibody prevalence that increased over time and was not different based on area, age group, or sex. Vaccinated individuals had higher antibody prevalence, and nearly all participants had antibody positivity for up to six months.
ABSTRACT
Background Several methodological tests are available to detect SARS-CoV-2 antibody. Tests are mostly used in the aid of diagnosis or for serological assessment. No tests are fully confirmatory and have variable level of diagnostic ability. We aimed at assessing agreement with three serological tests: quantitative anti receptor binding domain ELISA (Q-RBD), qualitative ELISA (WANTAI SARS-CoV-2 Ab) and qualitative chemiluminiscence assays (CLIA).Methods This study was a part of a large population based sero-epidemiological cohort study. Participants aged 1 year or older were included from 25 randomly selected clusters each in Delhi urban (urban resettlement colony of South Delhi district) and Delhi rural (villages in Faridabad district, Haryana). Three type of tests were applied to all the baseline blood samples. Result of the three tests were evaluated by estimating the total agreement and kappa value.Results Total 3491 blood samples collected from March to September, 2021, out of which 1700 (48.7%) from urban and 1791 (51.3%) from rural. Overall 44.1% of participants were male. The proportion of sero-positivity were 78.1%, 74.1% and 31.8% by Wantai, QRBD and CLIA tests respectively. The total agreement between Wantai and QRBD was 94.2%, 53.1% between Wantai and CLIA, and 56.6% between QRBD and CLIA. The kappa value between these three tests were 0.84 (95% CI: 0.80–0.87), 0.22 (95% CI: 0.19–0.24) and 0.26 (95% CI: 0.23–0.28).Conclusions There was strong concordance between Wantai and QRBD test. Agreement between CLIA with other two tests was low. Wantai and QRBD may be used interchangeably.
ABSTRACT
Background: Plaque reduction neutralization test (PRNT) is the gold standard to detect neutralizing capacity of the serum antibodies. Neutralizing antibody confers protection against further infection. The present study was done with the objective to measure the antibody level against SARS-CoV2 among laboratory confirmed COVID-19 cases and to evaluate whether the presence of anti-SARS-CoV2 antibodies indicate virus neutralizing capacity. Methods: One hundred COVID-19 confirmed cases were recruited. Sociodemographic details and history of COVID-19 vaccination, contact with positive COVID-19 cases, and symptoms were ascertained using a self-developed semi-structured interview schedule. Serum samples of the participants were collected within three months from date of the positive report of COVID-19. The presence of anti-SARS-CoV-2 antibodies (IgA, IgG and IgM antibodies), receptor binding domain antibodies (anti-RBD), and neutralizing antibodies were measured. Findings: Almost all participants had Anti-SARS-CoV2 antibodies (IgA, IgG and IgM) (99%) and Anti-RBD IgG antibodies (97%). However, only 69% had neutralizing antibodies against SARS-CoV2. Anti-RBD antibody levels were significantly higher among participants having neutralizing antibodies compared to those who did not. Interpretation: The present study highlights that presence of antibodies against SARS-CoV2, or presence of anti-RBD antibody does not necessarily imply presence of neutralizing antibodies. Funding: World Health Organisation
Subject(s)
COVID-19ABSTRACT
Mental health problems among children and adolescents are increasingly reported amidst the coronavirus disease (COVID-19) pandemic. In this umbrella review, we aimed to synthesize global evidence on the epidemiologic burden and correlates of child and adolescent mental health (CAMH) problems during this pandemic from existing systematic reviews and meta-analyses. We evaluated 422 citations and identified 17 eligible reviews on the epidemiology of CAMH in the context of COVID-19. Most of the reviews reported a high prevalence of anxiety, depression, sleep disorders, suicidal behavior, stress-related disorders, attention-deficit/hyperactivity disorder, and other mental health problems. Also, factors associated with CAMH such as age, gender, place of residence, educational attainment, household income, sedentary lifestyle, social media and internet use, comorbidities, family relationships, parents' psychosocial conditions, COVID-19 related experiences, closure of schools, online learning, and social support were reported across reviews. As most studies were cross-sectional and used nonrepresentative samples, future research on representative samples adopting longitudinal and intervention designs is needed. Lastly, multipronged psychosocial care services, policies, and programs are needed to alleviate the burden of CAMH problems during and after this pandemic.
Subject(s)
Anxiety Disorders , Attention Deficit Disorder with Hyperactivity , Depressive Disorder , COVID-19 , Sleep Wake DisordersABSTRACT
BackgroundQuarantine of healthcare workers (HCWs) exposed to COVID -19 confirmed cases is a well-known strategy for limiting the transmission of infection. However, there is need of evidence-based guidelines for quarantine of HCWs in COVID -19. MethodsWe describe our experience of contact tracing and risk stratification of 3853 HCWs who were exposed to confirmed COVID-19 cases in a tertiary health care institution in India. We developed an algorithm, on the basis of risk stratification, to rationalize quarantine among HCWs. Risk stratification was based on the duration of exposure, distance from the patient, and appropriateness of personal protection equipment (PPE) usage. Only high-risk contacts were quarantined for 14 days. They underwent testing for COVID-19 after five days of exposure, while low-risk contacts continued their work with adherence to physical distancing, hand hygiene, and appropriate use of PPE. The low-risk contacts were encouraged to monitor for symptoms and report for COVID-19 screening if fever, cough, or shortness of breath occurred. We followed up all contacts for 14 days from the last exposure and observed for symptoms of COVID-19 and test positivity. Results and interpretationOut of total 3853 contacts, 560 (14.5%) were categorized as high-risk contacts, and 40 of them were detected positive for COVID-19, with a test positivity rate of 7.1% (95% CI = 5.2 - 9.6). Overall, 118 (3.1%) of all contacts tested positive. Our strategy prevented 3215 HCWs from being quarantined and saved 45,010 person-days of health workforce until June 8, 2020, in the institution. We conclude that exposure-based risk stratification and quarantine of HCWs is a viable strategy to prevent unnecessary quarantine, in a healthcare institution. SummaryO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIQuarantine of HCWs is a well-known strategy for community and HCWs to prevent the transmission of COVID-19. C_LIO_LIThough success stories of prompt contact tracing and quarantine to control COVID-19 are available from countries like South Korea, Singapore, and Hong Kong, there is a scarcity of evidence that could guide targeted quarantine of HCWs exposed to COVID -19 in India. C_LI What does this study add?O_LIOnly 14.5% HCWs exposed to COVID-19 cases were stratified "high risk" contacts, and the most common reason for high-risk contacts was non-formal workplace interactions such as having meals together. C_LIO_LIThe overall test positivity rate among the high-risk contacts was 7.1%, while it was higher in symptomatic high-risk contacts as compared to those who were asymptomatic (10.2% vs. 6.3%). C_LI How might this impact on clinical practice?O_LIContact tracing and risk stratification can be used to minimize unnecessary quarantine of COVID-19 exposed health care workers and prevent the depletion of healthcare workers amidst the pandemic to continue the healthcare services optimally. C_LI