Community prevalence of antibodies to SARS-CoV-2 and correlates of protective immunity in an Indian metropolitan city

Ghose, Aurnab; Bhattacharya, Sankar; Karthikeyan, Arun S; Kudale, Abhay; Monteiro, Joy Merwin; Joshi, Aparna; Medigeshi, Guruprasad R.; Kang, Gagandeep; Bal, Vineeta; Rath, Satyajit; Shashidhara, L. S.; John, Jacob; Chaudhuri, Susmita; Nagarkar, Aarti

doi:10.1101/2020.11.17.20228155

Cited by 18 publications

(20 citation statements)

References 24 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Among the reported symptoms, the most common were fever (63.20%), followed by cough were substantially high (51.3%, 95% CI 39.9 -62.4) but showed wide variation among the included localities [19]. In a serosurvey set in Mumbai including slums and non-slum settings in July 2020, 54.1% of samples from slums compared to 16.1% of samples from non-slum areas were found to be positive for anti-SARS CoV2 antibodies [20] In the repeated cross-sectional serosurveys in Bhubaneswar, the highest seropositivity of 49.04% in the 16 th to 18 th September 2020 sampling was preceded by the highest 7-day average of the number of new COVID-19 cases as detected by rRT PCR or antigen testing in the city.…”

Section: Resultsmentioning

confidence: 98%

“…Subsequent surveys from different parts of India have reported higher rates of seropositivity which have corresponded to the phased reopenings in different parts. In a study performed during July and August, 2020, in five administrative sub-wards of Pune city in Maharashtra, the state with the highest number of COVID-19 cases until date, seropositivity rates were substantially high (51.3%, 95% CI 39.9-62.4) but showed wide variation among the included localities [11]. In a serosurvey set in Mumbai including slums and non-slum settings in July, 2020, 54.1% of samples from slums compared to 16.1% of samples from non-slum areas were found to be positive for anti-SARS-CoV-2 antibodies [12] In the repeated cross-sectional serosurveys in Bhubaneswar, the highest seropositivity of 49.04% during 16th to 18th September, 2020, was preceded by the highest 7-day average of the number of new COVID-19 cases as detected by rRT-PCR or antigen testing in the city.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys

et al. 2021

View full text Add to dashboard Cite

The study aims to estimate and compare the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence, the fraction of asymptomatic or subclinical infections in the population, determine the demographic risk factors and analyse the antibody development at different time points among adults in Bhubaneswar city, India. This was a serial three-round cross-sectional, community-based study where participants were selected from the residents of Bhubaneswar city using multi-stage random sampling. Blood samples were collected during household visits along with demographic and clinical data from every participant. Total anti-SARS-CoV-2 antibody present in serum was assessed using the electro-chemiluminescence immunoassay platform. Temporal comparisons of the community seroprevalence were performed against the detected number of cumulative cases, active cases, recoveries and deaths. A total of 3693 participants were enrolled in this study with a cumulative non-response rate of 18.33% in all the three rounds. The gender-weighted seroprevalence for the city in the first round was 1.55% (95% confidence interval (CI) 0.84–2.58), second round was 5.27% (95% CI 4.13–6.59) and in the third round was 49.04% (95% CI 46.39–51.68). In the first round, the seroprevalence was found to be highest in the elderly population, whereas the seroprevalence for the second and third phases was highest in the age group of 30–39 years. Seroprevalence showed an increasing trend over the three time periods, with the highest seropositivity rates among individuals sampled between 16 and 18 September 2020. By the third round, 93.93% of those who had previously been tested positive by real-time reverse transcription polymerase chain reaction had seroconversion and 46.57% of those who had been tested negative also showed seroconversion. Infection to case ratio during first round was 27.05, for second round and third round it was 5.62 and 17.91, respectively.

show abstract

Section: Resultsmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys

et al. 2021

View full text Add to dashboard Cite

show abstract

“…India’s urban COVID pandemic has been characterized as a paradox of widespread infection but low mortality. 8,24,25 Urban India still has a young age structure and young adults have low IFRs in nearly all countries. 24,25 The age-specific and temporal patterns suggesting substantial intergenerational transmission are consistent with Indian household composition.…”

Section: Discussionmentioning

confidence: 99%

“…The IFRs used values of 0.29%, 0.263% and 0.21%, drawn, respectively, from detailed serosurveys in Bangalore, Mumbai, and Pune. 6-8 We applied a reasonably large 30% correction factor based on RGI data on death reporting completeness, and previous analyses of under-reporting in selected low and middle-income countries 2,19 to arrive at adjusted COVID deaths which we then used to calculate the infection prevalence. Sensitivity analyses examined 0 to 50% undercount scenarios.…”

Section: Methodsmentioning

confidence: 99%

SARS-CoV-2 Seroprevalence in 12 Cities of India from July-December 2020

Velumani¹,

Nikam

Suraweera

et al. 2021

Preprint

View full text Add to dashboard Cite

Objectives: We sought to understand the spread of SARS-CoV-2 infection in urban India, which has surprisingly low COVID-19 deaths. Design: Cross-sectional and trend analyses of seroprevalence in self-referred test populations, and of reported cases and COVID mortality data. Participants: 448,518 self-referred individuals using a nationwide chain of private laboratories with central testing of SARS-CoV-2 antibodies and publicly available case and mortality data. Setting: 12 populous cities with nearly 92 million total population. Main outcome measures: Seropositivity trends and predictors (using a Bayesian geospatial model) and prevalence derived from mortality data and infection fatality rates (IFR). Results: For the whole of India, 31% of the self-referred individuals undergoing antibody testing were seropositive for SARS-CoV-2 antibodies. Seropositivity was higher in females (35%) than in males (30%) overall and in nearly every age group. In these 12 cities, seroprevalence rose from about 18% in July to 41% by December, with steeper increases at ages <20 and 20-44 years than at older ages. The ?M-shaped? age pattern is consistent with intergenerational transmission. Areas of higher childhood measles vaccination in earlier years had lower seropositivity. The patterns of increase in seropositivity and in peak cases and deaths varied substantially across cities. In Delhi, death rates and cases first peaked in June and again in November; Chennai had a single peak in July. Based local IFRs and COVID deaths (adjusted for undercounts), we estimate that 43%-65% of adults above age 20 had been infected (range of mid-estimates of 12%-77%) corresponding 26 to 36 million infected adults in these cities, or an average of 9-12 infected adults per confirmed case. Conclusion: Even with relatively low death rates, the large cities of India had remarkably high levels of SARS-CoV-2 infection. Vaccination strategies need to consider widespread intergenerational transmission.

show abstract

“…A subsequent study in Delhi, conducted in early August, obtained a seropositivity of 29.1% [7]. For Pune, in a study conducted between July 20 and Aug 5, 2020, an overall seropositivity of 51.3% was reported [8]. For the state of Karnataka, an overall infected population fraction of 27.3% – with that fraction including a large number of active cases – was obtained in a study conducted from early to mid-September, 2020 [9].…”

Section: Introductionmentioning

confidence: 99%

Optimizing testing for COVID-19 in India

Cherian

Krishna

Menon

2021

Preprint

View full text Add to dashboard Cite

COVID-19 testing across India uses a mix of two types of tests. Rapid Antigen Tests (RATs) are relatively inexpensive point-of-care lateral-flow-assay tests, but they are also less sensitive. The reverse-transcriptase polymerase-chain-reaction (RT-PCR) test has close to 100% sensitivity and specificity in a laboratory setting, but delays in returning results, as well as increased costs relative to RATs, may vitiate this advantage.India-wide, about 49% of COVID-19 tests are RATs, but some Indian states, including the large states of Uttar Pradesh (pop. 227.9 million) and Bihar (pop. 121.3 million) use a much higher proportion of such tests. Here we show, using simulations based on epidemiological network models, that the judicious use of RATs can yield epidemiological outcomes comparable to those obtained through RT-PCR-based testing and isolation of positives, provided a few conditions are met. These are (a) that RAT test sensitivity is not too low, (b) that a reasonably large fraction of the population, of order 0.5% per day, can be tested, (c) that those testing positive are isolated for a sufficient duration, and that (d) testing is accompanied by other non-pharmaceutical interventions for increased effectiveness. We assess optimal testing regimes, taking into account test sensitivity and specificity, background seroprevalence and current test pricing. We find, surprisingly, that even 100% RAT test regimes should be acceptable, from both an epidemiological as well as a economic standpoint, provided the conditions outlined above are met.Author summaryUsing network models, we study optimal ways of combining low sensitivity, relatively inexpensive point-of-care rapid antigen tests for COVID-19 with higher sensitivity but more expensive laboratory RT-PCR tests. We take into account background seroprevalence and current test pricing for such tests in India, finding that even purely rapid antigen test-based regimes can produce the same reduction in overall infections that pure RT-PCR tests are capable of. This is provided one can test at scale and isolate those testing positive effectively, that the sensitivity of the rapid test is not too low and that non-pharmaceutical interventions proceed in parallel for increased effectiveness.

show abstract

Community prevalence of antibodies to SARS-CoV-2 and correlates of protective immunity in an Indian metropolitan city

Cited by 18 publications

References 24 publications

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys

Seroprevalence of SARS-CoV-2 in Bhubaneswar, India: findings from three rounds of community surveys

SARS-CoV-2 Seroprevalence in 12 Cities of India from July-December 2020

Optimizing testing for COVID-19 in India

Contact Info

Product

Resources

About