scispace - formally typeset
Search or ask a question
Author

Zachary R Popkin-Hall

Bio: Zachary R Popkin-Hall is an academic researcher from University of North Carolina at Chapel Hill. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: The CO-HOST prospective cohort study as mentioned in this paper showed that household crowding in the context of high-inoculum infections may amplify the spread of COVID-19, potentially contributing to disproportionate impact on communities of color.
Abstract: BACKGROUND: Households are hotspots for SARS-CoV-2 transmission. In the US, the COVID-19 pandemic has had a disproportionate impact on communities of color. METHODS: Between April-October 2020, the CO-HOST prospective cohort study enrolled 100 COVID-19 cases and 208 of their household members in North Carolina, including 44% who identified as Hispanic or non-white. Households were enrolled a median of 6 days from symptom onset in the index case. Incident secondary cases within the household were detected by quantitative PCR of weekly nasal swabs (days 7, 14, 21) or by seroconversion at day 28. RESULTS: Excluding 73 household contacts who were PCR-positive at baseline, the secondary attack rate among household contacts was 32% (33/103, 95% CI 22%-44%). The majority of cases occurred by day 7, with later cases confirmed as household-acquired by viral sequencing. Infected persons in the same household had similar nasopharyngeal viral loads (ICC=0.45, 95% CI 0.23-0.62). Households with secondary transmission had index cases with a median viral load that was 1.4 log10 higher than households without transmission (p=0.03) as well as higher living density (>3 persons occupying <6 rooms) (OR 3.3, 95% CI 1.02-10.9). Minority households were more likely to experience high living density and had a higher risk of incident infection than did white households (SAR 51% vs. 19%, p=0.01). CONCLUSIONS: Household crowding in the context of high-inoculum infections may amplify the spread of COVID-19, potentially contributing to disproportionate impact on communities of color.

37 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: The results suggest that emerging SARS-CoV-2 variants of concern have increased transmissibility and the changes in estimated vaccine effectiveness underscore the challenges of developing effective vaccines concomitant with viral evolution.
Abstract: This systematic reviewe and meta-analysis evaluates household secondary attack rates of SARS-CoV-2 by variant and vaccination status.

100 citations

Posted ContentDOI
11 Jan 2022-medRxiv
TL;DR: To examine how emerging variants and increased vaccination have affected transmission rates, PubMed was searched from June 18, 2021, through January 7, 2022 to obtain SAR estimates and 95%CI, disaggregated by several covariates.
Abstract: We previously reported a household secondary attack rate (SAR) for SARS-CoV-2 of 18.9% through June 17, 2021. To examine how emerging variants and increased vaccination have affected transmission rates, we searched PubMed from June 18, 2021, through January 7, 2022. Meta-analyses used generalized linear mixed models to obtain SAR estimates and 95%CI, disaggregated by several covariates. SARs were used to estimate vaccine effectiveness based on the transmission probability for susceptibility (VE_S,p), infectiousness (VE_I,p), and total vaccine effectiveness (VE_T,p). Household SAR for 27 studies with midpoints in 2021 was 35.8% (95%CI, 30.6%-41.3%), compared to 15.7% (95%CI, 13.3%-18.4%) for 62 studies with midpoints through April 2020. Household SARs were 38.0% (95%CI, 36.0%-40.0%), 30.8% (95%CI, 23.5%-39.3%), and 22.5% (95%CI, 18.6%-26.8%) for Alpha, Delta, and Beta, respectively. VE_I,p, VE_S,p, and VE_T,p were 56.6% (95%CI, 28.7%-73.6%), 70.3% (95%CI, 59.3%-78.4%), and 86.8% (95%CI, 76.7%-92.5%) for full vaccination, and 27.5% (95%CI, -6.4%-50.7%), 43.9% (95%CI, 21.8%-59.7%), and 59.9% (95%CI, 34.4%-75.5%) for partial vaccination, respectively. Household contacts exposed to Alpha or Delta are at increased risk of infection compared to the original wild-type strain. Vaccination reduced susceptibility to infection and transmission to others.

66 citations

Journal ArticleDOI
TL;DR: In this paper , the authors explored the household transmissibility of SARS-CoV-2 in children in new-variants dominating periods and found that younger children were as susceptible as older children (RR = 0.18-0.30).

32 citations

Journal ArticleDOI
TL;DR: In this article, a strategy for identifying, recruiting, and genetically analyzing individuals who are naturally resistant to SARS-CoV-2 infection was proposed, along with a genetic and immunological determinants of resistance to infection per se.
Abstract: SARS-CoV-2 infections display tremendous interindividual variability, ranging from asymptomatic infections to life-threatening disease. Inborn errors of, and autoantibodies directed against, type I interferons (IFNs) account for about 20% of critical COVID-19 cases among SARS-CoV-2-infected individuals. By contrast, the genetic and immunological determinants of resistance to infection per se remain unknown. Following the discovery that autosomal recessive deficiency in the DARC chemokine receptor confers resistance to Plasmodium vivax, autosomal recessive deficiencies of chemokine receptor 5 (CCR5) and the enzyme FUT2 were shown to underlie resistance to HIV-1 and noroviruses, respectively. Along the same lines, we propose a strategy for identifying, recruiting, and genetically analyzing individuals who are naturally resistant to SARS-CoV-2 infection.

31 citations

Journal ArticleDOI
TL;DR: The Assessment of Transmission and Contagiousness of COVID-19 in Contacts (ATACCC) study was a UK prospective, longitudinal, community cohort of contacts of newly diagnosed, PCR-confirmed SARS-CoV-2 index cases as mentioned in this paper .

30 citations