Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 in the United States: Living Density, Viral Load, and 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.

COVID-19 Outbreaks in Settings With Precarious Housing Conditions in Germany: Challenges and Lessons Learned

“…The high attack rates of 12 and 22% among residents of RC1 and RC2, respectively, suggest that, in line with published evidence ( 1 – 3 ), overcrowding, and within-household transmission have likely played a significant role in the spread of the virus. It was assumed by local authorities that in addition to officially registered residents further not-registered persons lived in the RCs, in particular in RC2, therefore overcrowding was likely even more severe.…”

“…The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is easily transmissible by both symptomatic and asymptomatic individuals. Closed and densely inhabited environments favor transmission (1)(2)(3).…”

Household Secondary Attack Rates of SARS-CoV-2 by Variant and Vaccination Status

“…We identified 2097 records (1791 from PubMed, 306 from medRxiv, and 2 from reference lists of eligible articles) published between June 18, 2021, and March 8, 2022 (eFigure 1 in the Supplement ). Fifty-eight new studies 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 (eTable 2 in the Supplement ) were combined with 77 studies from ou...…”

“…Fifty-eight new studies 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 (eTable 2 in the Supplement ) were combined with 77 studies from our previous review 1 (see eTable 3 in the Supplement for references included from our previous review), with…”

SARS-CoV-2 Delta Variant in Jingmen City, Hubei Province, China, 2021: Children Susceptible and Vaccination Breakthrough Infection

“…The study of household SARs caused by the SARS-CoV-2 delta variant (B.1.617.2) was limited (Dougherty et al, 2021 ). In the previous studies of epidemics caused by the wide-type of SARS-CoV-2 or other related variants, household SARs varied from 3 to 32% in China and the US (Jing et al, 2020 ; Lewis et al, 2020 ; Li W. et al, 2020 ; Wu et al, 2020 ; Cerami et al, 2021 ). Compared with outbreaks caused by wide-type strain of SARS-CoV-2, the overall household SAR in this outbreak (25%) was higher than that in Guangzhou City, China (12.4–17.1%) and lower than that in the US households (29–32%) and Zhuhai City, China (32%) (Jing et al, 2020 ; Lewis et al, 2020 ; Wu et al, 2020 ; Cerami et al, 2021 ).…”