Spreading of COVID-19: Density matters

Wong, David W. S.; Li, Yun

doi:10.1371/journal.pone.0242398

Cited by 243 publications

(192 citation statements)

References 20 publications

(24 reference statements)

Supporting

Mentioning

176

Contrasting

Unclassified

Order By: Relevance

“…Our findings are consistent with previous research that have demonstrated a strong relationship between population density and other infectious diseases [4,6,7,9,35]. In the current SARS--CoV-2 pandemic, recent literature has been conflicting, where some research also suggests a density-dependence of COVID-19 transmission [17,36] and other measures of the severity of the outbreak [19,37], while other research suggests that there are other factors that can better explain the pandemic [18,38]. However, to our knowledge, our results are one of the first to show that population density is an important driver of COVID-19 transmission, even in areas where residents rely more on private modes of transportation.…”

Section: Discussionsupporting

confidence: 91%

Population density and basic reproductive number of COVID-19 across United States counties

2021

View full text Add to dashboard Cite

The basic reproductive number (R0) is a function of contact rates among individuals, transmission probability, and duration of infectiousness. We sought to determine the association between population density and R0 of SARS-CoV-2 across U.S. counties. We conducted a cross-sectional analysis using linear mixed models with random intercept and fixed slopes to assess the association of population density and R0, and controlled for state-level effects using random intercepts. We also assessed whether the association was differential across county-level main mode of transportation percentage as a proxy for transportation accessibility, and adjusted for median household income. The median R0 among the United States counties was 1.66 (IQR: 1.35–2.11). A population density threshold of 22 people/km2 was needed to sustain an outbreak. Counties with greater population density have greater rates of transmission of SARS-CoV-2, likely due to increased contact rates in areas with greater density. An increase in one unit of log population density increased R0 by 0.16 (95% CI: 0.13 to 0.19). This association remained when adjusted for main mode of transportation and household income. The effect of population density on R0 was not modified by transportation mode. Our findings suggest that dense areas increase contact rates necessary for disease transmission. SARS-CoV-2 R0 estimates need to consider this geographic variability for proper planning and resource allocation, particularly as epidemics newly emerge and old outbreaks resurge.

show abstract

Section: Discussionsupporting

confidence: 91%

Population density and basic reproductive number of COVID-19 across United States counties

2021

View full text Add to dashboard Cite

show abstract

“…However, a higher population density in the province was an independent predictor of SARS-CoV-2 seroprevalence when altitude was an adjusted factor. Although population density was not an important factor in COVID-19 spreading under strict lockdown policies [23], it has been also described as a relevant factor for SARS-CoV-2 transmission in less strict conditions [24][25][26][27]; therefore, some effect of population density on transmission in the period before the lockdown in Spain seems plausible.…”

Section: Discussionmentioning

confidence: 99%

Altitude and SARS-CoV-2 Infection in the First Pandemic Wave in Spain

Castilla

Fresán

Trobajo-Sanmartín

et al. 2021

IJERPH

View full text Add to dashboard Cite

After the first pandemic wave, a nationwide survey assessed the seroprevalence of SARS-CoV-2 antibodies in Spain and found notable differences among provinces whose causes remained unclear. This ecological study aimed to analyze the association between environmental and demographic factors and SARS-CoV-2 infection by province. The seroprevalence of SARS-CoV-2 antibodies by province was obtained from a nationwide representative survey performed in June 2020, after the first pandemic wave in Spain. Linear regression was used in the analysis. The seroprevalence of SARS-CoV-2 antibodies of the 50 provinces ranged from 0.2% to 13.6%. The altitude, which ranged from 5 to 1131 m, explained nearly half of differences in seroprevalence (R2 = 0.47, p < 0.001). The seroprevalence in people residing in provinces above the median altitude (215 m) was three-fold higher (6.5% vs. 2.1%, p < 0.001). In the multivariate linear regression, the addition of population density significantly improved the predictive value of the altitude (R2 = 0.55, p < 0.001). Every 100 m of altitude increase and 100 inhabitants/km2 of increase in population density, the seroprevalence rose 0.84 and 0.63 percentage points, respectively. Environmental conditions related to higher altitude in winter–spring, such as lower temperatures and absolute humidity, may be relevant to SARS-CoV-2 transmission. Places with such adverse conditions may require additional efforts for pandemic control.

show abstract

“…He reported that population density and employment density were positively correlated with COVID-19 mortality rates. Wand and Li [ 29 ] found that population density mattered in the spreading of COVID-19 on the U.S. county level. They demonstrated that population density alone accounted for up to 76 percent of cumulative infection cases in the U.S. from early March to late May 2020.…”

Section: Literature Reviewmentioning

confidence: 99%

Density or Connectivity: What Are the Main Causes of the Spatial Proliferation of COVID-19 in Korea?

Hong

Sung

2021

IJERPH

View full text Add to dashboard Cite

COVID-19 has sparked a debate on the vulnerability of densely populated cities. Some studies argue that high-density urban centers are more vulnerable to infectious diseases due to a higher chance of infection in crowded urban environments. Other studies, however, argue that connectivity rather than population density plays a more significant role in the spread of COVID-19. While several studies have examined the role of urban density and connectivity in Europe and the U.S., few studies have been conducted in Asian countries. This study aims to investigate the role of urban spatial structure on COVID-19 by comparing different measures of urban density and connectivity during the first eight months of the outbreak in Korea. Two measures of density were derived from the Korean census, and four measures of connectivity were computed using social network analysis of the Origin-Destination data from the 2020 Korea Transport Database. We fitted both OLS and negative binomial models to the number of confirmed COVID-19 patients and its infection rates at the county level, collected individually from regional government websites in Korea. Results show that both density and connectivity play an important role in the proliferation of the COVID-19 outbreak in Korea. However, we found that the connectivity measure, particularly a measure of network centrality, was a better indicator of COVID-19 proliferation than the density measures. Our findings imply that policies that take into account different types of connectivity between cities might be necessary to contain the outbreak in the early phase.

show abstract

Spreading of COVID-19: Density matters

Cited by 243 publications

References 20 publications

Population density and basic reproductive number of COVID-19 across United States counties

Population density and basic reproductive number of COVID-19 across United States counties

Altitude and SARS-CoV-2 Infection in the First Pandemic Wave in Spain

Density or Connectivity: What Are the Main Causes of the Spatial Proliferation of COVID-19 in Korea?

Contact Info

Product

Resources

About