Spread of Covid-19 in urban neighbourhoods and slums of the developing world

TL;DR

This study analyzes Covid-19 spread in developing world urban neighborhoods, revealing high concentration in slums, and introduces a stochastic network model that reproduces empirical patterns, highlighting slums as critical hotspots for outbreaks.

Contribution

The paper provides empirical evidence of inequality in Covid-19 distribution across neighborhoods and develops a stochastic model to simulate epidemic spread in slum and non-slum areas.

Findings

Slums contain the highest density of Covid-19 cases.

A small number of neighborhoods account for most cases (~70%).

Epidemic severity is greater in slums, with worse peak and total cases.

Abstract

We study the spread of Covid-19 across neighbourhoods of cities in the developing world and find that small numbers of neighbourhoods account for a majority of cases (k-index~0.7). We also find that the countrywide distribution of cases across states/provinces in these nations also displays similar inequality, indicating self-similarity across scales. Neighbourhoods with slums are found to contain the highest density of cases across all cities under consideration, revealing that slums constitute the most at-risk urban locations in this epidemic. We present a stochastic network model to study the spread of a respiratory epidemic through physically proximate and accidental daily human contacts in a city, and simulate outcomes for a city with two kinds of neighbourhoods - slum and non-slum. The model reproduces observed empirical outcomes for a broad set of parameter values - reflecting the potential validity of these findings for epidemic spread in general, especially across cities of the developing world. We also find that distribution of cases becomes less unequal as the epidemic runs its course, and that both peak and cumulative caseloads are worse for slum neighbourhoods than non-slums at the end of an epidemic. Large slums in the developing world therefore contain the most vulnerable populations in an outbreak, and the continuing growth of metropolises in Asia and Africa presents significant challenges for future respiratory outbreaks from perspectives of public health and socioeconomic equity.