By now the virus has reached every continent, with Antarctica being the latest casualty as of December 2020. The pandemic has spread to virtually every single country and territory around the world.
That was (naturally) not the case in the beginning. While there is continued discussion about whether indeed the virus originated in China, Wuhan was indeed the locus of the first major outbreak that caught the international spotlight.
Soon after this initial outbreak, neighboring countries, a few cruise ships and increasingly a broader group of countries around the world spotted coronavirus infections as they ramped up testing.
But it were the well-connected global centers of commerce and trade that visibly suffered the biggest outbreaks. It comes as no surprise that a place like New York City, which is so extensively externally connected, became the epicenter of a major outbreak. But before the US, it were the countries in Europe which were particularly badly hit, including the industrious industrial north of Italy.
Enters globalization. Globalization has fueled an intensification of all sorts of linkages across borders but its extent has varied drastically across types of markets. Information markets as well as financial markets are the most integrated internationally. Goods and especially services markets remain less integrated as do labor markets. The latter which is connected to the cross-border mobility of people matters most in this context.
The point is that virtually all countries have participated over the past four and especially last two decades in the process of globalization. But some have remained much less externally connected than others, such as parts of Latin America and Africa. This more limited external connectivity has likely slowed the initial phase of the spread.
The customary port of entry into a country is for most travelers a city. That’s the case too for viruses. So when the coronavirus travelled across borders, it will have likely found its way into urban settings first.
Cities in many developing countries exhibit environmental characteristics that are conducive to transmission. Think of high urban density, coupled with poverty and informality. People live, work and play in settings where physical distancing is more difficult. The latest estimates suggest that respectively 65 and 27 percent of urban populations in LICs and MICs live in slums. The lack of sanitary conditions is likely to amplify the spread of the virus further.
The multigenerational structure and large size of households in lower-income countries adds another layer of complexity, particularly given that a large share of the transmission happens in the pre-symptomatic stage.