From the 2017 plague in Madagascar to cholera in Haiti, recent infectious disease outbreaks have been centered in cities. The SARS virus was especially virulent in urban centers, including Hong Kong, Singapore, and Toronto. Ebola first appeared in rural areas in 2013, but it spiked after reaching urban centers in West Africa.

Cities of the global south have been growing faster than they’ve built infrastructure to prevent disease, says Thomas Bollyky, who heads the global health program at the Council on Foreign Relations and is the author of Plagues and the Paradox of Progress: Why the World is Getting Healthier in Worrisome Ways.

Health in high-income countries improved in the first half of the 20th century as a result of infrastructure and public works like sewers, piped water, and waste management. But low- and middle-income countries have mostly reduced mortality rates through modern treatments like drugs and vaccines, without always building strong health systems to prevent the emergence of diseases.

“Many of the gains we’ve seen over the last half-century have been against infectious diseases and children dying unnecessarily,” Bollyky says. “They may have masked the lack of progress in the broader well-being of societies and the capability of health systems to address health threats.”

Fiscal regimes mandated by the International Monetary Fund and the World Bank in the 1980s and 1990s didn’t help. They gutted budgets for public health and public infrastructure. International aid targeted initiatives like mass vaccination campaigns and disease-specific programs, which reduced deaths without necessarily improving overall health systems.

Many of those campaigns have been halted due to physical distancing measures as part of the response to Covid-19, which could lead to other problems. Millions of people deprived of vaccination and treatment could develop tuberculosis, measles, or polio over the next few months.

The global health community responded to past epidemics such as Ebola but has struggled to make sense of the social and economic dynamics of cities. There is little data in the scientific literature about the health needs of the billion people living in informal slums.

“Responses to epidemics often tend to be quite short term; they’re about controlling the epidemic,” says Annie Wilkinson, an anthropologist and health systems researcher at the Institute of Development Studies. “The big kind of emergency infrastructure rolls into town, and then it leaves. They’re just getting to grips with this urban dimension.”

That can lead to ill-suited policies. The World Health Organization’s advice on Covid-19, for instance, is largely inapplicable in slums, where maintaining social distance is impossible in overcrowded housing. So is washing your hands regularly when there is no running water at home. In the slum of Mukuru, in Nairobi, private water vendors hiked the price of water jerricans amid increased demand in response to sanitation guidelines. Stay-at-home orders are impractical when a day off work means there won’t be food on the table at the end of the day.

“There are big questions about how appropriate lockdowns are for low-income settings,” Wilkinson says. But she says there’s been little discussion of potential alternatives.

In some places, community groups are stepping in where health systems are lacking. Grassroots NGOs are coordinating food and mask donations in low-income neighborhoods in Mumbai through WhatsApp groups. In the Mfuleni township near Cape Town, South Africa, residents have planted urban gardens to grow and sell food locally. Muungano wa Wanavijiji, the Kenyan federation of slum dwellers, is tracking data on Covid-19 cases, as well as prevention and treatment activities, in the country’s informal settlements. Researchers are using the data to monitor the impact of localized initiatives by community workers, such as handwashing stations.

Support can come from unusual places. In Rio de Janeiro, drug gangs made headlines when they moved to enforce a curfew in some favelas, after Brazilian president Jair Bolsonaro questioned the seriousness of the pandemic.

“One of the really unique realities of cities is that they tend to be more nimble than a lot of other forms of government,” says Boyce, the Georgetown researcher. “They’ve enabled this form of creativity to do what they want and operationalize their guidance.”

Advantages of local domestic helper.