Mapping changes in housing in sub-Saharan Africa from 2000 to 2015.

Access to adequate housing is a fundamental human right, essential to human security, nutrition and health, and a core objective of the United Nations Sustainable Development Goals1,2. Globally, the housing need is most acute in Africa, where the population will more than double by 2050. However, existing data on housing quality across Africa are limited primarily to urban areas and are mostly recorded at the national level. Here we quantify changes in housing in sub-Saharan Africa from 2000 to 2015 by combining national survey data within a geostatistical framework. We show a marked transformation of housing in urban and rural sub-Saharan Africa between 2000 and 2015, with the prevalence of improved housing (with improved water and sanitation, sufficient living area and durable construction) doubling from 11% (95% confidence interval, 10-12%) to 23% (21-25%). However, 53 (50-57) million urban Africans (47% (44-50%) of the urban population analysed) were living in unimproved housing in 2015. We provide high-resolution, standardized estimates of housing conditions across sub-Saharan Africa. Our maps provide a baseline for measuring change and a mechanism to guide interventions during the era of the Sustainable Development Goals.

Crowding has consequences: Prevention and management of COVID-19 in informal urban settlements.

COVID-19 spreads via aerosols, droplets, fomites and faeces. The built environment that facilitates crowding increases exposure and hence transmission of COVID-19 as evidenced by outbreaks in both cool-dry and hot-humid climates, such as in the US prison system and dormitories in Singapore, respectively. This paper explores how the built environment influences crowding and COVID-19 transmission, focusing on informal urban settlements (slums). We propose policy and practice changes that could reduce COVID-19 transmission. There are several issues on how COVID-19 affects informal urban settlements. Slum populations tend to be younger than the overall population. Lower numbers of older people lessen the morbidity and mortality of the pandemic in slum areas. Second, many slum populations are highly mobile. By returning to their ancestral villages residents can avoid the risks of overcrowding and reduce the population density in a given area but may spread COVID-19 to other areas. Third, detection and registration of COVID-19 cases depends on patients presenting to health care providers. If the risk of visiting a health care centre outweighs the potential benefits patients may prefer not to seek treatment. The control and prevention of COVID-19 in informal urban settlements starts with organizing community infrastructure for diagnosis and treatment and assuring that basic needs (food, water, sanitation, health care and public transport) are met during quarantine. Next, community members at highest risk need to be identified and protected. Low-income, informal settlements need to be recognized as a reservoir and source for persistent transmission. Solutions to overcrowding must be developed for this and future pandemics. In view of the constant risk that slums present to the entire population decisive steps need to be taken to rehabilitate and improve informal settlements, while avoiding stigmatization.

Indicators linking health and sustainability in the post-2015 development agenda.

The UN-led discussion about the post-2015 sustainable development agenda provides an opportunity to develop indicators and targets that show the importance of health as a precondition for and an outcome of policies to promote sustainable development. Health as a precondition for development has received considerable attention in terms of achievement of health-related Millennium Development Goals (MDGs), addressing growing challenges of non-communicable diseases, and ensuring universal health coverage. Much less attention has been devoted to health as an outcome of sustainable development and to indicators that show both changes in exposure to health-related risks and progress towards environmental sustainability. We present a rationale and methods for the selection of health-related indicators to measure progress of post-2015 development goals in non-health sectors. The proposed indicators show the ancillary benefits to health and health equity (co-benefits) of sustainable development policies, particularly those to reduce greenhouse gas emissions and increase resilience to environmental change. We use illustrative examples from four thematic areas: cities, food and agriculture, energy, and water and sanitation. Embedding of a range of health-related indicators in the post-2015 goals can help to raise awareness of the probable health gains from sustainable development policies, thus making them more attractive to decision makers and more likely to be implemented than before.

Developing a common framework for integrated solid waste management advances in Managua, Nicaragua.

This article describes the municipal solid waste management system in Managua, Nicaragua. It updates an initial profile developed by the authors for the 2010 UN-HABITAT publication Solid Waste Management in the World's Cities and applies the methodology developed in that publication. In recent years, the municipality of Managua has been the beneficiary of a range of international cooperation projects aimed at improving municipal solid waste management in the city. The article describes how these technical assistance and infrastructure investments have changed the municipal solid waste management panorama in the city and analyses the sustainability of these changes. The article concludes that by working closely with the municipal government, the UN-HABITAT project Strengthening Capacities for Solid Waste Management in Managua was able to unite these separate efforts and situate them within a strategic framework to guide the evolution of the municipal solid waste management system in the forthcoming years. The creation of this multi-stakeholder platform allowed for the implementation of joint activities and ensured coherence in the products generated by the different projects. This approach could be replicated in other cities and in other sectors with similar effect. Developing a long term vision was essential for the advancement of municipal solid waste management in the city. Nevertheless, plan implementation may still be undermined by the pressures of the short term municipal administrative government, which emphasize operational over strategic investment.

Comparative analysis of solid waste management in 20 cities.

This paper uses the 'lens' of integrated and sustainable waste management (ISWM) to analyse the new data set compiled on 20 cities in six continents for the UN-Habitat flagship publication Solid Waste Management in the World's Cities. The comparative analysis looks first at waste generation rates and waste composition data. A process flow diagram is prepared for each city, as a powerful tool for representing the solid waste system as a whole in a comprehensive but concise way. Benchmark indicators are presented and compared for the three key physical components/drivers: public health and collection; environment and disposal; and resource recovery--and for three governance strategies required to deliver a well-functioning ISWM system: inclusivity; financial sustainability; and sound institutions and pro-active policies. Key insights include the variety and diversity of successful models - there is no 'one size fits all'; the necessity of good, reliable data; the importance of focusing on governance as well as technology; and the need to build on the existing strengths of the city. An example of the latter is the critical role of the informal sector in the cities in many developing countries: it not only delivers recycling rates that are comparable with modern Western systems, but also saves the city authorities millions of dollars in avoided waste collection and disposal costs. This provides the opportunity for win-win solutions, so long as the related wider challenges can be addressed.

Recommendations for building out mosquito-transmitted diseases in sub-Saharan Africa: the DELIVER mnemonic.

In sub-Saharan Africa, most transmission of mosquito-transmitted diseases, such as malaria or dengue, occurs within or around houses. Preventing mosquito house entry and reducing mosquito production around the home would help reduce the transmission of these diseases. Based on recent research, we make key recommendations for reducing the threat of mosquito-transmitted diseases through changes to the built environment. The mnemonic, DELIVER, recommends the following best practices: (i) Doors should be screened, self-closing and without surrounding gaps; (ii) Eaves, the space between the wall and roof, should be closed or screened; (iii) houses should be Lifted above the ground; (iv) Insecticide-treated nets should be used when sleeping in houses at night; (v) houses should be Ventilated, with at least two large-screened windows to facilitate airflow; (vi) Environmental management should be conducted regularly inside and around the home; and (vii) Roofs should be solid, rather than thatch. DELIVER is a package of interventions to be used in combination for maximum impact. Simple changes to the built environment will reduce exposure to mosquito-transmitted diseases and help keep regions free from these diseases after elimination. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.