The causes of under-five death shift as overall mortality rates decline. In low-income countries, infectious diseases cause a majority of the burden, often due to weakened nutrition and sanitation systems and lack of access to basic prevention and treatment interventions. In higher-income nations, deaths are increasingly due to causes that require more complex interventions to address, especially neonatal disorders (including preterm births).

Percentage of under-5 deaths by cause, 2017

Percentage of under-five deaths by cause, 2017. Total values: Low income 1,709,600; Lower Middle income: 3,139,975; upper middle income 472,291; high income 63,682; Global 5,391,562. The highest category for all categories is neonatal disorders: Low income 26%; Lower Middle income: 36%; upper middle income 37%; high income 43%; Global 33%. Other categories include: lower respiratory infections, non-communicable diseases, diarrheal diseases, malaria, meningitis, nutritional deficiencies, DPT, measles, HIV/AIDS, Tuberculosis, and other.
Source: IHME GBD 2017, World Bank

Many of the causes of under-five mortality interact with and compound each other. In addition, there are a number of underlying drivers that can weaken children and increase the likelihood that a child will die from what otherwise would be a serious but not life-threatening condition. For example, children who are malnourished are more likely to die of diarrhea and acute respiratory infections.

Some of these exacerbating underlying factors include:1

  • Poorly resourced, poor quality, inaccessible or culturally inappropriate health and nutrition services
  • Food insecurity
  • Inadequate feeding practices
  • Lack of hygiene and access to safe water or adequate sanitation
  • Female illiteracy
  • Early pregnancy and lack of birth spacing
  • Geographic, political, or financial barriers to accessing health care
Many of the solutions to under-five mortality are well-known. The key lever for reducing under-five mortality is an accessible, quality primary health care system that provides a continuum of care to women before they are pregnant, throughout their pregnancy, while giving birth, and post-partum, as well as to children through the critical first five years of life. For this reason, many efforts to reduce maternal mortality and neonatal mortality will also serve to reduce overall under-five mortality.2
  1. 1
    The State of the World’s Children 2008 Panels. UNICEF website. Accessed May 17, 2019.
  2. 2
    Kruk ME, et al. High-quality health systems in the Sustainable Development Goals era: time for a revolution. Lancet Glob Health. 2018; 6: e1196–252. Accessed January 7, 2020.

Why is it difficult to solve?