Nutrition and Communicable Disease
Nutrition and communicable disease is the area of public health nutrition concerned with the two-way relationship between nutritional status and infection: poor nutrition weakens host defences and raises susceptibility to and severity of infectious disease, while infection in turn worsens nutritional status through reduced intake, malabsorption, and increased metabolic demand. This mutually reinforcing relationship is classically described as a synergism between nutrition and infection.
Definition
Nutrition and communicable disease denotes the study of the bidirectional interaction between nutritional status and infectious disease, encompassing how undernutrition and specific nutrient deficiencies impair host defence and how infection degrades nutritional status.
Scope
The area orients the reader to how nutritional status interacts with communicable diseases across the lifecourse and at the population level. It frames the underlying nutrition-infection cycle and then points to detailed topics on immune function in malnutrition and on specific infections in which nutrition is a recognised co-determinant, notably HIV and tuberculosis. It is a reference overview of mechanisms and epidemiology, not clinical guidance.
Sub-topics
Key concepts
- Nutrition-infection synergism
- Host defence and immunocompetence
- Undernutrition as a risk factor for infection
- Infection-driven nutritional decline
- Micronutrient deficiency and immunity
- Population-level disease burden
Mechanisms
The nutrition-infection relationship runs in both directions. Undernutrition and specific micronutrient deficiencies impair barrier integrity and both innate and adaptive immune responses, increasing the frequency, severity, and case fatality of infections. Infection, conversely, suppresses appetite, impairs nutrient absorption, and raises catabolic demand, so that repeated or chronic infection drives nutritional decline. Scrimshaw and colleagues framed this as a synergism in which each condition aggravates the other, and Katona and Katona-Apte summarise the pathways by which the cycle is sustained.
Clinical relevance
Understanding the nutrition-infection interaction underpins how public health programmes interpret the coexistence of undernutrition and infectious disease in populations. The material describes how nutritional status and infection influence one another at the level of mechanism and population burden; it is reference-educational and is not a basis for individual diagnosis or treatment.
Epidemiology
Undernutrition is a major underlying contributor to the global burden of communicable disease, particularly among children in low- and middle-income settings, where it is implicated in a substantial share of infection-related deaths. The Lancet maternal and child undernutrition series quantified these exposures and consequences and helped place the nutrition-infection interaction at the centre of global child-survival agendas.
History
The modern framing of nutrition and infection as a synergistic interaction was consolidated in mid-twentieth-century work by Scrimshaw and colleagues, who drew together clinical and field observations into a unifying model. Subsequent decades extended the framework to micronutrient-specific immunity and to chronic infections such as HIV and tuberculosis, and large global syntheses in the 2000s re-established undernutrition as a leading underlying cause of communicable-disease mortality.
Key figures
- Nevin Scrimshaw
- Peter Katona
- Robert E. Black
Related topics
Seminal works
- scrimshaw-1997
- katona-2008
- black-2008
Frequently asked questions
- Why are nutrition and infection said to be synergistic?
- Because each worsens the other: undernutrition weakens immune defences and raises susceptibility to infection, while infection reduces intake and increases nutrient demands, degrading nutritional status. The two conditions therefore tend to reinforce one another.
- Which infections does this area focus on?
- Beyond the general nutrition-infection cycle and its effect on immune function, the detailed topics address HIV and tuberculosis, two communicable diseases in which nutritional status is a well-recognised co-determinant of risk and outcome.