Perspectives Posted on 2021-08-16 11:11:50
Opinions and strategies
Balancing the nutritional benefits and infection risks of livestock in low- and middle-income countries
A.H. Havelaar(1)* & S.L. McKune(2)
(1) Professor, Emerging Pathogens Institute, Food Systems Institute and Department of Animal Sciences, University of Florida, Gainesville, FL, United States of America.
(2) Research Assistant Professor, Department of Environmental and Global Health, Center for African Studies and Food Systems Institute, University of Florida, Gainesville, FL, United States of America.
* Corresponding author: [email protected]
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Normal child growth and development require an adequate diet, protection from major diseases, and sufficient gut health. Animal-sourced foods are the best available sources of high-quality, nutrient-rich food for young children . The sustainable intensification of livestock production in low- and middle-income countries (LMICs) helps to improve the livelihoods of the poor and can contribute to increased availability and consumption of animal-sourced foods . However, relationships between animal ownership and child growth are complex. Several studies report net beneficial effects, but other studies suggest that these beneficial effects can be reduced or even negated by the exposure of children to animal faeces .
Child gut health
Environmental enteric dysfunction (EED) is a chronic subclinical disorder of the intestines associated with settings of poverty and unsanitary living conditions. Colonisation by intestinal pathogens and malnutrition are important triggers for EED .
The MAL-ED study(1), a birth cohort study in eight LMICs, found that 24-month, length-for-age Z scores were positively associated with complementary food and negatively associated with diarrhoea and (asymptomatic) colonisation by specific enteropathogens. Among these, Campylobacter bacteria were the frequently found genus in the stools of children, most commonly without any clinical symptoms. There was a significant negative association between the Campylobacter burden in children and faltering linear growth .
Transmission of Campylobacter from livestock reservoirs occurs through food, direct animal contact, or environmental contamination. In industrialised countries, foodborne transmission from chicken reservoirs is the main pathway. Very few data are available describing Campylobacter reservoirs or transmission pathways for infection in children in LMICs. Formative research in Ethiopia has shown that children are typically colonised by multiple Campylobacter species and suggests that chickens and ruminants may be important reservoirs .
Animal-sourced foods are essential components of a healthy diet for children in LMICs. Understanding reservoirs and pathways of zoonotic pathogens is essential for safely managing livestock production and animal-sourced food consumption to protect child health. The Global Burden of Animal Diseases (GBADs) Human Health theme works at the interface of human and animal health and is well positioned to contribute to tackle this challenge.
(1) MAL-ED: Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development study .
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