Assessing the Impact of Animal Husbandry and Capture on Anemia among Women and Children in Low- and Middle-Income Countries: A Systematic Review.

Animal husbandry and capture (AHC) may mitigate anemia among women and children by supplying a source of micronutrient-rich animal source foods (ASF), yet may concurrently increase exposure to anemia-inducing pathogens such as Plasmodium spp., helminths, and enteropathogens. We conducted a systematic literature review to assess the relation between AHC and anemia among women of reproductive age, school-aged children, and children aged <5 y in low- and middle-income countries (LMICs). We used a 2-stage screening process, in which 1 reviewer searched 4 databases (PubMed, Web of Science, EMBASE, and Global Health) with predetermined search terms for relevant articles. Two reviewers then independently screened studies using a priori exclusion criteria, yielding a total of 23 articles included in the final review. We evaluated evidence from observational studies assessing animal-dependent livelihoods and livestock ownership, and interventions that promoted livestock and fish production. We found little consistency in anemia outcomes across the several AHC exposures and population groups. Poultry production interventions had modest benefits on anemia among women and children, although whether these improvements were a result of increased ASF consumption, or a result of the combined treatment study design could not be determined. Observational studies identified chicken ownership, and no other livestock species, as a risk factor for anemia among young children. However, there was limited evidence to evaluate pathways underlying these associations. Studies tended to rely on self-reported fever and diarrhea to assess illness, and no study directly assessed linkages between AHC, pathogen burden, and anemia. Thus, there is insufficient evidence to conclude whether AHC improves or worsens anemia among women and children in LMICs. Given the current interest in promoting animal production among low-income households, future studies with robust measures of livestock ownership, ASF consumption, pathogen burden, and anemia status are needed to understand the nuances of this complex and potentially contradictory relation.