Interactions involving intestinal nematodes of rodents experimental and field studies

Multiple species infections with parasitic helminths, including nematodes, are common in wild rodent populations. In this paper we first define differ ent types of associations and review experimental evidence for different ca tegories of interactions. We conclude that whilst laboratory experiments ha ve demonstrated unequivocally that both synergistic and antagonistic intera ctions involving nematodes exist, field work utilizing wild rodents has gen erally led to the conclusion that interactions between nematode species pla y no, or at most a minor, role in shaping helminth component communities. N evertheless, ne emphasize that analysis of interactions between parasites i n laboratory systems has been fruitful, has made a fundamental contribution to our understanding of the mechanisms underlying host-protective intestin al immune responses, and has provided a rationale for studies on pol)parasi tism in human beings and domestic animals. Finally, we consider the practic al implications for transmission of zoonotic diseases to human communities and to their domestic animals, and we identify the questions that merit res earch priority.