Although N. brasiliensis L3s are trapped in the skin of IL-5 transgenic mice for extended periods, indicative of susceptibility to eosinophil-mediated attack (Daly et al., 1999), other nematodes such as T. spiralis and Toxocara canis appear unaffected (Sugane et al., 1996; Hokibara et al., 1997; Dent et al., 1999), and eosinophilia may actually impair host resistance to T. spiralis (Dent et al., 1997). Here, IL5 is linked to Increased total eosinophil count.