Figure 3. Eosinopbilic abscess (MKbody) in

the liver of a ferret. The Splendore-Hoeppli reaction at the center of the lesion surrounds a degenerating microfilaria x2O0).

philic abscesses and granulomas, as observed in the ferret.10 The prominence of lesions in the liver rather than lung in the ferret may reflect a difference in the primary site of microfilarial clearance, although pulmonary histopathology in the ferret can be initially similar to that of TE in humans. As in the TE syndrome, ferrets develop prominent immune responses to filarial antigens, including immediate hypersensitivity to microfilarial antigens)11,12

Usefulness of Model

The ferret infected with B. malayi mimics several manifestations of lymphatic filariasis in which knowledge of the pathogenesis is incomplete. Persistent, severe filarial

Figure 4. Interstitialpneumonia in aferret immediately after clearance of microfilariae from the peripheral blood x 100).

lymphedema and the hyperresponsive syndrome of occult filariasis (TE) are not commonly reported in other experimental hosts, and the ferret will be of particular value in study of these manifestations. As an experimental model, the inflammatory reactivity and rapid development of chronic lymphostatic disease parallels that of individuals migrating to endemic areas rather than natives to these areas13; thus, the ferret model should have application in examining the immunopathology of the acute syndromes associated with infections in populations alien to endemic areas. In addition, the high immune responsiveness to infection could be useful for evaluating hypersensitivity reactions in treatment of lymphatic filariasis. The ferret is increasingly used as an experimental animal in