“…Frequently observed in the tropics or the subtropics, it has been variously described as Loeffler's syndrome, tropical eosinophilia, familial eosinophilia, or benign eosinophilic leukaemia. In 1940 this syndrome was shown to be associated with multiple eosinophilic granulomata in the liver, and in 1950, Mercer and his colleagues (Mercer, Lund, Bloomfield, and Caldwell, 1950) found that with this eosinophilia, Nematode larvae were sometimes to be seen in the tissues. In 1952, Beaver, Snyder, Carrera, Dent, and Lafferty suggested that the syndrome resulted from infection in man by a Nematode normally parasitic upon a lower animal; under these conditions the normal Nematode life cycle does not take place but is blocked by an eosinophilic granulomatous reaction at the stage where the larvae are in the tissues.…”