Sparganum proliferum, a Sparganum Infected with a Virus?

Electron micrographs of material from the case of proliferating sparganosis reported by Stiles, 1908, from Manatee County, Florida, show what appear to be type-c virus particles abundantly budding from the walls of internal cavities, presumably excretory ducts. The particles are spherical, approximately 85 mu in diameter. No similar structures were seen in corresponding thin sections of normal spargana. It is suggested that Sparganum proliferum is a worm whose genetic blueprint and organization have been profoundly altered by infection with a virus which simultaneously stimulates exaggerated growth and loss of morphogenetic control, as well as endowing the worm with a greatly extended life span. Sparganum proliferum is a rare aberrant tapeworm larva known only from man. It is characterized by continuous branching and budding, the resulting progeny invading the entire limb or region involved, and appearing under the skin as acneform pustular nodules from which living worms may be expressed. All tissues are invaded except bone. The buds have the histological components of ordinary spargana, but their organization and symmetry are profoundly disturbed, and for want of a scolex they do not mature when fed to presumptive definitive hosts such as the dog and cat (Mueller, 1938). In 1966 the senior author suggested that this peculiar form might be explained on the basis of hyperparasitism of a sparganum by an agent which simultaneously causes exaggerated growth stimulation and breakdown of morphogenetic control, as in the case of certain tumor-producing viruses. The present paper tends to validate this conjecture. MATERIALS AND METHODS When the senior author first began work on sparganosis in the 1930's, the late Maurice C. Hall, of the NIH, presented him with a vial of material from Gates' case, in Manatee County, Florida, reported by Stiles (1908). Recently the Armed Forces Institute of Pathology (AFIP) requested confirmation of a suspected case of sparganosis in a man who had died of Hodgkins' disease. Since only tissue sections were available a specific diagnosis could not be made, although the organism appeared to be a sparganum. In the course of a telephone conversation the above-mentioned viral Received for publication 10 November 1973. * This research has been supported by a continuing Grant AI-01876 from the NIH. t State University of New York. Upstate Medical Center, Syracuse, New York 13210. t Armed Forces Institute of Pathology, Washington, D. C. 20305. hypothesis was alluded to, along with the fact that material of Sparganum proliferum from the Florida case was available, although probably useless because it had been fixed and preserved since 1907 (Fig. 1). At this point the junior author stated that virus particles, if present, could be detected in fixed material even after a lapse of many years. Thus the present collaboration was born. Several pieces of Stiles' material were sent to the AFIP, and thin sections were examined by electron microscopy. Typical specimens of Spirometra mansonoides spargana were processed at the same time and served as controls for compari-