Of the 3 species of Echinococcus that cause hydatid disease in man, E. granulosus has two distinct biological forms. The more pathogenic, maintained by synanthropic hosts, forms local variants or """"""""strains,"""""""" attributed by some to clone-formation and other reproductive peculiarities. The neotropical E. vogeli is highly pathogenic, but its public health significance is undefined. E. multilocularis is the cause of alveolar hydatid disease (AHD), a severe and often lethal infection important in much of the northern hemisphere. Regarded as an emerging zoonosis in various regions, AHD in the United States mainly affects Eskimos in western Alaska, where the mortality is about 70% of cases. Chemotherapy with drugs of the benzimidazole group is beneficial, based on a 10-year clinical trial in Eskimo patients. Albendazole has been substituted for mebendazole because of greater therapeutic promise. Prevention of AHD depends on adequate epidemiological data, not now available. The proposed work would continue investigations in progress by the P.I. since 1949, and would emphasize: 1) Summary and computer-analysis of information derived from a long-term, intensive study (1956-1974) of the epidemiology of E. multilocularis on St. Lawrence Island (Alaska), under natural and hyperendemic conditions. At least 6 papers planned during the grant-period would provide information useful in devising methods of prevention and control. The study is unique, and would also provide information of basic scientific value. 2) Evaluation of lesions from patients, with or without therapy, would continue, using histological, immunohistochemical, and other methods, to contribute to better diagnosis, to evaluate chemotherapy, and to contribute to management of patients. 3) Cytogenetic studies of Echinococcus spp. would continue, using Giemsa-banding and other methods to define affinities and to elucidate reproductive processes in cestodes. 4) The description of post-larval development of E. vogeli would contribute to basic knowledge of a pathogen. 5) Effects of long-term passage of E. multilocularis in respective species of rodents would define rate and extent of strain-formation. These investigations are interrelated, and can be efficiently conducted concurrently.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI015172-08
Application #
3126051
Study Section
Tropical Medicine and Parasitology Study Section (TMP)
Project Start
1978-08-01
Project End
1989-11-30
Budget Start
1987-12-01
Budget End
1988-11-30
Support Year
8
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Washington
Department
Type
Schools of Public Health
DUNS #
135646524
City
Seattle
State
WA
Country
United States
Zip Code
98195
Rausch, R L; D'Alessandro, A (1999) Histogenesis in the metacestode of Echinococcus vogeli and mechanism of pathogenesis in polycystic hydatid disease. J Parasitol 85:410-8
Wilson, J F; Rausch, R L; McMahon, B J et al. (1992) Parasiticidal effect of chemotherapy in alveolar hydatid disease: review of experience with mebendazole and albendazole in Alaskan Eskimos. Clin Infect Dis 15:234-49
Rausch, R L; Wilson, J F; Schantz, P M (1990) A programme to reduce the risk of infection by Echinococcus multilocularis: the use of praziquantel to control the cestode in a village in the hyperendemic region of Alaska. Ann Trop Med Parasitol 84:239-50
Rausch, R L; Fay, F H; Williamson, F S (1990) The ecology of Echinococcus multilocularis (Cestoda: Taeniidae) on St. Lawrence Island, Alaska. II. Helminth populations in the definitive host. Ann Parasitol Hum Comp 65:131-40
Rausch, R L; Rausch, V R (1990) Reproductive anatomy and gametogenesis in Shipleya inermis (Cestoda: Dioecocestidae). Ann Parasitol Hum Comp 65:229-37
Condon, J; Rausch, R L; Wilson, J F (1988) Application of the avidin-biotin immunohistochemical method for the diagnosis of alveolar hydatid disease from tissue sections. Trans R Soc Trop Med Hyg 82:731-5
Rausch, R L; Fay, F H (1988) Postoncospheral development and cycle of Taenia polyacantha Leuckart, 1856 (Cestoda: Taeniidae). Second part. Ann Parasitol Hum Comp 63:334-48
Ali-Khan, Z; Rausch, R L (1987) Demonstration of amyloid and immune complex deposits in renal and hepatic parenchyma of Alaskan alveolar hydatid disease patients. Ann Trop Med Parasitol 81:381-92
Rausch, R L; Wilson, J F; Schantz, P M et al. (1987) Spontaneous death of Echinococcus multilocularis: cases diagnosed serologically (by Em2 ELISA) and clinical significance. Am J Trop Med Hyg 36:576-85
Rausch, R L; Wilson, J F; McMahon, B J et al. (1986) Consequences of continuous mebendazole therapy in alveolar hydatid disease--with a summary of a ten-year clinical trial. Ann Trop Med Parasitol 80:403-19