Parasitology

Original Articles

The distribution of Fasciola hepatica and Fasciola gigantica within southern Tanzania – constraints associated with the intermediate host

S. M. WALKERa1 c1, A. E. MAKUNDIa2, F. V. NAMUBAa2, A. A. KASSUKUa3, J. KEYYUa4, E. M. HOEYa1, P. PRÖDOHLa1, J. R. STOTHARDa5 and A. TRUDGETTa1

a1 School of Biological Sciences, The Queen's University of Belfast, 97 Lisburn Road, Belfast BT9 7BL

a2 Open University of Tanzania, Manyara Regional Centre, P.O. Box 271, Babati, Tanzania

a3 Department of Microbiology and Parasitology, Sokoine University of Agriculture, P.O. Box 3019, Morogoro, Tanzania

a4 Tanzania Wildlife Research Institute, P.O. Box 661, Arusha, Tanzania

a5 The Natural History Museum, Cromwell Road, London SW7 5BD, UK

SUMMARY

In East Africa, Fasciola gigantica is generally the causative agent of fasciolosis but there have been reports of F. hepatica in cattle from highland regions of Kenya, Ethiopia, Uganda and Zaire. The topography of the Southern Highlands of Tanzania provides an environment where the climatic conditions exist for the sustenance of lymnaeid species capable of supporting both Fasciola hepatica and F. gigantica. Theoretically this would allow interaction between fasciolid species and the possible creation of hybrids. In this report we present molecular data confirming the existence of the snail, Lymnaea truncatula, at high altitude on the Kitulo Plateau of the Southern Highlands, Tanzania, along with morphometric and molecular data confirming the presence of F. hepatica in the corresponding area. At lower altitudes, where climatic conditions were unfavourable for the existence of L. truncatula, the presence of its sister species L. natalensis was confirmed by molecular data along with its preferred fasciolid parasite, F. gigantica. Analysis based on a 618 bp sequence of the 28S rRNA gene did not reveal the presence of hybrid fasciolids in our fluke samples.

(Received September 19 2007)

(Revised November 27 2007)

(Revised November 28 2007)

(Accepted November 28 2007)

(Online publication January 21 2008)

Correspondence:

c1 Corresponding author: School of Biological Sciences, The Queen's University of Belfast, 97 Lisburn Road, Belfast, BT9 7BL. E-mail: s.m.walker@qub.ac.uk

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