Collection of S. haematobium eggs from hamsters

Introduction
The procedure for collection of S. haematobium eggs from the tissues of hamsters is similar to that described for the collection of S. mansoni eggs from mice. In practice, however, the majority of recoverable S. haematobium eggs are found in the walls of the intestines, rather than in the liver, even though it is obvious on gross examination that the liver contains many granulomatous lesions. In this respect, the situation is very different from that in the S. mansoni-infected mouse.

Equipment
Spray apparatus (the pump-type for dispensing insecticide – found in hardware stores)
Stainless steel sieves of decreasing pore sizes (Newark Wire Cloth; mesh openings of 420 µm, 180 µm, 105 µm, and 45 µm)
Dissecting instruments
Waring blender, with variable speed control
Glass petri dishes (100 mm dia) with flat bottoms
Cell strainer (Falcon #2340, 40 µm nylon)
Pasteur pipettes
Light box

Materials and reagents
1.2% NaCl
haematobium-infected hamsters

Procedure
Remove the cecum and intestines, and flush them clean with 1.2% NaCl. Most of the eggs will be in the walls of the cecum and large intestine.
When tissues are thoroughly cleaned, cut them into small pieces and blend in a Waring blender, following the procedures described for S. mansoni egg collection.

Follow-up comments/recommendations
One can usually obtain up to 50,000 mature schistosome eggs from a single hamster using the abdominal exposure method (from hamsters exposed to around 350 S. haematobium cercariae 3½ to 4 months earlier).

References
Tucker, M. S., Karunaratne, L. B., Lewis, F. A., Frietas, T. C., and Liang, Y-S. 2013. Schistosomiasis, in Current Protocols in Immunology 19.1.1-19.1.57, John Wiley and Sons, Inc., (R. Coico, Ed).  Published online November 2013 in Wiley Online Library (wileyonlinelibrary.com). doi: 10.1002/0471142735.im1901s103.