Exposure of hamsters to Schistosoma haematobium cercariae

 

Authors Yung-san Liang , Mei-Shei Su and Fred Lewis

 

Introduction

For the best results using percutaneous exposure with S. haematobium in hamsters, the abdomen is the preferred skin site for exposure.

 

Equipment

Animal clippers, fitted with a #40  blade

Dissecting microscope

 

Materials and Reagents

Sodium pentobarbital (90mg/Kg)

Fine-tipped (drawn) glass pasteur pipette

Aged tap water

 

Procedure

·         Anesthetize the hamster with an intraperitoneal injection of sodium pentobarbital.

·         Shave the abdomen with animal clippers.

·         Moisten the abdomen with a gauze sponge soaked with aged tap water.

·         Using a fine-tipped glass pipette and under a dissecting microscope, draw up a pre-determined number of cercariae and express the suspension onto the hamster’s abdomen. This procedure  allows for a good estimate of the number of cercariae applied to the skin.

·         Allow 15-30 minutes for the cercariae to penetrate.

·         Keep the hamster warm throughout the procedure with a warming lamp or heated pad.

·         Return the hamster to its cage once it recovers from the anesthesia.

 

Follow-up comments/recommendations

It is not possible to assess accurately the percentage of cercariae that penetrate the abdominal skin once they are applied; however, when the hamsters are perfused, one can expect that about 30% of the estimated number of cercariae applied to the skin to be recovered as adult worms at 3½ - 4 months post-exposure.

 

References

Liang, Y-S., Bruce, J.I., and Boyd, D.A. 1987. Laboratory cultivation of schistosome vector snails and maintenance of schistosome life cycles. Proceedings of the First Sino-American Symposium 1: 34-48.