Schistosome Snail Resource (SSR)

A shistosome snail sitting in a clear glass of water

A freshwater snail, Biomphalaria glabrata, shedding cercariae (the free-swimming larvae stage of the parasite) 

Supporting schistosomiasis research

Schistosome snail resource (SSR) is Wellcome Trust funded, open access biomedical resource that aims to generate and make freely available live schistosome life-cycle stages, snail intermediate hosts and related material for schistosomiasis research.

SSR is a collaboration between the Natural History Museum and London School of Hygiene and Tropical Medicine


Schistosomiasis is a chronic and debilitating tropical parasitic disease caused by schistosomes (Schistosoma spp.), transmitted by freshwater snails.

It is a Neglected Tropical Disease (NTD) of both humans and animals, with considerable health and economic impacts.

Endemicity is associated with low/middle-income countries with considerable disease burden within impoverished communities despite widespread control efforts. 

While substantial advances have been made in the control of schistosomiasis, the diversity and complexity of Schistosoma species and their specific fresh-water snail hosts warrants fundamental research requiring lifecycles, live material and diverse collections.

  • Schistosomiasis life cycle

    The life cycle of the schistosomiasis parasite

    Adult schistosomes: Adult schistosome worms inhabit small veins next to the intestine or the bladder.

    Schistosome eggs: The worms produce many eggs each day. Some eggs get caught in body tissue and cause tissue damage. Others exit the body by penetrating through wall of the bladder or intestine.

    The miracidium stage: Miracidia hatch from schistosome eggs in water.

    Freshwater snails: Miracidia infect snails where they develop and multiply in the snail tissue.

    The cercaria stage: Many schistosome cercariae emerge from snails. Cercariae swim in the water and can infect people by directly penetrating through the skin. 

Why do we need a schistosomiasis biomedical resource?

  • Complex life cycle that requires time consuming maintenance and a diverse combination of culture facilities. 
  • High costs make centralisation of resources an attractive option.
  • Only few strains are widely available in cultures. This lack of natural genetic heterogeneity leads to potential bias in research.

Without the availability of diverse Schistosoma lifecycles/live material, future research faces substantial obstacles.

shistosome snail

Bulinus truncatus,  image by  Adam Cieplinski

  • How to acknowledge the SSR in publications

    As the SSR is a Wellcome Trust funded open access resource it is necessary that the SSR is acknowledged in all outputs associated with the resource needs and that any publications and/or documents are sent to the SSR so that they can be documented for reported to the Wellcome Trust. We also request that you use the following acknowledgment in all outputs:  

    'We acknowledge the support of the Wellcome Trust funded Schistosome and Snail Resource (SSR) (Wellcome Trust Biomedical Resource Grant 221368/Z/20/Z (2021-2026) which is a collaborative project between the Natural History Museum and the London School of Hygiene & Tropical Medicine, for this research by the provision of ……….'

    For the material that originated from the Biomedical Research Institute please add the following acknowledgement in publications:  

    'The following reagent was provided by the NIAID Schistosomiasis Resource Center (SRC) for distribution through the NIH-NIAID Contract HHSN272201700014I.'

LSHTM logo and the schistosomiasis research group logo

Project summary

June 2021 to June 2026

A UK biomedical resource providing live schistosome life-cycle stages and their intermediate snail hosts to advance schistosomiasis research worldwide.

Funding: Wellcome Trust

What do we provide?

  • 'Standard/SSR model' Schistosoma and snail species.
  • Non-standard African species/strains of schistosome and snails.


Project team

Museum staff

London School of Hygiene and Tropical Medicine staff

Our webpage at the London School of Hygiene and Tropical Medicine