The Scottish Encounter with Tropical Disease
The drug praziquantel is effective against schistosomiasis. It is relatively cheap and widely available. No vaccine is available although research is revealing more about the immune response to the parasite. In addition to large-scale drug administration, control methods have focused on application of molluscicides to water in which the snail hosts are found. Avoiding snail infested water limits the risk of infection. Liver and Lung flukes Over 100 species of flukes infect humans either as adults or larvae. Hundreds of millions of people are infected with lung and liver flukes. They are usually acquired when eating infected intermediate hosts such as undercooked fish or shellfish. Sushi eaters beware! The most important human infectious flukes are Paragonimus westermani, the lung fluke that causes paragonimiasis, and the liver flukes Clonorchis (now Opisthorchis) sinensis and other Opisthorchis spp..
17 million people are infected with liver flukes which cause profound inflammation within the liver. Praziquantel is active against these parasites. Praziquantel is also active against the lung flukes which can be avoided by not eating uncooked shellfish or crustaceans.
2. Schistosome: cercaria
3. Coupling schistosomes
4. Biomphalaria snail
5. Schistosomiasis (splenomegaly)
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