Schistosoma species

MICROBIOLOGY

• Helminths (phylum Platyhelminthes, class Trematoda) that cause schistosomiasis, AKA blood flukes or bilharzia.
• Highly prevalent throughout tropical and lower-resource countries.
  • Freshwater infection, water mollusks intermediate hosts → infective cercariae enter the skin.
  • Life cycle (Schistosoma): photos of egg forms of S. mansoni, S. haematobium and S. japonicum.
• Three major species, geographically distinct:
  • S. mansoni (Africa, Middle East, Caribbean, South America)
  • S. haematobium (Africa, Middle East)
  • S. japonicum (China, Southeast Asia, Philippines)
  • Minor species:
    • S. intercalatum (West and Central Africa, usually a cause of lower GI tract disease)
    • S. mekongi (Laos, Cambodia)