MBBS IV CA TEST EPIDEMIOLOGY OF COMMUNICABLE DISEASES

Which schistosome species primarily resides in the vesical venous plexus of the human host?

• S. mansoni

• S. japonicum

• S. haematobium

• S. mekongi

Which freshwater snail genus serves as the intermediate host for Schistosoma japonicum?

• Bulinus

• Biomphalaria

• Oncomelania

• Lymnaea

In schistosomiasis, Katayama fever is most strongly associated with infection by:

• S. haematobium

• S. japonicum and S. mansoni

• S. intercalatum

• S. mekongi

Which pathology is most specifically associated with chronic S. haematobium infection?

• Symmers' pipe-stem periportal fibrosis

• Squamous cell carcinoma of the bladder

• Portal hypertension

• Embolic egg granulomas in brain

The infective stage of schistosomes for humans is the:

• Miracidium

• Cercaria

• Sporocyst

• Schistosomulum

Which diagnostic method is most appropriate for quantifying S. mansoni egg load in stool samples?

• Filtration technique

• Kato-Katz technique

• ELISA for CCA

• Rectal biopsy

Which of the following is NOT a core control strategy for schistosomiasis?

• Elimination of the snail vector

• Avoidance of pollution of surface water

• Use of praziquantel mass drug administration

• Exclusive reliance on immunization programs

In S. haematobium endemic areas, which single clinical sign is considered almost diagnostic in the absence of laboratory confirmation?

• Portal hypertension

• Visible haematuria

• Katayama fever

• Bladder calcification

Which is the correct chronological order of events in the life cycle of schistosomes in the human-snail system?

• Egg → Sporocyst → Miracidium → Cercaria → Schistosomulum

• Egg → Miracidium → Sporocyst → Cercaria → Schistosomulum

• Miracidium → Egg → Sporocyst → Cercaria → Schistosomulum

• Egg → Cercaria → Sporocyst → Miracidium → Schistosomulum

A 35-year-old fisherman from the Nile Delta complains of progressive abdominal swelling, jaundice, and occasional hematemesis. Ultrasound shows periportal "pipe-stem" fibrosis, and stool examination reveals large eggs with lateral spines. Which species is the most likely cause?

• S. haematobium

• S. japonicum

• S. mansoni

• S. intercalatum