Which parasite is the primary cause of hematuria in urinary schistosomiasis?

• Hematuria refers to the presence of blood in the urine. This symptom typically indicates an issue within the urinary tract.

• A. Schistosoma haematobium: This parasite is the causative agent of urinary schistosomiasis. The adult worms reside in the venous plexus of the bladder, and their eggs are deposited in the bladder wall, leading to inflammation and damage. Hematuria (blood in urine) is a hallmark symptom of this infection.
• B. Taenia saginata: This is the beef tapeworm, which causes intestinal infection (taeniasis). Symptoms are usually mild gastrointestinal discomfort or are asymptomatic. It does not cause hematuria.
• C. Enterobius vermicularis: This is the pinworm, which causes enterobiasis, an intestinal infection primarily characterized by perianal itching. It does not cause hematuria.
• D. Hookworm: Hookworms (Ancylostoma duodenale and Necator americanus) cause intestinal infections, leading to iron-deficiency anemia due to chronic blood loss from the intestines. They do not cause hematuria.

Schistosoma haematobium is directly associated with urinary tract involvement and hematuria.

The final answer is $\boxed{\text{A. Schistosoma haematobium}}$