Canada's Summer McIntosh takes gold in the women's 400m freestyle event at the World Aquatics Championships in Singapore as American Katie Ledecky finishes with the bronze.

Canadian swimming sensation Summer McIntosh said she was in "the best shape of my life" after obliterating the field to win the world 400m freestyle gold on Sunday, with great rival Katie Ledecky only third.

The United States team at the swimming world championships in Singapore is battling a case of “acute gastroenteritis” that compromised performances on the opening day of eight days of competition