Scrutiny over the gifts and support provided by George Cottrell to Mr. Farage, the Reform U.K. leader, will continue even after he won last week’s special election in Clacton.

Grifols, a Spanish company, said “unfounded attention” on its blood plasma business in Canada had led it to temporarily end collections at 17 clinics.

Our reporter, Apoorva Mandavilli, goes inside a mosquito factory in Brazil, where scientists are producing millions of mosquitoes to fight deadly tropical diseases in a warming world.