Chinese women have made their strongest showing on Forbes magazine's list of the world's most powerful women.

The World Health Organization (WHO) calls for urgent research into different strains of the Zika virus and says that health services in affected areas should be ready for potential increases in the incidence of neurological syndromes and/or congenital malformations.

The head of the World Health Organization warns that the Zika outbreak would likely worsen before nations besieged by the mosquito-borne virus linked to thousands of birth defects in Brazil see relief.