The secretary-general of the World Health Organization (WHO), Margaret Chan, visited Wednesday a children's center in Recife, capital of Brazil's northeastern state Pernambuco, which is worst hit by the Zika epidemic.

At a press conference later, Chan, alongside Carissa Etienne, director of the Pan American Health Organization, said her visit was to learn more about the severity of the epidemic.

"We need to deepen our study of the link between Zika and microcephaly. Zika is a mystery. We are still trying to find answers. However, Brazil has competent people. I am not afraid of the mosquito. The work being done is excellent," Chan noted.

Chan continued to praise the efforts made by the Brazilian government against Zika. "It is not easy to fight this problem but it is being done... We are counting on the population of Brazil to reduce the population of the Aedes aegypti (mosquito). If Brazil mobilizes, it will cause similar mobilizations in other Latin American countries," she predicted, adding that support would also be provided to mothers of babies with microcephaly for years to come.

Pernambuco state has suffered the most cases of microcephaly among the country's newborns. For the moment, out of 1,601 suspected cases, 290 have been confirmed and 1,188 are under investigation.

From Recife, Chan will travel to Rio de Janeiro, where she will visit the Oswaldo Cruz Foundation, an internationally renowned center for tropical disease research, which is leading the fight against the Aedes aegypti mosquito.