WHO Director: Zika Crisis Will Get Worse before Getting Better

"Things could get worse before it gets better. We should be prepared for surprises," said the health specialist in a press conference on Wednesday in Rio de Janeiro where she concluded her two-day visit to Brazil, the country most affected by Zika.

Chan said that 40 countries have already registered indigenous cases of Zika and that this number is likely to increase.

She warned that the number of cases of babies born with microcephaly in other countries is also expected to rise, as it is happening in Brazil, but she said that the link between the virus and the defect is not yet scientifically proven.

But the specialist adds, "Zika is the most probable cause (for the increase in cases of microcephaly) until proven otherwise."

As for the Olympic Games, she said that Brazil is doing important work together with the International Olympic Committee (IOC) to reduce risks and ensure that the event is something "pleasant" for Brazilians, visitors and the athletes themselves.

Chan applauds the efforts made by the Brazilian government to tackle the mosquito carrying the Zika virus. According to the WHO director, Brazil is the epicenter of this new epidemic which threatens the world, but the Brazilian government was able to respond appropriately.

"The protocols, scientific knowledge and technologies developed by Brazil will serve as a guide for the rest of the world. What we have seen in Brazil is the best way to combat this problem," she said.