The World Health Organization (WHO) and the Pan American Health Organization (PAHO) on Thursday advised pregnant women not to travel to Rio de Janeiro during the Olympics even though the games will take place during Brazil's wintertime when there are fewer active mosquitoes and the risk of being bitten is lower.

According to a statement, WHO and PAHO recognize that athletes and visitors are seeking more information on the risks of Zika and ways to prevent infection while attending the 2016 Rio Olympic and Paralympic Games in the summer.

Brazil is one of the 58 countries and territories which to date report continuing transmission of Zika virus by mosquitoes.

Zika virus disease usually causes mild symptoms, and most people will not develop any symptoms. However, there is scientific consensus that Zika virus is a cause of microcephaly and other brain malformations and disorders in babies born to women who were infected with Zika virus during pregnancy.

WHO and PAHO encourage athletes and visitors to Rio de Janeiro, and other areas where Zika virus is circulating to follow the travel advice provided by WHO and their countries' health authorities, and consult a health worker before travelling.

Whenever possible, during the day, protect themselves from mosquito bites by using insect repellents and by wearing clothing that covers as much of the body as possible.

Considering the Zika virus could be transmitted by unsafe sex, WHO and PAHO suggest athletes and visitors to practice safer sex or abstain from sex during their stay and for at least four weeks after their return, particularly if they have had or are experiencing symptoms of Zika virus.

WHO is providing public health advice to the government of Brazil and, under a Memorandum of Understanding, the International Olympic Committee and, by extension, the Rio 2016 Local Organizing Committee, on ways to further mitigate the risk of athletes and visitors contracting Zika virus during the Games.

An important focus of WHO advice revolves around measures to reduce populations of Aedes mosquitoes which transmit chikungunya, dengue and yellow fever in addition to Zika virus.