If U.S. athletes and support staff slated to travel to Rio de Janeiro for the 2016 Summer Olympics in August are afraid of contracting the Zika virus there, they should consider not going at all, officials with the United States Olympic Committee told sports federations last month, Reuters reported Monday.

The announcement took place during a conference call in late January, when USOC officials told the federations that participants should not go "if they don't feel comfortable going," Donald Anthony, the president of USA Fencing, said, according to Reuters.

Over the past year, Brazil has seen an outbreak of the mosquito-borne virus that health authorities suspect is linked to a spike in babies born with the birth defect microcephaly, which can cause brain damage and disability. The World Health Organization declared Feb. 1 that the outbreak constituted a global public health emergency, after nearly 4,000 babies in Brazil were reported born with microcephaly, or abnormally small heads, since the beginning of 2015.

Neighboring countries in Latin America have also reported cases of the Zika virus, prompting health authorities to warn women who are pregnant or plan on becoming pregnant to postpone or avoid traveling to those areas. In countries that are experiencing outbreaks, officials have urged women to put off having children, as the virus is believed to pose the most severe risk to the unborn. Of the adults who contract the virus, 80 percent never show symptoms. 

RTX25W06 Children carry flags on a float with the Rio 2016 Olympics logo in Rio de Janeiro's Sambadrome before the start of a Carnival parade, Sunday, Feb. 7, 2016. Photo: Reuters/Pilar Olivares

The U.S. Olympic Committee has not publicly issued recommendations for athletes regarding Zika virus and the Olympic Games. A search for the term "Zika" on its official website turns up zero results. The same search on the International Olympic Committee's website produces the same, and a news release on the IOC's website posted Friday makes no mention of the virus or public health concerns. Instead, it advertises "22 test events to warm up the city for the Olympic and Paralympic Games."

Officials have been firm that the Olympics will go on, despite concerns about the virus. 

Thomas Bach, the president of the International Olympic Committee, said last week that he was "very confident" the Olympics would go forward, while George Hilton, Brazil's sports minister, said Thursday, "The Brazilian government is fully committed to ensure that the 2016 Rio games take place in an atmosphere of security and tranquility." The question of canceling the games, he said, was "not in discussion."