The World Health Organization will hold an emergency meeting in Geneva Monday to discuss an action plan to stop the spread of the Zika virus.
Brazil has been hardest hit by the Zika virus, which is thought to have arrived there in 2014 during the World Cup soccer tournament. Since then, it has exploded - with estimates of at least 1.5 million people infected in Brazil alone - and could spread to four million across the Americas in the next 12 months, reports CBS News' chief medical correspondent Dr. Jon LaPook.
It has become an all-too-common scene - health officials spraying insecticide in the hopes of killing the Aedes aegypti mosquito, which is responsible for the Zika virus sweeping through Latin American and the Caribbean.
The virus has been suspected of causing an increase in cases of microcephaly - children born with unusually small heads, often with brain damage.
More than 4,100 suspected cases of microcephaly have been reported so far in Brazil, and pregnant women fear other side effects from the virus.
At least 31 cases have been reported in the United States - all related to recent travel.
"The public doesn't know everything about the Zika virus. We don't know exactly the consequences of the virus, only the microcephalus," said Maria Fernanda Laudisio de Lucca of São Paulo who is pregnant.
Tourism will also likely suffer, despite officials downplaying risks to visitors.
Rio's famed Carnival festival begins February 5th. Health workers took to the streets, armed with instruments and information.
Brazil is also set to host the summer Olympics in August. Other events like a wrestling test match are already underway and athletes are taking precautions, using bug spray and staying indoors.
"It's kind of scary, but there's nothing really you can do, like if you get bit, you get bit," said USA wrestler Alyssa Lampe.
If the World Health Organization declares the virus a public health emergency, it will only be the fourth time the organization so, putting Zika in the same company as the H1N1 flu, Ebola and the resurgence of polio.