(CNN) If Brazilians are worried about the Zika virus, it clearly didn't show during this weekend's pre-Carnival celebrations.
The sun and heat brought thousands of people out into the streets of Brazil's main cities.
Carnival doesn't officially start until Thursday, but it's customary to start celebrations earlier.
According to Brazilian state run news agency Agencia Brasil, as many as 300,000 revelers enjoyed the festivities in the center of Rio de Janeiro over the weekend.
Brazil is one of several South American countries where the Zika virus has spread in recent months. The World Health Organization is considering declaring a public health emergency, and is holding emergency meetings to discuss the mosquito-borne disease.
Five things you need to know about Zika
However, Brazilians and tourists didn't let the threat of the virus get in the way of their partying.
People sang and danced as they made their way through the city's historic streets following "electric trios," or sound cars, where performers stand on top of big trucks flanked by massive sound systems.
On Saturday, party-goers also took to the streets in front of Rio's iconic Ipanema beach and Sugarloaf Mountain.
Not to be outdone by Rio de Janeiro, Sao Paulo also hosted over 50 "street blocks" over the weekend. Parades moved block-by-block on designated routes, snarling traffic.
To round out the weekend, the Bangala Fumenga block, normally from Rio de Janeiro, brought their party to Sao Paulo's main avenue.
Zika is commanding worldwide attention and causing alarm due to the apparent connection between the virus and microcephaly, a neurological disorder that results in babies being born with abnormally small heads. Health officials have issued travel warnings, urging pregnant women not to visit affected areas.
Since November, Brazil has seen more than 4,000 cases of microcephaly in babies born to women who were infected with the Zika virus during their pregnancies.
With no treatment or vaccine available, the only protection against the virus is to avoid travel to areas with an active infestation. Locals and tourists have been encouraged to use mosquito repellant and cover up.