Brazilian President Dilma Rousseff has vowed to wage a house-by-house fight against the Zika virus ©Getty Images

Brazilian President Dilma Rousseff has vowed to wage a “house-by-house fight” against the Zika virus amid growing concerns surrounding the South American country's ability to safely host this year’s Olympic and Paralympic Games in Rio de Janeiro.

Cases of the virus, which is spread by mosquitoes, have boomed in recent months, with infected patients typically suffering symptoms including fevers, rashes, joint pain and conjunctivitis.

Pregnant women have been deemed at most risk with the virus being linked to a rise in the number of children being born with birth defects.

Brazil is the country worst affected by the Zika outbreak with 270 confirmed cases of microcephaly, which can lead to babies being born with small heads and under-developed brains, and 3,448 being investigated by the country's Ministry of Health.

Rousseff said at a regional summit in Ecuador that Brazil would place "extreme emphasis" on wiping out mosquito breeding grounds and searching for a vaccine against Zika, for which there is no specific treatment.

"It's going to be a house-by-house fight," she said.

"Although we don't have a vaccine today, I'm sure we will have one, though it will take time."

Rousseff rejected comments made earlier this week by her Health Minister Marcelo Castro, who claimed Brazil was losing the battle against the virus.

Castro announced on Monday (January 25) that 200,000 soldiers would be deployed to go house-to-house as part of a mosquito control campaign, and that insect repellent will be handed out to at least 400,000 pregnant women.

Health workers fumigate in an attempt to eradicate the mosquito which transmits the Zika virus
Health workers fumigate in an attempt to eradicate the mosquito which transmits the Zika virus ©Getty Images

The International Olympic Committee is due to issue guidelines later today for athletes and visitors taking part at Rio 2016 with President Thomas Bach insisting steps are being taken to protect the event.

A group of Brazilian activists, lawyers and scientists, meanwhile, is due to deliver a petition to Brazil’s Supreme Court in two months’ time asking to allow abortions for women who have contracted the virus.

Abortions are currently illegal in Brazil, except in health emergencies or cases of rape or, since 2012, another brain condition known as anencephaly - the absence of a major portion of the brain, skull, and scalp that occurs during embryonic development.

The United States National Institutes of Health (NIH) claims to have two potential Zika vaccines in development, one of which is based on an experimental West Nile vaccine that could be repurposed for Zika and, according to NIH, enter clinical trials by the end of this year.

Margaret Chan, director general of the World Health Organization, admitted Zika had gone "from a mild threat to one of alarming proportions".

She has set up a Zika "emergency team" which is scheduled to meet on Monday (February 1) to determine whether Zika should be treated as a global emergency.