Brazil has not addressed the root causes of the Zika outbreak including poor sanitation and a lack of clean water access for slum residents despite declaring the public health emergency over in May, human rights campaigners and the UN officials said.
The mosquito-borne Zika virus was linked to more than 2,500 birth defects and caused an 18-month public health emergency in South America's largest country.
But campaigners on Thursday said a lack of government investment in sanitation services for the poor, insecure water access and other conditions which exacerbated the crisis are still present in Brazil, raising the potential for future outbreaks.
"Other Zika-affected countries should recognise that human rights problems can contribute to the rapid escalation and impact of the Zika epidemic," said Amanda Klasing, a researcher for Human Rights Watch (HRW).
TRT World's Kerry Alexandra has more details.
Conditions ripe for mosquito breeding
More than one-third of Brazil's 206 million people lack access to a continuous water supply, leaving residents with few options other than filling containers for household use.
Left uncovered these water containers can become breeding grounds for mosquitoes and the diseases they carry.
In Brazil's poor northeast - where Zika hit hardest - less than 25 percent of the population was connected to waste water systems in 2015, HRW said, echoing statements from the UN officials about who was most impacted by the virus.
"Zika happens in a historical context ... it mainly affects the periphery, mainly affects brown, black and young women," said Jamie Nadal, a representative of the UN Population Fund during a conference earlier this year.
Lack of adequate facilities
Across the country, more than 35 million Brazilians lack adequate facilities for the safe disposal of human waste.
Brazilian authorities say they are working to improve sanitation, especially for the country's urban poor who live in slums or favelas, but a recession and political turmoil has hampered the government's investment ability.