Disadvantaged by poverty, unsanitary housing and poor to non-existent health services, the people of Rio de Janeiro's teeming favelas are preparing for the worst when the coronavirus takes a grip on Brazil.
"The irony is that the disease was brought to Brazil by plane, by the rich, but it is among the poor that it will explode," said Paulo Buss, director of the centre for international relations at Fiocruz, a benchmark public health research centre.
The confirmation on Saturday of a first case of COVID-19 in the City of God, an emblematic favela which inspired the 2002 film of the same name, has set alarm bells ringing.
Almost a quarter of Rio's inhabitants – or 1.5 million people – live in the favelas, crowded jumbles of tin-roof shacks and narrow, impromptu streets.
Rio City Hall told AFP it had "intensified prevention campaigns in the favelas," as the number of coronavirus cases in Brazil has shot to 1,546, with 25 deaths, making it the hardest-hit country in Latin America.
The standard advice from municipal authorities recommends that people who feel they may be infected self-isolate in a separate room from the rest of their family.
"If your home only has one room, infected people should stay at least a metre away from other family members," says City Hall.
"Official statistics show that most of the favela houses have two or three rooms, with five to eight inhabitants. How can you isolate an infected person in these conditions?" asked Buss.
Beyond the high population density, unsanitary conditions in some dwellings also pose problems.
"In the favela, most houses have few windows, which prevents good air circulation, prevents daylight from entering and promotes the spread of respiratory diseases," said Patricia Canto, pulmonologist at the National School of Public Health.
"People who do not have a formal job must continue to go out to work because they have no choice. Either they die of hunger, or they risk dying by catching the coronavirus," said Joelma Sousa, of the NGO Redes da Mare, located in a set of favelas near Rio's international airport.
But Sousa is especially worried about the hit and miss nature of the health services.
"The clinics are sorely lacking in equipment and staff. These days, they are closed at 3:00 pm, three hours earlier than normal, because there is no doctor left," she said.
In Tabajaras, Ribeiro says locals are facing another problem.
"Here, the most practical way to climb the heights of the hill is by motorbike taxi. We are going to ask the police to no longer make it compulsory for passengers to wear a helmet, otherwise the same helmet will pass from head to head."
That is just one of the many daily puzzles for poor neighbourhoods in Rio in the midst of a global pandemic.