Rio de Janeiro has more than 640 deaths from coronavirus in its favelas, a new information dashboard showed on Thursday, part of an effort to combat underreporting of the disease in the city’s slums.

The dashboard, a collection of charts and information arranged in a graphic display, aggregates coronavirus data from about 120 of Rio’s estimated 1,000 poor neighbourhoods, said Theresa Williamson, head of Catalytic Communities, a non-profit that created the counting system with local groups.

About 1.3 million people live in Rio’s favelas, where COVID-19 infection rates are feared to be higher due to poor nutrition, cramped housing and ill health, but cases are difficult to count.

“Now that the dashboard has been launched, we want to reach the highest possible number of territories,” Williamson said at a news conference, adding: “Because of underreporting, we are still far away from recognizing the true situation.”

More than 7,000 people have died from COVID-19 in Rio.

Nationally, Brazil has the world’s second-highest COVID-19 death toll, with more than 67,000 fatalities, 1.71 million confirmed cases and one of the highest daily rates of new infections.

Because the rates in favelas are hard to track, community members started keeping their own counts, with help from non-profits, and the dashboard integrates data from about 30 favela-based rapporteurs, government information and news reports.

Residents from favelas may also report if they think they have the disease and whether their symptoms are mild or severe.

Williamson said she hoped that as residents add symptom data to the platform, hotspots of contagion will become visible, indicating areas that require attention.

In some cases, the number of dead on the dashboard is far higher than the number officially recognized by Rio de Janeiro’s government.

For example, while the city’s tally lists 83 dead at Complexo da Maré, the non-profit’s dashboard shows 112 fatalities in the favela.

“This is going to be a great step forward in the real accounting of cases in favelas,” said Rafael Oliveira of the non-profit Favela Vertical, in Gardenia Azul, one of Rio’s slums.

According to the dashboard, about 33 people died in Gardenia, and 195 were infected.

“Unfortunately we never had a normal quarantine,” said Oliveira. “So the most we can do is damage control, and count our cases and our dead.”

While the dashboard reaches only about 10% of Rio’s favelas, they are some most populous ones, like Rocinha, one of Latin America’s largest slums with a population of more than 100,000 people.

The dashboard and its methodology were supported by Brazil’s leading public epidemiological institute, Fiocruz.