Brazil declares state of emergency due to surge in dengue fever cases just as millions of tourists from around the world arrive for Rio carnival

• Rio this year has already recorded almost half the dengue cases is saw in 2023
• The city is just four days away from hosting the famed Rio carnival

Rio de Janeiro has declared a state of emergency amid surging dengue fever cases just as millions of tourists are set to arrive in Brazil for the city’s famous carnival.

Meanwhile Sao Paulo, Brazil’s biggest city, opened an emergency operations centre on Tuesday to cope with the spreading number of infections.

Cases of the mosquito-borne disease have also risen sharply in Argentina, where a record 10,000 cases were reported in the first three weeks of the year.

Paraguay has meanwhile declared a health emergency over dengue. It has registered 36 deaths since December, including 12 children, officials there said.

Rio de Janeiro declared the public health emergency Monday, four days ahead of the official opening of its famed carnival.

Authorities announced the opening of 10 dedicated treatment centre to alleviate pressure on Rio’s overwhelmed hospitals.

Authorities also will use ‘smoke cars’ in regions with the highest incidence of cases, diffusing an insecticide in the air. 

‘It’s a good thing they opened this centre. The hospitals can’t handle the situation alone,’ patient Luciana Ferreira told AFP in the working-class Curicica neighborhood.

Since the beginning of 2024, the municipality has registered more than 10,000 dengue cases. That is just under half of the total cases – 23,000 – recorded throughout all of 2023. 

The announcement comes as tourists and revellers are pouring into Rio to take part in street parties and attend the samba schools’ flamboyant parades.

Among Rio state’s operational plans for Carnival, presented by Gov. Cláudio Castro on Monday, is the ‘Against Dengue Every Day’ campaign.

That will entail the distribution of repellents, stickers, bandannas and hats with warnings about the disease to audiences at the Sambadrome, where a 15-second notice about the fight against the infection also will be shown.

Dengue is a viral infection transmitted to humans through the bite of infected mosquitoes and is more common in tropical climates. 

Frequent rains and high temperatures, which accelerate the hatching of mosquito eggs and the development of larvae, make the famously hot city of Rio susceptible to dengue outbreaks.

But the problem is national. The explosion of dengue cases across Brazil has caused at least four states – Acre, Minas Gerais and Goias, in addition to the Federal District – to declare public health emergencies.

The capital, Brasilia, has opened an emergency field hospital.

Thirty-one people have died of dengue, according to the Brazilian health ministry, which is still analysing another 234 deaths that may also have been caused by the disease.

Sao Paulo is testing a drone that uses larvicide to combat mosquitos in hard-to-reach areas.

Brazil plans to start a public vaccination campaign against dengue this month – though a lack of doses from the vaccine’s maker, Japanese pharmaceutical company Takeda, means only children ages 10 to 14 will be targeted.

Brazil’s government says it is studying options to produce a dengue vaccine domestically.

In March 2023, Brazil approved a vaccine against dengue and became the first country in the world to offer a dengue vaccine through the public health system, according to the health ministry. 

More than 3 million people were due to receive a jab in 2024.

On Monday, the Brazilian air force set up a 60-bed field hospital in the Federal District in Ceilandia that was due to begin treating patients.

‘Our objective is to relieve emergency care units in the region, given that today the Federal District accounts for around 20 percent of dengue cases in the country,’ air force commander Lt. Brig. Marcelo Kanitz Damascene said in a statement.

Dengue, which can cause hemorrhagic fever, infects an estimated 100 million to 400 million people yearly, though most cases are mild or asymptomatic, according to the World Health Organisation.

Most people who get dengue don’t develop symptoms, but if they do these can include high fever, headache, body aches, nausea and a rash, according to the World Health Organisation. 

While most get better after a week or so, some develop a severe form and require hospitalization. In such cases, dengue can be fatal.

Climate change, which leads to increased temperatures and high rainfall, is associated with a higher risk of dengue, WHO said in December.

Rio Mayor Eduardo Paes urged ‘cariocas’ – as the residents of Rio are known – to eliminate sources of still water, used by mosquitoes as breeding grounds.

‘Unlike the COVID-19 pandemic, in which individual citizens couldn’t do much more than demand that governments get the vaccine, in the case of dengue much depends on the action of each citizen,’ Paes said.