Carnival is here, and Rio has a health emergency

Authorities have declared a public health emergency because of an outbreak of dengue fever, a mosquito-borne illness.

RIO DE JANEIRO — Rio de Janeiro has declared a public health emergency because of an outbreak of mosquito-borne dengue fever, the city announced just days before Carnival celebrations kicked off across Brazil.

The outbreak wasn’t expected to derail Carnival, which officially started Friday night and runs until Feb. 17, but it has prompted a slew of special measures by the city in hopes of containing the illness. Most infections produce only mild symptoms, but dengue occasionally causes death. There is no specific treatement for the illness.

Rio city hall announced the opening of 10 care centers, the creation of an emergency operations center and the allocation of hospital beds for dengue patients. Authorities also will use “smoke cars” in regions with the highest incidence of cases, diffusing an insecticide in the air.

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 revelers are pouring into Rio to take part in street parties and attend flamboyant parades.

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

Rio Mayor Eduardo Paes urged residents 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.

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.

ERALDO PERES/AP Dengue patients wait to receive treatment in a provisional clinic in the Santa Maria neighborhood of the capital city of Brasilia late last month.

SILVIA IZQUIERDO/AP A municipal health worker in Rio de Janiero empties a bucket of water in the Copacabana neighborhood. Mosquitoes use standing water as a place to breed.