São Paulo closed its zoo and botanical gardens Tuesday as a yellow fever outbreak that has led to 70 deaths is picking up steam.

The big Inhotim art park, which attracts visitors from all over the world, also announced that all visitors would have to show proof of vaccination to be allowed in. The park said the measure was preventative and no case of yellow fever had been found there.

Cases of yellow fever have been rising in Brazil during the Southern Hemisphere summer rainy season, and health officials are planning to vaccinate millions of people in the coming weeks in the hopes of containing the outbreak.

Authorities did not say when the São Paulo zoo or nearby botanical gardens would reopen. The zoo said in a statement that a wild monkey was found dead last week in the park that contains the zoo and tests Monday confirmed it was positive for yellow fever.

According to figures put out by each state, 148 cases have been confirmed in the southeastern states of Minas Gerais, São Paulo and Rio de Janeiro. Of those, 69 people have died. A week ago, the Health Ministry had confirmed 34 cases and 19 deaths in those states; it also confirmed one case in the capital district that ended in death.

A child gets a vaccine against yellow fever at an outpatients clinic in Sao Paulo Photograph: Fernando Bizerra Jr./EPA

São Paulo has registered the most cases, with 81, and the World Health Organization recommended last week that foreigners planning to travel anywhere in the state be vaccinated for the mosquito-borne disease. Brazil’s own recommendations include only parts of the state.

Much of Brazil is considered at risk for the yellow fever, but last year it saw its largest outbreak of the disease in decades, including in areas not previously thought to be at risk. More than 770 people were infected, and more than 250 died. Minas Gerais was at the epicenter of that outbreak, and it declared a state of emergency last week.

Yellow fever typically causes fever, muscle pain and nausea; some patients also experience the jaundice from which the disease gets its name.