The government of Brazil's southeastern state of Minas Gerais has decreed a state of emergency for its public health system due to an outbreak of yellow fever in 94 of its 853 cities.

The decree was published Saturday in the state's official gazette and allows the government to contract health providers without going through a bidding process.

Since July 2017, 35 cases of yellow fever have been confirmed in Brazil and 20 people have died, according to the latest figures from the health ministry.

The World Health Organization said earlier this week that all of Sao Paulo state is also at risk for yellow fever and recommended that international visitors to be vaccinated.