RIO DE JANEIRO, Jan. 24 (Xinhua) -- The death toll from yellow fever in heavily-populated southeast Brazil has risen to 53, according to Brazil's Health Ministry.

Over the reported period, from July 2017 to Jan. 23, the region, home to Brazil's two largest cities, Sao Paulo and Rio de Janeiro, has also registered 130 confirmed cases of the virus and 162 suspected cases.

The World Health Organization (WHO) has issued a warning on Jan. 16 to foreign travelers headed to Sao Paulo state, the most populated in Brazil, cautioning the state was at risk for yellow fever.

In recent weeks, hospitals in Sao Paulo and Rio have been overcrowded with patients.

The highest number of deaths was reported in the southeastern state of Minas Gerais with 24 cases, followed by Sao Paulo with 21 and Rio de Janeiro with seven.

The health ministry has distributed 57.4 million vaccines nationally in an attempt to control the plague last year.

Apart from human deaths, the virus has also killed 453 animals, mainly monkeys and most in Sao Paulo, where authorities closed several zoos on Tuesday after a howler monkey died from the virus.

Primates are the main carriers of the virus, which is transmitted via mosquitoes.

In an earlier outbreak of yellow fever in Brazil from December 2016 to April 2017, a total of 3,131 cases were reported, including 392 deaths, according to the report Epidemiological Update: Yellow Fever, jointly released by the WHO and the Washington-based Pan American Health Organization.