BRASILÉIA, Brazil — Of the odyssey that delivered him to this town in the Brazilian Amazon, Wesley Saint-Fleur could muster only a look of exhaustion and bewilderment.

Months ago, he boarded a bus in Haiti, before getting on a plane in the Dominican Republic, landing first in Panama and then in Ecuador. That was where his wife gave birth to their son, Isaac, he said, bouncing the 4-month-old infant on his knee and brandishing the boy’s Ecuadorean identification card. Then they continued by bus yet again, through Ecuador and Peru. Next, they trekked by foot in Bolivia, where, he said, the police robbed him and his wife of their clothing and their life savings: $320 in cash.

“Then we finally got to Brazil, which I’m told is building everything, stadiums, dams, roads,” said Mr. Saint-Fleur, 27, a construction worker, one of hundreds of Haitians who gather each day around the gazebo in Brasiléia’s palm-fringed plaza. “All I want is work, and Brazil, thank God, has jobs for us.”

Gambling everything, thousands of Haitians have made their way across the Americas to reach small towns in the Brazilian Amazon over the past year in a desperate search for work, including a surge of hundreds arriving in recent days amid fears that Brazil’s government could slow the influx before it overwhelms the authorities here.