NEW YORK — Dr. Craig Spencer, the physician now being treated for Ebola in New York City, is the kind of globe-trotting do-gooder who could walk into a small village in Africa and, even though he didn’t know the language, win people over through hugs alone, according to people who worked with him.

Even before leaving for Guinea this summer to fight Ebola with Doctors Without Borders, the 33-year-old had amassed an ordinary man’s lifetime worth of world travel, much of which was in the service of the poor.

In the past three years alone, Spencer, an attending physician at New York-Presbyterian Hospital/Columbia University Medical Center, had been to Rwanda to work on an emergency care teaching curriculum, volunteered at a health clinic in Burundi, helped investigate an infectious parasitic disease in the Democratic Republic of Congo and traveled to 32 villages in Indonesia to do a public health survey.

“He was never afraid of getting his hands dirty or his feet dirty,” said Dr. Deogratias Niyizonkiza, founder of Village Health Works, the aid group that brought him to Burundi for four months in 2012.

“He went into this environment, a country that is truly off the mark, without knowing the language and he would make everyone feel so comfortable. It’s really a daunting task and yet he helped the people immensely,” Niyizonkiza said.

In between it all, Spencer ran the ING New York City Marathon in 2013, finishing with a respectable amateur time of 3 hours, 43 minutes.

Spencer was hospitalized at New York City’s Bellevue Hospital Center on Thursday, six days after returning from Guinea. Health officials said he began feeling tired on Tuesday, spent a day out in the city on Wednesday, and then alerted authorities when he developed a fever Thursday morning.

Experts have assured the public that there is little chance that Spencer spread the virus prior to developing symptoms, but his case prompted the governors of New York and New Jersey to order a mandatory quarantine for travelers who had contact with Ebola patients in three West African countries.