Salvadoran fisherman who returned home this week after more than a year adrift at sea says 'I want to be alone with my family'

José Salvador Alvarenga has surprised doctors with his good physical condition, though they caution that the famed castaway is psychologically fragile as he recovers from what he has described as more than a year adrift at sea surviving on raw fish, turtles and bird blood.

All of the doctors who examined Alvarenga after he returned to his native El Salvador said he appears shaken and has asked to be given as much privacy as possible amid an international media furore over his apparent ordeal.

"I want to be alone with my family. They should give me time to talk after I have recovered, because right now I'm in no shape to explain anything," Alvarenga said from his hospital bed in a video shown to the press on Wednesday by the ministry of public health. "That's what I'm asking them, that they leave me in peace, so I can recover, that they don't bother my family, so I can be well. Nothing more than that."

Alvarenga underwent a battery of tests after being taken to hospital upon his return home from the Marshall Islands, where he showed up after what he has described as 6,500-mile (10,500km) journey from Mexico across the Pacific that began when his small fishing boat was thrown off course by bad weather.

He told doctors that several large ships came near his small fishing boat but none tried to rescue him, even though sailors on at least one even waved at him.

"They passed close by, he asked them for help and they didn't want to provide it," said El Salvador's minister of public health, Maria Isabel Rodriguez. "There was one that almost destroyed his little boat because it came so close, but nobody helped him."

Although he was close to despair, "his desire to live was greater, he thought of his family and said that he wanted to live", Rodriguez said.

The medical team that examined Alvarenga at the San Rafael hospital in the Salvadoran capital said he was in remarkably good physical health, with no skin lesions from overexposure to the sun and no cardiovascular or kidney issues. His only physical problem, doctors said, was a case of anaemia.

"All of the exams have been basically close to normal. It's incredible," Rodriguez said.

She and other Salvadoran experts who looked at Alvarenga's results said they had no doubt about the veracity of his tale, which left many sceptical even in the absence of an alternate explanation for his sudden appearance on the Marshall Islands' Ebon atoll.

"He challenges ideas about human physiology that we've had for a long time, but miracles exist and I don't think there's any reason to doubt him," hospital director Yeerles Ramirez told reporters.

Rodriguez said that after Alvarenga arrived at the San Salvador airport on Tuesday and saw dozens of waiting reporters, photographers and cameramen, "he quickly fell into a depression and started crying because he's not ready to talk to the whole world".

Alvarenga, 37, has asked for tortillas and a pupusa, a thick stuffed corn tortilla that is a Salvadoran speciality, and he has already eaten a tortilla with cheese, Rodriguez said.

The fisherman will remain hospitalised for at least two days while he rests and undergoes a series of exams, among them a test of his kidney function, Ramirez told reporters outside the hospital.

Alvarenga's story stunned the world when he washed up on Ebon almost two weeks ago, appearing robust and barely sunburned after more than a year at sea. But he had started out a much larger man, and doctors found that he was swollen and in pain from the ordeal, suffering from dehydration.

The journey back home after a week of rest and medical treatment in the Marshall Islands capital of Majuro was marked by long layovers in Honolulu and Los Angeles, where doctors checked his health and ability to continue the trip.

Alvarenga said he worked in a fishing village on the Pacific coast of Mexico's southern Chiapas state, where he embarked. A man with his nickname, "Cirilo", had been registered as missing with civil defence officials there. They said a small fishing boat carrying two men, the other named Ezequiel Cordoba, disappeared during bad weather on 17 November 2012, and no trace of them or the craft was found during an intense two-week search.

Cordoba died after about a month when he couldn't eat the raw fish and turtles, Alvarenga has said.