Post traumatic stress likely for castaway

A castaway who says he survived 13 months adrift in the Pacific appears to be suffering post-traumatic stress syndrome, a doctor says, as officials confirmed he had been living in Mexico illegally.

Jose Salvador Alvarenga, a fisherman from El Salvador, washed up on a remote Pacific atoll over a week ago, telling a remarkable story of floating 12,500 kilometres from Mexico in his 24-foot boat after the engine broke down.

He initially appeared to be in good spirits and reasonable health, but he has been in and out of hospital since being brought to the Marshalls capital Majuro last Monday.

At a media conference on Thursday, the 37-year-old was sullen and uncomfortable, mumbling a short thank-you to people in the Marshall Islands before departing the venue clutching two men for support.

Franklyn House, a retired American doctor working with the California-based Canvasback Missions group in the Marshall Islands, has observed and spoken with Alvarenga several times since his arrival, although he is not the attending physician.

Fluent in Spanish, House said he believes Alvarenga is suffering post-traumatic stress syndrome because of the change in his demeanour from Monday when he was engaged with doctors to being withdrawn on Thursday.

"The first couple of days he was in the hospital, he was engaged and normal," House told AFP. "Thursday he showed signs of post-traumatic stress."

A diplomat from El Salvador's embassy in Japan, Diego Dalton, met with the castaway and "confirmed that the health of Mr Alvarenga is broken", the country's foreign ministry said in a statement.

"His physical condition has to improve for him to begin the return trip, which does not have a defined date," it added.

Alvarenga, who said he survived on a diet of raw fish and birds while drinking turtle blood, urine and rainwater, is also suffering from dehydration and back problems.

Manila-based Mexican diplomat Christian Clay Mendez, who jetted in to help handle Alvarenga's repatriation, said he had been in Mexico illegally for 15 years, which is why he would go back to El Salvador.

But he said that if after his return to El Salvador, he "goes through the proper channels, I'm sure that our embassy people in El Salvador would be more than willing to assist in getting him to Mexico legally".

"We'd be willing to look into that," he added.