BANGKOK (AFP) - Thailand's hospital-bound King Bhumibol Adulyadej is still being treated for fever and water on the brain, the palace said Monday (Aug 1) in the latest in a series of updates on the 88-year-old's health.

The world's longest-reigning monarch is widely revered and his frail health is a matter of great public concern.

He is confined to a wheelchair and has not been seen or spoken in public for nearly a year.

But in recent months the palace has begun releasing regular updates on his health.

The king's reign has spanned seven tumultuous decades and most Thais have never known another monarch.

Analysts say a decade-long political crisis is in part motivated by elites jostling for primacy once his reign ends.

Bhumibol has spent most of the past two years in hospital in Bangkok for a series of ailments, including bacterial infections, breathing difficulties, heart problems and hydrocephalus - a build-up of cerebrospinal fluid often dubbed water on the brain.

In the latest statement by the Royal Household Bureau on Monday night, doctors said they continued to use antibiotics to treat the infections causing his fever.

"After taking antibiotics his condition has got better but he still has some fever," the statement said.

Doctors added that they had continued to adjust a catheter to drain excess spinal fluid, with satisfactory results.

Bhumibol is seen by most Thais as a unifying force in a nation bitterly divided along political lines.

Schoolchildren learn of his good works, cinemagoers must stand for the royal anthem and giant portraits of the monarch tower over most major roads.

But detailed discussion of his reign and the role of the monarchy is all but impossible in Thailand because of one the world's strictest lese majeste laws.

Use of the laws has skyrocketed in the last two years since the military took over in a coup, with some people jailed for as much as 30 years.