Fears are growing for the health of former U.S. President George Bush, Snr. after he was admitted to an intensive care unit.

The ex-leader, 88, was taken to a hospital in Houston, Texas last month (Nov12) for treatment to a bad cough following a bout of bronchitis, but he was still in the medical centre over the festive holidays after developing a fever.

Now it has emerged Bush, Snr. was transferred to an intensive care unit on Sunday (23Dec12). His spokesman says the former politician has suffered "a series of setbacks including a persistent fever".