Only 30 percent of $4.6 million requested to help hundreds of thousands of people affected by Sudan's worst floods in living memory has been received and more heavy rains are expected, aid officials said on Tuesday.

Afaf Bukhari from the Sudanese Red Crescent said 72 people have died in the flooding, 73,839 houses have been partially or completely destroyed, and more than 11,000 cattle have been lost.

Bukhari said aid was needed to provide relief, shelter, and access to clean water, and to establish mobile health units.

"Some 30 percent of the requested amount has been received from a figure of about $4.6 million," she told reporters in Khartoum.

"If they respond very quickly of course we can reach these people very quickly especially in the remote areas where the roads are cut off," she added.

Bukhari also called on the local community to mobilise to help those in need.

The floods have surpassed the levels set in 1988 when a million people forced to flee their homes, the International Federation of Red Cross and Red Crescent Societies said earlier this month.

On Tuesday a World Health Organisation official said a cholera outbreak in Sudan's east had spread because of the floods, killing 49 people.

John Clarke from the U.N. Development Programme (UNDP) said the rains had come early but the response has been effective.

He said the U.N. agencies were preparing in advance for more rains, and undertaking vaccination programmes, education and repairing schools destroyed in the floods.