Heavy rains and flooding have killed at least 38 people in Bolivia according to the Bolivian Defence Ministry, as authorities declared a state of emergency in response to the crisis.

The floods have washed away people's homes and are causing illnesses, survivors said on Friday.

In the northeastern department of Beni, navy and army officials came together as they prepared to reach isolated communities cut-off by the floods.

Officials reported that over 17,000 hectares of prime agricultural land has been flooded across Bolivia, devastating subsistence farmers and leaving communities without food and drinking water.

According to local media, the intense rains which had started in October 2013, have affected nearly 45,000 families in more than 100 municipalities, around five times more than last year, with the central and northern regions of the country hardest hit.

Captain Jose Ramiro Prado Flores told Reuters they will try and reach communities near the Secure River.

"We're on our way to Santa Maria together, it's about a 39-hour journey and there we will distribute the aid which is rice, sugar, noodles, oil and flour to all coastal communities of the Secure River," he said.

Medics will join army officials in the journey as officials fear the spread of disease in flood-ravaged regions.

"This is a hospital boat that will provide medical services, that will assist also in giving food but could also evacuate people voluntarily is they would like to go back to the city of Trinidad or any community that could have them in healthy conditions," said Presidency Minister Juan Ramon Quintana.

With relentless rains expected to batter parts of Bolivia until mid-March, some believe the recent floods could be worse than the country's devastating 2007 "El Nino" floods which displaced nearly half a million people.