Fiji's Ministry of Health says it fears disease could affect those hit by last week's massive flooding.
The clean up continues in Western, Central and Northern arts of Viti Levu which saw the were worst damage to roads, buildings and other infrastructure.
Many homes will need to be cleaned properly before people can inhabit them again, due to the risk of disease.
A Health Promotion officer, Philip Komai, says he advises people to take extra precautions, but admits it is difficult as some areas still have no electricity or clean water.
"Try and maintain cleanliness, even though we understand that they are in flooded areas, and some of their homes may still be flooded, but we are informing the people right now after the flood, when the flood is passed, there is now the possibility of diseases outbreak such as typhoid, the diarrhoea, the dengue, the leptospirosis as well as scabies."
Philip Komai says officials are advising for water to be boiled, food to be kept properly while urging people not to eat condemned food from shops.
And he is also urging people to use proper toilet facilities where possible.
An appeal has started in Fiji today to get the children back to school in the worst flood affected areas.
The school term in the country starts next Monday.
Fijivillage reports various media, including Communications Fiji Limited radio stations and the website fijivillage, have organised the appeal that will run until next Saturday.
It's to raise funds to assist children to go back to school.
Meanwhile, Fiji's interim government estimates the recent flooding has caused damage totalling about 30.5 million US dollars.
The interim Minister for Indigenous Affairs, Ratu Epeli Nailatikau, says damage to water and sewerage totals about 4.7 million US dollars, to roads 8.3 million US dollars, to agriculture 14.5 million US dollars, and damage to health 288 million US dollars.
Ratu Epeli says these are preliminary figures until the actual cost assessment is completed.
And the Nadi Chamber of Commerce is pleading with the interim Government to pressure commercial banks to defer all loan repayments for the next six months to help those affected by the floods especially the business community.
The Fiji Times reports the Chamber president, Dr Ram Raju, says most businesses in Nadi had been destroyed and it would take members at least six months to rebuild their business.
Dr Raju says members are appealing to the Minister for Commerce and the bank managers to defer all loan repayments.
He says soft loans should be made available to business owners trying to start again.
Dr Raju says some businesses will collapse because they lost everything in t he floods.
However, he is optimistic the business community and the public of Nadi would bounce back from the disaster.
Dr Raju said they have met with the Fiji Electricity Authority which has assured businesses that power will be restored this week
Meanwhile, Fiji police are urging people to exercise caution while being housed at flood evacuation centres, after an alleged rape of a 14-year old evacuee.
A 20-year old male tertiary student is now being questioned by police over the incident and the girl has sought help from victim support agencies.
Police say the girl was allegedly raped while taking a bath in a nearby river.
A spokesperson for Fiji police, Ema Mua, says people who dont know each other are often thrown together during a disaster type situation, and police are advising people to move around in groups and stay with people they know.
We have also cautioned evacuees to exercise security themselves y'know in terms of looking after the children and all that, knowing their whereabouts because when this type of incident happens, then we realise it too late.
Fiji police spokesperson, Ema Mua
Officials say just over 4,000 people remain in emergency shelters on Viti Levu, mostly in the Western Division.