Fiji's Health Ministry has sent teams to the eastern and central divisions to assess health risks following Cyclone Tomas.
One person has been confirmed dead and UNICEF estimates that about 150,000 people could have been directly affected by the cyclone.
Disaster management officials are assessing the damage and health teams will try to determine any possible sources of infection and raise public awareness.
This comes in light of a typhoid outbreak, in which 114 people have been confirmed ill over the past weeks.
The ministry's spokesperson, Iliesa Tora, says health staff are concerned about people contracting water borne diseases following the destructive winds and rain.
"We've just had typhoid cases before the cyclone and that's something we're concerned about. We're also concerned about other things, like leptospirosis and diarrhoea, especially that now in the rural areas the water system would be affected in some way. That's a concern to us also."
Communications continue to be difficult.
Ratu Mikaele Radodro, who is originally from Taveuni but lives in Suva now, says most phone lines to his home island are down, but he managed to speak to his family.
Ratu Mikaele says the storm has badly affected three villages and a few additional settlements.
Most of the houses have been blown off. The community is a farming community and the crops have been badly damaged. About 25 people were in the hospital when the roof was taken off, mostly from the maternity unit.
Ratu Mikaele says New Zealand and Australian air force staff have dropped supplies to the villagers, including tents, when they flew over the area to assess the destruction.