Diarrohea is already affecting people living on Vanuabalavu in Fiji's northern Lau islands, as a warning of drought-related outbreaks across the country is issued.
The Metereological Service says the severe drought in Fiji is likely to produce outbreaks of diarrhoea and dengue fever.
But the head of the public health laboratory and communicable diseases says diarrhoea has been a problem on Vanuabalavu since about 2005.
Dr Eric Rafai says with low levels of piped water people are now relying increasingly on water in tanks, which are prone to contamination.
"Some of them are having difficulty boiling water because it's their major complaint is they don't like the taste of the water when it's boiled. So it's an issue of more education for our team on Vanuabalavu."
Dr Eric Rafai says test results determining exactly what is causing the diarrhoea should be available in a couple of days.