The medical aid organisation, Medicins sans Frontieres, says the death toll from Papua New Guinea's latest outbreak of cholera is around 300, and more deaths are expected.
The head of mission, Hernan del Valle, says the outbreak in Western Province, which has been raging for about five weeks, will continue to spread.
PNG has been beset by cholera for the past 16 months with the northern provinces and then Port Moresby affected but the disease is claiming many more lives in Western Province.
Mr del Valle says poor transport and communication facilities mean there is little surveillance of the disease and that's why the death toll is so high.
"We are working on it. There has been response from the provincial health authorities but my concern at this point is that the response is confined to Daru Island, which is just a small island in the south of the province and now the cholera is in the Middle Fly regions going up north, and we don't have enough data from the region. We are despatching a team to go there."