During the 2015 El Nino drought, communities have suffered from the lack of safe and clean water, says Dr Mike Bourke, Papua New Guinea's prolific agricultural and demographic expert.
Dr Bourke said the water shortage became a reality earlier during the drought and was widespread, causing difficulties for people to get sufficient and safe water for drinking and washing.
This increased the labour tasks for women and girls to travel long distances looking for water, he added.
Many communities found it "difficult to wash their bodies and clothes" and there were instances of "increase in skin and internal diseases," said Dr Bourke, who is also a senior research fellow at the Australian National University.
Dr Bourke made these comments when giving a mid-December update on the impact of frost and drought in PNG during a seminar in Port Moresby this week.
He added that while communities managed to get water somehow, there was great concern for the "purity" of it.
Dr Bourke said some districts and schools saw school closures, either partial or total closure.
"Grade 9 and 11 students in Namatanai (New Ireland) were sent home because there was no more water in the tanks.
"Water supply issues remain in some locations," he said.
The water shortage was experienced across all parts of the country, with varying intensities across locations.
Dr Bourke said the impact of the present drought and frost will continue between December-January despite the rain received.
He said there had been widespread rain between November and December but the amount received was "not universal".