A nurse on the Vanuatu island of Emae says overcrowding is making people more vulnerable to disease.
Donald Kalsong is the Nurse in charge of the Vaemauri Health Centre which serves around 1200 people in the Shepherd group.
Mr Kalsong says he has seen many cases of diaarhoea, colds and influenza since last week's cyclone.
He says many people are without shelter.
"People get too crowded altogether after their homes have been damaged so it's likely that it transmits very fast because they are crowded altogether sharing kitchen utensils and towels and all this."
Mr Kalsong says the health centre was also severely damaged.
"The roof went off and we don't have much shelter to treat patients. Since our roof of the clinic, the outpatients and the general ward are damaged so so far we don't have enough space for treating patients."