In the cramped and unsanitary environment of a refugee camp, disease can spread extremely quickly.

Merlin, one of the 12 groups on the Disasters Emergency Committee, says there are already unconfirmed reports of hepatitis C at one of the camps.

Dr Bruce Laurence, medical director of Merlin, said simple steps could help prevent the spread of disease.

But Albania, Europe's poorest country, lacks the facilities to ensure all those who need help get it, he said.

The current situation

Dr Laurence outlined the current situation for BBC News Online.

Refugees need basics like blankets and shelter

He said: "The danger at the moment is that people are very exposed to the elements without adequate shelter.

"The other danger is the overcrowding in the camps without adequate sanitation and perhaps even limited supplies of clean water and not enough food.

"The big dangers of this are diarrhoeal diseases such as dysentery and respiratory diseases such as pneumonia.

"There have been many cases reported of physical trauma - gunshot wounds, beatings, rapes - and mental trauma due to displacement and loss of loved ones."

He also said there were unconfirmed reports of an outbreak of hepatitis C in the Albanian border town of Kukes.

Future risks

There have already been reports of cases of measles in the camps, and the disease could have a massive impact if not kept in check, Dr Laurence warned.

He said: "Many of the people crossing the border, particularly children, may not have been immunised - and the immunisation programme in Kosovo will not have been very good in recent years.

Typhus was also a concern for the future, he said.

"We've just had a communication from our team in the field saying typhus is a big worry," he said.

Steps to fend off disease

"What is needed wherever there are refugees are the basics of shelter, blankets, food, water, sanitation, drugs and medical care."

Aid agencies' first job is to establish the scale of health problems

He said Merlin's first task would be to assess the situation on the ground and then to take preventive measures to ensure disease cannot gain a foothold in the camps.

These would aim to improve sanitation. A vaccination programme could then be launched.

"Dealing with it from the curative end isn't enough - we have to take preventive measures and make sure people are given what they need," Dr Laurence said.

At the same time, the charity will monitor the health situation.

"One of the things you need in a situation like this is good health information so you can follow the diseases that are taking hold, people's nutrition status and vaccination status."

Establishing clinics

However, aid agencies would in some circumstances have to set up their own clinics to be able to provide the necessary care.

"Ideally, we'll work through whatever local clinics there are, but, remembering that Albania is the poorest and least developed part of Europe, if we find areas where they are not functioning then we will have to set up our own clinics."

These would be basic tent clinics run by doctors and nurses especially brought in to the region.

But Dr Laurence warned that it was not necessarily the refugees whose health was most at risk.

"The biggest problem - and the biggest number of people affected - is in Kosovo, and there's no access to them.

"It may be that nearly half a million people now have come out, but that still leaves a million people inside and no-one is able to see them or help them at all.