More than a month since floods started ravaging Pakistan’s northwest region, relief workers on the ground say the emergency will “get worse before it gets better.”

Not only has up to half of the affected population – 17 million – still not been reached since towns and farmland were flooded by water from extremely heavy monsoon rains, but the situation is continuing to deteriorate.

Unsanitary conditions and a lack of clean water are causing outbreaks of diarrhea and concerns about cholera. Children, wearing the same muddy clothes for days, are developing skin diseases, and many families are unable to begin the grieving process and bury their dead because there is no dry land on which to bury them.

"What we hear from the people living in the camps is that they are hanging on, surviving on what little food and water they receive, wearing the clothes they escaped the floods in, and trying to keep their children and livestock alive," reported Mike Bailey, regional advocacy manager for Christian relief group World Vision. "The truth is that, despite of the amount of aid that has already been provided in some places, many people are in worse shape now than they were two weeks ago."

According to World Vision, access to the hardest-hit areas remains one of the biggest challenges in this disaster. Some towns, including those in Punjab, are still inaccessible more than four weeks after the flooding began as the floods have significantly damaged roads and bridges. Communication is also difficult due to damaged telephone lines; mobile phone networks are still not functioning in many of the worst-affected areas.

So while the United Nations, the Pakistani army and a host of local and international relief groups have rushed aid workers, medicine, food and water to the affected regions, they are unable to reach many of the eight million people who are in need of emergency assistance.

"It's still difficult to assess the full extent of the damage, but we know that children and families are still in desperate need of the most basic things like food, clean water, and shelter," said Bailey. "Even when we focus on providing the most urgently-needed relief supplies, we've still been able to reach just one-tenth of the people we're trying to help in the next three months."

Earlier this week, the World Food Program said it needed 40 heavy helicopters to airlift food to the 800,000 people cut off from the heavily damaged road network.

Last Saturday, the United States said it would deploy an additional 18 helicopters to help with the relief effort. The U.S. military is already operating 15 helicopters and three C-130 aircraft in the country, the U.S. Embassy said in a statement.

Meanwhile, donors have given about two-thirds of the $460 million the U.N. requested for emergency aid, according to the head of the World Food Program. But the food agency itself has less than half the money it needs to feed those affected.

For weeks now, local authorities have been struggling to cope with the disaster that has overwhelmed the Pakistani government and international partners who have stepped in to help.

The floods started about a month ago in the northwest after extremely heavy monsoon rains and have slowly surged south along the Indus River, devastating towns and farmland. More than 1,600 people have died and 17 million have been affected by the floods.

According to reports, water levels are beginning to drop in southern Pakistan as the floodwaters flow down the Indus River into the Arabian Sea - a good sign given the growing number of cases of severe diarrhea and malaria caused by dirty water that offers a perfect breeding ground for insects and disease.

The United Nation's World Health Organization said Tuesday that more than 500,000 cases of acute diarrhea and nearly 95,000 cases of suspected malaria have been treated since the floods first hit.

Once all the floodwaters recede, the country will still be left with a massive relief and reconstruction effort that will cost billions of dollars and take years. An estimated one million homes have been damaged or destroyed - five times as many as were hit by this year's earthquake in Haiti.

The scale of the disaster has raised concerns about the stability of nuclear-armed Pakistan, which is already reeling from al-Qaida and Taliban violence and massive economic woes.