By Sebastien Malo

NEW YORK (Thomson Reuters Foundation) – Hurricane Matthew, which slammed into Haiti this week, has created the worst humanitarian crisis in the impoverished nation since a devastating earthquake hit six years ago, according to the United Nations.

The storm ripped through Haiti on Tuesday, causing heavy flooding and knocking down houses.

Citing Haitian authorities, a spokesman for U.N. Secretary-General Ban Ki-moon said at least 350,000 people needed immediate assistance.

The full impact remained unclear, however, with communications down in many of the worst-affected areas.

Here are what some of the world’s leading aid agencies expect will be humanitarian needs in Haiti in the storm’s wake.

Helene Robin, Handicap International’s head of emergency operations:

“Initial information reaching us is worrying. Many affected people have lost their homes, crops, and livestock. We will have to face a logistical challenge to reach these very remote areas and provide humanitarian assistance which these isolated populations need. We also fear that the floods caused by Hurricane Matthew entail substantial health risks such as the spread of cholera.” Carlos Veloso, World Food Programme’s country director:

“Because of the severity in the south, we expect that certain roads will be closed and we need to repair them immediately. The second big challenge will be the access to populations in the mountains in the south. Normally access here is not easy, and with a hurricane the strength of Matthew it will become more difficult.” Sylvie Savard, country representative in the joint office of the Lutheran World Federation and Diakonie Katastrophenhilfe in Haiti:

“The most affected groups are those most vulnerable living in areas along the coast, in low lying areas or close to steep slopes. Many people, especially in rural areas, live in poorly constructed homes that could not stand up to the winds and rains. People have been evacuated to save their lives, but the storm and the floods will have swept away what little they have.” Jean Claude Fignole, Oxfam’s influence program director in Haiti:

“Our first response will concentrate on saving lives by providing safe water and hygiene kits to avoid the spread of cholera. Right now there are at least 10,000 people displaced from their homes and in need of safe shelter, water and food.” Ravi Tripptrap, Malteser International Americas’ executive director:

“The floods have been particularly damaging in the slum community of Cité Soleil. Sewage canals are overflowing and filling the streets with garbage and human waste; make-shift shanty homes have been washed away. This is where our help is needed.”

(Reporting by Sebastien Malo, Editing by Ellen Wulfhorst. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women’s rights, trafficking, property rights and climate change. Visit http://news.trust.org)