The death toll for Haiti’s cholera outbreak has reached 544, while thousands more are being treated in hospitals for the intestinal disease that causes severe diarrhoea, vomiting and abdominal pain.

Cholera can be fatal even though it can be easily treated through rehydration and antibiotics. But in a country that lacked access to clean water even before the January earthquake, treatment is not always within reach.

Hurricane Tomas, which brought heavy rains last week, raised fear that the spread of the disease would worsen. Cholera spreads through contaminated water and the hurricane triggered flooding and mudslides in some areas.

“Standing water, mud, lack of garbage collection, and limited sanitation availability make the camps a potential flashpoint for cholera outbreak,” said US-based Partners in Health, according to The Associated Press.

Aid agencies and authorities are currently concerned that the cholera outbreak has reached the capital Port-au-Prince, endangering the 2.5 to 3 million that live there. On Monday, health authorities confirmed to AP that a three-year-old boy who has not travelled outside of the city has the disease. There are at least another 114 suspected cases of cholera in Port-au-Prince being tested.

The cholera outbreak in Haiti began in late October and hit the Artibonite Valley, an agricultural area, the hardest. There was no documented case of cholera outbreak in Haiti before last month.

Christian relief and development agencies are working in Haiti to respond to the outbreak.

Compassion International, which has worked in Haiti since 1968, has child development centres that are providing purified water, water sanitation tablets and water filtration systems to the Compassion-assisted children and their families.

“Without access to clean water, inexpensive medical treatments and basic education, the poor in Haiti as well as other countries will continue to suffer and die needlessly from survivable disease,” wrote Mark Hanlon, senior vice president of Compassion US, in a recent column. “The only way to effectively beat these ancient enemies that prey on the poor is to defeat poverty.”

Baptist World Aid, the relief and development arm of the Baptist World Alliance, has sent more than $12,000 to Haiti to fight against the cholera outbreak. The funds will be used to transport patients, pay for medical aid and supplies, and get clean water to those in need, according to Baptist Haiti Mission, the local member body.

Meanwhile, Water Missions International, an engineering relief and development Christian nonprofit, recently sent 20 water treatment systems that is en route to Haiti. Each water treatment system designed by the group can be set up and operational within two hours and provide 5,000 Haitians with their daily water needs for less than a penny per person per day. The water systems being sent will provide 100,000 Haitians with access to sustainable, safe water.

“We have to remember that hundreds of thousands of Haitians are living under pieces of plastic and even small winds could be devastating,” said George Greene III, Water Missions International founder, in a statement Friday. “The potential for a significant cholera outbreak in these conditions multiplies.”

Water Missions International has already sent 115 water treatment systems to Haiti. The organisation installed 10 additional systems in October in response to the cholera outbreak, providing 50,000 more people in the Artibonite Valley with safe water.