At least 217 people have died in the worst cholera outbreak to have hit Sierra Leone, according to humanitarian officials.
Oxfam, British-based charity organisation, said on Thursday that the disease had reached almost double emergency thresholds with over 12,000 reported cases.
It said the number of people affected is "likely to increase significantly in the next month".
Increasing overcrowding and early rains in cities such as capital city, Freetown, have pushed the number of reported cases spiraling from the previous record of 10,000 in 1994.
Aid groups say there has been a spike in reported cholera cases since mid-July and the onset of the rainy season.
Some 82 deaths have been reported in neighbouring Guinea, while other cases have been seen in Mali and Niger.
Cholera is an infection of the small intestine, contracted by eating or drinking contaminated food or liquids. It can cause acute diarrhoea and vomiting and can kill within hours.
The International Federation of Red Cross and Red Crescent Societies (IFRC) have launched an emergency appeal for $1.14m and have warned that the outbreak risks sparking a wider health crisis unless its causes are tackled more aggressively.
Amanda McClelland, emergency health coordinator for the IFRC, issued a statement saying: "The disease has the potential to cause a serious humanitarian crisis."
She explained that the level of aid coverage was still "very low", adding "it is an urgent to step up our efforts as the situation is deteriorating quickly ... We need more funds to deliver the most effective response".
"We are projecting more cases considering we have a month more of heavy rainfall," she added.
The money spent on tackling the roots of the outbreak so far has been spent on health promotion activities and on helping affected families prepare oral rehydration solutions and build suitable toilets.
Sidie Yahya Tunis, the spokesman for the Health Ministry citied the expansion of the poor suburbs of Freetown as a factor in the disease's spread.
"It's not just that we have more people in the slums, we have more slum areas in the Western Area (around Freetown) as
well," he told Reuters news agency.