(SOUNDBITE) (English) MEDECINS SANS FRONTIERES (DOCTORS WITHOUT BORDERS) EMERGENCY CO-ORDINATOR, GERT VERDONCK, SAYING: ''Of course, the spread of any kind of epidemic will be a lot quicker here." These people are waiting for medical treatment in Mozambique's city of Beira.
Nurses distribute a chlorinated concentrate - a temporary solution to prevent the spread of waterborne disease - an inevitable result of Cyclone Idai which has left a total of 1.85 million people in need of help, according to the U.N..
Cholera - if left untreated - can kill within hours.
(SOUNDBITE) (English) MEDECINS SANS FRONTIERES (DOCTORS WITHOUT BORDERS) EMERGENCY CO-ORDINATOR, GERT VERDONCK, SAYING: "As long as food supply is not restored, as long as water supply is not restored, as long as there is no chlorination of the water and people are now in dire need as we have seen people drinking water from the streets that were still standing there and yeah, this (spread of disease) will go very quickly." At least 686 people across Mozambique, Zimbabwe and Malawi have already been reported killed by the cyclone which made landfall on March 14.
Subequent disease could claim still more lives.
The secretary general of the International Federation of the Red Cross (IFRC) described the situation as a '"ticking bomb.'' 900,000 doses of oral cholera vaccine is being dispatched by the World Health Organisation.
The shipment is expected to arrive within 10 days.
Aid is slowly getting to those stranded as the water recedes.
This is the Portuguese navy delivering 800 kilograms of food by boat to hundreds of people in Buzi on Monday.
But Mozambique's disaster zone is roughly the size of Luxembourg...and getting help to the most needy remains difficult.
On Tuesday, the United Nations' humanitarian agency asked for 282 million dollars to fund the first three months of the disaster response.
So far, only 2 percent of that amount has been funded.