Inside a cholera treatment centre Luanda, Angola, March, 2006

The CTC itself is quite basic: at the entrance there is a disinfection area where everyone is sprayed with chlorine, to kill the bacteria that cause cholera. Cholera is highly contagious so it's crucial that infected people are isolated and anyone who comes into contact with them is disinfected.

There is also a triage area for newly arrived patients, a pharmacy, water points, latrines, and several large tents with rows upon rows of beds. Each bed has a hole in the middle and two buckets underneath, one labelled 'vÃ?³mito' the other 'excremento'.

It would be easy to be shocked by the indignity of it all, but the only way to treat cholera is to allow patients to flush the bacteria out of their bodies and to rehydrate them as quickly as possible. For those who reach a centre in time, recovery is fast.

Most patients at the centre are put on intravenous drips containing Ringer's lactate fluid to rehydrate them. MSF staff work around the clock putting people on these drips, a doctor might do up to fifty IVs in one morning. Once patients are on the drips they must be constantly monitored. If too much is given to a young child, there is the risk of flooding their lungs. If it is not given quickly enough to an adult, they could die from dehydration.

When a cholera outbreak is first suspected, stool samples are used to diagnose the illness.

By the time that a CTC is set up, such tests are hardly necessary. The majority of people coming to the centre will be infected, with the most severely affected easily identifiable by what one nurse describes as 'cholera eyes' - sunken eyes that show no recognition of the people around them, or their surroundings.

Most patients in this centre are from Boa Vista, one ofluanda's biggest slum areas where the cholera outbreak has been most severe. Yet parents such as Florinda Mateus, whose five-year old son is receiving treatment, find that with limited public transport, getting to the CTCs is not always easy:

"I saw the notices on TV about cholera so I knew to bring Nelo here, but the normal buses wouldn't take us so I had to call a taxi. They charged me 1,500 kwanza, much more than usual, because they knew my son was ill."

Other patients reported they were too scared of being robbed to come to the centre at night, so each morning the CTC sees a surge in patient numbers. Often this delay means patients are so dehydrated when they arrive at the centre that little can be done for them.

Public education is integrated into a cholera response, to help prevent the spread of the illness, but unfortunately cholera prevention is not just a question of knowledge. As Julia Parker, who helped organise such education in Angola says "The people we've been talking to in Luanda know they should wash their hands and treat their water but the conditions here just don't favour good hygiene."