20 January 2001
WHO case definition for suspected cholera: A case of cholera should be suspected when
in an area where the disease is not known to be present, a patient
aged five years or more develops severe dehydration or dies from acute
in an area where there is an outbreak of cholera, a patient aged
five years or more develops acute watery diarrhoea, with or without vomiting.
MSF case definition for presumed cholera:
Any patient developing a rapid onset of severe watery diarrhoea
(usually with vomiting), resulting in severe dehydration.
Patients must be quickly rehydrated with oral rehydration salts (ORS)
or Ringer's lactate, depending on the level of dehydration and
conscious level. Recommendations on the proportion of patients that
need intravenous treatment vary with the guidelines: the WHO states
80?0% of cholera can usually be adequately treated with ORS solution
alone, and that 20% of the patients can be rehydrated by intravenous
treatment. However experience has shown that this proportion is too
low for refugee settings and that it can reach 75%, probably because
the proportion of severe dehydration is higher.
CHOLERA TREATMENT UNIT
The decision to open such a unit should be taken early (eg when five
new cases are being admitted daily).
CHOLERA TREATMENT UNIT REQUIREMENTS
The estimated number of daily patient admissions should be calculated
on the basis of the expected attack rate (around 5% in camp
situations), the size of the population, the expected duration of the
outbreak (which should be estimated at one month to ensure optimal bed
capacity), the average length of hospitalisation (three days) and the
stage reached in the outbreak (there will be more patients at the
For instance, in a camp population of 50,000 people:
2,500 cases can be expected during the course of the outbreak
(attack rate of 5%)
In refugee camps, overcrowding, poor sanitation and inadequate water
supplies combined with the disorganisation of services have
considerably increased the risk of cholera epidemics.
Although cholera is a major killer, it should be remembered that acute
diarrhoea - due to other causes than cholera - kills far more than
cholera in refugee settings.
According to the WHO, a cholera outbreak should be suspected when
a patient older than five years develops severs dehydration or dies
from acute watery diarrhoea, or
there is a sudden increase in the daily number of patients with
acute watery diarrhoea, especially patients who pass 'rice water'
stools typical of cholera.
In refugee or displaced settlements, any adult death by dehydration is
thus highly suspect.
An outbreak is declared as soon as there is a single
In open situations, the attack rate mostly varies from 1-2%, while in
refugee camps, around 5% of the population may be expected to develop
clinical cholera. The rate has been even higher in some epidemics.
Cholera is a disease that can rapidly kill if left untreated: up to
50% of patients may die in the absence of treatment.
In most refugee or displaced populations, cholera is a significant
health risk, and particularly high when populations come from, or pass
through or settle in a cholera-infected area.