Transcript Cholera Prevention 10 Key factors UNICEF West and Central Africa OBJECTIVE OF NORWAY INITIATIVE • Develop systems for cholera prevention and outbreak response and to extend the benefits.

Cholera
Prevention
10 Key factors
UNICEF West and Central
Africa
OBJECTIVE OF NORWAY
INITIATIVE
• Develop systems for cholera
prevention and outbreak response
and to extend the benefits over a
longer time frame to reduce
diarrhoeal disease incidence.
1. What are the symptoms?
• Very rapid onset of vomiting and diarrhoea with
large volumes of very watery (rice water type)
stools (>3 times a day)
• Severe de-hydration, = low pulse, undetectable
blood pressure, sunken eyes, wrinkled hands
and feet
• Slow recovery of shape after depression of skin
• No urine output
• Laboratory confirmation but count all suspected
cases and treat
2. How is it transmitted?
It is caused by a bacterium (Vibrio cholerae) which
lives naturally in brackish/freshwater amoeba,
and is transmitted through -:
• Unsafe water (7/8 investigations in Latin America
identified this as a major route)
• Unwashed fruit and veg (or washed in bad
water), left over rice not re-heated (3
investigations +Lusaka 2004),
• Lack of handwashing (food preparation, hand
shaking, childcare)
• Cooked and uncooked sea food – vibrio survives
light cooking (2 investigations)
3. Who is most at risk?
• Those living near lagoons / low lying areas
with fresh/ brackish water/ fishing populations
• With unsafe water sources
• With poor faecal disposal practices
• With poor personal hygiene
• With poor food hygiene (esp. moist food of
neutral acidity)
• Close to cholera patients in early stages
(hyper-infectivity) and dealing with bodies
4. When does cholera become
epidemic?
• After heavy period of rainfall
• When water temperatures rise
• When normal diarrhoeal incidence
increases
• Endemic cholera with good sanitation
needs permanent source of vibrio, but with
poor sanitation higher secondary
transmission can maintain endemic status
5. How long does it take?
• Incubation period 2hrs-5 days
• Infection 7-14 days, but most people do not
become ill or show any symptoms
• Only about 10-20% of infected people show
moderate or severe symptoms.
• Moderate symptoms difficult to differentiate
from other types of acute diarrhoea
• Group O blood group highest risk
6. How is it treated?
• Greatest risk in first 24 hours, so re-hydrate as
soon as possible
• Normally ORS (rice- rather than glucose-based
reduces purge rate,- sodium = or > 75mmol/l)
• If vomiting, give intravenous fluid replacement
(eg Ringer’s lactate) –extreme cases.
• Give food as soon as patient can take it
• Extreme cases only should have 1-3 days
antibiotic (esp doxycycline single dose) to
shorten illness, when vomiting stops
7. How is it prevented?
• Blocking routes of transmission – water
disinfection (source and /or household),
hand washing, sanitation, good food
hygiene and well-cooked
• Cholera vibrio doesn’t like acid
environment (block with acidic water eg.
With citrus juice, healthy stomach acid
levels, acid food)
• Oral vaccine (Dukoral) only for IDP setting
8. What proportion will die?
• Most people who die, do so within the first day of
symptoms appearing
• Without any treatment about 50% of people
survive
• With adequate re-hydration less than 2% will die
• With good surveillance, rapid establishment of rehydration, and anti-biotics for worst cases, almost
all deaths can be avoided (<0.2% die)
9.Risky cultural practices/
beliefs
The following beliefs about causes of cholera may
reduce effectiveness of key messages -:
• Witchcraft, eye, wind, climatic change cause the
sickness
• Children’s stools are not dangerous
• Soap is believed to wash away luck
The following practices increase risks
• Anal washing is often not followed by hand-washing
• Handshaking transfers bacteria directly from one
person to the next
• Burial ceremonies may spread disease
10. What are Key Messages?
• Bad water is one source of cholera (disinfect
source or stored water) but others, especially
contaminated food (clean and cook well) and
associated lack of hand washing (essential times
and methods for handwashing) should also be
highlighted
• Rapid transfer to clinics or use of ORT corners
speeds up treatment and reduces cross infection.
• Re-hydration as early as possible saves the most
lives- water quality in OR is of little importance
• Good surveillance systems can identify causes and
reduce infection rates
Africa’s global dominance?
Africa's percentage of Global cholera
120%
100%
80%
60%
40%
20%
0%
1996
1998
2000
2002
2004
2006
Country
West Africa
League
Table
(sorted on mortality)
Central African Republic
Congo
Cameroon
Guinea
Mali
Mauritania
Togo
DR Congo
Chad
Niger
Côte d'Ivoire
Nigeria
Burkina Faso
Sierra Leone
Ghana
Benin
Senegal
Guinea-Bissau
Equatorial Guinea
Cape Verde
Liberia
Gabon
TOTAL
Total cases Incidence/1000 Mortality
1997-2004 Ranking
Average
785
18
15.189
8,319
5
11.285
16,556
9
9.639
3,974
14
9.269
6,276
12
8.530
576
19
8.348
8,536
6
6.985
137,349
4
6.743
23,943
3
6.467
4,457
16
5.968
11,239
10
5.495
46,803
15
5.409
2,224
20
4.071
3,472
11
3.829
26,280
7
2.431
7,614
8
2.290
1,598
21
1.890
21,968
1
1.866
59
22
1.695
133
17
0.752
42,497
2
0.474
635
13
0.000
375,293
Incidence/1
0.206579
2.291736
1.051175
0.475359
0.497188
0.200697
1.778333
2.682598
2.867425
0.386088
0.686771
0.387086
0.180813
0.590175
1.283767
1.189688
0.15104
16.15294
0.122661
0.3325
12.81188
0.488462
Typical cholera curve
Endemic 1. Cholera
reservoir, constant or
sporadic few cases
Epidemic. Triggered by
factors in 4. reaches
peak and then preventive
measures dominate
Endemic 2. Continued
levels higher than
endemic 1 while person
to person infection
continues