V. cholerae - Filippo Pacini

Cholera in the AMERICAS: Peru 1991 and
Haiti 2010, lessons for XXI century
EDUARDO GOTUZZO, M.D. FACP,FIDSA
Chief, Department of Infectious Diseases, Tropical Medicine and
Dermatology - HOSPITAL NACIONAL CAYETANO HEREDIA
Director, Institute of Tropical Medicine “Alexander von
Humboldt” - UNIVERSIDAD PERUANA CAYETANO HEREDIA
SIMPOSIUM FILIPPO PACINI.-PISTOIA JUNE 2012

EPIDEMIOLOGY
THE AGENT
PATHOPHYSIOLOGY
CLINICAL PICTURE
TREATMENT
PREVENTION AND CONTROL
RECENT EPIDEMICS

EPIDEMIOLOGY
Transmission
» fecal-oral route; foodborne and waterborne
» person to person
Reservoir
» acquatic environments; free living cycle, non-culturable state
» human reservoir
Infectious dose; 10 2
to 10 6
Incubation period; 14h to 5 days
Endemic vs. epidemic patterns
Seasonality; warm seasons

EPIDEMIC AND ENDEMIC PATTERNS
Feature Epidemic Endemic
Age at greatest risk all ages.- children (2-15)
mainly adults
Transmission single route many routes
Reservoir absent acquatic
humans
Asymptomatic infection less common more common
Secondary spread high low
Type of studies to evaluate risk factors
case-control cohort studies

SEVEN PANDEMICS OF CHOLERA
Pandemic Year Comments
1 1817-23 Fisrt epidemic in the modern era
2 1829-51 Herman in Russia conceived the idea of giving
intravenous fluids
O´Shaugnessy and Latta infused saline
solutions to 15 patients; 5 survived
3 1852-9 Filippo Pacini coined the name V. cholerae
John Snow; the role of water, 1855
4 1863-79 Cholera was considered a moral problem
5 1881-96 Koch identified the Kommabacillen, 1883
6 1899-1926 Rogers reduced mortality with IV fluids
7 1961 .... Cash reported the succesful use of ORS
Greenough reported the utility of tetracycline in
severe cholera

THE PANDEMICS OF CHOLERA
Seventh Previous six
Pandemic Pandemics
Place of origin Celebes Islands India-Bangladesh
Time to reach India 10 years immediately
Biotype El Tor Classical
Duration, y more than 40 12 (mean)
Resistant strains common uncommon
Asymptomatic common uncommon
carriers

EPIDEMIOLOGICAL DIFFERENCES BETWEEN
THE TWO BIOTYPES OF V. cholerae O1
%
100
80
60
40
20
0
El Tor Classical
Asymptomatic
Some
dehydration
Severe
dehydration

LEADERS ACQUIRING CHOLERA
• Peter Tchaikovsky
• George Hegel
• George Baron Cuvier
• Duke of Wellington
• Thomas Hodgking
J. Inf. Dis. 1984, 6(6):802

LIFE CYCLE OF Vibrio cholerae

Vibrio cholerae

THE AGENT
Vibrio cholerae is a Gram negative bacilli, facultatively
anaerobic, motile and curved
It grows in alkaline conditions (6

MODEL FOR THE TRANSMISSION OF CHOLERA FROM
THE ENVIRONMENT TO HUMANS

Vibrio cholerae ON THE SURFACE OF A
COPEPODE

PATHOPHYSIOLOGY
V. cholerae O1 and O139 have one or more copies of
the genes ctxA and ctxB that encode the cholera toxin
the cholera toxin has 2 sub-units: A or active and B for
binding to a specific receptor, ganglioside GM1
the A sub-unit activates the adenylate cyclase enzyme
increasing cAMP levels:
» promotes secretion of chloride by crypt cells
» blocks absorption of sodium and chloride by villus cells
the role of other toxins is less clear; zone ocludens,
shigella like toxin, accessory enterotoxin

ELECTROLYTE CONCENTRATIONS IN CHOLERA STOOLS
AND COMMON SOLUTIONS USED FOR ITS TREATMENT
Na + Cl - K + HCO3 -
Cholera stool
adults 130 100 20 44
children Intravenous solutions
100 90 33 30
Ringer´s lactate 130 109 4 28*
Dhaka solution 133 154 13 48
Normal saline 154 154
WHO ORS 75 65 20 10**
Concentrations are in mmol/L, * lactate instead of bicarbonate, ** trisodium citrate

“ At Athens a man was seized with cholera. He
vomited, and was purged and was in pain, and
neither the vomiting nor the purging could be
stopped; and his voice failed him, and he could
not be moved from his bed, and his eyes were
dark and hollow, and spasms from the stomach
held him, and hiccup from the bowels. He was
forced to drink, and the two (vomiting and
purging) were stopped, but he became cold “
HIPPOCRATES

STOOL SAMPLE OF A CHOLERA PATIENT
rice watery diarrhea with a fishy odour

A CHOLERA PATIENT FROM DHAKA, ICDDR,B

STOOL SAMPLE OF A CHOLERA PATIENT

Number of cases x 1000
500
400
300
200
100
0
NUMBER OF CHOLERA CASES REPORTED
TO WHO, 1984-2005
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Asia Africa America
Weekly Epidemiological Record 2006;81:297-308.

FOODBORNE TRANSMISSION
Country of origin Year Implicated food
Italy 1973 Raw shellfish (mussels)
Portugal USA
1974 Raw shellfish (cockles)
Louisiana 1978 Cooked crabs
Texas 1981 Cooked rice
Colorado 1988 Raw oysters
Imported, Ecuador 1991 Cooked crabs in salad
Imported, Peru 1991 Shrimp and fish in salad
Peru 1991 Cooked leftover rice
cebiche, eating at street
vendors

CLINICAL FINDINGS BY DEGREE OF DEHYDRATION
Some
Severe
Loss of body weight 5-9% > 9%
Mentation Radial pulse
alert-restless drowsy, coma
rate normal-rapid very rapid
intensity weak feeble
Respiration normal-deep deep-rapid
Skin elasticity normal retracts slowly
Eyes normal very sunken
Voice normal-hoarse not audible
Urine production normal oliguria

SITUATION OF PERU DURING 1991
• Hyperinflation around 2 million per cent
• Crowding of the population along big cities; terrorism
• Unemployment
• Lack of sanitation and water supply
• El Niño

WATER SUPPLY AND SANITATION
• International drinking water and sanitation decade
» the goal was to extend and upgrade municipal and
village water and sanitation in Latin America in the 80s
» public water sources in 88% of urban cities and 55% of
rural villages during 1988
» 49% of urban populations were served by sanitary
sewerage systems before 1990
• Intermitent water delivery, suction in water lines
• 75% of water systems did not treat water properly
• less than 10% of all sewage was treated correctly

THE CHOLERA EPIDEMIC IN PERU
The epidemic started simultaneously in three distant cities
along the coast, during the third week of January 1991
In less than three months all major cities reported cases
Very high attack rates, but low case fatality rates
High case fatality rates in rural areas of the jungle
More than 25000 cases per week in 1991
Waterborne and foodborne transmission; cebiche
From where did V. cholerae originate ?

From where did V. cholerae originate ?
23 Oct, 24 and 29 Dec 1990
11 December 1990
26 Dec 1990, and 16 Jan 1991
• PIURA (28 Jan 91)
• CHICLAYO
• TRUJILLO
13 January 1991
• CHIMBOTE (24 Jan 91)
• CHANCAY (23 Jan 91)
• LIMA
Seas C. Am J Trop Med Hyg 2000;62:513-7.
Distance from Lima
1050 Km
763 Km
570 Km
440 Km
60 Km

El Niño Current
Humboldt Current

Study case control-CHOLERA CASES
Cayetano Heredia Hospital
(Feb-Mar 1991)
Risk factors
1. Drink water outside the home
2. Consume food from street vendors (chicha, ice cream
fresh cheese)
3. Relative with diarrhea
4. Unemployed people

RISK FACTORS FOR CHOLERA, PERU 1991
Risk factor Cases Controls OR (95%CI)
Drinking unboiled water 62 30 3.8 (1.5-9.8)
59 28 3.1 (1.3-7.3)
Adding ice to beverages 88 63 4.0 (1.0-17)
Drinking on street vendors 56 19 17.0 (2.2-133)
Eating on street vendors 26 5 8.0 (2.2-29)
Eating cool leftover rice 38 22 2.1 (1.1-4.5)
Drinking boiled water 62 92 0.1 (0.02-0.5)
Drinking acidic beverages 52 77 0.4 (0.2-0.7)

ENVIRONMENTAL SPREAD OF CHOLERA IN PERU
Sample V. cholerae/dl
Lima
sea water 10 4
river water 10 3
municipal sewage 10 5
finfish (skin, intestines) present
Titicaca lake, Puno 4
River water, Iquitos 10 3
Sea water, Callao 10 4
Tamplin ML, Carrillo CC. Lancet 1991;338:1216-7.

NEW ISSUES IN PREVENTION AND CONTROL
• Detecting V. cholerae in the environment:
» detection of V. cholerae O1 in the environment
preceded the appearance of cases in the community
by 2-3 months
» detection of V. cholerae O1 in the sewage of Lima city
preceded the appearance of cases
• Abundance of V. cholerae O1 correlates with the
abundance of copepods. Plankton mass and displacement
can be explored by using satellite images
• The integration of several disciplines including
epidemiology, marine biology, microbiology, medicine, and
satellite imagery may prevent global epidemics

THE CHOLERA EPIDEMIC IN PERU

ACUTE RENAL FAILURE AT CAYETANO HEREDIA
HOSPITAL DURING 1992
incidence rate was 10.6 per 1000 (19,826 studied), higher
among the elderly; 10% vs 1.3%
non-oliguric ARF predominated
59% required dyalisis
mean duration (SD) of hospitalization 11.2 (7.2) days
overall case fatality rate was 18%:
» higher in oliguric ARF; 26% vs 4%, p

CHOLERA IN ESPECIAL POPULATIONS
Cholera in children:
» clinical presentation is similar
» more atypical findings; fever, seizures and coma
» hypokalemia, hyponatremia and hypoglycemia are
more commonly seen compared to adults
Pregnants:
» clinical presentation is similar
» 50% of fetal death during third trimester
Cholera in the elderly:
» high rate of complications
» high mortality rates

PRINCIPLES OF REHYDRATION THERAPY
Rapid replacement of fluid deficits
Correction of metabolic acidosis
Correction of potassium deficits
Replacement of continuous fluid losses

PRACTICAL GUIDELINES FOR THE
TREATMENT OF CHOLERA
1 Evaluate the degree of dehydration on arrival
2 Rehydrate patients in two phases
a rehydration phase: lasts 2-4 hours
b maintenance phase: until diarrhea abates
3 Register output and input in pre-designed charts, and
review the data collected periodically

PRACTICAL GUIDELINES FOR THE
TREATMENT OF CHOLERA
4 Use the IV route only to rehydrate:
a severely dehydrated patients; rate of infusion during
rehydration phase 50-100 ml/Kg/h
b patients with some dehydration not tolerating PO
c high stool purgers (>10 ml/Kg/h) during maintenance
5 Use ORS for all patients during the maintenance phase
at a rate of 800-1000 mL/h, matching ongoing losses
6 Discharge patients only if:
a oral tolerance 1000 ml/h
b urine output 40 ml/h
c stool volume 400 ml/h

ANTIMICROBIALS IN CHOLERA
their use is not lifesaving
effective antimicrobials reduce:
» the volume of stools by half
» the excretion of vibrio
» fluid requirements for rehydration
single dose regimens are preferred
tetracyclines are the first choice, but resistant strains
have emerged recently
erythromycin or quinolones are alternatives against
resistant strains

CHOLERA IN ZAIRE, 1994
• 1.2´Hutus fled Rwanda to Kivu-Zaire during the second
week of July 1994
• 3 days later V. cholerae O1, Inaba, El Tor, resistant to
tetracyclines and cmx, was isolated from a patient with
diarrhea
• 32000 cases in approximately one month
• CFR: 8-23%, 50% did not receive therapy
• utility of available vaccines in preventing the spread of
cholera
• the epidemic of cholera was followed by an epidemic of
multiresistant S. dysenteriae type 1

CHOLERA IN CONGO

COUNTRIES WHERE V. cholerae O139 CASES
HAVE BEEN DETECTED
Countries 1993 1994 1995 1996 1997 1998
Bangladesh + + +
China + +
India + + + +
Indonesia +
Malaysia + +
Myanmar + +
Nepal + +
Pakistan +
Sri Lanka +
Thailand + +

CHOLERA. PREVENTION AND CONTROL
Early case-finding
Establishing treatment centers
Treatment of cases
Epidemiological investigations
Laboratory support
Health education
Water supply and food safety
Sanitation
Restriction of trade and travel

Cholera 1991
THIS PANDEMIC COULD PRODUCE 3-4
MILLION CASES WITH A MORTALITY OF
30,000 IN LATIN AMERICA
Carlyle Guerra De Macedo (PAHO)

THE CHOLERA EPIDEMIC IN PERU
Incidence x 100,000
100
80
60
40
20
0
TOTAL NUMBER OF CASES/CUMULATIVE
INCIDENCE RATES (X 100,000)
1991 322,562/1434
1992 239,139/1066
1993 62,366/278
1994 23,887/106
1995 15,628/69
1991 1992 1993 1994 1995

Number of cases x 1000
CHOLERA IN THE AMERICAS: NUMBER OF
NOTIFIED CASES, AND CASE FATALITY RATE
1991-2005
500
400
300
200
100
0
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Number of cases Case fatality rate (%)
2
1.5
1
0.5
0
Case fatality rate (%)

NUMBER OF CASES AND NUMBER OF
COUNTRIES REPORTING CHOLERA, 1990-2005
Number of cases x 1000
800
700
600
500
400
300
200
100
0
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Number of cases Number of countries
Weekly Epidemiological Record 2006;81:297-308.
100
90
80
70
60
50
40
30
20
10
0
Number of countries

CHOLERA AMONG TRAVELERS
Taylor D. et.al. CID 1996;22:1109-10.
Travelers from/to Year Incidence (x100,000)
USA/Asia 1960-80 0.17
Western nations/Asia 1991 0.05
Western nations/Ecuador 1991 0.30
Japan/Bali 1991 13.0
USA embassy employees 1991-3
all employees 30.0
U.S. citizens 44.0
Peruvian citizens in Lima 136.0

HOST RISK FACTORS
Age
Malnutrition
Pregnancy
Breast feeding
O blood group
Infection by Helycobacter pylori*
Other conditions that reduce gastric acidity
* León-Barúa R. Trans R Soc Trop Med Hyg. 2006;100:567-72

ROLE OF O BLOOD GROUP
• Hospitalized patients with cholera were most likely to
be of O blood group than controls
• Volunteers carrying the O blood group presented
more severe diarrhea when challenged with V.
cholerae O1
• In a study conducted in Lima; people with O blood
group had almost 5 times higher risk to acquire
severe cholera than people with other blood groups:
( RR 4.8, 95%CI 2.2-10.7)
• The underlying mechanism is not clearly understood

IMPACT OF THE CHOLERA EPIDEMIC
• effect of El Niño during 1991
• reduction in trade, commerce and tourism
» reduction in exportation of fish and shellfish
» reduction in exportation of all agricultural products
» severe reduction of tourism
• positive impact
» international cooperation
» investment in sanitation and water supply

Positive aspects of cholera epidemic
• Investment in environmental sanitation
• Application of medical and public health knowledge to
control
• Reduction >30% in children mortality
• A notable reduction in Typhoid fever

T.F.: Impact of cholera in Peru

CHOLERA IN THE WORLD: 1996-2005
Cholera during 1996-2005 is almost confined to Africa:
» 95% 95%
of the world cases in 2005 are reported from Africa
» 31 African countries are reporting cases in 2005
» continuing epidemics in Ghana, Guinea-Bissau, Mauritania
and Senegal
» uneven distribution of CFR: 18% in Guinea to 0.22 in South Africa
» trend toward reduction in CFR over the last 7-8 years
Marked reduction in the number of cases and CFR from
Asia and Latin America
Weekly Epidemiological Record 2006;81:297-308.

NEW ISSUES IN PREVENTION AND CONTROL
Detecting V. cholerae in the environment:
» detection of V. cholerae O1 in the environment preceded the
appearance of cases in the community by 2-3 months
» detection of V. cholerae O1 in the sewage of Lima city
preceded the appearance of cases
Abundance of V. cholerae O1 correlates with the
abundance of copepods. Plankton mass and displacement
can be explored by using satellite images
The integration of several disciplines including
epidemiology, marine biology, microbiology, medicine, and
satellite imagery may prevent global epidemics

Cholera slides from Bangladesh
• 1. Epidemiology: 4 years of surveillance 4 different areas of Bangladesh
in
• 2 Predicting outbreaks from environmental assays
• 3. Zoolplankton with V. cholerae
• 4. Phytoplankton with V. cholerae
• 5. Satellite imaging.of Bangladesh and Bay of
Bengal, during no epidemics epidemic.
and during large

In October 2010, epidemic cholera broke out in
Haiti
• Cholera had not been reported in Haiti for more than a century 1
• Disease spread rapidly in the absence of natural immunity,
clean water, and proper sanitation 2
Deaths
(n)
140
120
100
80
60
40
20
0
Total deaths, Haiti, 20 October 2010–4 April 2011 3
20/10/10
27/10/10
03/11/10
10/11/10
17/11/10
24/11/10
01/12/10
08/12/10
15/12/10
22/12/10
29/12/10
05/01/11
12/01/11
19/01/11
26/01/11
02/02/11
09/02/11
16/02/11
23/02/11
02/03/11
09/03/11
16/03/11
23/03/11
30/03/11
Week beginning
Since the 1st laboratory-confirmed case report of cholera was made on
19 October 2010, cholera has killed >4500 people in Haiti 3
1. Chin C-S et al. N Engl J Med 2011;364:33-42; 2. Cyranoski D. Nature 2011;469:273-4;
3. PAHO. Available at http://new.paho.org/blogs/haiti/?p=1959

ien ha echado el Vibrio cholerae en el rio Artibonite?
Agua potable:un lujo mas que un derech

The cholera epidemic has not been contained
within Haiti
• Since the beginning of the outbreak in Haiti, imported
cases have been notified in various countries, including
the Dominican Republic
» The 1st laboratory-confirmed case was reported in the
Dominican Republic on 16 November 2010 1
» In the same week, the US reported an imported case
in a patient from Florida 1
» Up to 26 February 2011, there were 568 laboratorylaboratoryconfirmed cases and 6 deaths in the Dominican Republic 2
1. PAHO. Epidemiological Alert (23 November 2010). Available at: http://new.paho.org/hq/index.php?
option=com_content&tak=view&id+1239&Itemid=1091&lang=en;
2. PAHO. Epidemiological Alert (February 8 to 26, 2011). Available at:
http://new.paho.org/hq/index.php?option=com_content&task=view&id=5153&Itemid=2206

analysis
demonstrate
s close
identity
between
Haitian and
South Asian
El Tor O1
cholera
strain
Cholera was most likely imported to Haiti by
visitors from South Asia
The Haitian
strains do
not resemble
Latin
American
cholera or
Chin C-S et al. N Engl J Med 2011;364:33-42
strains

Polluted water is the most common source of
cholera transmission
Life cycle of V. cholerae
Large
volumes of
hyperinfective
V. cholerae
3
4
Poor sanitation
Poor people are more vulnerable
to infection with V. cholerae
Discharge in the environment
5
Epidemic
spread of
cholera
Free-swimming
V. cholerae
Non O1,
O139
Genetic
exchanges
O1, O139
2
1
V. cholerae attached to
aquatic life forms
Contaminated
food and water

Contact with freshly shed V. cholerae is much
more likely to cause disease
Transmission via contaminated
water (higher ID 50 ) accounts for
slower dynamics
Transmission through contact with
fresh feces or vomit (lower ID 50 )
causes explosive epidemics

Crowding and poor sanitation exacerbate
cholera transmission
Cholera is transmited
vi a
t h e f ec al –or al r out e,
with epidemics often
ocuring after war,
civil unrest, and natural
disasters, when water or
fod suplies become
c ont ami nat ed wi t h
V . c h ol er ae, compounded
by crowded living
conditions with
l i mi t ed s ani t at i on
Zuckerman JN et al. Lancet Infect Dis 2007;7:521-30

A multiple approach is critical for effective and
sustainable cholera control
• Safe water
• Food safety
Remain as longterm
preventive
• Sanitation
measures
• Health
Fast-acting education supplementary measure:
implementation of vaccination
WHO. Weekly epidemiological record 2010;85:117-28. Available at: http://www.who.int/wer/2010/wer8513.pdf

Vaccine against cholera:
easy administration, no needle, no pain
Dukoral
• Licensed in 60 countries (first licensed in
1991)
• High acceptance
• Excellent tolerability
• Local intestinal and systemic immunity,
providing herd protection
• Prequalified by the WHO for United Nations
purchase
• Previous use during complex emergencies in
Indonesia, Sudan and Uganda, as well as in
the urban slums of Mozambique
Waldor MK et al. N Engl J Med 2010; 363:2279-2282

Reactive mass vaccination can prevent cholera
cases and deaths
The number of cases that would have been prevented during the 2008-2009 outbreak in
Zimbabwe using the currently licensed 2-dose oral cholera vaccine
Total
cholera
cases
Attac
k
rate/
1000
Rapid
response a
Total number (%) of
cholera cases prevented
(50% vaccine coverage)
Delayed
response b
Maximum
delay c
Rapid
response a
Total number (%) of
cholera cases prevented
(75% vaccine coverage)
Delayed
response b
Maximum
delay c
98,591 7.39 34,900 (40) 12,789(13) 474 (0) 59,100 (60) 19,183 (19) 711 (1)
Population 13,349,000, outbreak duration 54 weeks
A rapid response with 50% vaccination coverage could have prevented
34,900 (40%) cholera cases and 1,695 (40%) deaths
a 10 weeks between 1st reported case and total community immunization;
b 21 weeks between 1st reported case and total community immunization;
c 33 weeks between 1st reported case and total community immunization
Reyburn R et al. PLoS Negl Trop Dis 2011;5:e952

Is the need to choose between options for cholera
control in Haiti still reasonable?
Improvements in provision of clean water and sanitation have not been
sufficient so far, in Haiti or elsewhere 1,2
Maintaining provision of clean water and sanitation can be difficult 3
The incidence of new cases may increase with the upcoming rainy
season 4
Endemic cholera may persist in Haiti at the end of the current epidemic,
with continued intermittent outbreaks generating more cases and deaths
than previously estimated 3,5
Averting even a modest number of cases will save lives 6
However, large scale cholera vaccination remains
difficult to implement due to limited vaccine
supply 1-6
1. Ryan ET. PLoS Negl Trop Dis 2011; 5(1): e1003;
2. Waldor MK et al. N Engl J Med 2010; 363:2279-2282;
3.Sack DA. Lancet 2011; 377:1214-1216
4.Andrews JP and Basu S. Lancet 2011; 377:1248-1255;
5. Chao DL et al. Proc Natl Acad Sci USA 2011;108:7081-7085;
6. Tuite AR et al. Ann Intern Med 2011;Mar 7 [Epub ahead of print]

Ministerio de Salud
Dirección General de Epidemiología
Situación Actual del Cólera en Haití
al 17 de abril del 2011
Departamentos Población
Desplazados
15%
Artibonite 1299398 162509
Central 581505 90997
Grande anse 363377 119871
Nippes 263551 33351
North 823043 13531
North Est 309918 8500
Nord Ouest 531198 45862
Ouest 3096967 660885
Sud 621651 88533
Sud est 484675 32253
Total 8375283 1256292
Desplazados: Post terremoto 12 de enero 2010

Summary
• Epidemic cholera broke out in Haiti in October 2010,
with >4500 deaths to date
• Cholera was most likely imported to Haiti from South Asia by human
activity
• Cholera follows a fecal–oral route of transmission,
is characterized by acute profuse watery diarrhea,
and can kill the patient within a day
• WHO recommends reactive oral cholera vaccines alongside
treatment, provision of clean water, and improved sanitation to
control endemic and epidemic cholera
• Large-scale vaccination in Haiti is difficult to implement due to
limited vaccine supply, as well as potential for relaxation of
sanitation and diversion of other healthcare resources, but would
save a substantial number of lives

Pre-emptive and reactive cholera vaccination are
recommended by WHO for outbreak control
• Pre-emptive vaccination should be used to prevent potential
outbreaks and contain actual outbreaks,
targeting at-risk groups
» During complex emergencies that compromise water
and sanitation
» When neighboring regions experience an outbreak
» When disease incidence increases in an endemic region
• Reactive vaccination should be considered, depending on local
factors
• Vaccination for outbreak control must achieve
high population coverage
• Vaccination should be in conjunction with treatment, provision of
clean water, and improved sanitation
WHO. Weekly epidemiological record 2010;85:117-28. Available at: http://www.who.int/wer/2010/wer8513.pdf

NEW ISSUES IN PREVENTION AND CONTROL
• Detecting V. cholerae in the environment:
» detection of V. cholerae O1 in the environment
preceded the appearance of cases in the community
by 2-3 months
» detection of V. cholerae O1 in the sewage of Lima city
preceded the appearance of cases
• Abundance of V. cholerae O1 correlates with the
abundance of copepods. Plankton mass and displacement
can be explored by using satellite images
• The integration of several disciplines including
epidemiology, marine biology, microbiology, medicine, and
satellite imagery may prevent global epidemics

CHANGING PATTERNS IN
CHOLERA EPIDEMICS
Cholera is still a major public health problem in
developing countries
Changes in the agent, the environment, and the host
promote cholera transmission
The implementation of effective and timely emergency
preparedness programs is urgently needed
Predicting future epidemics will require multidisciplinary
work

“ The scientific community and world
leaders must therefore work together
to use knowledge and its applications
to improve the conditions of the
planet. The connection between
cholera and the environment provides
a paradigm for this perspective”
Colwell RR. Intern Microbiol 2004;7:285-9.

“ From the time the cholera
proclamation was issued, the local
garrison shot a cannon from the
fortress every quarter hour, day and
night, in accordance with the local
superstition that gun powder purified
the atmosphere”
Gabriel García Márquez. Love in the time of cholera