Cholera

Question 1

Cholera Learning objectives

Answer 1

– Describe the causative agent for Cholera and
human exposure
– Describe infection and transmission
– Disease burden globally
– Disease burden in South Africa
– Describe risk factors for the disease transmission
– Methods for prevention and control

Question 2

What is the Causative agent of Cholera?

Answer 2

The agent was first identified by Robert Koch in 1883
• Caused by a Gram-negative bacteria called Vibrio cholerae
• Survives in both fresh and saltwater
It has 200 serogroups.

A serogroup =a group of serotypes with similar but distinguishable serological reactions

Question 3

The two Serogroups that cause epidemic

Answer 3

Two serogroups (O1 and O139) or types of Vibrio cholerae bacteria can produce cholera toxin that causes the disease we call cholera. About 1 in 10 people infected with cholera toxin-producing O1 or O139 Vibrio cholerae experience severe, life-threatening illness, and both serogroups can cause widespread epidemics.

Serogroups are further differentiated into serotypes Inaba or
Ogawai

Question 4

O1 serogroup

Answer 4

• classical (highly virulent, with high mortality) – caused 2 major
pandemic waves
• El Tor (low virulence, as a result has greater spread)- responsible for
the 7th pandemic

Question 5

The History of Cholera.

Answer 5

Cholera has its origins in the Bay of Bengal
• Earliest western record of Cholera epidemics dates
back to the 16th century with cases recorded in India
• Global pandemics of ‘‘Asiatic cholera’’ were first documented in 1817
• Occasional outbreaks in China due to trader contact
and in the Middle East due to the pilgrims
• Since 1817 it spread globally due to colonization, industrialization, military conflicts, and mass migration

Question 6

The six pandemics of Cholera

Answer 6

from 1817 on and off till 1923

Question 7

Cholera was the first disease that what?

Answer 7

• First disease for which modern public health surveillance, monitoring, and reporting was implemented in terms of the International Health Regulations.
• Several African countries (including South Africa) affected by Cholera.

Question 8

The 7th Cholera pandemic

Answer 8

-Started in 1961 caused by
V. cholerae O1 El Tor

-Lower virulence of El Tor results in less severely ill, thus more
mobile, hosts capable of infecting others over a longer period of
time
• Spread across continents

• Major outbreaks in the past 40 years occurred in Peru in 1991,
The Soviet Union from 1961 onwards, and South Africa from August
2000

• This pandemic has persisted for 40 years and shows no sign of
abating

Question 9

The Epidemiology of Cholera currently

Answer 9

• Occurs in tropical and sub-tropical climates of
the world
• Communities with poor access to water and
sanitation
• Majority of affected people live in Africa and
Asia

Question 10

In Africa most outbreaks are caused by

Answer 10

El Tor serotype Inaba / Vibrio cholerae O1

No cases of O139 have ever been reported in Africa

Question 11

Cholera in South Africa.

Answer 11

– March 1974- cases on the mines in eastern Gauteng
– 1978 – 3 tourists who contracted cholera locally
– 1980-1987, 25251 cases of cholera (serotype Inaba)
were bacteriologically proven (Gauteng, KZN)
– However, the majority of the cases isolated in the
2008/2009 outbreak in SA was serotype, Ogawa.

Question 12

Cholera is Category 1 notifiable disease in South Africa. What does that mean?

Answer 12

It means that Cholera requires immediate reporting by the most rapid means
available upon diagnosis followed by a written or
electronic notification to the Department of Health within
24 hours of diagnosis by health care providers, private
health laboratories or public health laboratories;
– Reported to the National Institute of Communicable
Diseases

Question 13

Cholera Modes of Trnasmission

Answer 13

• Faecal contaminated water or food is the most important source of infection

• Both symptomatic and asymptomatic people
secrete infective bacteria in their stool

• Cholera is communicable for as long as bacteria is secreted in stool

• Can be person-to-person transmission via:
– Contaminated water and food
– Contaminated cooked or uncooked fish
– Eating food or drinking water with contaminated hands.

Question 14

Risk factors for Cholera.

Answer 14

1. Demographics
2. Socio-economics
3. Water sources and availability
4. Food
5. Latrines
6. Hygiene
7. Social behavior
8. Blood type
9. Gastric acidity
10. HIV

Question 15

Social behavior, Blood type, Gastric acidity, HIV as risk factors for Cholera.

Answer 15

Social behavior
– Close contact with known case of cholera increase risk of infection
– Attending mass gatherings and funerals increased the risk for disease

• Blood type
– higher risk of symptomatic cholera among patients with blood group O

• Gastric Acidity
– Decreased acidity increases the risk for disease
– positive Helicobacter pylori immunoglobulin G was associated with risk of
cholera

• HIV
– Increased risk with HIV positivity

Question 16

Food, Latrines, and Hygiene as risk factors for Cholera.

Answer 16

• Food
– Consuming partially cooked or raw food is a risk factor
– Consuming food outside of the home or from street vendors increased
risk of disease
– Drinking water from rivers with infestation increases the risk of disease
– Vitamin A deficiency is a risk factor
– Breastfeeding is protective

• Latrines
– Open defaecation and communal toilets increase the risk of disease
– Access to flush toilets decreases the risk of infection

• Hygiene
– Handwashing with soap and water decreased the risk of disease
– Washing all utensils before use decreases the risk
– Washing hands after using the toilet decreased the risk
– Bathing in water infested with cholera increases the risk

Question 17

Demographics, Socio-economics and Water sources and availabity as Riak factors for Cholera.

Answer 17

• Demographics
– Variable information on age and sex. No strong evidence to suggest that anyone’s age group or sex is more affected than the other.

• Socio-economics
– Households from a lower socio-economic grouping are at greater risk of
getting the disease.

• Water sources and availability
– River sources and water stored in containers increase the risk of infection
– Having to walk distances to get water was associated with increased risk
– Chlorination of water decreases the risk of disease.

Question 18

Cholera Symptoms and signs.

Answer 18

Untreated mortality can be as high as 50% amongst those who are

1, Painless watery diarrhea [rice water stool, with flecks of mucus]
2. Nausea and profuse vomiting may happen early in the onset.
3. Majority are febrile [kids more than adults]
4. Results in rapid dehydration
5. Muscle cramps, acidosis, peripheral vasoconstriction, and ultimately
renal and circulatory failure, arrhythmias, and death may occur if treatment is not given timeously.

infected,
#People infected with the agent are highly infectious- they
contaminate water and food sources with which they come into
contact with

Question 19

What happens the V Cholerae gets i nto your body?

Answer 19

• Short incubation period (2-5 days / in a few hours)
• V Cholerae produces enterotoxins that damage the gastrointestinal
mucosa.

Question 20

Diagnosis of Cholera

Answer 20

Mainstay is based on case definition and
laboratory diagnosis
• Case definition
– In an area where cholera is not known to be present you have a patient who develops severe dehydration or dies from acute
watery diarrhea
– In an area where there is an outbreak and a patient develops
acute watery diarrhea with /without vomiting

• Laboratory diagnosis
– Stool specimen confirming V. cholera O1 or O139
– Serogroup of Vibrio and antimicrobial sensitivity must
be collected.

Question 21

Treatment of Cholera

Answer 21

• Rehydration is very important
– Oral rehydration solution (ORS) / IV fluids
• Antibiotic: Ciprofloxacin for 3 days
• Children ≤ 5 years should be given zinc (10-14 days)
• Feed as soon as possible. Breastfed children continue
feeding throughout the illness
• Discharge when
– No longer dehydrated
– Can take ORS
– No vomiting

NB: ineffective treatments: anti-diarrhoeal medication; sugar
drinks

Question 22

ORAL CHOLERA VACCINE (OCV)

Answer 22

• Two oral doses (7-14 days apart) of OCV protect for at
least three years ( children <6 yrs give 3 doses)
• Average efficacy of about 58% and effectiveness of 76
% (lower in children < 5 yrs)
• Since 2013, 56 campaigns in 15 countries and more
than 13 million doses administered
• OCV stockpile has allowed for an increasing trend
toward cholera vaccine use in affected countries
• Effectively bridging emergency response and longer-term cholera control with a WASH focus

Question 23

The two main objectives of Control and Prevention of Cholera

Answer 23

– Reduce transmission, morbidity and mortality
– Reduce mortality (CFR<1%) by ensuring access to
timely and good quality treatment

Question 24

Global Task Force on Cholera Control (GTFCC)

established with aims of:

Answer 24

– Global Roadmap to 2030: Ending Cholera
– Aim is to reduce cholera deaths by 90%
– Focus is on
• Early detection and quick response to contain
outbreaks
• A targeted multi-sectoral approach to prevent cholera
recurrence
• An effective mechanism of coordination for technical
support, advocacy, resource mobilization, and
partnership at local and global levels

Question 25

EARLY DETECTION AND RESPONSE TO

CONTAIN OUTBREAKS

Answer 25

• Early warning surveillance systems
– Confirmation of suspected cases
– Good laboratory culture and diagnostic capacity
– Monitoring outbreaks and tracking strains

• Pre-positioning stocks of essential supplies
– ORS, IV fluids, cholera kits, cold chain equipment

• Preparedness and implementation of water,
sanitation and hygiene (WASH) systems
• Community engagement
• Mass vaccine campaigns with OCV
• Preparedness of the health care system,
– set-up of dedicated health care facilities (Cholera Treatment Centers
(CTCs) and Cholera Treatment Units (CTUs)) and training of HCWs [health care workers]

Question 26

BASIC WASH PACKAGE

Answer 26

• Basic water supply: access to safe drinking water sources
(either household connection, public standpipe, borehole, protected dug
well, protected spring, or rainwater collection) within a 30-minute round-trip
plus household or other disinfection
• Basic sanitation: access to improved sanitation facilities
(connection to a public sewer, connection to a septic system, pour-flush
latrine, simple pit latrine, ventilated improved pit latrine)
• Basic hygiene: access to a hand-washing station with soap and
water for every household
• Community engagement to manage WASH resources and
to promote safe hygiene practices

Question 27

COMMUNICATION WITH PUBLIC [about an outbreak]

Answer 27

• Media plays a very important role in
communicating with the public to get messages
out to the public.
– Radio, television, posters, newspapers and public
talks (schools, grant days, churches, clinics)
– Clear and precise messages
– Adapt messages to social, cultural and economic
circumstances of target communities ( example
chlorine / soap may not be affordable)

Question 28

Messages To The Public

Answer 28

• Drink safe water
• Purify water- 5mls chlorine in 20-25 litres of water mixed and
allowed to stand for at least 2 hrs (preferably overnight) before
use
• Safe disposal of human waste – do not contaminate water
sources
• Do not eat contaminated / uncooked / partially cooked food ·
• Foods of vegetable origin should be peeled or shelled
• Boil milk and water before drinking
• Breastfeed babies where possible
• Go to a health facility if you have watery diarrhoea.
• Follow national guidelines for burial/ cremation of the deceased

Question 29

FOOD SAFETY

Answer 29

• Environmental Health Practitioners important to
monitoring food safety in restaurants and street
vendors
• Health education should include
– Exclude infected persons from food preparation
– Prepare food under hygienic conditions
– Wash fruit and vegetable with clean water
– Cook food thoroughly and eat when hot
– Prevent contamination of food by flies or infected water
– Wash hands after using the toilet and prior to preparing food
– Do not eat from a communal container
– Reheat leftover food

Question 30

Prevention of disease occurrence by targeting multi-sectoral interventions in cholera hotspots includes:

Answer 30

• Identifying of hotspots requiring priority action and
analysis of local transmission pattern.
• Implementing a package of selected effective
control measures adapted to the local transmission
pattern

Question 31

• Identifying of hotspots requiring priority action and analysis of local transmission pattern.

Answer 31

– Accurate morbidity, mortality and environmental data on cholera
– Risk and vulnerability assessment in hotspots
– mapping of existing safe water sources, sanitation systems,
capacities for surveillance , existing isolation treatment facilities and
quality of health service delivery, and community engagement.

Question 32

• Implementing a package of selected effective control measures adapted to the local transmission pattern.

Answer 32

– Strengthening surveillance, health systems
– Sustaining WASH
– Large scale Oral Cholera vaccination
– Community participation and cross-border collaboration

Question 33

An effective mechanism of coordination for technical support,
resource mobilization, and partnership at local and global levels.

Answer 33

• Nationally-led cross-sectoral cholera control
programs
– Each country must have a national program
– Multi-sectoral action must be led by national
governments of cholera-affected countries

• The GTFCC as a strong coordination platform
– goal of the GTFCC is to support national and inter-country capacities by providing a strong platform for
advocacy and communications, fundraising, inter-sectoral coordination, and technical assistance.

Question 34

What is meant by GTFCC?

Answer 34

Global Task Force on Cholera Control.