, PLEASE USE THIS DOCUMENT AS A GUIDE ONLY
Question 1
1.1 Apply the WHO ten (10) steps of an outbreak investigation to Cholera in South Africa.
Applying the WHO Ten Steps of Outbreak Investigation to Cholera in South Africa
The World Health Organization's ten-step framework provides a structured and systematic approach
to investigating and controlling outbreaks. When applied to cholera in South Africa, these steps offer
a comprehensive pathway from early detection to long-term prevention. The recent experiences with
cholera outbreaks in 2023 and 2024 demonstrate the practical relevance of this framework in guiding
an effective public health response, as documented by the National Department of Health (2023).
Step 1: Prepare for Fieldwork
The first step involves establishing a multidisciplinary investigation team and securing the necessary
logistical resources before an outbreak occurs. This proactive preparation is essential for a swift and
effective response. In South Africa, this translates to ensuring that rapid response teams are
pre-identified and trained, comprising epidemiologists, laboratory scientists, environmental health
practitioners, clinicians, and risk communication experts, according to guidelines published by the
World Health Organization (2018). Logistical preparation includes prepositioning supplies such as
rapid diagnostic tests (RDTs), specimen transport media like Cary-Blair, oral rehydration salts, and
intravenous fluids in high-risk areas. The National Department of Health (2023), in collaboration
with partners like the World Health Organization and UNICEF, works to coordinate these elements
to ensure readiness for a potential outbreak. A key output of this step is the development and regular
updating of a national cholera preparedness and response plan, as recommended by the World Health
Organization (2018). The outbreak investigation team must also establish communication protocols,
secure transport arrangements, and ensure that all personnel have access to personal protective
equipment before fieldwork commences.
Step 2: Establish the Existence of an Outbreak
This critical step involves confirming that the number of observed cases exceeds the expected
baseline for a specific time and place. For cholera in South Africa, this requires reviewing routine
surveillance data from the Notifiable Medical Conditions system to detect any unusual increase in
acute watery diarrhea cases. The National Institute for Communicable Diseases (2023) has
documented that South Africa maintains a surveillance system where cholera is a notifiable condition,
enabling the detection of signals that may indicate an outbreak. The World Health Organization
(2018) emphasizes that establishing the existence of an outbreak requires comparing current case
numbers against historical data for the same season and geographic area, considering factors such as
population growth and improved reporting. In the 2023 outbreak, an increase in cases in
Hammanskraal, Gauteng, triggered this verification process, leading to the formal declaration of an
outbreak once the epidemiological threshold was exceeded. This step also involves notifying national
and international health authorities, including the World Health Organization under the International
Health Regulations, as required by South Africa's obligations as a signatory to these regulations.
, Step 3: Verify the Diagnosis
Step three requires laboratory confirmation of Vibrio cholerae to ensure that reported cases are
accurately identified. In South Africa, this involves collecting stool specimens from suspected cases
and transporting them to the National Health Laboratory Service or other designated laboratories for
culture and confirmation, as described by the National Institute for Communicable Diseases (2023).
Rapid diagnostic tests (RDTs) may be used in field settings for early screening, but the World Health
Organization (2018) recommends that all positive RDT results be confirmed by culture to maintain
specificity. Laboratory confirmation not only validates the outbreak but also enables antimicrobial
susceptibility testing to guide treatment decisions. During the 2023 outbreak, the National Institute
for Communicable Diseases (2023) played a central role in confirming cases and providing
laboratory support to provincial health authorities. Verification of diagnosis also involves ruling out
other causes of acute watery diarrhea, such as rotavirus or enterotoxigenic Escherichia coli, to ensure
that control measures are appropriately targeted.
Step 4: Formulate a Working Case Definition
The fourth step involves developing a clear and practical case definition that distinguishes suspected,
probable, and confirmed cases. The World Health Organization (2018) provides standard case
definitions for cholera, which are then adapted to the specific outbreak context. In the South African
context, a suspected case is typically defined as any person aged two years or older with acute
watery diarrhea (three or more loose stools in 24 hours) with or without vomiting, in an area where
an outbreak is occurring. A confirmed case is one with laboratory confirmation of Vibrio cholerae
O1 or O139 by culture or polymerase chain reaction. This case definition is communicated to all
healthcare facilities and field teams to ensure standardized case identification and reporting, as
recommended by the World Health Organization (2018). The case definition must be reviewed and
revised as the outbreak evolves and more information becomes available about the affected
populations and transmission patterns.
Step 5: Find and Count Cases
Step five involves systematic case finding to identify all affected individuals and generate a line list
for analysis. Active surveillance is essential, as passive reporting often underestimates the true
burden of disease, according to the World Health Organization (2018). In South Africa's cholera
outbreaks, this involves visiting healthcare facilities, conducting community door-to-door searches,
and reviewing mortality records to identify missed cases. The National Department of Health (2023)
coordinates this process through district health teams, ensuring that all confirmed and suspected
cases are recorded on standardized case investigation forms. The line list includes demographic
information, clinical presentation, laboratory results, exposure history, and outcome data, enabling
systematic tracking and analysis. During the 2023 outbreak, enhanced surveillance was implemented
in affected communities to identify all cases and contacts, with data entered into the electronic
Notifiable Medical Conditions system for real-time monitoring, as described by the National Institute
for Communicable Diseases (2023).
Question 1
1.1 Apply the WHO ten (10) steps of an outbreak investigation to Cholera in South Africa.
Applying the WHO Ten Steps of Outbreak Investigation to Cholera in South Africa
The World Health Organization's ten-step framework provides a structured and systematic approach
to investigating and controlling outbreaks. When applied to cholera in South Africa, these steps offer
a comprehensive pathway from early detection to long-term prevention. The recent experiences with
cholera outbreaks in 2023 and 2024 demonstrate the practical relevance of this framework in guiding
an effective public health response, as documented by the National Department of Health (2023).
Step 1: Prepare for Fieldwork
The first step involves establishing a multidisciplinary investigation team and securing the necessary
logistical resources before an outbreak occurs. This proactive preparation is essential for a swift and
effective response. In South Africa, this translates to ensuring that rapid response teams are
pre-identified and trained, comprising epidemiologists, laboratory scientists, environmental health
practitioners, clinicians, and risk communication experts, according to guidelines published by the
World Health Organization (2018). Logistical preparation includes prepositioning supplies such as
rapid diagnostic tests (RDTs), specimen transport media like Cary-Blair, oral rehydration salts, and
intravenous fluids in high-risk areas. The National Department of Health (2023), in collaboration
with partners like the World Health Organization and UNICEF, works to coordinate these elements
to ensure readiness for a potential outbreak. A key output of this step is the development and regular
updating of a national cholera preparedness and response plan, as recommended by the World Health
Organization (2018). The outbreak investigation team must also establish communication protocols,
secure transport arrangements, and ensure that all personnel have access to personal protective
equipment before fieldwork commences.
Step 2: Establish the Existence of an Outbreak
This critical step involves confirming that the number of observed cases exceeds the expected
baseline for a specific time and place. For cholera in South Africa, this requires reviewing routine
surveillance data from the Notifiable Medical Conditions system to detect any unusual increase in
acute watery diarrhea cases. The National Institute for Communicable Diseases (2023) has
documented that South Africa maintains a surveillance system where cholera is a notifiable condition,
enabling the detection of signals that may indicate an outbreak. The World Health Organization
(2018) emphasizes that establishing the existence of an outbreak requires comparing current case
numbers against historical data for the same season and geographic area, considering factors such as
population growth and improved reporting. In the 2023 outbreak, an increase in cases in
Hammanskraal, Gauteng, triggered this verification process, leading to the formal declaration of an
outbreak once the epidemiological threshold was exceeded. This step also involves notifying national
and international health authorities, including the World Health Organization under the International
Health Regulations, as required by South Africa's obligations as a signatory to these regulations.
, Step 3: Verify the Diagnosis
Step three requires laboratory confirmation of Vibrio cholerae to ensure that reported cases are
accurately identified. In South Africa, this involves collecting stool specimens from suspected cases
and transporting them to the National Health Laboratory Service or other designated laboratories for
culture and confirmation, as described by the National Institute for Communicable Diseases (2023).
Rapid diagnostic tests (RDTs) may be used in field settings for early screening, but the World Health
Organization (2018) recommends that all positive RDT results be confirmed by culture to maintain
specificity. Laboratory confirmation not only validates the outbreak but also enables antimicrobial
susceptibility testing to guide treatment decisions. During the 2023 outbreak, the National Institute
for Communicable Diseases (2023) played a central role in confirming cases and providing
laboratory support to provincial health authorities. Verification of diagnosis also involves ruling out
other causes of acute watery diarrhea, such as rotavirus or enterotoxigenic Escherichia coli, to ensure
that control measures are appropriately targeted.
Step 4: Formulate a Working Case Definition
The fourth step involves developing a clear and practical case definition that distinguishes suspected,
probable, and confirmed cases. The World Health Organization (2018) provides standard case
definitions for cholera, which are then adapted to the specific outbreak context. In the South African
context, a suspected case is typically defined as any person aged two years or older with acute
watery diarrhea (three or more loose stools in 24 hours) with or without vomiting, in an area where
an outbreak is occurring. A confirmed case is one with laboratory confirmation of Vibrio cholerae
O1 or O139 by culture or polymerase chain reaction. This case definition is communicated to all
healthcare facilities and field teams to ensure standardized case identification and reporting, as
recommended by the World Health Organization (2018). The case definition must be reviewed and
revised as the outbreak evolves and more information becomes available about the affected
populations and transmission patterns.
Step 5: Find and Count Cases
Step five involves systematic case finding to identify all affected individuals and generate a line list
for analysis. Active surveillance is essential, as passive reporting often underestimates the true
burden of disease, according to the World Health Organization (2018). In South Africa's cholera
outbreaks, this involves visiting healthcare facilities, conducting community door-to-door searches,
and reviewing mortality records to identify missed cases. The National Department of Health (2023)
coordinates this process through district health teams, ensuring that all confirmed and suspected
cases are recorded on standardized case investigation forms. The line list includes demographic
information, clinical presentation, laboratory results, exposure history, and outcome data, enabling
systematic tracking and analysis. During the 2023 outbreak, enhanced surveillance was implemented
in affected communities to identify all cases and contacts, with data entered into the electronic
Notifiable Medical Conditions system for real-time monitoring, as described by the National Institute
for Communicable Diseases (2023).
