Case study:
An outbreak of diarrhea in Parbatia, Orissa, India
2-week course for District Surveillance Officers, India
Version 3.1 - Revised after pilot testing
Case study developed for the training of the district surveillance officers of the Indian
Integrated Disease Surveillance Programme (IDSP). It is inspired by an investigation
conducted by Dr Amitav Das, 2003 scholar of the Master of Applied Epidemiology (MAE) Field Epidemiology Training Programme (FETP) from the National Institute of Epidemiology
(NIE), Indian Council of Medical Research (ICMR), Chennai, Tamil Nadu, India. Dr Das was
an FETP scholar assigned to the State of Orissa at the time of the investigation.
Learning objectives
At the end of the case study, the participant will be able to:
1. Review the steps of an outbreak investigation;
2. Work with the laboratory to confirm the diagnosis during an outbreak;
3. Describe an outbreak in terms of time, place and person characteristics;
4. Understand the principles of analytical epidemiology during an outbreak investigation;
5. Formulate conclusions and recommendations;
6. Communicate recommendations for action to the relevant target groups;
7. Write a report;
8. Work with other sectors to ensure the implementation of the recommendations.
Use of computer tools (word processors, spreadsheet) will be encouraged during the case
study so that participants can become more familiar with them.
Note: While the story supporting this case study is a cholera outbreak, this case study does
focus on cholera-specific issues but on general principles in outbreak detection and response.
Using this case study in a class
Duration and organization
This case study is divided in eight parts of two hours each organized so that (1) each part is
done following the corresponding classroom activities and that (2) the case study is spread
over the duration of a whole week.
Learning approach
This is designed as a stand-alone case study and does not come with a facilitator’s guide. The
answers to all the questions in each section are provided as an introduction to the following
section. To run this case study in a class, it is proposed to distribute it one part at a time.
Participants take turns reading it out loud, paragraph by paragraph. Reading everything out
loud and in turns has two advantages. First, everyone can quickly participate and go beyond
the inhibition of having her/his voice heard in a large room. Second, time is given to the
whole class to understand the issue and think about the answers. The participant reading the
question may try to answer it if s/he can propose an answer. Otherwise, the matter is
discussed as a group. The next participant reads the next question and so on until the end of
the page. After distributing the next part, participants continue reading the text in that manner
until the case study is over. Once the epilogue has been read, it is proposed to go back to the
first page to read the objectives again. This re-iterates the learning and provides additional
clarification opportunities.
Part 1: A cluster of acute diarrhea in Parbatia, Orissa (2 hours)
On 14 November 2003, a primary health centre (PHC) from the district of Dhenkanal, state of
Orissa reported a cluster of five cases of acute, severe diarrhea with dehydration among adults
in the village of Parbatia (Figure 1) to the district public health authorities. The cluster
seemed to have started with a single case, with secondary spread. The population of the
village in 2003 was 946. The diagnosis of cholera was suspected. Health care workers locally
heavily chlorinated the wells in the village and called for assistance. On 15 November 2003,
an epidemiologist in training assigned to the state of Orissa initiated an investigation and
arrived in the village in the morning.
Question 1.A
What processes do you use in your district for rumour/ outbreak verification?
Question 1.B
What should be done in this specific situation to determine whether this is an outbreak or not?
What information would you need?
Question 1.C
What is the key administrative step that must be taken to send the alert? Work by group to
take necessary action using the template that applies.
Question 1.D
What kind of team needs to be constituted to investigate this outbreak?
Figure 1: Map of Parbatia village, Orissa, 2003 1
1
Each household can be located on this simplified map through its row and column coordinates (e.g., Household
of initial case is Column I- Row 6)
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
2
Part 2: Working with the laboratory for a diagnosis (2 hours)
First section
Public health officials in Dhenkanal district relied on (1) analysis of surveillance data and (2)
a rumour register to detect outbreaks. In both situations, signals were investigated initially
before the alert was decided. The epidemiologist compared diarrhea surveillance data for the
village and for the rest of the primary health care centre (PHC) area in the months of
November for the years 2001, 2002 and 2003 (Figure 2). This confirmed an unusual increase
of incidence. Further investigations ruled out recent population influx or any change in the
reporting system. Thus, this episode was considered an outbreak.
Figure 2: Incidence of acute diarrhea in the village of Parbatia and the corresponding
Primary health Centre (PHC), Orissa, India, November 2001-2003
4.5
4
Incidence (%)
3.5
3
PHC
Village
2.5
2
1.5
1
0.5
0
2001 Nov
2002 Nov
2003 Nov
Months
The investigator wrote a first information report (e.g., on the basis of the template of the
Integrated Disease Surveillance System [IDSP], Box 1), constituted a rapid response team
(epidemiologist, medical officer in charge of the primary health centre, laboratory technician)
and initiated the investigation. He defined a case using a variation of the WHO guidelines as
the occurrence of severe acute watery diarrhea with or without vomiting in a resident of
Parbatia in November 2003. Now, he required a laboratory confirmation for the diagnosis.
Question 2.A
What basic practical issues need to be considered before collecting specimens?
Question 2.B
What kind of specimens should be taken? How many case-patients should be sampled? What
kind of patients should the epidemiologist select to take specimens?
Question 2.C
What kind of infection control measures should be in place to collect the specimens?
Question 2.D
What is a transport medium? When should it be used? What kind of transport media should
be used to take stool specimens in this case?
Question 2.E
When is there a need for a cold chain for the transport of laboratory specimens?
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
3
Box 1: First Information Report [FIR] for diarrhea outbreak, Parbatia, Orissa, 2003.
FIRST INFORMATION REPORT FORM – FORM C
Officer In Charge CHC/PHC – Trigger-1 Response:
General information
State: Orissa
District: Dhenkanal
Town / PHC: XXX/ XXXX
Ward / Village: Parbatia
Population: 946 (2003 census)
District code No: XXX Unique identifier Reporting unit: XXX
Background information
Person reporting the outbreak: Health care worker from the Parbatia village
Date of report: 14 November 2003
Date investigations started: 15 November 2003
Person(s) investigating the outbreak: Dr Amitav Das, Epidemiologist in Training
Details of investigation
Describe how the cases were found (may include: (a) house-to- house searches in the affected area; (b) visiting
blocks adjacent to the affected households; (c) conducting record reviews at local hospitals; (d) requesting
health workers to report similar cases in their areas, etc.):
There was one initial case of severe diarrhea in a person living in the middle of the village where there are 13
wells (6 unprotected and 7 protected) and 5 tube wells. This initial case was followed by 4 cases, suggesting
secondary spread. A number of adult cases have dehydration. The diagnosis of cholera is suspected.
Descriptive epidemiology
1. Cases by time, place and person (attach case based reporting forms and relevant graphs and maps).
One case followed by a cluster, Initial case in the middle of the village, adults affected.
2. Age-specific attack rates and mortality rates. No deaths reported so far.
3. High-risk age groups and geographical areas. N/A
Description of control measures taken. Health workers immediately chlorinated the wells.
Brief description of problems encountered: N/A
Factors which, in your opinion, contributed to the outbreak. Unprotected wells that are numerous in the
village require investigations.
Conclusions and recommendations

Outbreak of acute diarrheal disease, probably cholera, in a village with many unprotected wells.

Rapid response team for investigation and control measures.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Second section
After having ensured that boxes and transport would be available and that the laboratory was
ready to accept the specimens, the epidemiologist decided to take rectal swabs. Rectal swabs
are small enough to allow easy and safe transport. They are also sufficient to yield Vibrio
cholerae when it is present. He decided to sample 10 patients meeting the case definition for
laboratory testing. He made sure that those had not received antibiotics. This number was
sufficient to obtain more then one positive culture. It is also reasonable as an excessive
number of specimens could overwhelm the laboratory. To take rectal swabs, he used a sterile
cotton tipped swab that he introduced in the rectum until it became moist. He used gloves and
an apron. He washed hands before and after the procedure. He took care to avoid cross
contaminations between specimens during collection and handling.
A transport medium is a medium used to transport specimens when it is expected that the
specimens will take more than two hours to reach the laboratory. In this specific case, the
epidemiologist decided to use a Cary Blair transport medium. However, the sampling of
patients was delayed because there were no stocks of transport medium in the district (It had
to be brought from the state capital). Cold chain is generally needed for all specimens, with a
few exceptions. One of these exceptions is shipment of rectal swabs for cholera culture in
Cary Blair medium that can reach the laboratory within 24 hours. In contrast, stool specimens
for bacterial culture are always transported under cold chain. In this specific case, the
laboratory in the state capital could be reached within 24 hours and the cold chain was not
necessary.
While the epidemiologist prepared to send the rectal swabs to the laboratory, the assistant of
the epidemiologist asked him what kind of forms he should send along with these specimens.
Question 2.F
What kind of contacts should be made with the laboratory prior to sending the specimens?
Question 2.G
What kind of information should be included with each specimen sent to the laboratory?
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
5
Third section
The epidemiologist immediately called the laboratory of the Regional Medical Research
Centre (RMRC) in Bubaneshwar, Orissa, to speak with the microbiologist. First, he explained
the situation and provided details about the initial results of the epidemiological investigation.
Second, the epidemiologist made note of the laboratory contact name, title, phone number and
e-mail address and the exact location to which the specimens had to be delivered. Third, the
microbiologist assigned an “outbreak number” for the specimens. As part of this discussion
they recognized the issue of potential media attention around an outbreak of cholera. Thus,
they clarified that the laboratory results would be reported directly back to the epidemiologist
for appropriate interpretation and dissemination to the designated public health authority. The
same would be responsible for broader communication to the public.
After terminating this phone conversation, the epidemiologist instructed his assistant to
complete a form with the following information for each specimen:
1. Type of specimen;
2. Name;2
3. Place of residence;
4. Date of onset and date of collection;
5. Signs and symptoms of the patient;
6. Prior antibiotic treatment if any (Which in this case will be: none for all specimens);
7. Outbreak number.
Question 2.H
What kind of package is necessary to prepare these specimens for transport?
Question 2.I
What precautions are needed to transport this package to the laboratory?
Question 2.J
Now that the laboratory confirmation has been organized, what is the next step of the
epidemiological investigations?
2
For diagnostic specimens, a complete identifier is needed while for research purposes, a confidential identifier
might be appropriate.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Part 3: Generating hypotheses with descriptive epidemiology (2
hours, computer practical)
The epidemiologist followed the WHO packaging recommendations for category B
specimens (Figure 3). First, the specimen was placed in a primary watertight receptacle with
thick walls. Second, this primary receptacle was placed in a second watertight container and
surrounded by absorbent material (e.g., cotton). This secondary watertight container had the
specimen data form taped on its surface while another copy was sent directly to the laboratory
by fax. Third, the secondary container was placed in a hard box (e.g., wood, metal, cardboard,
plastic) and surrounded by more absorbent material. This box displayed the address of the
laboratory and the contact information of the sender (A biohazard label is not needed for
category B specimens). Once the rectal swabs were packaged correctly, they could be
transported safely and in the absence of additional precautions. The person who carried the
specimens was informed that all precautions had been taken and reassured that there was no
risk of infection. He was also asked to confirm the date and time of delivery of the specimens
at the lab.
Figure 3: Transport of rectal swabs taken during an outbreak of suspected cholera 3
As a next step of the investigation, the team searched for cases door-to-door, summarized the
information in the form of a line listing (Table 1). For each case-patient, they collected
information that would allow a time (date of onset), place (residence) and person (age and
sex) analysis. They also enquired about whether food had been consumed from outside the
village and about whether the patient was drinking water from a well located close to the
house of the initial case patient. The team also obtained a census of the village (Table 2).
Question 3.A
Using the data on the line listing, describe the course of the outbreak over time: Analyze the
data by hand (do not enter the line listing in the computer) and prepare an epidemic curve by
hand or on the computer.
Question 3.B
Using the data on the line listing, describe the outbreak in terms of distribution among
persons: Analyze the data by hand and prepare a table of incidence by age and sex by hand or
on the computer.
3
Class 6.50 package reproduced from the WHO Biosafety guide (initially provided by the International Air
Transport Association, IATA).
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
7
Question 3.C
Using the data on the line listing, describe the outbreak in terms of its geographical
distribution. Analyze the data by hand. Then, you can either prepare a spot map on a hard
copy (Figure 1) or ask your facilitator for an electronic version of the blank map (Figure 1)
and prepare a map on the computer.
Table 1: Line listing of cases of acute diarrhea, Parbatia village, Orissa, India,
November 2003
ID
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
4
Age
(Years)
Sex
Date of
onset
20
25
28
60
55
35
35
22
18
0
25
43
2.5
21
29
3
45
35
60
62
55
55
53
12
14
35
70
1
20
14
75
31
52
62
1
35
51
0
60
5
65
F
F
M
M
F
M
M
F
M
F
M
M
M
F
F
M
F
F
F
M
F
M
F
F
F
F
F
F
F
F
M
F
F
M
M
F
F
F
M
M
M
10.11.03
12.11.03
13.11.03
13.11.03
13.11.03
13.11.03
14.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
15.11.03
16.11.03
16.11.03
16.11.03
16.11.03
16.11.03
17.11.03
17.11.03
17.11.03
17.1103
17.11.03
17.11.03
17.11.03
18.11.03
18.11.03
18.11.03
18.11.03
19.11.03
19.11.03
19.11.03
19.11.03
19.11.03
21.11.03
Household
Location 4
I-6
J-6
F-1
D-7
I-9
K-7
K-5
I-6
I-7
D-10
J-10
M-7
R-6
L-6
A-7
K-10
K-8
J-8
I-8
A-9
A-11
L-8
J-9
R-7
A-9
K-6
Q-9
K-4
L-7
L-6
M-7
K-8
K-10
K-7
K-5
I-9
I-6
J-6
J-6
D-7
J-8
Taken food
outside village
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Drinking water from the
well used by the initial
case-patient
No
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
No
No
No
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Refers to coordinates on the map (Figure 1)
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
8
Question 3.D
Describe the distribution of the cases by time, place and person.
Question 3.E
Interpret the time, place and person distribution of the cases. Can you use this information to
generate hypotheses?
Table 2: Census of the village of Parbatia, Orissa, November 2003
Age groups
0 to 4
5 to 14
15 to 24
25 to 34
35 to 44
45 to 54
55 to 64
65 and +
Total
Female
Male
53
94
61
70
66
43
32
46
465
Total
60
96
67
74
63
45
35
41
481
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
113
190
128
144
129
88
67
87
946
9
Part 4: Testing hypotheses through comparisons (2 hours)
First section
The results of the laboratory testing came back to confirm the diagnosis of cholera (Vibrio
cholerae O1, biotype El-tor, serotype Ogawa). The description of the epidemic curve (Figure
4) indicated that there was an initial case with a date of onset on 10 November. Then, there
was an increase in the number of cases followed by a slower decrease. As an interpretation,
the investigators suspected a common source outbreak (with the initial case as a source case),
although the second part of the epidemic curve stretched to the right could also suggest
secondary person-to-person transmission, at least for the second part of the outbreak.
Figure 4: Cases of cholera by date of onset, Parbatia, Orissa, India, November 2003
14
Number of cases
12
10
8
6
4
2
0
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Date of onset, November 2003
The attack rate was high among adults, which was compatible with the diagnosis of cholera
(Table 3).
Table 3: Attack rates of cholera by age and sex, Parbatia, Orissa, India, 2003
Number of cases
Age group
(In years)
Sex
Total
0 to 4
5 to 14
15 to 24
25 to 34
35 to 44
45 to 54
55 to 64
65 and +
Male
Female
Total
6
4
5
5
6
4
8
3
17
24
41
Population
Incidence
113
5%
190
2%
128
4%
144
3%
129
5%
88
4%
67
12%
87
3%
481
3%
465
5%
946
4%
Most cases were clustered around an unprotected well located close to the residence of the
initial case-patient. Hypothesis generating interviews with this index case-patient indicated
that this person fell sick and soiled her clothes with diarrhea. Thus, she left her house (shown
with a triangle on the map) and crossed the road to the unprotected well (Figure 5) to wash
her soiled clothes there.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
10
Figure 5: Cholera cases by residence, Parbatia, Orissa, India, November 2003
On the basis of the description of the outbreak by time, place and persons and the hypothesis
generating interviews, the investigators suspected that the initial case patient had
contaminated the well while washing her clothes when she was sick and that the
contamination of the well led to a common source outbreak, maybe with a certain degree of
subsequent person-to-person transmission. The well in question was unprotected with no brim
and no platform. Most case-patients were drinking water from that well.
Figure 6: The well where the initial case-patient came to wash clothes, Parbatia, Orissa,
India, 2003
Question 4.A
Is the information collected so far sufficient to incriminate the well in this outbreak?
Question 4.B
What additional piece of epidemiological evidence would strengthen the evidence?
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
11
Second section
While the descriptive epidemiology pointed to the well as the source of the outbreak, the
epidemiologist decided to strengthen his investigation with an analytical study. He decided to
compare each case of cholera with two unaffected neighbours in terms of the proportion of
persons who drank water from the suspected well. The idea is that if the well is indeed the
source of the outbreak, then a higher proportion of case-patients than unaffected neighbours
should have drunk water from the well. The epidemiologist collected information regarding
40 cholera cases and 80 unaffected neighbours of similar age and sex (Table 4). The initial
case was excluded from this analysis, because since this case-patient is suspected to be the
source of infection, she could not have acquired the disease from herself.
Question 4.C
Compile the data on Table 4 to compare case patients and healthy villagers in terms of
drinking water from the suspected well. What does this tell you? (Tip: It may be useful to
construct a two by two table to break down cases and non cases according to their water
consumption habits)
Question 4.D
Compile the data on Table 4 to compare case patients and healthy villagers in terms of eating
food from outside of the villager. What does this tell you? (Tip: It may be useful to construct
a two by two table to break down cases and non cases according to their food consumption
habits)
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Table 4: Line listing of unaffected neighbours, Parbatia village, Orissa, India, November
2003
Age
(Years)
ID
Sex
Drinking water from
Taken food
the well used by the
outside village
initial case-patient
Age
(Years)
ID
Sex
Taken food Drinking water from
outside village the well used by the
initial case-patient
1
21
M
No
No
41
55
F
No
No
2
20
M
No
No
42
56
F
No
No
3
27
F
No
No
43
55
F
No
No
4
26
F
No
No
44
55
F
No
Yes
5
77
M
No
Yes
45
53
F
No
No
6
74
M
No
Yes
46
51
F
No
No
7
60
M
No
Yes
47
13
F
No
Yes
8
62
M
No
Yes
48
12
F
No
Yes
9
55
F
No
Yes
49
16
F
No
No
10
55
F
No
Yes
50
15
F
No
No
11
37
M
No
Yes
51
35
F
No
No
12
35
M
No
Yes
52
37
F
No
No
13
36
M
No
No
53
71
F
No
No
14
35
M
No
No
54
68
F
No
No
15
23
F
No
No
55
1
F
No
No
16
20
F
No
No
56
1
F
No
No
17
16
M
No
No
57
19
F
No
Yes
18
16
M
No
No
58
22
F
No
No
19
1.5
F
No
No
59
13
M
No
No
20
1.8
F
No
No
60
15
M
No
No
21
26
M
Yes
No
61
74
M
No
No
22
27
M
No
Yes
62
77
M
No
No
23
42
M
No
Yes
63
33
F
No
No
24
44
M
Yes
Yes
64
30
F
No
No
25
3
M
No
Yes
65
52
F
No
No
26
3.5
M
No
Yes
66
53
F
No
No
27
23
F
No
Yes
67
1
M
No
No
28
22
F
No
Yes
68
1
M
No
No
29
27
F
No
Yes
69
35
F
No
No
30
29
F
No
Yes
70
37
F
No
No
31
3.8
M
No
No
71
53
F
No
No
32
4
M
No
No
72
50
F
No
No
33
46
F
No
No
73
0
F
No
No
34
43
F
No
No
74
1
F
No
No
35
34
F
No
No
75
62
M
No
No
36
35
F
No
No
76
58
M
No
Yes
37
61
M
No
No
77
5
M
No
No
38
61
M
No
No
78
6
M
No
No
39
64
M
No
No
79
67
M
No
No
40
60
M
No
No
80
64
M
No
Yes
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
13
Part 5: Formulating recommendations for action (2 hours)
When comparing the cases of acute diarrhea with the non cases, one can see that not only
there is a high proportion of case-patients (29/40, 70%) who drunk water from the well, but
also, that this high frequency of well water consumption is unique to the cases: Among
unaffected neighbours, fewer persons (23/80, 30%) drunk water from the well. This
substantial difference among cases and unaffected neighbours supports the hypothesis that the
well was the source of the outbreak. This difference among cases and unaffected neighbours
does not exist when the issue of eating food from outside of the village is examined.
Table 5: Consumption of water from the suspected well among case-patients and
unaffected neighbours, Parbatia, Orissa, India, 2003
Drunk well water
Did not drink well water
Total
Cases of acute
diarrhea
Unaffected
neighbours
Total
29
23
51
11
57
69
40
80
120
The investigators have now concluded that the cholera outbreak may have been caused by an
unprotected well that had been contaminated by an initial case-patient who washed her
clothes soiled with feces while she was convalescent. They also understand that the epidemic
curve suggests a certain amount of person-to-person transmission.
Break in small groups for the three next questions.
Question 5.A
What recommendations can be proposed for the short term? Evaluate these recommendations
in terms of whether:
(a) They are based upon the results of the investigation;
(b) They are specific (not too vague);
(c) They are feasible;
(d) They are cost-effective;
(e) They are acceptable to the community.
Question 5.B
What recommendations can be proposed for the longer term? Apply the same checklist to
evaluate your recommendations.
Question 5.C
Come to a consensus as to which of the potential recommendations you will keep (according
to your checklist). As a group, prepare a plan of action to determine how you would proceed
to implement these recommendations. Ask yourselves: What? who? how? When?
One you have completed your plans of action as a group, gather with other groups and
compare your plans.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Part 6: Communicating results of the investigation (2 hours)
The epidemiologists reviewed the recommendations that were suggested by the investigation
group according to the proposed evaluation criteria (Table 6).
Feasible
Cost-effective
Acceptable
Stop using the well
Chlorinate the well
Implement sanitation
Provide alternate water supply
Promote hand washing
Promote safe food handling
Boil drinking water
Forbid washing of clothes in wells
Provide piped water supply
Protect the wells
Bore more tube wells
Construct toilets
Educate for proper sanitation
Chlorinate the wells regularly
Educate for personal hygiene
Education for safe use of wells
Specific
1.
2.
3.
4.
5.
6.
7.
8.
1.
2.
3.
4.
5.
6.
7.
8.
Evidence-based
Possible long term
recommendations
Possible short term
recommendations
Table 6: Review of the possible recommendations that could be formulated for the
cholera outbreak in Parbatia, Orissa, 2003
++
++
++
?
++
++
++
++
++
++
-?
-++
++
++
++
++
++
++
++
++
++
+
-+
-++
++
++
++
?
?
++
-++
----++
++
++
?
++
++
?
++
-+
--?
-++
++
+
+
+
+
?
++
?
++
?
?
---++
On the basis of this review, a limited number of recommendations were selected (Table 7).
Table 7: Summary of recommendations, cholera outbreak, Parbatia, Orissa, 2003
Short
term
Long
term
1.
2.
3.
4.
5.
6.
Details about the recommendations
What?
Who?
How?
Warn that the well is dangerous
 Health worker
 Discussions
Chlorinate the well
 Panchayat
 Guidelines
Provide alternate water source
 Panchayat
 Making plans
Ban clothe washing in well
 Panchayat
 Making rule
Protect the well involved
 Pamchayat
 Brims, platform
Educate for safe use of wells
 Health worker
 Discussions






When?
Evenings
Immediately
Immediately
Immediately
ASAP
Evenings
Now the epidemiologist needs to communicate the findings of the investigation with the
villagers, the district collector and the local press (through the administrative clearance).
Question 6.A
Divide the class in three groups each of these three audiences and answer these questions:
a. How can the audience be characterized?
b. What may the concern(s) of this audience?
c. What do we expect from the audience?
d. What is the best way (media) to reach the audience?
e. What is the tone we should use to reach the audience?
f. What should be the content of the message?
Question 6.B
As a group, prepare the communication material to be used with your audience to get across
the message needed.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Part 7: Writing the report (2 hours)
Three audiences have been characterized and communication elements identified (Table 8).
Table 8: Preparing the communication of the results of the investigation with three
selected audiences, cholera outbreak, Parbatia, Orissa, 2003
Villagers
Audience
characteristics
 Rural
 Illiterate
 Misconceptions




Concern(s) of
the audience




Behaviour you
want from the
target audience
 Direct case-patients to
medical care
 Stop using the dangerous
well
 Use wells safely






Media to reach
the audience
 Small group discussions
in local language
 Public address system
Tone to use
 Sympathetic
 Helpful
Content of the
message
 Seek care if sick: You
will be fine
 Protect yourself: Stay
away from well, use
other water source and
use wells safely
Avoid disease
Seek treatment
Fear death
Protect themselves
Audiences
District collector
Administrator
Managerial
Responsible
Accountable
Control the situation
Prevent deaths
Provide care for sick
Avoid panic
Avoid press scandal
Support plans for
protection of wells
 Manage inter-sector
coordination
 Briefing note given
(illustrated if needed)
in person with
personal briefing
 Managerial
 Big picture





Facts, figures
Summary of findings
Recommendations
Action taken
Action needed from
collector
Press
Investigative
Intelligent
Opinion makers
Potentially
mischievous
 The truth must be
told
 “Make a story” to
sell papers




 Report the truth
 Stick to facts
 Reassure the
population
 Communicate new
plans for safer wells
 Explain that
unprotected wells
can be risky
 Press release
 Press briefing
 Interview with
SOCO
 Factual
 Sincere
 Professional
 Fact and figures
 Cause of outbreak
 Control measures
 Messages for the
population
 Current risks if any
Using this matrix, the investigators prepared prompts for the health education sessions (Box
2), a briefing note for the district collector (Box 3) and a press release (Box 4) 5.
Box 2: Talking points for the small group discussion, cholera outbreak, Parbatia,
Orissa, 2003.










5
Do you know about the recent diarrhea outbreak?
Do you know what caused the recent diarrhea outbreak?
Do you know how the disease is called?
Do you know how it is passed on in general?
Do you know what caused the recent outbreak?
Do you know what to do if you get cholera?
Which well should be avoided for the moment in the village?
Can you list the safe sources of water supply in the village now?
What are the important steps to keep the well water clean?
Would it be better for the village to have wells with brims and platform?
For clearance through the appropriate administrative procedure
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Box 3: Briefing note for the district collector, cholera outbreak, Parbatia, Orissa, 2003.
An outbreak of cholera affected the village of Parbatia (Population: About 900 persons) from
10 to 21 November 2003. The outbreak is now over. 41 cases occurred, with no deaths.
Investigations by a team from the primary health centre identified that the source of infection
was an unprotected well. The well became contaminated because an initial patient affected
with cholera washed her clothes soiled with feces in the well. To control the outbreak, four
actions were initiated. First, we barred access to the well. Second, we organized access to
alternate water sources. Third, we chlorinated the well. Fourth, we educated the population
about the need to use well safety and to abstain from washing clothes directly in it. In the
longer term, we seek your assistance to support efforts with the public health engineering
department so that unprotected wells that remain in the district be fixed and protected to
become safer. Finally, since we have had recurrent questions from the press, we have drafted
this press release that summarizes the situation to show it is under control. We would be
grateful if you could provide comments and suggestions on this draft press release so that we
can get your clearance and share it with the local newspaper.
Box 4: Draft press release for clearance, cholera outbreak, Parbatia, Orissa, 2003.
Note for the press: Cholera outbreak in Parbatia village, Orissa
An outbreak of cholera affected the village of Parbatia during the month of November 2003.
41 cases occurred, with no deaths. Investigations identified an unprotected well with no brim
and no platform as the cause of the outbreak. The well became contaminated because an
initial patient affected with cholera washed her clothes soiled with feces in the well. This
outbreak is now under control following a number of interventions by the public health team:
The dangerous well was barred for use and alternate water sources were organized. The
population is now safe. To make sure than such outbreaks do not recur, the district collector is
planning efforts so that all wells in the district will now have brims and platform. Meanwhile,
the population is reminded that under no circumstances should wells be used to wash clothes
directly in them. For further information, please contact Dr Amitav Das, spokesperson for this
outbreak at the Primary Health Center of Dekhanal at the following phone number:
(0XX) XXX XXX XX.
The epidemiologist must now write his investigation report for the District Medical Officer
and the State surveillance unit.
Question 7.A
Outline the sections that the report should include to prepare a list of headings, subheadings.
Question 7.B
Expend these headings and subheadings by adding bullet points so that you generate a high
level outline of less than one page.
Question 7.C
Specify what key annexes you would include in the report.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Part 8: Working with other sectors (2 hours)
The epidemiologist has completed a high level outline of the report (Box 5) for further
expansion into a full report of less than 10 pages. He must now work with the rural
engineering department to implement the recommendations agreed upon.
Question 8.A
Divide the class in two groups: Health sector and rural engineering department. For each
group, list:
a. Your concern in this issue;
b. What could be the concern of the other group in this issue;
c. What would you like to obtain from the other group.
Question 8.B
Debrief your results across groups and come to a consensus.
Question 8.C
On the basis of this exercise, what is the best strategy to approach the rural engineering
department to make sure the recommendations will be implemented?
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Box 5: High-level outline of the investigation report
Parbatia cholera outbreak investigation report (Orissa, 2003)
Background
 On 14 November 2003, village health workers informed of a cluster of diarrhea with
dehydration among adults in Parbatia village, Denkhanal district, Orissa
 On 15 November 2003, the rapid response team initiated the investigation
Methods
Epidemiological methods
 We used WHO cholera case definition
 We searched for cases door to door in the village
 We compared the current rates to the background
 We described the outbreak by time, place and person
 We compared cases with unaffected neighbours with respect to the suspected exposure
Laboratory methods
 We collected rectal swabs for bacterial culture
Environmental investigations methods
 We examined the water sources in the village
Results
Epidemiological methods
 Rates of acute diarrhea were in clear excess of the background in the village
 We identified 41 cases and no death (attack rate: 4.3%)
 There was an initial cluster on 10 November followed by a peak around 15 November and
possible secondary spread. The last case occurred on 21 November.
 Cases were clustered around a well where an initial case patient washed her soiled clothes.
 Attack rates were highest among older adults
 80% of the 40 cases had drunk water from the well compared with 30% of non-cases.
Laboratory methods
 Rectal swab grew Vibrio Cholera O1 biotype El tor
Environmental investigations methods
 The well that caused the outbreak was unprotected, without any brim or platform
Conclusions
 A cholera outbreak affected Parbatia village. The most likely source was an unprotected
well that had been contaminated by an initial source patient who had washed her soiled
clothes in it.
Recommendations
 We barred access to the suspected well and disinfected it
 We educated the population about the risk associated with unhygienic use of wells
 The local government issued a note to forbid the washing of clothes in wells
 Plans are under way to protect the well that caused the outbreak with a brim and a platform
Annexes
 Epidemic curve, spot map, table of incidence by age and sex, photo of the well and case/
neighbour table
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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Part 9: Epilogue
After a review of potential inter-sector collaboration issues (Table 9), the incriminated well
was protected few months after the outbreak and new wells in the district were being
constructed with protections (Figure 7).
Table 9: Issues in inter-sector collaboration, Parbatia, Orissa, 2003
Recommendations
Warn that the
well is dangerous
Chlorinate the
well
Provide alternate
water source
Ban clothe
washing in well
Protect the well
involved
Educate for safe
use of wells
Concerns of the
public health
department
Concerns of the rural
engineering
department
Proposed way forward
 The well is
dangerous and
should not be
used.
 The well is
contaminated and
must be
disinfected.
 Those who
cannot use the
well need water.
 Pointing to the well may
suggest rural
engineering is to blame.
 Explain that the well
became dangerous because
it was not used properly.
 Well disinfection must
take place according to a
specific technical
protocol.
 Use of water sources in a
village may follow a
number of informal
social rules that need to
be respected.
 Clothe washing
caused the recent
cholera outbreak.
 Lack of
protection may
have facilitated
contamination.
 Unsafe use of
well expose to
cholera.
 The rural engineering
department cannot
enforce such rule.
 Due to limited resources,
all unprotected wells
cannot be protected at
once.
 None.
 Engage rural engineering
into conducting the
disinfection as
recommended.
 Engage rural engineering
and the Panchayat so that
the population can be
directed to alternate water
sources in a feasible way
when the well is unusable.
 Panchayat must enforce
the ban of clothe washing
in the wells.
 The well of the outbreak
should be protected as a
matter of priority.
 Both department need to
promote safe use of wells
in a coordinated manner.
Figure 7: The Parbatia outbreak well protected with a new platform and brim (left) and
a new protected well constructed after the outbreak (right), Orissa, India, 2004
Although this case study only covered a cholera outbreak, you can use the skills and steps you
learned in this exercise for the next outbreak you will encounter in your district, even if it is
transmitted through a different route (e.g., vector borne) or prevented through the use of
vaccine (e.g., measles). This will ensure than information will lead to action, as was the case
for the Parbatia outbreak.
An outbreak of cholera in Parbatia, Orissa, India. District course version. Version 3.1 – 16 January 2008
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