Year 4 Public Health Paeds- Group WorkOutbreak and Immunisation
Participant Pack
Objectives:
By the end of this case study, the participant will be able to:
 Understand the approach of descriptive epidemiology
 Interpret an Epidemic Curve
 Appreciate the importance of communicable diseases surveillance systems in outbreak
detection
 Be aware of the basic steps in outbreak investigation and control, building on knowledge on
key aspects of communicable diseases:
o Source
o Incubation period
o Infectious period
o Transmission pathway
o Infectivity
o Susceptibility
 Appreciate the resources required to manage an outbreak and the multi-disciplinary
approach required
 Understand the role of vaccination in prevention and control of vaccine preventable
diseases
 Reflect on factors influencing vaccine uptake
Pre-requisite
Participants will be expected to be familiar with:
 The basic facts on measles infection:
o Incubation period
o Infectious period
o Transmission pathway
o Infectivity
o Susceptibility
o Clinical picture including potential sequela
o Clinical management including diagnostic tests
 Communicable diseases surveillance process in England, including concept of NOIDS
 MMR vaccine basic facts:
o NHS childhood immunisation schedule
o Efficacy
o Contra-indications
o Andrew Wakefield Paper: Press coverage and impact on uptake
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Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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Section 1
You are a Foundation Year 2 doctor based with the Tumbleton GP practice in Wythenshawe and
have recently started seeing your own patients. It is a busy day, with a full waiting room and after a
long wait, your 4th patient of the day enters your consultation room. The patient is 3 year old boy
presenting with a 38C° temperature, a cough and an erythematous rash on their face and trunk. The
child’s mother explains that she thinks her son has measles because his cousin had it 2 months ago.
Question 1: What would you do? What else would you like to know?
Question 2: What is your differential diagnosis at this stage?
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Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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The child’s mother explains that her son’s illness started 4 days ago, with sniffles, a cough and a
fever, then the rash appeared yesterday, first on the top of the face next to the hairline, then it
spread to the chest. The rash doesn’t seem to be itchy and there are no blisters. She hadn’t noticed
anything else wrong with her son apart from a slightly sticky red left eye. The patient’s cousin did not
see a doctor for his illness as it only lasted 2 days and he is not registered with a GP. She does not
know whether her son has ever had any Measles containing vaccine. They are part of a Traveller
community. They have not travelled anywhere recently, except for a large family event in London
two weeks ago, where many children were present, some of them with a colds and coughs. The
mother was told by a family member in London that their daughter who had a cold at the family
event went to hospital with a rash 2 days after the family event.
You now strongly suspect measles infection.
Question 3: How could you confirm your diagnosis?
Question 4: How would you treat the patient?
Question 5: What possible sources of infection have you identified, which one is the more likely?
Question 6: How could you prevent further spread?
Question 7: What systems are in place in England to help with preventing further spread in these
types of situation, and what is your role as a clinician in this system?
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The case’s mother is concerned as she suspects that a few of the children living on their traveller site
may not have had the MMR vaccine. The other children are not registered with your practice.
Question 8: How can you arrange for these children to be followed up?
Question 9: What is the potential risk to others in the GP practice from this episode?
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Section 2
You are a Foundation Year 2 doctor on placement with the Health Protection Team in the greater
Manchester Public Health England (PHE) Centre. You receive a call from the MRI Laboratory notifying
you of a positive measles PCR result for 15yr old girl in the Wythenshawe area, the test was taken 4
days ago by a GP.
You speak to the father of the case and go through the standard questionnaire with him and
establish the following:
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The case’s rash started 5 days ago
The case’s parents had refused MMR vaccination for her because her cousin is autistic
The case has not travelled recently
The case attends Billingsworth secondary school in Wythenshawe, but is currently not
attending because although she is better, the parents want to avoid her passing on any
infection
Question 10: What is the link between autism and MMR vaccination?
Question 11: Can the case go back to school?
Question 12: Is there a risk of transmission to other people in the school? If so, what factors does
this depend on?
Question 13: Could you have known about this case earlier?
Question 14: What are the next steps in the public health management of this case as usually carried
out by PHE?
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Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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The following day, you receive a call from the MRI laboratory notifying you of another positive PCR
result for measles in a 16 year old boy from the Wythenshawe area. You speak to the case and go
through the standard questionnaire with him and establish the following:
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The case’s rash started 3 days ago
The case had had one dose of MMR as a child
The case has not travelled recently
The case attends Billingsworth secondary school in Wythenshawe, but he has been off sick
for the last 2 days. He is in the same maths class as the 15 year old case notified yesterday
Question 15: How can someone who is vaccinated with MMR catch measles?
Question 16: Could these cases have transmitted the infection from one to the other?
Question 17: Could this be an outbreak?
Question 18: What possible initial actions would you consider for the school?
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The following day another 3 suspected cases are notified by GPs, both attending Billingsworth
secondary school in Wythenshawe, both with 0 MMRs and both aged 16.
An outbreak control team (OCT) is convened. The OCT includes the Health Protection Team, the
Local Authority Public Health Team (Director of Public Health), a PHE Microbiology consultant, the
local community infection control team (who have good links with the Secondary School), the PHE
Screening and Immunisation team, and the PHE Communications officer.
Investigation
Question 19: What would the case definition for this outbreak be?
Question 20: How would you assess the risk of further case developing?
Control
Question 21: What measures could be considered to limit onward spread in school and beyond?
The OCT decide to:
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Send warn and inform letters to all parents via school management
Arrange a school based immunisation session where all pupils identified as having 0 or 1
dose of MMR are offered MMR (consent letters sent to parents via school management)
Inform local health services of the outbreak and the need to be aware of symptoms of
measles and the recommendations for testing, exclusion and notification to the Health
Protection Team.
Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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Two weeks later: there are now 12 cases linked to this outbreak. You get a phone call from a
paediatrician at Wythenshawe hospital notifying a case of suspected measles on their paediatric
ward. The case’s rash started yesterday and who attends Billingsworth secondary school. When you
follow-up this case, you find out that the case lives with their parents. The case’s mother is 8 months
pregnant and the case’s father is an A&E Consultant at Wythenshawe Hospital
Question 22: What would you do about the case in hospital?
Question 23: What would you do about the case’s mother?
Question 24: What would you do about the case’s father?
By this stage the epidemic curve for this outbreak and the social network analysis diagram look like
this.
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Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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Question 25: How would you interpret these figures?
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Year 4 Public Health Paeds- Group Work- Outbreak and Immunisation
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Eight weeks later, the epidemic curve and social network analysis for the outbreak for the outbreaks
look like this. There are now a number of cases in nearby primary schools too, and some amongst
adults with no links to the Billingsworth secondary school.
Question 26: How would you interpret these figures?
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Question 27: How could the cases in nearby primary schools be explained?
Question 28: How could the adult cases with no links to Billingsworth secondary school be
explained?
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Ten weeks later, the outbreak is declared over by the OCT. As part of the overall review of the
outbreak, you review the Health Protection Team’s electronic records for any cases in the area
before the first case at Billingsworth secondary school and find the records of a confirmed case of
measles: a 3 year old boy notified by the Tumbleton GP practice a few months ago.
On reviewing this case’s record, you establish the following:
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The case’s rash started 20 days before the first case at the Billingsworth secondary school
developed their rash
The case did not attend any school or nursery
The case has 3 siblings:
o A one year old who is cared for at home, no MMRs
o A 15 year old who attends Billingsworth secondary school in Wythenshawe, no
MMRs
o A 21 year old who works in Trafford Park, No MMRs
Complete MMR vaccination (appropriate for age) was advised for all sbblings
Question 29: Who is the likely index case for this outbreak?
Question 30: Can you think of possible reasons why the index case did not have a record on the
health protection team electronic record system?
Question 31: Could knowing about the index case or managing the index case in a different way
have made a difference?
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