Epidemiology Report: Measles Outbreak in a Local Suburb

This epidemiology report analyzes a measles outbreak in a local suburb, focusing on the virus rubeola and its transmission. The report details the initial cases, determination of the population at risk, and confirms the outbreak status. It explores determinants of infection spread, emphasizing contact, vectors, and contaminated food/water. The report also discusses the limitations of passive surveillance and advocates for active surveillance. It covers disease prevention levels, specifically immunization strategies, and compares high-risk individual and population strategies for increasing immunization rates. The report concludes by outlining steps to improve immunization rates within the local DHB using a high-risk individual strategy, providing a comprehensive overview of the outbreak and potential interventions.

Running Head: EPIDEMIOLOGY
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Epidemiology
Name
Institutional affiliation

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Table of Contents
1.0 Introduction..............................................................................................................................3
1.1 Measles......................................................................................................................................3
1.2 Determination of the Population at Risk...............................................................................4
2.0 Is this case an Epidemic or an Outbreak?.............................................................................5
3.0 Determinants of the spread of an infection...........................................................................6
4.0 Confirmation of the Existence of an Outbreak.....................................................................7
5.0 Insufficiency of a passive surveillance system to the case....................................................8
6.0 Level of Disease Prevention That Incorporates Immunization...........................................9
7.0 Comparison of High-risk Individual Strategy and Population Strategy............................9
8.0 How to Increase Immunization Rates in the Local DHB Using a High-risk Individual
Strategy.........................................................................................................................................10
9.0 Reference List.........................................................................................................................12

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1.0 Introduction
Working as an epidemiologist demands a lot of dedication, inner drive, and
determination. It will be my primary role to research and establish the primary origin of the virus
rubeola that causes measles (Colligan, 2011). Measles being a highly contagious disease widens
my area of research in order to establish the root of the virus, various contamination methods and
how to stop its spread in the suburbs. The actual ground cover will be the vital player in the
research so as to visit the hospitalized, get detailed information on the vaccination programs of
those partially vaccinated and gain a vivid understanding of why they never underwent full
vaccination. Information obtained will henceforth be implemented to curb instances of new
infections and prevent similar cases in the long run.
1.1 Measles
Measles is an extremely contagious and infectious disease that emanates from
the Measles Virus, scientifically known as rubeola. Upon infection, which mainly occurs
through exposure to infected persons, the incubation period ranges between 10-12 days for
symptoms to become visible. Early signs and symptoms include; fever rising to over
40 °C (104.0 °F), swollen eyes, running nose and coughs. Two to three days in the symptomatic
stage, small whitish spots; popularly known as “Koplik’s spots” could start forming inside the
mouth of the infected individual. Thereafter, around 3-5 days after the initial symptoms, there is
the development of a red, flat rash on the face which later spreads to the rest of the body (Burd,
Fraser & Liebson, 2010). About 30% of the total infection cases develop complications in the
later stages of the disease progression. Such complications vary amongst individuals but the most

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commonly reported and dangerous ones include among others; pneumonia, brain inflammation
diarrhea and several cases of blindness.
The main mode of transmission is through air whereby the virus is easily
transmitted through sneezes and coughs. Contacts with secretions of the nose and mouth is also
an alternative mode of transmission. An infected person can only be infectious to those around
him/her four days before the onset of the rash until four days after the rashes develop. A research
conducted amongst 10 un-immune individuals sharing the same living space with infected
persons revealed that 9 of them will definitely get infected. However, only 3% of reported cases
are of individuals contracting the disease for the second time. Once suspicious signs and
symptoms are sighted, however, testing is highly recommended for the sake of public health
safety.
1.2 Determination of the Population at Risk
Establishment of diagnostic criteria is crucial during measurement of disease
frequency in a population. It is the general assumption during any case study that the population
is classified into two discrete classes i.e. the affected and the non-affected. I would, therefore,
implement the following measures in assessing the whole population to determine the quota at
risk. The key drivers in adopting the measures I used was due to their consistency with the issue
at hand.
Incidence is one consideration which will help me reveal the rate at which
new cases of measles infection occur within my region of work and thus figure out the
population at risk. It all begun with eight cases of infection with three of the eight individuals
getting hospitalized. A burning question running through my mind as an epidemiologist is, could

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the five un-hospitalized individuals pose a threat to the general population? Assuming the
population at risk is fairly constant, I will measure incidence as;
Number of new cases: Population at risk × time during which cases were ascertained
Alteration in the population at risk resulting from factors such as deaths, migrations or even
births could bring about significant discrepancies in the results obtained. (Nelson & Williams,
2014)
Prevalence would be another consideration to make. This is the proportion of
the whole population that is infected with measles. The higher the number of infections there are
in a population, the greater the percentage of contact between the infected and the non-infected
and hence the higher the chances of new infections. The only way that prevalence could pose
little or no threat to the uninfected population will only be if the infected individuals are
contained separately. I will measure prevalence as; Prevalence = incidence x average duration.
(Bennett, Dolin, Blaser, Mandell & Douglas, 2015)
2.0 Is this case an Epidemic or an Outbreak?
An outbreak is a situation whereby there is a sudden increase in the
occurrences of a disease in a particular place over a certain period of time. On the other hand, an
epidemic is a rapid spread of an infectious disease to a large number of people within a given
population in a very short period. This period could be two weeks or less. (Jekel, 2007). This
case began with only eight patients. These kids could have possibly transmitted the virus before
they even developed any visible signs that were reasonable enough to cause alarm. With all the
eight patients attending the same school, this gives a clear explanation as to why there were high
chances of spreading. There are also high chances that there are many more infected individuals
who have already contracted the virus but is still at the incubation period. It is also notable that

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more children from neighboring suburbs also had visible signs of the disease. The above
explanation qualifies this scenario to be an outbreak.
3.0 Determinants of the spread of an infection
Health disorders caused by organisms such as bacteria, viruses parasites or
fungi are referred to as infectious diseases. Majority of these organisms live in and/or on our
bodies but, unless only under certain conditions can some of them cause diseases. There are
various modes of transmitting an infection which includes; insects or animal bites, person to
person, ingestion of contaminated food and/or water and exposure to organisms in the
environment. The mode by which an infected child transmitted the measles virus to a healthy
child within the school was being determined by various factors as that I was able to pinpoint
have discussed them below.
Contact is the easiest way to contract most infectious diseases. Contact can be
further divided into two i.e. direct contact and indirect contact. An infected child could have
transmitted the measles virus to a healthy child through person to person contact by touches,
coughs or even by sneezing on the child. Indirect contact between infected and uninfected
children is also a great determinant of the spread of the measles virus. This could be through
contacting objects such as books, pens or even door-knobs that an infected child had already
touched. (Macera, Shaffer & Shaffer, 2013)
The other determinant of whether an infected child transmitted the virus to a
healthy one is the presence of biting insects within the school compound. A common insect such
as a mosquito could have bitten a child carrying the measles virus and transmitted the virus to a
healthy child once it bites the child. Such carriers are known as vectors and are a great
determinant of the spread of an infection.

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Lastly, another great determinant is the food and water that the children were
ingesting in the school. If the food or water is contaminated, a healthy child inevitably contracted
the disease. Children also have a habit of sharing utensils such as spoons and this is also a great
determinant of whether the virus spread when the saliva of an infected child contaminated the
food of a healthy child who then ingests the food.
4.0 Confirmation of the Existence of an Outbreak
Once an outbreak is suspected, the response by medical practitioners needs
not only to be fast but also aggressive. After receiving the reports of eight infected cases of
measles, I had to take immediate action to determine several factors that relate to the existence of
an outbreak. Such factors include the level of susceptibility in the population and the risk and
chances of spread and complications. I, therefore, undertook the following steps to verify the
existence of measles in the suburbs.
1. Preparation for field work
2. Definition and identification of cases
3. Diagnosis and verification of diagnosis of the reported cases
4. Measuring the frequency of adverse outcome and analyzing the data in terms of place
time, place and person. (Rothman, Greenland & Lash, 2008)
Having prepared fully for actual ground coverage in the suburbs, defining and
screening closely the identified cases was the next step (Ryan et al., 2014). Determining the
cause of the reported cases is a positive approach to determine whether there is an outbreak or
not. Cases of an outbreak are definitely caused by similar factors. Unless closely observed,
several strains may portray similar signs leading to an epidemiologist confusing them to be one

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case whereas all the cases are not on a single disease. From the data availed in the medical
institutions where the children had been taken, the causes as recorded were similar. All the
children including those not hospitalized admitted to having developed similar initial signs and
symptoms after being in close contact with patient 0.
Taking a look at the diagnostic methods used by the hospital medics to
ascertain the actual disease from the signs, symptoms and laboratory tests, a confirmation of
measles outbreak was positive. Results obtained from the samples sent to the laboratory strongly
identified and linked the cases to measles. It is worth noting however that the children who were
not vaccinated were the first ones to contract the disease followed by those who were partially
vaccinated. The vaccinated children who acquired the virus were confirmed to be victims of
poor-syndrome resulting in low disease-fighting and prevention capability (Gupta, 2013).
Once the diagnosis is confirmed, it is easy to ascertain the existence of an
outbreak by Measuring the frequency of adverse outcome and analyzing the data in terms of
place time, place and person. Such analysis brings into the limelight the susceptibility of various
children to measles and its interconnection between vaccinated children and those who are not
vaccinated (Bannister, Gillespie & Jones, 2009). ‘Place’ is another point of consideration as it
emerged that all the children who were victims of the virus were from the same school. During
the outbreak trajectory, reported cases of measles increased and hence, following the above
reports, it can be un-doubtfully concluded that there was an outbreak of measles in the suburb.
5.0 Insufficiency of a passive surveillance system to the case
Passive surveillance involves monitoring the community health through
studying unsolicited cases that have been brought to the attention of public health officers. As an
epidemiologist, active surveillance would be the best to use in this case as it involves individual

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feedback from health workers who are having direct contact with the infected cases (World
Health Organization, 2018). Extra measures are taken with an aim of data collection and
diagnoses confirmation to facilitate submission of more complete and detailed health reports. It
is also under active surveillance that necropsy examination is to be conducted on samples of
clinically healthy children in the population (Gregg, 2008). Using passive surveillance, in this
case, would therefore not be exhaustive in the evaluation of all factors in consideration by an
epidemiologist.
6.0 Level of Disease Prevention That Incorporates Immunization.
There are three levels of disease prevention which are, primary prevention,
secondary prevention and tertiary prevention (Vorvick, 2013). Prevention at primary level
involves taking of actions with a chief aim of preventing the manifestation of a disease in the
body of an individual (Maciosek, Coffield. 2010). It raises resistance potential against diseases
and injuries should one get exposed. Immunization falls under this category as it involves
administration of a vaccine which plays a vital role in the stimulation of the immune system of
the body to provide protection from subsequent infections. Immunization has been proved to
control and eliminate lethal and highly infectious diseases that are life-threatening.
7.0 Comparison of High-risk Individual Strategy and Population Strategy.
High-risk individual strategy is a model aimed at identification of individuals
with a likelihood of having higher diseases incidences. It bases on the prevalence of risk factors
that are modifiable and known to be the causing factors of the disease in question or individual
characteristics associable to higher incidences of the disease. Once such factors are identified,
interventions are formulated targeting these individuals in order to modify the risk of the disease

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prevailing to them. This strategy has brought about approaches focusing on better identification
procedures of those at risk which is only achievable by; seeking to unleash additional risk
factors, increasing accuracy in the measurement of risk factors and conducting randomized trials
of evidence of efficacy. (Chiorelo, Paradis, Paccaud. 2015)
Population-based strategies, on the other hand, are more general and target the
population of a given locality at large. Strategies that could be implemented here include;
legislations, media-based strategies, and education on health and effects of drugs and substance
abuse. Such interventions can be termed to as ‘one size fits all’ as they leave no allowance for
specific populations targeting. They are however expensive to run and are therefore uncommon
and not preferred when compared to high-risk individual strategies.
8.0 How to Increase Immunization Rates in the Local DHB Using a High-risk Individual
Strategy
Increasing the rates of immunization locally is one way of curbing cases of
infectious diseases outbreaks. The district health board plays a vital role in ensuring that the
highest possible number of children is vaccinated from all infectious diseases. There are various
ways that I could use within the DHB to ensure the same.
Use of standing orders is the most effective way to increase vaccination rates.
These include orders for the provision of recommended vaccines to patients and strict follow-up
of office policies and procedures on how to conduct vaccination to all eligible patients. Provider
prompts which involves the use of electronic health records (EHRs) is another way of improving
the rates. EHRs are in most cases pop up alerts that provide notification to a health officer that a
certain patient is due or late for a particular scheduled vaccination. Majority of EHRs have these

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prompts pre-installed and provide an allowance for customization within the office. (Feemster,
2017)
I could also consider holding of family-friendly office hours as an alternative
and effective way of increasing immunization rates within the locality. This involves
encouraging families to attend vaccination clinics, more preferably during the weekends or after
work hours. This greatly increases the number of parents that turn up to avail their children for
vaccination as it hardly interferes with their daily routine schedules. An alternative method
would be to use automatic immunization reminder-recall systems. Such systems first identify and
then notify parents or guardians of such children who are due to be immunized and remind those
that are late for a vaccination scheduled to take place. Reminder or recall methods include auto-
dialers, phone calls made by a staff member, use of mail reminder cards and sending of text
messages.
Formulation of educative programs is another way to raise the rates of
immunization. Such programs once created in the DHB are thereafter implemented to the parents
within the locality. They are aimed at informing parents or guardians the need of vaccines and
that vaccines are safe and effective. Any opportunity to educate parents and guardians sighted by
the DHB officials should be snatched and utilized appropriately. They should be clearly
informed of what vaccine their children are to receive in the next visit and the repercussions of
missing the vaccine (Offit & Moser, 2011). In conclusion, the DHB staff should offer strong
recommendations to parents. Research has proven that parents strongly fall in line with the
advice they receive from their pediatricians. Do not just merely mention the availability of
vaccines but instead, strongly recommend all the vaccines that a child is scheduled to receive.

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9.0 Reference List
Bannister, B., Gillespie, S., & Jones, J. (2009). Infection: Microbiology and
Management(pp.515-530). New York, NY: John Wiley & Sons.
Bennett, J., Dolin, R., Blaser, M., Mandell, G., & Douglas, R. (2015). Mandell, Douglas, and
Bennett's Principles and practice of infectious diseases. Philadelphia: Elsevier /
Saunders.
Burd, L., Fraser, V., & Liebson, E. (2010). Encyclopedia of Diseases and Disorders. Tarrytown:
Marshall Cavendish.
Chiolero, Arnaud; Paradis, Gilles; Paccaud, Fred (2015). "The pseudo-high-risk prevention
strategy". International Journal of Epidemiology.
"Clinical Educators Guide for the prevention and control of infection in healthcare" (PDF).
NHMRC, Commonwealth of Australia. 2010. Archived (PDF) from the original on 2015-
04-05. Retrieved 2018-16-05
Colligan, L. (2011). Measles and mumps. Tarrytown, NY: Marshall Cavendish Benchmark.
Feemster, K. (2017). Vaccines: What Everyone Needs to Know. Oxford University Press.
Gregg, M. (2008). Field epidemiology. Oxford: Oxford University Press.
Gupta, S. (2013). Disease outbreak management: Hospital Administrators’ Perspective. Jaypee
Brothers Publishers.
Jekel, J. (2007). Epidemiology, biostatistics, and preventive medicine. Philadelphia: Saunders
Elsevier.