1. The document defines key epidemiological terms like epidemic, outbreak, endemic, pandemic, herd immunity, incubation period, and quarantine. It also describes different types of epidemics such as point source, propagated, and continuous exposure epidemics.
2. The stages of outbreak investigation are outlined which include verifying the diagnosis, confirming the outbreak, defining the population at risk, conducting a rapid search for cases, analyzing the data, formulating hypotheses, and reporting findings.
3. Trigger levels for different diseases are discussed to determine the appropriate response level based on the number and severity of cases. Line listing of cases is also described as a tool to collect epidemiological information during an outbreak investigation.
Investigation of Acute Gastroenteritis Epidemic (AGE) and its stepsMohsin Ansari
Steps of investigation of any epidemic are illustrated in the given slide especially for acute gastro-enteritis epidemic. Also the prevention of AGE is also given and at the end how to submit a report is also given.
Investigation of Acute Gastroenteritis Epidemic (AGE) and its stepsMohsin Ansari
Steps of investigation of any epidemic are illustrated in the given slide especially for acute gastro-enteritis epidemic. Also the prevention of AGE is also given and at the end how to submit a report is also given.
1. 1st GNM Community H Nsg - Unit 4 Epidemiology.pptxthiru murugan
Community Health Nursing IEpidemiology
By,
Thiru murugan
UNIT-IV: Principles of Epidemiology and Epidemiological methods:
Definition and aims of epidemiology, communicable and non-communicable diseases.
Basic tools of measurement in epidemiology
Uses of epidemiology
Disease cycle
Spectrum of disease
Levels of prevention of disease.
Disease transmission – direct and indirect.
Immunizing agents, immunization and national immunization schedule.
Control of infectious diseases.
Disinfection
Epidemiology:
Introduction: Epidemiology is derived from Greek word “epidemic”
EPI – up on,
DEMOS – people;
LOGOS – study.
Epidemiology means the study of disease in human population.
Definition: “epidemiology is defined as the study of the distribution and determinants of diseases or health problems”.
Terminologies used in epidemiology:
Infection: the entry and multiplication of an infectious agent in the body of man or animal.
Endemic: the constant presence of a disease in particular area or population. Ex- malaria, dengue, chikungunya.
Epidemic: an out break of disease from one area to other area in a community. Ex - cholera, polio, small pox
Sporadic: refers to a disease that occurs infrequently and irregularly. Ex - Tetanus, rabies, and plague.
Pandemic: a disease which spreads from country to country or over the whole world. Ex - swine flu, HIV, COVID – 19.
Zoonosis: diseases or infections transmitted from animals to men. Ex - rabies.
Incubation period: this is the time interval between the entry of the disease agent into the body and the appearance of first sign & symptom of the disease.
Carrier: a person who harbors or carry the disease agent with or without having any outward signs and symptoms.
Isolation: a separation of a person with infectious disease (communicable disease) from contact with other human beings to avoid spread of disease.
Quarantine: a quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease
Pathogenicity: ability to cause the disease.
Contagious: a disease that is transmitted through contact.
Reservoir: the habitat ( place for living) where an infectious agent living, grows and multiplies.
Virulence: measure the severity of disease.
Fomites: inanimate articles other than food or water contaminated by the infectious discharges.
Vector: usually an arthropod eg. Mosquito which transfers an infectious agent from an infected person to a healthy person.
Aims
To describe the distribution and size of disease problems in human
To identify the etiological factors.
To provide the data (information) essential to the preparation) implementation (providing) & evaluation (checking the outcome).
Communicable and non-communicable diseases:
Communicable diseases are diseases that spread from person to person. Ex - polio, typhoid, chickenpox, TB,AIDS
Non-communicable disease (NCD) are disease that is not spread from one person to another. Ex - most heart disease
1. 1st GNM Community H Nsg - Unit 4 Epidemiology.pptxthiru murugan
Community Health Nursing IEpidemiology
By,
Thiru murugan
UNIT-IV: Principles of Epidemiology and Epidemiological methods:
Definition and aims of epidemiology, communicable and non-communicable diseases.
Basic tools of measurement in epidemiology
Uses of epidemiology
Disease cycle
Spectrum of disease
Levels of prevention of disease.
Disease transmission – direct and indirect.
Immunizing agents, immunization and national immunization schedule.
Control of infectious diseases.
Disinfection
Epidemiology:
Introduction: Epidemiology is derived from Greek word “epidemic”
EPI – up on,
DEMOS – people;
LOGOS – study.
Epidemiology means the study of disease in human population.
Definition: “epidemiology is defined as the study of the distribution and determinants of diseases or health problems”.
Terminologies used in epidemiology:
Infection: the entry and multiplication of an infectious agent in the body of man or animal.
Endemic: the constant presence of a disease in particular area or population. Ex- malaria, dengue, chikungunya.
Epidemic: an out break of disease from one area to other area in a community. Ex - cholera, polio, small pox
Sporadic: refers to a disease that occurs infrequently and irregularly. Ex - Tetanus, rabies, and plague.
Pandemic: a disease which spreads from country to country or over the whole world. Ex - swine flu, HIV, COVID – 19.
Zoonosis: diseases or infections transmitted from animals to men. Ex - rabies.
Incubation period: this is the time interval between the entry of the disease agent into the body and the appearance of first sign & symptom of the disease.
Carrier: a person who harbors or carry the disease agent with or without having any outward signs and symptoms.
Isolation: a separation of a person with infectious disease (communicable disease) from contact with other human beings to avoid spread of disease.
Quarantine: a quarantine is a restriction on the movement of people, animals and goods which is intended to prevent the spread of disease
Pathogenicity: ability to cause the disease.
Contagious: a disease that is transmitted through contact.
Reservoir: the habitat ( place for living) where an infectious agent living, grows and multiplies.
Virulence: measure the severity of disease.
Fomites: inanimate articles other than food or water contaminated by the infectious discharges.
Vector: usually an arthropod eg. Mosquito which transfers an infectious agent from an infected person to a healthy person.
Aims
To describe the distribution and size of disease problems in human
To identify the etiological factors.
To provide the data (information) essential to the preparation) implementation (providing) & evaluation (checking the outcome).
Communicable and non-communicable diseases:
Communicable diseases are diseases that spread from person to person. Ex - polio, typhoid, chickenpox, TB,AIDS
Non-communicable disease (NCD) are disease that is not spread from one person to another. Ex - most heart disease
Global launch of the Healthy Ageing and Prevention Index 2nd wave – alongside...ILC- UK
The Healthy Ageing and Prevention Index is an online tool created by ILC that ranks countries on six metrics including, life span, health span, work span, income, environmental performance, and happiness. The Index helps us understand how well countries have adapted to longevity and inform decision makers on what must be done to maximise the economic benefits that comes with living well for longer.
Alongside the 77th World Health Assembly in Geneva on 28 May 2024, we launched the second version of our Index, allowing us to track progress and give new insights into what needs to be done to keep populations healthier for longer.
The speakers included:
Professor Orazio Schillaci, Minister of Health, Italy
Dr Hans Groth, Chairman of the Board, World Demographic & Ageing Forum
Professor Ilona Kickbusch, Founder and Chair, Global Health Centre, Geneva Graduate Institute and co-chair, World Health Summit Council
Dr Natasha Azzopardi Muscat, Director, Country Health Policies and Systems Division, World Health Organisation EURO
Dr Marta Lomazzi, Executive Manager, World Federation of Public Health Associations
Dr Shyam Bishen, Head, Centre for Health and Healthcare and Member of the Executive Committee, World Economic Forum
Dr Karin Tegmark Wisell, Director General, Public Health Agency of Sweden
Antibiotic Stewardship by Anushri Srivastava.pptxAnushriSrivastav
Stewardship is the act of taking good care of something.
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
WHO launched the Global Antimicrobial Resistance and Use Surveillance System (GLASS) in 2015 to fill knowledge gaps and inform strategies at all levels.
ACCORDING TO apic.org,
Antimicrobial stewardship is a coordinated program that promotes the appropriate use of antimicrobials (including antibiotics), improves patient outcomes, reduces microbial resistance, and decreases the spread of infections caused by multidrug-resistant organisms.
ACCORDING TO pewtrusts.org,
Antibiotic stewardship refers to efforts in doctors’ offices, hospitals, long term care facilities, and other health care settings to ensure that antibiotics are used only when necessary and appropriate
According to WHO,
Antimicrobial stewardship is a systematic approach to educate and support health care professionals to follow evidence-based guidelines for prescribing and administering antimicrobials
In 1996, John McGowan and Dale Gerding first applied the term antimicrobial stewardship, where they suggested a causal association between antimicrobial agent use and resistance. They also focused on the urgency of large-scale controlled trials of antimicrobial-use regulation employing sophisticated epidemiologic methods, molecular typing, and precise resistance mechanism analysis.
Antimicrobial Stewardship(AMS) refers to the optimal selection, dosing, and duration of antimicrobial treatment resulting in the best clinical outcome with minimal side effects to the patients and minimal impact on subsequent resistance.
According to the 2019 report, in the US, more than 2.8 million antibiotic-resistant infections occur each year, and more than 35000 people die. In addition to this, it also mentioned that 223,900 cases of Clostridoides difficile occurred in 2017, of which 12800 people died. The report did not include viruses or parasites
VISION
Being proactive
Supporting optimal animal and human health
Exploring ways to reduce overall use of antimicrobials
Using the drugs that prevent and treat disease by killing microscopic organisms in a responsible way
GOAL
to prevent the generation and spread of antimicrobial resistance (AMR). Doing so will preserve the effectiveness of these drugs in animals and humans for years to come.
being to preserve human and animal health and the effectiveness of antimicrobial medications.
to implement a multidisciplinary approach in assembling a stewardship team to include an infectious disease physician, a clinical pharmacist with infectious diseases training, infection preventionist, and a close collaboration with the staff in the clinical microbiology laboratory
to prevent antimicrobial overuse, misuse and abuse.
to minimize the developme
One of the most developed cities of India, the city of Chennai is the capital of Tamilnadu and many people from different parts of India come here to earn their bread and butter. Being a metropolitan, the city is filled with towering building and beaches but the sad part as with almost every Indian city
The dimensions of healthcare quality refer to various attributes or aspects that define the standard of healthcare services. These dimensions are used to evaluate, measure, and improve the quality of care provided to patients. A comprehensive understanding of these dimensions ensures that healthcare systems can address various aspects of patient care effectively and holistically. Dimensions of Healthcare Quality and Performance of care include the following; Appropriateness, Availability, Competence, Continuity, Effectiveness, Efficiency, Efficacy, Prevention, Respect and Care, Safety as well as Timeliness.
Medical Technology Tackles New Health Care Demand - Research Report - March 2...pchutichetpong
M Capital Group (“MCG”) predicts that with, against, despite, and even without the global pandemic, the medical technology (MedTech) industry shows signs of continuous healthy growth, driven by smaller, faster, and cheaper devices, growing demand for home-based applications, technological innovation, strategic acquisitions, investments, and SPAC listings. MCG predicts that this should reflects itself in annual growth of over 6%, well beyond 2028.
According to Chris Mouchabhani, Managing Partner at M Capital Group, “Despite all economic scenarios that one may consider, beyond overall economic shocks, medical technology should remain one of the most promising and robust sectors over the short to medium term and well beyond 2028.”
There is a movement towards home-based care for the elderly, next generation scanning and MRI devices, wearable technology, artificial intelligence incorporation, and online connectivity. Experts also see a focus on predictive, preventive, personalized, participatory, and precision medicine, with rising levels of integration of home care and technological innovation.
The average cost of treatment has been rising across the board, creating additional financial burdens to governments, healthcare providers and insurance companies. According to MCG, cost-per-inpatient-stay in the United States alone rose on average annually by over 13% between 2014 to 2021, leading MedTech to focus research efforts on optimized medical equipment at lower price points, whilst emphasizing portability and ease of use. Namely, 46% of the 1,008 medical technology companies in the 2021 MedTech Innovator (“MTI”) database are focusing on prevention, wellness, detection, or diagnosis, signaling a clear push for preventive care to also tackle costs.
In addition, there has also been a lasting impact on consumer and medical demand for home care, supported by the pandemic. Lockdowns, closure of care facilities, and healthcare systems subjected to capacity pressure, accelerated demand away from traditional inpatient care. Now, outpatient care solutions are driving industry production, with nearly 70% of recent diagnostics start-up companies producing products in areas such as ambulatory clinics, at-home care, and self-administered diagnostics.
Leading the Way in Nephrology: Dr. David Greene's Work with Stem Cells for Ki...Dr. David Greene Arizona
As we watch Dr. Greene's continued efforts and research in Arizona, it's clear that stem cell therapy holds a promising key to unlocking new doors in the treatment of kidney disease. With each study and trial, we step closer to a world where kidney disease is no longer a life sentence but a treatable condition, thanks to pioneers like Dr. David Greene.
CHAPTER 1 SEMESTER V - ROLE OF PEADIATRIC NURSE.pdfSachin Sharma
Pediatric nurses play a vital role in the health and well-being of children. Their responsibilities are wide-ranging, and their objectives can be categorized into several key areas:
1. Direct Patient Care:
Objective: Provide comprehensive and compassionate care to infants, children, and adolescents in various healthcare settings (hospitals, clinics, etc.).
This includes tasks like:
Monitoring vital signs and physical condition.
Administering medications and treatments.
Performing procedures as directed by doctors.
Assisting with daily living activities (bathing, feeding).
Providing emotional support and pain management.
2. Health Promotion and Education:
Objective: Promote healthy behaviors and educate children, families, and communities about preventive healthcare.
This includes tasks like:
Administering vaccinations.
Providing education on nutrition, hygiene, and development.
Offering breastfeeding and childbirth support.
Counseling families on safety and injury prevention.
3. Collaboration and Advocacy:
Objective: Collaborate effectively with doctors, social workers, therapists, and other healthcare professionals to ensure coordinated care for children.
Objective: Advocate for the rights and best interests of their patients, especially when children cannot speak for themselves.
This includes tasks like:
Communicating effectively with healthcare teams.
Identifying and addressing potential risks to child welfare.
Educating families about their child's condition and treatment options.
4. Professional Development and Research:
Objective: Stay up-to-date on the latest advancements in pediatric healthcare through continuing education and research.
Objective: Contribute to improving the quality of care for children by participating in research initiatives.
This includes tasks like:
Attending workshops and conferences on pediatric nursing.
Participating in clinical trials related to child health.
Implementing evidence-based practices into their daily routines.
By fulfilling these objectives, pediatric nurses play a crucial role in ensuring the optimal health and well-being of children throughout all stages of their development.
CHAPTER 1 SEMESTER V PREVENTIVE-PEDIATRICS.pdfSachin Sharma
This content provides an overview of preventive pediatrics. It defines preventive pediatrics as preventing disease and promoting children's physical, mental, and social well-being to achieve positive health. It discusses antenatal, postnatal, and social preventive pediatrics. It also covers various child health programs like immunization, breastfeeding, ICDS, and the roles of organizations like WHO, UNICEF, and nurses in preventive pediatrics.
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How many patients does case series should have In comparison to case reports.pdfpubrica101
Pubrica’s team of researchers and writers create scientific and medical research articles, which may be important resources for authors and practitioners. Pubrica medical writers assist you in creating and revising the introduction by alerting the reader to gaps in the chosen study subject. Our professionals understand the order in which the hypothesis topic is followed by the broad subject, the issue, and the backdrop.
https://pubrica.com/academy/case-study-or-series/how-many-patients-does-case-series-should-have-in-comparison-to-case-reports/
2. 🞕Epidemic: [Greek: epi (upon) demos (the people)]
The occurrence in a community or region of cases of an
illness, specific health related behaviour, or other health
related events clearly in excess of normal expectancy.1
A Dictionary of Epidemiology – 3rd ed; LastJM. 2000.
The “unusual” occurrence in a community or region of
disease, specific health related behaviour, or other health
related events clearly in excess of “expected occurrences”.2
Park’sTextbook of Preventive andSocial Medicine – 21st ed; ParkJE. 2010
The occurrence in a community or region of a group of
illnesses of similar nature, clearly in excess of normal
expectancy, and derived from a common or from a
propagated source.3
Epidemiology – 4th ed;Gordis L. 2004
3. 🞕 Outbreak:
An epidemic limited to a localised increase in the incidence
of a disease, e.g., in a village, town, or closed institution. (=
upsurge)1
A Dictionary of Epidemiology – 3rd ed; LastJM. 2000.
A term used for a small, usually localised epidemic in the
interest of minimising public alarm.2
Park’sTextbook of Preventive andSocial Medicine – 21st ed; ParkJE. 2010
An outbreak is the occurrence of illness, specific health
related behaviour, or other event clearly in excess of
normal expectancy in a community in a specified time
period.An outbreak is limited or localised to a village,
town, or closed institution.4
Checklist forCRRT for outbreak investigation, NICD 2008
4. 🞕 According to the OxfordTextbook of Public Health the criteria for
judging that an outbreak has happened can be one of the
following.5
The occurrence of a greater number of cases or events than normally
occur in the same place when compared to the same duration in past
years.
🞔 E.g. Kaposi's sarcoma, NewYork - 30 in 1981; only 2-3 previous yrs.
A cluster of cases of the same disease occurs which can be linked to
the same exposure.
🞔E.g. 3 athletes admitted with acute febrile illness after triathlon in
Springfield, Illinois.Triathlon related to illness. Leptospira.
A single case of disease that has never occurred before or might have a
significant implication for public health policy and practice can be
judged an outbreak which deserves to be investigated.
🞔E.g. - Avian flu (H5N1) Hong Kong in a 3-year boy in May 1997 alerted local
auth. and scientists around the world to start a full-scale investigation.
5. 🞕 Endemic:The constant presence of a disease or
infectious agent within a given geographic area or
population group, without importation from outside;
may also refer to the usual or expected frequencyof
the disease within such area or population group.
A Dictionary of Epidemiology – 3rd ed; LastJM. 2000.
🞕Pandemic:An epidemic usually affecting a large
proportion of the population, occurring over a wide
geographic area such as a section of a nation, the
entire nation, or a continent or the world.
A Dictionary of Epidemiology – 3rd ed; LastJM. 2000.
6. 🞕 When formerly isolated populations are exposed to disease.
19th century – measles in Faroe islands.
🞕 When susceptible population is introduced to an endemic
area – streptococcal sore throat outbreaks when new recruits
arrived atGreat Lakes NavalStation,USA.
SUSCEPTIBLE IMMUNE
DISEASE
OUTBREAK
NO
OUTBREAK
7. 🞕 Herd Immunity:The immunity o f a group or
community.The resistance of a group to invasion
and spread of an infectious agent, based on the
resistance to infection of a high proportion of the
individuals members of the group.1
🞕 When a large proportion of the population is
immune, the entire population is likely to be
protected, not only those who are immune.
🞕Degree depends on –
Extent of random mixing of the population
Agent and transmission characteristics.
Environmental factors.
Number of susceptibles and immunes in the population.
8. 🞕Incubation Period: Interval from receipt of infection
to the time of onset of clinical illness.1
Important in case of isolating infected people to prevent
transmission.
Isolation or quarantine should be greater than maximum
incubation period.
Useful if disease may be introduced into new areas.
9. 🞕 Quarantine:The restriction of activities of well
persons or animals who have been exposed to a case
of communicable disease during its period of
communicability (i.e. contacts) to prevent disease
transmission during incubation period if infection
should occur.1
From quarante giorni (40 days).
Plague (Black Death) Europe, 1374 –Venetian Republic
1377, Ragusa detained travellers in an isolated
area, initially for 30 days and, when it did not work, for 40
days
10. Common-source epidemics
Single source or point source epidemics
Continuous or multiple exposure epidemics
Propagated epidemics
Person to person
Arthropod vector
Animal reservoir
Slow (modern) epidemics
11. Point Source: A point source outbreak occurs
when there is one single source that exists for a
very short time and all cases have common
exposure to it in that same particular period.
Ex: food poisoning
12. 🞕Common source single exposure
First case and the last case happen within one
incubation period
Rapid rise in number of cases followed by rapid decline
Example:
🞔 Food poisoning due to spoiled food item in a feast.
🞔 Bhopal gas tragedy ( 198
13. 🞕Common source multiple exposure:There is only one
source, which provides continuous or intermittent
exposure over a longer period
🞕Example:
Prostitute transmitting STD to her clients
Typhoid Mary
Water supply contamination due to leaky pipes.
🞔 Continuous if leak is constant.
🞔 Intermittent if leak occurs during pressure variations.
14. 🞕Propagated epidemic: This kind of outbreak is
caused by a transmission from one person to
another person.
🞕Example: SARS, H1N1 influenza
15. To define the magnitude
To determine the particular conditions and
factors responsible for the occurrence of the
epidemic
To identify the cause, source of infection, and
modes of transmission
To formulate prevention and control measures
16. To control the current outbreak.
Prevention of future outbreaks.
Describe new diseases and learn more about known
diseases.
Evaluation of the effectiveness of prevention
programmes.
Evaluation of the effectiveness of the existing
surveillance system.
Training health professionals.
Responding to public, political, or legal concern .
17. 🞕 The first person who comes across news
of an outbreak / The health worker/ ANM
🞕PHC medical officer / the CHC in charge
🞕 The District health officer / District RRT
or DEIT/ State RRT
🞕 Specialized agencies like NCDC (NICD).
18. 1. Verification of the diagnosis
2. Confirmation of existence of outbreak
3. Defining population at risk – Map,Count
4. Rapid search for cases and characteristics
5. DataAnalysis –Time, Place, Person
6. Formulation of hypothesis
7. Testing of hypothesis
8. Evaluation of ecological factors
9. Further investigations
10. Reporting
19. 🞕Verify rumours
🞕Technical, Administrative and Logistics
arrangement
🞕PrepareOutbreak Management Kit according to
initial information
🞕Brief members of the investigating team regarding
Roles & responsibilities
Methods of personal protection
Team composed of:
1. Nodal officer (Epi/ PHS)
2. Clinician
3. Microbiologist
4. HealthAssistant
5. District/ Local administration
nominee
6. Other personnel as required
20. Verification of the diagnosis is usually made on
clinical and laboratory parameters.
Ensure that the problem has been properly
diagnosed -- the outbreak really is what it has been
reported to be
🞔Review clinical findings and laboratory results for
affected people
🞔 Visit or talk to several of the people who became ill
For outbreaks involving infectious or toxic chemical
agents, be certain that the increase in diagnosed
cases is not the result of a mistake in the
laboratory.
21. Incidence rate is calculated by dividing the total cases
by the population at risk.
This rate is
compared with the
rate occurring in
the same
population, during
the corresponding
period of the
previous years.
362
1861
600
101
1189
213
148
15
0 0 0
4
1
1
0
0
0
0
0
0
0
0
10
2
1800
1600
1400
1200
1000
800
600
400
200
0
7year average incidence vs. 2003 incidence of Dengue in
Delhi
2000
J F M A M S O N D
J J A
months of reporting
n
o
.
o
f
c
as
e
s
2003
avg
22. • Clustering of cases or deaths
• Increases in cases or deaths
• Single case of disease of epidemic potential
• Acute febrile illness of an unknown etiology
• Two or more linked cases of disease with outbreak
potential(e.g., Measles, Cholera, Dengue, Japanese
encephalitis or plague)
• Unusual isolate (Cholera O 139)
• Unusual presentation
• Environmental factors e.g. rainfall, climate
• Shift in age distribution of cases
• High vector density
• Natural disasters
23. ⚫Rumourregister
⚫To be kept in standardized format in each
institution
⚫Community informants
⚫Privateand publicsector
⚫Media
⚫Importantsourceof information, not to neglect
⚫Review of routinedata – surveillance data
⚫Triggers (There are triggers for each condition under
surveillance, Various trigger levels may lead to local or
broader response)
24. 🞕Threshold for diseases under surveillance that trigger pre-
determined actions at various levels
🞕 Based upon the number of cases in weekly report
🞕 Trigger levels depend on:
Type of disease
Case fatality (Death / case ratio)
Number of evolving cases
Usual trend in the region
25. Trigger Significance Levels of response
1 Suspected /limited outbreak • Local response by health
worker and medical officer
2 Outbreak • Local and district response
by district surveillance
officer and rapid response
team
3 Confirmed outbreak • Local, district and state
4 Wide spread epidemic • State level response
5 Disaster response • Local, district, state and
centre
26. 🞕Examples:
Trigger levels for Dengue
🞔 Trigger 1
• Clustering of 2 similar case of probable Dengue fever in a village
• Single case of Dengue hemorrhagic fever
🞔 Trigger 2
• More than 4 cases of Dengue fever in a village 1000 population.
Triggers for syndromic surveillance
🞔 Fever
• More than 2 similar case in the village (1000 Population)
🞔 Jaundice
• More than two cases of jaundice in different houses irrespective
of age in a village or 1000 population
28. • Severityof illness
• Numberof cases
• Source / modeof transmission
• Availabilityof preventive & control measures
• Availabilityof staff & resources
• Public, political and legal concerns
• Public health programconsiderations
•Potential toaffectothers if thecontrol
measures are not taken
• Researchopportunity
29. 🞕Pseudo-outbreaks:
Artifact in the numerator:
🞔Increased awareness
🞔Reporting of prevalent cases as incident cases (e.g.;
hepatitis C, sleeping sickness)
🞔Laboratory error
Variation of the denominator:
🞔Rapidly changing population denominators
🞔Migrants or refugees
30. 🞕 Obtain a map of the area
🞕Counting of the population
🞕Helps to calculate the denominator for further
calculation of attack rates.
🞕Provides us with the possible number of people at
risk.
🞕Mapping helps us to know area: ecological and
environmental factors.
31. 🞕Map :
Detailed,Current map of the area.
If not available – prepare
Information: Natural landmarks, Roads,All dwelling
units,Sources of water,Other important features
🞕 Counting:
Census by age and sex
Lay health workers
House to house visits
32. 🞕Includes: Framing a case definition, searching for
cases and doing a epidemiological survey.
🞕A case definition is a standard set of criteria for
deciding whether an individual should be classified as
having the health condition of interest.
Criteria
Clinical and/or biological criteria,
Time
Place
Person
🞕 Case definition should be
balanced, practical, reliable and applied without bias.
33. Example - Measles: 3 definitions
Fever and runny nose
Too sensitive
Too many other illnesses produce same symptoms
Call many illnesses “measles”
Fever and rash and Koplik’s spots and conjunctivitis
Too specific
Many cases of measles do not have all these signs
Miss many real cases of measles
IDSP case definition: Fever of 3-7 days duration, with
generalized maculopapular rashes; with history of cough, coryza,
conjunctivitis or Koplik’s spots.
34. Suspect -Fewer of the typical clinical features
Probable- Typical clinical features of the disease
without laboratory confirmation.
Confirmed- Typical clinical features with laboratory
verification.
Laboratory
Verification
Clinical
Features
Confirmed Case
+
Probable Case Possible Case
++ ++ +
35. 🞕Example: E. coli O157 outbreak at
Restaurant X on 31/3/2010
Possible: diarrhea (3 loose stools per day) and
ate food purchased at restaurantX on 31/3
Probable: bloody diarrhea and ate food
purchased at restaurantX during on 31/3
Confirmed: culture positive with “outbreak”
PFGE pattern and ate food purchased from
restaurantX on 31/3
36. 🞕Case Definition may need to be updated within
an investigation
Broad to specific
🞔 Infection with E. coliO157 vs. infection with the outbreak
strain (defined by PFGE pattern)
Location of exposure
🞔 SARS outbreak (travel within 10 d of onset):
• In February:China/HK/Hanoi/Singapore
• InApril:Toronto,Canada added
• In May:Taiwan added
Dates of exposure can change
🞔 SARS outbreak: to meet the case definition-dates of
exposure dependant on location of exposure
37. 🞕The first cases to be recognized are usually only a small
proportion of the total number
🞕To identify other cases, use as many sources possible
Passive Surveillance - Relies on routine notifications by
healthcare personnel
Active Surveillance - Involves regular outreach to potential
reporters to stimulate reporting of specific conditions;
investigators are sent to the afflicted area to collect more
information
🞔 Contact physician offices, hospitals, schools to find
persons with similar symptoms or illnesses
🞔 Send out a letter
, telephone or visit the facilities to collect
information
🞔 Through media alerts asking people to get checked
39. 🞕 The information is collected by “line listing”.
Aline list is like a nominal roll of the cases being reported
to the various health care establishments (like
dispensaries, general practitioners or admitted to the
hospitals)
Constitutes and updates a database of cases
Done by hand or by Excel.
40.
41. 🞕The survey team will go for “door to door” survey
in the affected area and ask if any person had
suffered with symptoms fitting into case definition
(Rapid Household Survey)
🞕If yes, their details were recorded on the
epidemiological case - sheet and required samples
are taken and dispatched to the hospital/ reference
laboratory.
Epidemiological case sheet =Case interview form
Detailed information from the case relevant to the
disease under study.
42. Information includes:
• Name,Age, Sex, Occupation, Social class
• Time of onset of disease, Signs & Symptoms
• Personal contact at home, work, school
• Travel history, attendance at large gatherings
• History of previous exposure/injections,
• Special events such as parties attended, foods
eaten, and exposure to common vehicles such as
water, food and milk
45. 🞕Characterizing an outbreak by time, place and
person is called descriptive epidemiology.
🞕 Descriptive epidemiology is important because:
What is reliable and informative (e.g., similar exposures)
What may not be as reliable (e.g., many missing
responses to a particular question)
Provides a comprehensive description of an outbreak by
showing its trend over time, its geographic extent (place)
and the populations (people) affected by the disease
46. 🞕Development of
proportional
distribution of cases
according to host
characteristics
(age, race, sex)
or
by exposures
(occupation, leisure
activities, use of
medications, tobacco,
drugs).
47. 🞕Count
Count the cases in each age and sex groups
🞕Divide
Obtain census denominators for each age and sex groups
🞕Compare
Estimate the incidence for each:
🞔 Age group
🞔 Sex group
48. 🞕An attack rate is the proportion of a well-defined
population that develops illness over a limited
period of time, such as during an epidemic or
outbreak
🞕 What are the age and gender specific attack rates?
🞕What age and gender groups are at highest and
lowest risk of illness?
🞕In what other ways do the characteristics of the
cases differ significantly from those of the
general population?
Purpose => Identification of sub-group(s) at risk
49. Characteristics Number of
cases
Population Attack
rate per
100,000
Age group 0-4 50 255,755 19.6
5+ 51 1,795,383 2.8
Sex Male 48 1,032,938 4.6
Female 53 1,018,200 5.2
Total 101 2,051,138 4.9
Attack rate of measles by age and
sex, Cuddalore, Tamil Nadu,
India, 2004-2005
51. What is the exact period of the outbreak?
What is the probable period of exposure?
Is the outbreak likely common source or
propagated?
52. 1.Count cases by
time of onset
2. Eyeball
distribution
to choose interval
3 . Finalize
Drawing the epidemic curve based on time distribution of cases
53. 🞕Interpretation of epidemic curve
Shape – type of epidemic
An early case in the curve may represent source of the
epidemic
Give information about the time course of an epidemic
and what the future course might be
In a point-source epidemic of a known disease with a
known incubation period, epidemic curve provides
information to identify a likely period of exposure
Shape of epidemic curve illustrates type of epidemic.
56. Continuous common source outbreak:
An abrupt increase in the number of cases but, new cases
persist for a longer time with a plateau shape instead of a
peak before decreasing.
58. 🞕Propagated source outbreak:
Increase in the number of cases with progressive peaks
16
14
12
10
8
6
4
2
0
1 4 7 10 13 16 19 22 25 28 31 34
Date
Number
of
cases
59. 🞕The spatial relationships
of cases are shown best
on a spot map.
🞕Aspot map showing
the location of cases can
give an idea of the
source of infection like
maps show that the
cases occurred in
proximity to a body of
water, a sewage
treatment plant, or its
outflow. DRAWINGA ROUGH SPOT MAP
60.
61. 🞕Questions to be asked and answered:
What is the most significant geographic distribution
of cases?
Place of residence?Workplace?
Do the attack rates vary by place?
Relation to any landmark or possible source?
62. 🞕 Usually we generate hypotheses from the beginning of
the outbreak, however, at this point, the hypotheses
are sharpened and more accurately focused.
🞕 To consider what is known about the disease itself:
A. What is the agent’s usual reservoir?
B. How is it usually transmitted?
C. What vehicles are commonly implicated?
D. What are the known risk factors?
63. 🞕Talk to people who are ill: In-depth open
interviews,Group discussions
🞕Hypotheses should be proposed in a way that they
can be tested.
64. 🞕After a hypothesis is formulated, one should be able to
show that:
all additional cases, lab data, and epidemiologic
evidence are consistent with the initial hypothesis
no other hypothesis fits the data as well
🞕 Observations that add weight to validity:
The greater the degree of exposure (or higher dosage
of the pathogen), the higher the incidence of disease
Higher incidence of disease in the presence of one risk
factor relative to other factors
65. 🞕 Approaches:
Comparison of hypothesis with known/ established facts.
Analytic epidemiology to test the hypothesis
🞕First method is used when the evidence is so strong
that hypothesis need not be tested
Example - A 1991 investigation of an outbreak of vitamin D
intoxication in Massachusetts.
All affected drank milk from local dairy.
Hypothesis - dairy was source, milk vehicle of excess vit D.
Visit to dairy, they quickly recognized that far more than
the recommended dose of vitamin D was inadvertently
being adding to the milk.
No further analysis was necessary.
66. 🞕Analytic epidemiology is used when cause is less
clear.
Cohort studies
Case control studies
🞕What to use?
Case
control
Cohort
Rare disease/ large community +++ -
Common disease/ small community - +++
Complete population accessible +/- +++
Large amount of resources + ++
Limited resources +++ -
67. FOOD
ATE and ILL
N (%)
ATE and NOT ILL
N (%)
ODDS RATIO
TOMATOES 14 (82) 30 (86) 0.83
CHICKEN 13 (71) 34 (94) 0.11
ALFAALFA
SPROUTS
10 (67) 6 (17) 8.25
Example:
Case control study for an outbreak of Acute Gastroenteritis
following a dinner.
68. 🞕These are additional studies undertaken to
corroborate the findings of the epidemiological
study.
Environmental studies
Microbiological studies
Entomological studies
69. 🞕Environmental studies often help explain why an
outbreak occurred and may be very important in
certain settings.
Example: Site of contamination of irrigation canal with
cattle urine in an outbreak of Leptospirosis in
southeasternWashington,August 1964.
Pond connected to
irrigation canal
And
Cattle around the site
70. 🞕Microbiological studies can clinch the relationship
between suspected source and outbreak.
Example: In the above outbreak of Leptospirosis, culture
of urine from the cattle, water of the canal and blood of
affected children yielded the same strain of L. pomona.
Also, the children who had recovered showed increased
anti leptospiral antibodies.
71. 🞕Entomological studies help identify the vector
responsible for the outbreak.
May also give useful insight into the life cycle of the
pathogen and the mode of transmission
Example:
Vector surveillance
in Chikungunya
affected villages of
Latur and Beed
districts of
Maharashtra, 2006
72. 🞕 Additional epidemiologicstudies
What questions remain unanswered about the disease?
What kind of study used in a particular setting would
answer these questions?
When analytic studies do not confirm the hypotheses
🞔reconsider the original hypotheses
🞔look for new vehicles or modes of transmission
🞕 Additional investigations
Further lab studies
🞕Refine hypothesis till confirmation
73.
74. 🞕Report provides a blueprint for action.
🞕It also serves as a record of performance and a
document for potential legal issues.
🞕It serves as a reference if the health department
encounters a similar situation in the future.
🞕In public health literature serves the purpose of
contributing to the knowledge base of epidemiology
and public health
🞕Daily interim reports and final report.
75. Contents of a Report:
1. Back ground
2. Historical data
3. Methodology of investigation
4. Analysis of data (clinical data, Epidemiological
data, modes of transmission, Lab data,
Interpretation of data)
5. Control measures
6. Evaluation
7. Preventive measures
76. Report to be submitted
by investigating
officer/ team to the
next higher authority
within one week of
completion of
investigations
77. 🞕Appropriate control measures
based on Epidemiological, Clinical, Environmental
findings
To prevent further spread of disease
🞕 The elements of epidemic control include:
1.Controlling the source of the pathogen (if known)
Remove or inactivate the pathogen
2.Interrupting the transmission.
Sterilize environmental source of spread; vector control
3.Modifying the host response to exposure.
Immunization; Prophylactic chemotherapy
78. 🞕Control measures should be implemented at
the earliest.
🞕DO NOT wait for laboratory confirmation to
start control measures.
79. 🞕Follow up of outbreak
Detect last case
Detect and treat late complications
Complete documentation
🞕Evaluation of outbreak management including
investigations (by local authorities)
Genesis of outbreak
Early or late detection of outbreak
Preparedness for outbreak
Management of the outbreak
Control measures taken and their impact
80. 🞕Documentation and sharing the lessons learnt
Post outbreak seminar.
Feedback to local health authorities, RRTs and other
concerned.
Developing case studies on selected outbreaks for
training purposes.
81. Audience Medium Focus of the
content
Communication
objective
Epidemiologists,
laboratory
•Report •Epidemiology •Documentation of
the source
Public health
managers
•Summary •Recommendations •Action
Political leaders •Briefing •Control measures •Evidence that the
situation is under
control
Community •Press release,
interview
•Health education •Personal steps
towards prevention
Scientific
community
•Presentation,
manuscript
•Science •Scientific progress
POSSIBLE MATRIX FORCOMMUNICATIONOF
INVESTIGATION RESUL
TSAND FINDINGS
82. 🞕An outbreak of fever,URI & loose motion among the
boarders of PTS, Jharoda kalan, Delhi was reported to
the MS ofSJH byCDMO ofSW district of Delhi on
10.07.09 .
🞕 Cause for concern – Panic d/t novel H1N1 cases in Delhi
🞕RRT composition –
Epidemiologist, Physician, Microbiologist and other
doctors. (11.07.09)
🞕Case definition:A person with acute onset of fever with
or without sore throat, diarrhea, headache, body ache
starting from 2nd July 2009 onward.
🞕Line listing, Epidemiological case sheet (with travel
history), Lab analysis of samples for H1N1.
83. 🞕Descriptive:
Time – Start = 2nd Jul, Peak = 7th Jul, Fall afterwards
Place – Start inTent # 40, 25 & 8; then spread. clustered
around tent no 1,9,20, 22, 27, 36 &37.
Person – 61 cases. Mean age 22.2 yrs (20-49).
🞕Environmental: Crowded, ill ventilated tents. Humid
environment with low temperature.
🞕Lab: H1N1 negative. InfluenzaA +ve.
🞕Recommendations:
Reduce crowding, Improve ventilation
Increase staffing in dispensary and Proper record maintainance
Prompt identification and reporting of changes in disease
frequency.
84. 🞕Outbreak of jaundice among the residents of Sector 8 of
RK Puram, New Delhi was reported to the MS of SJH by
CDMO ofSW district of Delhi on 06.04.2011.
🞕Initial report by DSO suggested sudden onset of
jaundice.
🞕RRT – Epidemiologist, Physician, Microbiologist and
other personnel.ToCGHS, dispensary on 06.04.2011
🞕Case defn : A person with signs and symptoms of
jaundice with or without elevated serum
aminotransferase levels from 1st January 2011 onwards
🞕Verification of outbreak by review of records of CGHS
dispensary.
85. 🞕Rapid survey, Line listing, Spot map, Clinical
examination, Epidemiological case sheet, Blood
samples, Environmental study
🞕Descriptive:
Time – Rise from 15th Jan, Peak 1st week March, Decline
afterwards. Max cases in March (11/21)
Place –Clustering around N block & adjacent to Palam rd
Person – 15-30 yrs (50%), M > F (58.3/ 41.7)
🞕 Lab: 3/5 recent cases +ve forAnti HEV IgM.
2/6 water samples – Fecal contamination
86. 🞕 Environmental: Water & sewer lines running
close, Intermittent water supply – Booster
pumps, Latrine near water storage tank, Sewer lines not
de-silted – overflowing, Damaged water lines. Absent
residual chlorine.
🞕 Conclusion:Confirmed outbreak of jaundice. Lab results
Acute Hepatitis E. Damaged water lines and
contamination from sewer lines responsible.
🞕Recommendations:
Proper record maintenance inCGHS dispensary(diagnosis, S/s)
Monitoring and repairing of water lines
Sewer lines should not be close to water supply pipeline
Regular de-silting and cleaning of sewer line.
Proper chlorination of water supply.
87. 1. A Dictionary of Epidemiology – 3rd ed; Last JM.
2000.
2. Park’sTextbook of Preventive and Social Medicine
– 21st ed; Park JE. 2010.
3. Epidemiology – 4th ed;Gordis L. 2004.
4. Checklist forCRRT for outbreak investigation, NICD
2008
5. OxfordTextbook of Public Health – 4th ed; 2002
6. Mausner & Bahn Epidemiology:An Introductory
Text – 2nd ed; Mausner JS, KramerS. 1985.
88. 7. R Bonita, R Beaglehole, T Kjellström. Basic
Epidemiology:WHO;2nd Edition.
8. Outbreak Investigations Around The World: Case
Studies in Infectious Disease Field Epidemiology;
MarkS Dworkin. 2010
9. Steps of outbreak investigation; Epidemiology in
the classroom. Excite,CDC. From www.cdc.gov
10. Raut DK, Roy N, Nair D, Sharma R. Influenza A virus
outbreak in PoliceTraining School, Najafgarh, Delhi
– 2009. Indian J Med Res; Dec 2010; 132: 731-732