Surveillance of infections;
pandemic plans
MUDr. Marie Kolářová, CSc.
Ústav ochrany a podpory zdraví LF MU
Spring 2019
Preventive,
repressive
measures
If the epidemiology of infection is know, we can interfere with
transmission:
„BREAKING THE CHAIN OF INFECTION“
Different infections have different epidemiologies and
thus require different methods of control
3
Isolation of patients:
- dpt. of infectious diseases -VHA, acute VHB, Typhus abdominalis,..,
- „high degree of isolation“ - ebola,
- at home - influenza, varicella,….
- barriers nursing technique – MRSA, VRE in hospital, ….
SOURCE
OF INFECTION
MODE
OF TRANSMISSION
SUSCEPTIBLE
ORGANISM
Prevention of
infectious
diseases
4
SOURCE
OF INFECTION
MODE
OF TRANSMISSION
SUSCEPTIBLE
ORGANISM
HANDWASHING, DISINFECTION OF HANDS
LINEN WASHING,
CLEANING
GOOD PREPARING OF FOOD, SAFE WATER……..,
………
DISINFECTION
STERILIZATION
Prevention of
infectious
diseases
5
Active immunisation
A live or inactivated substance (e.g., a protein, polysaccharide) capable of producing an immune response is
administered to the organism to target specific antibodies against that antigen.
Protein molecules (immunoglobulin) produced by B lymphocytes to help eliminate an antigen
Passive immunisation
Transfer of antibodies produced by one human or other animal to another.
Temporary protection
Transplacental most important source in infancy
SOURCE
OF INFECTION
MODE
OF TRANSMISSION
SUSCEPTIBLE
ORGANISM
i m m u n i t y
– natural (nonspecific),
- acquired (vaccination)
Prevention of
infectious
diseases
Preventive,
repressive
measures
In the practical part it is preoccupied with
preventive measures
repressive measures
related to infectious diseases
EPIDEMIOLOGY
is the study (scientific, systematic, data-driven)
of the distribution (frequency, pattern)
and determinants (causes, risk factors)
of health-related states or events (not just
diseases)
in specified populations (patient is community,
individuals viewed collectively),
and the application (since epidemiology is a
discipline within public health) of this study to the
control of health problems.
Epidemiologic
investigations
Epidemiologic investigations are largely
mathematical descriptions of persons in
groups, rather than individuals.
The basic quantitative measurement in
epidemiology is
a count of the number of persons in the group
being studied who have a particular disease.
9
Solving
health
problem
Step 1
Date collection
Step 2 Assessment
Step 3
Hypothesis testing
Step 4
Action
Surveillance; determine
time, place and person
Inference
Determine how and why
Intervention
Solving health
problem
Epidemiologists arrange their data in various
ways,
depending on what aspect of the information
they want to emphasize.
One of the most powerful tools an
epidemiologist can use is case
reporting:
reporting specific diseases to
* local,
* state and
* national health authorities,
who accumulate the data
Milestones in the eradication of smallpox
1789 Edward Jenner invents a smallpox vaccine.
1966 The World Health Organization (WHO) launches a massive global
campaign to eradicate smallpox.
1972 Smallpox vaccinations are discontinued in the United States.
1975 and 1977 The last cases of the two known variants of smallpox occur in
the world, in Bangladesh and Somalia.
1978 Two people are sickened in a lab accident in England; one dies.
1980 The WHO declares smallpox eradicated.
1991 Smallpox virus DNA is mapped.
1999 The WHO sets this deadline, by which remaining lab stocks of the virus are to
be destroyed. The deadline will be postponed again and again.
2003 Millions of doses of vaccine are produced to hedge against a biological attack.
2011 WHO's decision-making body will meet in May to again vote on whether to kill
the remaining live viruses.
Face lesions on boy with smallpox.
Public Health Images Library (PHIL) ID # 3.
Source: CDC/Cheryl Tyron
Smallpox recognition
card, c.1973, courtesy
Dr. Damodar Bhonsule,
Panjim, Goa, India.
Smallpox lesions on skin of trunk.
Picture taken in Bangladesh, 1973.
Public Health Images Library (PHIL) ID #284. Source: CDC/James Hicks
Eradication of smallpox
Czech experts
A key figure in the global eradication program
smallpox was prof. MUDr. Karel Raska, MD.,
who drove in the sixties division
Communicative Diseases of theWHO
Secretariat in Geneva.
He promoted the establishment of a new, independent units "Eradication of
smallpox"and ensure its initial financial and material support, not only in Geneva,
but also in regional offices ofWHO.
With its support of the program also attended the 20 Czechoslovak health
professionals (14Czechs and Slovaks 6), mainly epidemiologists.
They participated in both the preparation methodology and procedures, thus
working directly in infested areas.
Ruralvaccinator inUnitedProvinces, British
India,c.1930, private collection ofDr.Sanjoy
Bhattacharya
Variola virus, which causes smallpox, was once the scourge of the world.
This virus passes from person to person through the air.
A smallpox infection results in fever, severe aches and pains, scarring sores
that cover the body, blindness in many cases, and, often, death.There is no
effective treatment.
Although vaccination and outbreak control eliminated smallpox in the United
States by 1949, the disease still struck an estimated 50 million people
worldwide each year during the 1950s.
In 1967, theWorld Health Organization (WHO) launched a massive vaccination
campaign to rid the world of smallpox —and succeeded.
The last natural case of smallpox occurred in Somalia in 1977.
Ali Maow Maalin, cook twenty-three of the hospitals in the Somali Merce.
He contracted when he showed the path of the ambulance chauffeur who drove
two sick children to camp insulation.
In 1978 was ill photographer Medical School in Birmingham, England. She was killed
by a virus that escaped from a neighboring lab.
Mr.JohnWickett,ofthe
WorldHealthOrganization,
withthelastpersontohave
contracted–andsurvived–
naturallyoccurringsmallpox
inSomalia.
(1977),courtesyMr.JohnWickett.
Smallpox eradication was
officially announced
at the 33rd General Assembly WHO
8. May 1980.
SURVEILLANCE
Surveillance represents a number of long-term and
complex programmes, in which experts of various
medical fields participate together, for example
epidemiologists, microbiologists, hygienists, clinicians
etc. Other non-medical personnel, such as statisticians,
vets and ecologists, may also participate alongside
medical personnel.
The epidemiologist is usually the initiator and organiser
of the program.
Surveillance was initially started in the field of infectious
diseases.
SURVEILLANCE
The systematic
 collection,
 analysis,
 interpretation, and
 dissemination of health data on an ongoing basis,
to gain knowledge of the pattern of disease
occurrence and potential in a community,
in order to control and prevent disease in the
community.
SURVEILLANCE
 Surveillance is put into effect in three successive stages:
 Obtaining the necessary data such as the number of sick, the
number of dead, data from microbiological laboratories on
circulation and qualities of etiological agent, clinical information
on symptomatology of individual diseases, monitoring of
vaccination and collective immunity of population, monitoring of
infections with animals, and data of natural sciences on vectors.
 Analysis of collected data, including evaluation of information
and suggestion of measures. Long-term surveillance gives the
possibility of making a prognosis of the occurrence of a given
disease for the future.
 Guaranteeing qualified information to all concerned people who
can further use it for improvement of their own measures and
theories.
SURVEILLANCE
Surveillance programmes can be carried out on a large
scale such as for districts and regions.
In the Czech Republic, surveillance programmes exist
for poliomyelitis, pertussis, diphtheria, measles, viral
hepatitis, alimentary infections and influenza.
Under the general guidelines released by WHO,
surveillance of influenza is carried out on an
international level.
 BENCKO, Vladimir, et al. Hygiene and Epidemiology : Selected Chapters. 2nd edition. Prague. 2008. ISBN 80-246-0793-X.
European
Tuberculosis
Surveillance Network
The European Tuberculosis Surveillance Network consists
of TB surveillance experts from all 53 countries belonging to
the World Health Organization’s European Region, including
30 EU/EEA Member States.
Under the joint coordination of ECDC and the World Health
Organization’s Regional Office for Europe, the network
collects, validates, analyses and disseminates European TB
surveillance data.
The purpose of the network is to identify the epidemiological
patterns of TB in the Region and monitor progress towards
TB elimination, with key surveillance and monitoring findings
published in an annual report.
In addition, the network aims to further strengthen TB
surveillance in Europe.
Terminology and
Definitions
 Sporadic disease
 Endemic disease
 Epidemic(outbreak)
 Pandemic disease
 Zoonosis,
epizootic and
enzootic
 Eradication
 Elimination
 Nosocomial
infection
 Attack rate
 Opportunistic
infection
 Immunity passive
active
 Individual
immunity
 Herd immunity
 Virulence
 Incubation period
 Infectivity period
 Latent period
 Probability ratio
 Chain of infection
 Host (source)
 Reservoir
 Transmission
Direct
Indirect
Biologic
Vertical
 Susceptible host
 Incidence and
 prevalence
 Case definition
Chain of infections
(epidemic proces)
THE CAUSATIVE AGENT OF INFECTION (bacteria, viruses, fungi, prions, protozoa)
1. the presence of rezervoir (source) of infection
man, animal at the ende of incubation period
acute stage
cariers
2. the way of transmission A/ direct contact
touching, kissing or sexual intercourse (Staphylococcus spp., Gonococcus spp.,HIV …),
- vertical transmission – from mother to fetus (VHB, VHC, HIV, listeria, rubella,
cytomegalovirus…)
B/ indirect contact
- inhalation of droplets containing the infectious agents (TBC, measles, influenza…)
- ingestion of food or water that is contaminated (salmonella, giardia, Norwalk virus, VHA….)
- biological transmission by insects (malaria, borellia….)
3. the susceptibility of the population or its individual members to the
organism concerned Host factors : a g e , n u t r i t i o n, g e n e t i c s
i m m u n i t y – natural (nonspecific),
- acquired
THE INFECTION
= 1. source of infection
……….
Disease trends
 Incidence - measures the number of new cases over time.
This number measures an individual chances of developing or
contracting the disease.
Number of new cases within a specified time period
Total number of people in the population
 Prevalence – measures the total number of cases of disease
in a population.
Total number of diseases individuals
Total number of people in the population at a given time
Terminology and
definitions
 Case definition: a set of standard criteria for deciding whether a person has
a particular disease or health-related condition, by specifying clinical,
laboratory andd epidemiological criteria and limitations on time, place and
person.
 Attack rate: proportion of non-immune exposed individuals who become
clinically ill.
 Zoonosis is an infection that is transmissible under natural conditions from
vertebrate animals to man, e.g. rabies, plague, bovine tuberculosis…..
 An epizotic is an outbreak (epidemic) of disease in an animal population,
e.g. rift valley fever.
 An enzotic is an endemic occurring in animals, e.g. bovine TB.
 Nosocomial (hospital acquired) infection is an infection originating in a
patient while in a hospital or another health care facility. It has to be a new
disorder unrelated to the patient’s primary condition.
Eradication and
Elimination
Eradication is an absolute process, an “all or
none” phenomenon, restricted to termination of
infection from the whole world.
Smallpox eradication was officially
announced at the 33rd General Assembly
WHO
8. May 1980.
 The term elimination is sometimes used to
describe eradication of a disease from a large
geographic region. Disease which are amenable
to elimination in the meantime are polio,
measles and diphtheria.
Herd immunity
(also called herd effect,
population immunity, or
social immunity)
is a form of indirect protection from infectious disease
that occurs when a large percentage of a population
has become immune to an infection, thereby providing
a measure of protection for individuals who are not
immune.
In a population in which a large number of individuals are
immune, chains of infection are likely to be disrupted,
which stops or slows the spread of disease.
The greater the proportion of individuals in a community
who are immune, the smaller the probability that those
who are not immune will come into contact with an
infectious individual.
Individual immunity
can be gained through recovering from a natural
infection or through artificial means such as
vaccination.
Some individuals cannot become immune due to
medical reasons and in this group herd immunity
is an important method of protection.
Herd immunity
(also called herd
effect,
population immunity,
or social immunity)
Once a certain threshold has been reached, herd immunity
gradually eliminates a disease from a population.
This elimination, if achieved worldwide, may result in the
permanent reduction in the number of infections to zero, called
eradication.
This method was used for the eradication of smallpox in 1977
and for the regional elimination of other diseases] Herd
immunity does not apply to all diseases, just those that are
contagious meaning that they can be transmitted from one
individual to another.] Tetanus, for example, is infectious but not
contagious, so herd immunity does not apply].
Occurrence of
Diseases
Sporadic Disease that occurs occasionally in a
population.
Endemic Disease constantly present in a population
at all times – malaria is present in Africa at all time
because of the presence infected mosquitos.
Epidemic or outbreak Disease occurence among
a population that is in excess of what is expected in a
given area in a short time – the Ebola virus in parts of
Africa is in excess of what is expectes for this region.
Pandemic Disease or condition that spread across
world - – HIV/AIDS is one of the worst global diseases
in history.
01.04.2019
Definition of
a pandemic
A pandemic is an epidemic extending over a wide
geographic area, affecting whole continents.
It involves the high incidence of a disease over a
large territory (continent) over a specific period of
time.
According to the WHO definition, an influenza
pandemic is characterized by the spread of a
pandemic virus within communities in at least 2
countries of a single WHO region and at least
one other country in another WHO region.
01.04.2019
The rise of the
pandemic strain
01.04.2019
The rise of the
pandemic strain
01.04.2019
Pandemic
preparedness
Pandemic preparedness is most effective if it is built on
general principles that guide preparedness planning for
any acute threat to public health. This includes the
following:
Pandemic preparedness, response and evaluation
should be built on generic preparedness platforms,
structures, mechanisms and plans for crisis and
emergency management.
To the extent possible, pandemic preparedness should
aim to strengthen existing systems rather than
developing new ones, in particular components of
national seasonal influenza prevention and control
programmes.
New systems that will be implemented during a pandemic
should be tested during the inter-pandemic period.
Adequate resources must be allocated for all aspects of
pandemic preparedness and response.
01.04.2019
Pandemic
preparedness
 The planning process, implementing what is planned, testing and revising
the plan in order for key stakeholders to familiarise themselves with the
issues at hand, may be even more important than the pandemic plan
itself.
 Pandemic response requires that business continuity plans and surge
capacity plans be developed for the health sector and all other sectors
that could be affected by a pandemic to ensure sustained capacity during
a pandemic.
 The response to a pandemic must be evidence-based where this is
available and commensurate with the threat, in accordance with the IHR.
Planning should be based on pandemics of differing severity while the
response is based on the actual situation determined by national and
global risk assessments.
 Not all countries will be in a position to contribute to global risk
assessment, nor conduct evaluations such as pandemic vaccine
effectiveness. They must all have the capacity to access and interpret
data for risk assessment provided by WHO, ECDC, and from other
countries or sources.
01.04.2019
Pandemic
preparedness
Preparing for an influenza pandemic is a continuous
process of planning, exercising, revising and translating
into action national and subnational pandemic
preparedness and response plans.
A pandemic plan is thus a living document which is
reviewed at intervals and revised if there is a change in
global guidance or evidence-base; lessons learned
from a pandemic, an exercise, or other relevant
outbreak; or changes to national or international
legislation related to communicable disease prevention
and control :
01.04.2019 ECDC
Pandemic
preparedness