Preventive epidemiological
measures;
principles of vaccination
MUDr. Marie Kolářová,CSc.
Ústav ochrany a podpory zdraví LF MU
Spring 2019
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.
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.
 Diseases preventable by vaccination
 Sexually transmitted diseases
 Viral hepatitis
 Food- and waterborne diseases and diseases of
environmental origin
 Diseases transmitted by non-conventional agents
(prions)
 Airborne diseases
 Zoonoses (other than those listed above)
 Serious imported diseases
 Vector-borne diseases
 Special health issues (HAI, antibiotic resistence)
Diseases and
special health
issues under
EU surveillance
Global Disease
Elimination and
eradication
 During the 25 years since the certification of smallpox eradication
there has been considerable debate among public health
practitioners about how existing health technologies can best be used
to decrease infectious disease incidence and prevalence.
 Interruption of transmission has often been envisaged as the ultimate
goal, and standard public health concepts of disease reduction have
been defined or re-defined.
 In 1998, Dowdle proposed a definition of control as a reduction in the
incidence, prevalence, morbidity or mortality of an infectious disease
to a locally acceptable level;
 elimination as reduction to zero of the incidence of disease or
infection in a defined geographical area;
 and eradication as permanent reduction to zero of the worldwide
incidence of infection
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.
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.
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
2. the way of transmission A/ direct contact
B/ indirect contact
3. the susceptibility of the population or its individual members
to the organism concerned
THE INFECTION
= 1. source of infection
……….
Preventive,
repressive
measures
If the epidemiology is know, we can interfere with transmission:
„BREAKING THE CHAIN OF INFECTION“
Different infections have different epidemiologies and
thus require different methods of control
Preventive,
repressive
measures
In the practical part it is preoccupied with
preventive measures
repressive measures
related to infectious diseases
0
10000
20000
30000
40000
50000
60000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
0
10000
20000
30000
40000
50000
60000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Varicella -- chickenpox
0
10000
20000
30000
40000
50000
60000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Varicella -- chickenpox
Salmonellosis
0
10000
20000
30000
40000
50000
60000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Varicella -- chickenpox
Campylobacteriosis
Salmonellosis
0
10000
20000
30000
40000
50000
60000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Varicella -- chickenpox
Campylobacteriosis
Salmonellosis
231,7/100 000
111,3/100 000
490,4/100 000
0
200
400
600
800
1000
1200
1400
1600
1800
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
VHA 15,8/100 000
VHC 10,4/100 000
VHB 0,8/100 000
VHE 3,9/100
0
500
1000
1500
2000
2500
1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Tuberculosis ČR
2 079 případů = 20,2/100 000
505 případů = 4,9/100 000
TB notification rates per 100 000 population by year
of reporting, EU/EEA, 1995-2016
11,4/100 000
Cases per 100 000 population
1,96/100 000
Tetanus
Diphtheria
0
500
1000
1500
2000
2500
3000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Wooping cough
Vaccination in pregnancy is recommended
0
0,5
1
1,5
2
2,5
3
3,5
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
0
50
100
150
200
250
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Measles
0
1000
2000
3000
4000
5000
6000
7000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Mumps
0
1000
2000
3000
4000
5000
6000
7000
8000
1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
Rubella, German measles
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, 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
……….
Preventive,
repressive
measures
If the epidemiology is know, we can interfere with transmission:
„BREAKING THE CHAIN OF INFECTION“
Different infections have different epidemiologies and
thus require different methods of control
EpidemiologyofSmallpox
Smallpox was a systemic disease.
After an average incubation period of 12 days,
a high fever accompanied by non-specific general symptoms
abruptly appeared. The fever then receded and a characteristic
skin eruption appeared. Subsequently the fever rose again, and
serious complications generally developed (pulmonary, cardiocirculatory,
neurological, etc.), resulting in death in up to 50% of
cases.
Survivors who overcame this phase would see the rash
resolving, leaving permanent scars.
No effective therapy was available.
EpidemiologyofSmallpox
THE CAUSATIVE AGENT OF INFECTION
dsDNA virus
Poxviridae; Chordopoxovirinae
Orthopoxvirus: Variola major virus
EpidemiologyofSmallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source):
Only infected humans
Smallpox patients became contagious
once the first sores appeared
in their mouth and throat.
They spread the virus when they coughed or sneezed and
from their nose or mouth spread to other people.
They remained contagious until their last smallpox scab fell off.
Smallpox recognition
card, c.1973, courtesy
Dr. Damodar Bhonsule,
Panjim, Goa, India.
EpidemiologyofSmallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source):
Only infected humans
These scabs and the fluid found in the patient’s sores also contained the variola virus.
The virus can spread through these materials or through the objects contaminated by
them,
such as bedding or clothing.
People who cared for smallpox patients and washed their bedding or clothing had to
wear gloves and take care to not get infected.
Rarely, smallpox has spread through the air in enclosed settings,
such as a building (airborne route).
EpidemiologyofSmallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source):
Only infected humans
Incubation period (the length of time the virus is in a person’s body before they look or feel sick. During this period, a person usually has
no symptoms and may feel fine..:
This stage can last anywhere from 7 to 19 days (although the average length is 10 to 14 days).
The first symptoms include:
 High fever
 Head and body aches
 Sometimes vomiting
A rash starts as small red spots on the tongue and in the mouth. These spots change into sores that
break open and spread large amounts of the virus into the mouth and throat.
Smallpox may be contagious during phase with first symptoms, but is most
contagious during the next 2 stages (early rash and pustular
rash and scabs).
EpidemiologyofSmallpox
1.the presence of rezervoir (source):
Only infected humans
Once the sores in the mouth start breaking down,
a rash appears on the skin, starting on the face and spreading to the arm
and legs, and then to the hands and feet.
Usually, it spreads to all parts of the body within 24 hours.
As this rash appears, the fever begins to decline, and the person may start to feel better.
By the fourth day, the skin sores fill with a thick, opaque fluid and often have a dent in the center.
Once the skin sores fill with fluid, the fever may rise again and remain high until scabs form over the bumps.
After 10 days
The sores become pustules (sharply raised, usually round and firm to the touch, like peas under the skin).
 After about 5 days, the pustules begin to form a crust and then scab.
By the end of the second week after the rash appears, most of the sores have scabbed over.
EpidemiologyofSmallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source): Only infected humans
2. the way of transmission:
Smallpox was mainly spread by direct and fairly prolonged
face-to-face contact between people.
Smallpox patients became contagious once the first sores appeared in their
mouth and throat.
They spread the virus when they coughed or sneezed
and droplets from their nose or mouth spread to other
people.
They remained contagious until their last smallpox
scab fell off.
Smallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source): Only infected humans
2. the way of transmission: Usually transmitted via inhalation of droplets.
3. the susceptibility general
The disease was preventable by an effective live-attenuated vaccine
whose large scale use lead to its eradication.
The smallpox vaccine contains live vaccinia virus,
not a killed or weakened virus like many other vaccines.
Smallpox
THE CAUSATIVE AGENT OF INFECTION: Orthopoxvirus: Variola major virus
1.the presence of rezervoir (source): Only infected humans
2. the way of transmission: Usually transmitted via inhalation of droplets.
3. the susceptibility general
For most people with healthy immune systems, live virus vaccines are
effective and safe. Sometimes a person getting a live virus vaccine
experiences mild symptoms such as rash, fever, and head and body aches. In
certain groups of people, complications from the vaccinia virus can be severe.
Smallpox vaccination can protect from smallpox for about 3 to 5 years.
After that time, its ability to protect you decreases. If people need long-term
protection, thay need to get a booster vaccination.
The vaccine has been effective in preventing smallpox infection in 95% of
those vaccinated. In addition, the vaccine was proven to prevent or
substantially lessen infection when given within a few days after a person was
exposed to the variola virus.
Preventive,
repressive
measures
In the practical part it is preoccupied with
preventive measures
repressive measures
related to infectious diseases
Preventive anti-
epidemic
measures
is a set of measures to prevent the infection of
susceptible individuals:
primary , when we prevent impact of external risk
factors , or we will increase the resistance of the
individual (epidemiology)
Secondary prevention is early to find (diagnosis),
treatment and prevention of further development
of the disease and complications (clinical
medicine)
Tertiary prevention monitors patients who have
overcome the disease
Preventive anti-
epidemic
measures
 Include:
Increasing hygienic standards of the population - the most important is
compliance with sanitary regulations relating to water supply , food ,
manufacturing and food handling , waste water , waste , faeces and so
forth.
Vaccination - in order to induce maximum collective immunity.
Evidence and vector control (and the people with them living in the same
household) - on the territory concerned health authorities must register for
(eg. Portability typphoid, salmonella, bacillary dysentery and diphtheria);
must be under constant medical supervision , regular microbiologically
examined or treated . Must submit certain restrictive measures , always
report a change of residence must not endanger their actions of another
person .
Measures to prevent the introduction of infection into collectives entrance
examinations (to work, camp, army, morning filters in nurseries
and kindergartens), prevent the entry into the collective persons that could
be a source of infection (important information too).
Preventive anti-
epidemic
measures
Prophylactic desinfection - aims to reduce the number of pathogens in
the external environment (public buildings, medical facilities, public
transport, drinking water, waste water from hospitals, milk pasteurisation).
Border protection - a system of measures protecting the borders of the
introduction of diseases from foreign persons , materials , goods,
imported animals . It is, among other things. Persons who come from
countries with endemic or epidemic occurrence of serious communicable
diseases . Such passengers must show a valid vaccination certificate, if
you do not or are not vaccinated, subjected to medical supervision,
quarantine or vaccination. Quarantine diseases as plaque, yellow fever
and cholera. As for the people, not absolute boundaries conserve data.
More important is the protection of imported commodities , which must
be accompanied by a certificate of health or veterinary authorities about
their health .
Health education - raising awareness of health and culture of the
inclusion of basic hygiene and epidemiology in school and extracurricular
educational facilities.
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
(85 – 95 %) 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 1980
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.
WHO Health
statistics
and information
system
The World Health Organization (WHO) is a specialized
agency of the United Nations that is concerned with
international public health.
It was established on 7 April 1948 headquartered in
Geneva, Switzerland.
The WHO is a member of the United Nations
Development Group. Its predecessor, the Health
Organization, was an agency of the League of Nations.
World health statistic
The World Health Statistics series is WHO’s
annual compilation of health statistics for its 194
Member States.
WHO's annual World Health Statistics reports
present the most recent health statistics for the
WHO Member States.
 World Health Statistics 2017 focuses on the health and health-related Sustainable
Development Goals (SDGs) and associated targets by bringing together data on a wide
range of relevant SDG indicators.
 In some cases, as indicator definitions are being refined and baseline data are being
collected, proxy indicators are presented.
 In addition, in the current absence of official goal-level indicators, summary measures of
health such as (healthy) life expectancy are used to provide a general assessment of the
situation.
European Centre for
Disease Prevention and
Control
An agency of the
European Union
The European Centre for Disease Prevention and
Control (ECDC) was established in 2005.
 It is an EU agency aimed at strengthening Europe's defences
against infectious diseases. It is located in Solna, Sweden.
 ECDC core functions cover a wide spectrum of activities:
surveillance, epidemic intelligence, response, scientific advice,
microbiology, preparedness, public health training, international
relations, health communication, and the scientific journal
Eurosurveillance.
 ECDC disease programmes cover antimicrobial resistance and
healthcare-associated infections; emerging and vector-borne
diseases; food- and waterborne diseases and zoonoses; HIV,
sexually transmitted infections and viral hepatitis; influenza and
other respiratory viruses; tuberculosis; and vaccine-preventable
diseases. All in all, ECDC monitors 52 communicable diseases.
 Diseases preventable by vaccination
 Sexually transmitted diseases
 Viral hepatitis
 Food- and waterborne diseases and diseases of
environmental origin
 Diseases transmitted by non-conventional agents
(prions)
 Airborne diseases
 Zoonoses (other than those listed above)
 Serious imported diseases
 Vector-borne diseases
 Special health issues (HAI, antibiotic resistence)
Diseases and
special health
issues under
EU surveillance
Work Programmes and
long-term strategies
 Long-term surveillance strategy 2014–2020
 The final strategy is divided into six priorities:
 1 Consolidating surveillance, increasing its efficiency and enhancing the
outputs and their impact
 2 Developing standards, improving data quality and sharing best practices
in surveillance
 3 Promoting use of surveillance data
 4 Strengthening capacity in surveillance
 5 Controlling expansion
 6 Monitoring the strategy.
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.
Global Disease
Elimination and
eradication
 During the 25 years since the certification of smallpox eradication
there has been considerable debate among public health
practitioners about how existing health technologies can best be used
to decrease infectious disease incidence and prevalence.
 Interruption of transmission has often been envisaged as the ultimate
goal, and standard public health concepts of disease reduction have
been defined or re-defined.
 In 1998, Dowdle proposed a definition of control as a reduction in the
incidence, prevalence, morbidity or mortality of an infectious disease
to a locally acceptable level;
 elimination as reduction to zero of the incidence of disease or
infection in a defined geographical area;
 and eradication as permanent reduction to zero of the worldwide
incidence of infection
Health 2020:
the European
policy for health
and well-being
Health 2020 is the new European health
policy framework.
It aims to support action across government
and society to:
“significantly improve the health and wellbeing
of populations,
reduce health inequalities,
strengthen public health and ensure peoplecentred
health systems that are universal,
equitable, sustainable and of high quality