Transcript Peculiarities of infectious diseases Contagenicity

Introduction to clinic
of infectious diseases
Infectio – Latin word “to infect,
contaminate”
Infectious process - interrelation of
pathogenic microorganism and
macroorganism in environment
conditions
D. Fracastori
(1478 - 1553)
D. Samoylovych
(1724 - 1810)
E. Jenner
(1749 - 1823)
R. Koch
(1843 - 1910)
L. Pasture
(1822 - 1895)
I. I.
Mechnikov
(1845 - 1916)
Peculiarities of infectious diseases

Contagenicity – dangerous for surrounding people

Specificity – every disease has the specific
infectious agent

Periodicity –
 incubation period;
 initial (prodromal) period;
 period of acute illness;
 period of convalescence or reconvalescence.
Post-infection immunity

Cyclicity – ability to epidemic spreading after some

period of time
Interrelations
Species inherited immunity
Symbiosis:
 Synoikia – mutual being, when one species
uses another as a living place without harming it
 Mutualism – symbiosis, that is profitable for
both organisms
 Commensalism – one organism gets a benefit
from other without harming it
Parasitism – microorganism (parasite) feeds
with the saps or tissues of the host harming it.
Most infectious diseases belong to this kind of
symbiosis
 Endogenous
diseases (autoinfections)
– caused by human own microflora
(pathogenic or half-parasites) of the skin,
respiratory or alimentary tracts, conjuctive,
genitals
diseases – caused after
penetration of the microorganisms from
the environment
 Exogenous
Basic negative factors affecting
immune system:
 Human
demographics and behavior
 Technology and industry
 Economic development and land use
 International travel and commerce
 Microbial adaptation and change
 Violation of public health measures
Intensity of epidemiologic
process:



Sporadic
Epidemic
Pandemic
Classification of infectious diseases
symptoms according to their diagnostic
importance: (by J. Bilibin)
I.
II.
Main symptoms (pathognostic) :
symptoms which are characteristic for
one disease only.
Supporting or optional symptoms:
symptoms, which are may be present in
some infectious diseases, they give
possibility to differentiate diseases.
Diagnostic methods:
 Clinical:
• investigation
• epidemiological anamnesis
 Laboratory:
• virological
• bacteriological
• parasitological
• serological
• allergic
• biological
• immunoenzyme etc,
Points of epidemiological
anamnesis:



Life style and living conditions of the
patient
Patient’s occupation
Previous diseases and preventive
vaccinations
Basic symptoms of infectious
diseases:
1.
2.
3.
4.
5.
6.
7.
Fever
Rash
Diarrhea
Respiratory syndrome
Jaundice
Meningeal signs
Lymphoadenopathy etc
Fever conditions:
(acute) temperature rise – patient
clearly fix the hour of the disease onset
 Gradual rise
 Fast
Classification of fevers:
(37,0 – 37.9 0C)
 Moderate (38,0 – 39,9 0C)
 High (40,0 – 40,9 0C)
 Hyperpyrexia (41 0C and higher)
 Subfebrile
Types of fever curves:









Constant fever (febris continua)
Remittent fever (febris remittens)
Intermittent fever (febris intermittens)
Recurrent fever (febris recurrens)
Undulant fever (febris undulans)
Hectic fever (febris hectica)
Distorted fever (febris inversa)
Acute undulating fever (febris undulans acuta)
Relapsing fever (febris recidiva)
Elements of exanthema:

Roseola
 Macula
 Papula
 Erythema
 Tuberculum
 Nodus
 Urtica (hives)
 Vesicula
 Pustula
 Herpes

Bulla (blister)
 Hemorrhage (petechiae,
purpura, ecchimosis)
 Erosio
 Ulcus
 Dyschromia cutis
 Squama
 Crusta
 Cicatrix
Roseola

Red or purple-red
 Diameter 2-5 mm
 Spherical form
Macula

Similar to roseola
 Diameter 5-20 mm
 Color same as
roseola’s
Papule

Red or purple-red
 Diameter 1-20 mm
 Proliferation of
epidermis with
vasodilatation
Erythema

Result of large
maculae joining
 Inflammatory fields
 Diameter from 2 cm
and higher
Tuberculum

Formations without
cavities
 Granulematous
inflammatory infiltrate
Node

Limited dense
formation
 Diameter 1-5 cm
 Spherical or oval form
Vesicula

Small cavity formation
containing serous or
serouse-hemorrhagic
fluid
 Half-round element
 Diameter from 1 to 5
mm
 After damaged
erosion develops
Bulla (Blister)

Cavity formation
 Dimension up to
10 cm
Hemorrhages

Extravasation into the
skin
 Different kinds and
dimensions
Ulcer

A deep defect of the
skin (epidermis,
derma, underline
tissues)
Enanthema – rashes on the mucous
membranes
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