classification of infectious diseases Flashcards
infection
successful colonisation of a host by a microorganism
etiological classification
by presumed cause
more useful for objective diagnostic and prevention
eg bacteria, prions, mycoplasma, virus, fungi
clinical classification
signs/symptoms linked by common pathology
more useful for treatment and management
herpes virus infections
acute infectious diseases with resp signs, neuro signs and abortion
characteristic = latent infection - lack of demonstrable infectious virus between episodes of recurrent disease
retroviral infection
persistent viral infection
Ab detection - indication of infection
prone to mutations
classification based on modes of transmission
contagious or non contagious
soil related - tetanus, botulism, anthrax
food borne
vector borne
airborne
contagious transmission
direct or indirect
non contagious diseases
toxins - tetanus, botulism
vector borne diseases - WN, blue tongue
prionic diseases
peracute disease duration
few hours to 1 day
acute disease duration
1-7 days
subacute disease duration
1-3 weeks
chronic disease duration
more than 3 weeks
clinical stages of acute infectious disease
incubation - generalisation - organ specific manifestation
incubation period
period between exposure and onset of clinal symptoms
phase during which the pathogen begins active replication without producing recognisable symptoms in the host
generalisation period
changes in bodys vitals - temp, HR, RR
fatigue and general weakness
hyperaemia and mucosal hemorrhage
swollen and pain full lymph nodes
loss of appetite
obstipation
organ specific manifestation
the specific symptoms and their localisations in the period of illness provide diagnostic information
prodromal period
manifestation of the first non specific symptoms of the disease, characteristic of the general intoxication of the microorganism
clinal manifestation stages
prodromal
stadium incrementi - increase in clinical manifestation
stadium fastigii - maximum severity of clinical manifestations
stadium decrementi - attenuation of clinical signs
convalescence - period of complete recovery
clinical manifestation of chronic infectious disease
long and slow development of signs
cachexia
weakness, anemia
period changes in vitals
organ specific localisation depends on localisation of process
granuloma - primary (portal of entry) and secondary (metastasis)
classification of infectious diseases
etiology
duration
duration and symptoms of disease
clinical manifestation of infectious diseases according to organ systems
acute infectious diseases
septicaemia
exanthematous diseases
localised infectious diseases
malignant edema and enterotoxemia - clostrial disease
CNS diseases
chronic infectious diseases
specific inflammation - TB, glanders, actinomycosis
non-specific inflammation - Brucellosis
mycoses - dermatomycoses
mycotoxicoses
tumours - enzootic bovien leukosis, bovien papillomatosis
emerging infectious diseases
those whose incidence has increased within the past 2 decades or threatens to increase in the near future
emergence can be due to
spread of a new agent
recognition of an infection that has been present in the population but has gone undetected
to the realisation that an established disease has an infectious origin
reemerging infectious disease
reappearance or re emergence of a known infection after a decline in incidence
an increase in frequency is a result of change of pathogenic virulence and pathways pf causative agents or occurrence of a new clinical form of disease
clinical syndrome of acute infectious diseases
sepsis - systemic illness caused by microbial invasion of normally sterile parts of the body
rapid development of disease and death
exanthematous diseases
epitheliotropic viruses
changes on skin and mucosa
general infectious syndrome
catarrhal syndrome
epithelial cells of internal organs - resp or GI
secondary bacterial infections
low mortality
generalised infectious diseases with organ specific manifestation
weak general infection with a strong local infection
eg contagious agalactia in goats
localised infectious diseases
infectious keratoconjunctivitis
strangles
infectious diseases of CNS
usually acute (rabies) or peracute (aujeskys)
categorised separately due to public health importance
signs are usually consequence of septicaemia in some generalised infectious diseases - anthrax, listeriosis, classical swine fever
meningoencephalitis - non purulent = viral
purulent = bacterial
clostridial diseases
malignant edema and enterotoxemia
peracute
local myositis
multifactorial diseases
erysipelas
bovine enzootic bronchopneumonia
enzootic pneumonia of calves
acute infectious disease - pathological findings
moderate malnutrition
exudates in body cavities
hyperaemic and inflamed mucosa
submucosal, subcutaneous and cutaneous haemorrhage
swollen and inflamed lymph nodes
enlarged and inflamed parenchymal organs
