Lecture 4. classification of inf. dis.

1. Classification of the infection Classification of the infection
diseasesdiseases
Sorokhan V.D., MD, PhDSorokhan V.D., MD, PhD
Bukovinian State Medical UniversityBukovinian State Medical University
Department of the infectious diseases and Department of the infectious diseases and
epidemiologyepidemiology

2. Microbiological Classification of Infectious Microbiological Classification of Infectious
DiseasesDiseases
Protozoa
Helminths
Parasitic
Prion
Disseminated
Localized
Fungal
DNA virus
RNA virus
Enveloped vs non-enveloped
Viral
Gram-negative
Gram-positive
Bacterial

3. Gram-negative bacteriaGram-negative bacteria
Gram-negative Gram-negative
bacteria are bacteria are
those that are those that are
stained red or stained red or
pink by pink by
Gram stainingGram staining
Gram-negative
Pseudomonas aeruginosa bacteria
(pink-red rods)

4. Gram negative
Cocobacilli
H. Influenzae, B. Pertussis
Brucella spp., F. Tularensis
P. Multosida, L. pneumophila
Cocci
Neisseria spp.
Bacilli
N. Meningitidis
Glucose and
maltose +
N. Gonnorrhoeae
Glucose +
Lactose + Lactose -
Slow fermenter
Citrobacter
Serratia
Fast fermenter
Klebsiella
E.Coli
Enterobacter
Oxidase +
V.Cholerae
P. aeruginosa
Strict anaerode
B. fragilis
Oxidase -
Urease –
Y. Pestis
S. Dysenteriae
Salmonnela spp.
Urease +
P. Mirabilis
H. pylori

5. Gram-positive bacteriaGram-positive bacteria
Gram-positive Gram-positive bacteriabacteria
are those that are are those that are
stained dark blue or stained dark blue or
violet by violet by Gram stainingGram staining. .
This is in contrast to This is in contrast to
Gram-negative bacteriaGram-negative bacteria
, which cannot retain , which cannot retain
the crystal violet stain, the crystal violet stain,
instead taking up the instead taking up the
counterstaincounterstain ( (safraninsafranin
or or fuchsinefuchsine) and ) and
appearing red or pink.appearing red or pink.
Gram-positive
Bacillus anthracis bacteria
(purple rods) in
cerebrospinal fluid sample.
The other cells are
white blood cells.

6. Gram positive
cocci
Bacilli, Corinebacterium
Clostridium, Listeria, Bacillus
Staphylococcus
catalase +
Streptococcus
catalase -
S. Aureus
Coagulase +
Coagulase -
β-hemolytic
α-hemolytic
S. Pneumoniae
S. Viridans
S. Mutans
γ-hemolytic
E. Faecalis
E. Faecium
S. Epidermis
Novobiocin
sensitive
S. Saprophyticus
Novobiocin
resistant
Group A
S. Piogenes
Group B
S.agalactiae

7. highly motile Gram-
negative, but
stains poorly
Borrelia
burgdorferi
Borrelia
AerobicUnencapsulated Small
coccobacilli
Gram-
negative
Brucella abortus
Brucella canis
Brucella
melitensis
Brucella suis
Brucella
aerobic Encapsulated Small
coccobacilli
Gram-
negative
Bordetella
pertussis
Bordetella
Curved, spiral,
or S-shaped
with single,
polar
flagellum
Shape
microaerophilic characteristic
darting
motion
Gram-
negative
Campylobacter
jejuni
Campylobacter
Respiration Motility Capsulation Gram
staining
Important
species
Genus
Basic laboratory characteristics

8. Obligate
anaerobic
mostly motile Large, blunt-
ended rods
Gram-
positive
Clostridium
botulinum
Clostridium
difficile
Clostridium
perfringens
Clostridium
tetani
Clostridium
Mostly
facultative
anaerobic
nonmotile unencapsulated Small,
slender,
pleomorphic
rods
Gram-
positive
(unevenly)
Corynebacterium
diphtheriae
Corynebacterium
Facultative or
strictly aerobic
motile Small, round,
ovoid
(not Gram-
stained)
Chlamydia
pneumoniae
Chlamydia
trachomatis
Chlamydophila
psittaci
Chlamydia and
Chlamydophila
Round to
ovoid
Shape
Facultative
Anaerobic
Gram-
positive
Enterococcus
faecalis
Enterococcus
faecium
Enterococcus
Respiration Motility Capsulation Gram
staining
Important
species
Genus

9. strictly aerobic Small,
pleomorphic
coccobacillus
Gram-
negative
Francisella
tularensis
Francisella
Ranging from
small
coccobacillus
to long,
slender
filaments
Gram-
negative
Haemophilus
influenzae
Haemophilus
Facultative
anaerobic
Short rods Gram-
negative
Escherichia coli Escherichia
Curved or
spiral rods
pultiple polar
flagella
Shape
rapid,
corkscrew
motility
Gram-
negative
Helicobacter
pylori
Helicobacter
Respiration Motility Capsulation Gram
staining
Important
species
Genus

10. highly motile Long, very
slender,
flexible,
spiral- or
corkscrew-
shaped rods
Gram-
negative, but
stains poorly
Leptospira
interrogans
Leptospira
Distinct
tumbling
motility in
liquid
medium
Slender, short
rods
Gram-
positive,
darkly
Listeria
monocytogenes
Listeria
motile unencapsulated Slender rod in
nature,
cocobacillary
in laboratory.
monotrichious
flagella
Gram-
negative, but
stains poorly
Legionella
pneumophila
Legionella
Long, slender
rods
Shape
aerobic nonmotile (none) Mycobacterium
leprae
Mycobacterium
tuberculosis
Mycobacterium
ulcerans
Mycobacterium
Respiration Motility Capsulation Gram
staining
Important
species
Genus

11. aerobic Kidney bean-
shaped
Gram-
negative
Neisseria
gonorrhoeae
Neisseria
meningitidis
Neisseria
Obligate aerobic motile encapsulated rods Gram-
negative
Pseudomonas
aeruginosa
Pseudomonas
Plastic,
pleomorphic
(none) Mycoplasma
pneumoniae
Mycoplasma
Small, rod-like
coccobacillary
Shape
Gram-
negative, but
stains poorly
Rickettsia
rickettsii
Rickettsia
Respiration Motility Capsulation Gram
staining
Important
species
Genus

12. Facultative
anaerobic
rods Gram-
negative
Shigella sonnei Shigella
Facultative
anaerobic
Round cocci Gram-
positive,
darkly
Staphylococcus
aureus
Staphylococcus
epidermidis
Staphylococcus
saprophyticus
Staphylococcus
Facultative
anaerobic
Gram-
negative
Salmonella typhi
Salmonella
typhimurium
Salmonella
ovoid to
spherical
Shape
Facultative
anaerobic
nonmotile Gram-
positive
Streptococcus
agalactiae
Streptococcus
pneumoniae
Streptococcus
pyogenes
Streptococcus
Respiration Motility Capsulation Gram
staining
Important
species
Genus

13. Facultative
anaerobic
rapidly
motile
Short,
curved, rod-
shaped with
single polar
flagellum
Gram-
negative
Vibrio
cholerae
Vibrio
Facultative
Anaerobe
nonmotile encapsulated Small rods Gram-
negative,
stains
bipolarly
Yersinia
pestis
Yersinia
highly
motile
Long,
slender,
flexible,
spiral- or
corkscrew-
shaped rods
Gram-
negative,
but stains
poorly
Treponema
pallidum
Treponema
Shape Respiration Motility Capsulation Gram
staining
Important
species
Genus

14. Clinical characteristicsClinical characteristics
Large, grayish,
nonhemolytic
colonies with
irregular borders on
blood agar
Direct
immunofluorescence
Anthrax
vaccine
autoclaving of
instruments
In early infection:
Penicillin
Doxycycline
Ciprofloxacin
Cutaneous
anthrax
Pulmonary
anthrax
Gastrointestinal
anthrax
Contact with
sheep, goats and
horses
Inhalation or skin
penetration
through abrasions
of spore-
contaminated
dust
Bacillus anthracis
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

15. Direct
immunofluorescence
PCR amplification
Pertussis
vaccine, DPT
vaccine
Macrolide
antibiotics
Azithromycin
Erythromycin
Clarithromycin
Whooping cough
Complications:
Secondary
bacterial
pneumonia
Contact with
respiratory
droplets expelled
by infected
human hosts.
Bordetella
pertussis
Microscopy using
Giemsa or
Wright stain
PCR
serology (low
precision rate)
Lyme vaccine
wearing
clothing that
limits skin
exposure to
ticks
insect
repellent
Early stages:
cephalosporins
amoxicillin
doxycycline
If arthritic
symptoms have
appeared:
Longer courses
of antibiotics
Lyme disease Ixodes ticks
reservoir in deer,
mice and other
rodents
Borrelia
burgdorferi
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

16. Culture (difficult
and time
consuming)
Agglutination
serology
Combination
therapy of:
doxycycline
streptomycin or
gentamicin
Brucellosis Direct contact
with infected
animal
Oral, by ingestion
of unpasteurized
milk or milk
products
Brucella abortus
Brucella canis
Brucella
melitensis
Brucella suis
Symptomatically
by fluid and
electrolyte
replacement
Ciprofloxacin in
severe cases
Acute enteritis Fecal/oral from
animals
(mammals and
fowl)
Contaminated
meat (especially
poultry)
Contaminated
water
Campylobacter
jejuni
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

17. None for routine use None Doxycycline
Erythromycin
Community-
acquired
respiratory
infection
Respiratory
droplets
Chlamydia
pneumoniae
Cellular cytoplasmic
inclusions by
immunofluorescence
DNA hybridization
ELISA for
lipopolysaccharides
No vaccine
Erythromycin
or silver
nitrate in
newborn's
eyes
Safe sex
Azithromycin
Erythromycin
Tetracyclines
Doxycycline
Nongonococcal
urethritis (NGU)
Lymphogranuloma
venereum (LGV)
Trachoma
Inclusion conjunctivitis of the newborn
(ICN)
Sexual (NGU,
LGV)
Direct or
contaminated
surfaces and flies
(trachoma)
Passage through
birth canal (ICN)
Chlamydia
trachomatis
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

18. Rise in antibody titre
Complement fixation
indirect
immunofluorescence
Tetracycline
Doxycycline
Erythromycin
(less efficient)
Psittacosis Inhalation of dust
with secretions or
feces from birds
(e.g. parrots)
Chlamydophila
psittaci
Mouse inoculation
detects toxin from
food, intestinal
contents or serum
Culture in standard
aerobic culture
Proper food
preservation
techniques
Antitoxin (horse
antiserum)
Botulism Spores from soil
and aquatic
sediments
contaminating
vegetables, meat
and fish
Clostridium
botulinum
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

19. ELISA for
Toxin ELISA for toxin
A or B
Endoscopy for
pseudomembrane
None Discontinuing
predisposing
antibiotic
Fluid and
electrolyte
replacement
Vancomycin or
metronidazole if
severe
Pseudomembranous
colitis
Spores both
indoors and
outdoors
Human flora,
overgrowing
when other flora
is depleted
Clostridium
difficile
Microscopically
Blood agar culture,
forming double-zone
β-hemolysis
Sugar fermentation
Organic acid
production
Appropriate
food handling
Food poisoning:
Self-limiting;
Supportive care
is sufficient
Gas gangrene
Acute food
poisoning
Anaerobic
cellulitis
Spores in soil
Human flora in
vagina and GI
tract
Clostridium
perfringens
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

20. (difficult) DPT vaccine Tetanus immune
globulin
Horse antitoxin,
alternatively
Sedatives
Muscle relaxants
Mechanical
ventilation
Tetanus Spores in soil
infecting
puncture
wounds, severe
burns or surgery
Clostridium tetani
no rapid)
Culture on
Tinsdale agar,
followed by
immunologic
precipitin
reaction
DPT vaccine Horse serum
antitoxin
Erythromycin
Penicillin
Diphtheria Respiratory
droplets
Part of human
flora
Corynebacterium
diphtheriae
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

21. Culture in 6.5%
NaCl
Can hydrolyze
esculin in
presence of bile
No vaccine
Hand washing
and other
nosocomial
prevention
Penicillin and an
aminoglycoside
Vancomycin
Quinupristin and
dalfopristin
Nosocomial
infections
Part of human
flora,
opportunistic or
entering through
GI tract or
urinary system
wounds
Enterococcus
faecalis and
Enterococcus
faecium
Culture on
MacConkey agar
and study
carbohydrate
fermentation
patterns: Lactose
fermentation
(most E. coli
strains). Gas
production in
glucose
fermentation
Mannitol
fermentation
(no vaccine or
preventive drug)
Food and water
preparation
Hand washing
and disinfection
UTI:
Co-trimoxazole
Fluoroquinolone,
e.g. ciprofloxacin
Meningitis:
Cephalosporin and
gentamicin
combination
Diarrhea:
Antibiotics above
shorten duration
Electrolyte and fluid
replacement
Urinary tract
infections
(UTI)
Diarrhea
Meningitis in
infants
Part of gut flora,
spreading
extraintestinally
or proliferating in
the GI tract
Escherichia coli
(generally)
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

22. rarely cultured)
Serology
Avoiding insect vectors
Precautions when
handling wild animals
or animal products
Streptomycin
Gentamicin
Tularemia vector-borne by
anthropods
Infected wild or
domestic animals,
birds or house
pets
Francisella
tularensis
Culture on
chocolate agar with
hemin (factor X) and
NAD+ (factor V)
Quellung reaction
Immunofluorescence
staining of capsule
Detection of capsular
antigen in CSF or
other body fluids
Hib vaccine to infants
Rifampin
prophylactically
Meningitis:
(resistance-tests
are required first)
Third generation cephalosporin
, e.g. cefotaxime
or ceftriaxone
Ampicillin and
sulbactam
combination
Bacterial
meningitis
Upper
respiratory tract
infections
Pneumonia,
bronchitis
Droplet contact
Human flora of
e.g. upper
respiratory tract
Haemophilus
influenzae
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

23. Microscopically Corkscrew
movement
Urease-positivity by
radioactively labeled urea
Serology by ELISA
(No vaccine or
preventive
drug)
Tetracycline,
metronidazole
and bismuth salt
combination
Peptic ulcer
Risk factor for
gastric carcinoma
and gastric
B-cell lymphoma
Colonizing
stomach
Unclear
person-to-
person
transmission
Helicobacter
pylori
Culture from respiratory
secretions on buffered charcoal
yeast extract enriched with L-
cysteine, iron and α-
ketoglutarate
Serology, including direct
immunofluorescence and
radioimmunoassay for antigen
in urine
Hybridization to ribosomal RNA
using DNA probe
(no vaccine or
preventive
drug)
Heating water
Macrolides, e.g.
erythromycin or
azithromycin
Fluoroquinolones
Legionnaire's
Disease
Pontiac fever
Droplet
contact, from
e.g. cooling
towers,
humidifiers, air
conditioners
and water
distribution
systems
Legionella
pneumophila
laboratory diagnosis Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

24. Dark-field microscopy
on fresh blood smear
(but doesn't stain
well)
Serologic
agglutionation tests
(no vaccine)
Doxycycline
Prevention of
exposure
Rodent control
Penicillin G
Tetracycline,
e.g.
doxycycline
Leptospirosis Food and water
contaminated
by e.g. urine
from wild or
domestic
animals.
Leptospira
survives for
weeks in
stagnant water
Leptospira
interrogans
Isolation from e.g.
blood and CSF
Beta-hemolysis and
catalase production
on blood agar
Microscopy for
morphology and
motility
(no vaccine)
Proper food
preparation and
handling
Ampicillin
Co-trimoxazole
Listeriosis Dairy products,
ground meats,
poultry
Vertical to
newborn or
fetus
Listeria
monocytogenes
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

25. Tuberculoid form:
Hard to isolate (diagnosis
on clinical findings and
histology of biopsies)
Lepromatous form:
Acid-fast staining from
e.g. skin scrapings
BCG vaccine
shows
some
effects
Tuberculoid form:
Dapsone and rifampin
Lepromatous form:
Clofazimine
Leprosy
(Hansen's
disease)
Prolonged
human-human
contact, e.g.
through
exudates from
skin lesions to
abrasion of
other person
Mycobacterium
leprae
Ziehl-Neelsen stain
showing acid-fast
bacteria
Hybridization probes for
DNA, succeeded by PCR
Culture on
Lowenstein-Jensen agar
BCG
vaccine
Isoniazid
Standard "short"
course:
First 2 months,
combination: Isoniazid
Rifampicin Pyrazinamide
Ethambutol
Further 4 months,
combination: Isoniazid
Rifampicin
Tuberculosis Droplet contact Mycobacterium
tuberculosis
laboratory diagnosis Preventi
on
Treatment Diseases Transmission Species
Species of human pathogenic bacteria

26. (difficult to culture)
Serologic tests, e.g.
complement fixation test

DNA probes on
sputum specimens
Doxycycline and
erythromycin
Mycoplasma
pneumonia
Human flora
Droplet contact
Mycoplasma
pneumoniae
Microscopy showing
gram-negative
diplococci, often with
PMNs
Culture on
chocolate agar, giving
positive oxidase test
and fermentation of
glucose and maltose
in 5% CO2 in air
NmVac4-A/C/Y/W-135
vaccine
Rifampin
Penicillin G
Cefotaxime
Ceftriaxone
Meningococcal
disease including
meningitis
Waterhouse-Friderichsen
syndrome
Respiratory
droplets
Neisseria
meningitidis
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

27. Colourless
colonies on
MacConkey agar.
Production of
pyocyanine and
fluorescein
Positive oxidase
test. No lactose
fermentation.
(no vaccine)
Topical
silver sulfadiazine
for burn wounds
Aminoglycoside
and anti-
pseudomonal β-
lactam
Pseudomonas infection
Localized to eye, ear,
skin, urinary,
respiratory or
gastrointestinal tract or
CNS, or systemic with
bacteremia, secondary
pneumonia bone and
joint infections,
endocarditis, skin, soft
tissue or CNS
infections.
Infects
damaged
tissues or
people with
reduced
immunity
Pseudomonas
aeruginosa
Serology
Immunofluorescence
against Rickettsia
antigens
no preventive
drug or approved
vaccine)
Vector control,
such as clothing
Prompt removal of
attached ticks
Doxycycline
Chloramphenicol
Rocky mountain
spotted fever
Bite of infected
wood or
dog tick
Rickettsia
rickettsii
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

28. Isolation from blood,
feces, bone marrow,
urine or rose spots on
skin
Colorless, non-lactose
fermenting colonies
on MacConkey agar
Serology for
antibodies against
O antigen
Ty21a and ViCPS
vaccines
Hygiene and food
preparation
Ceftriaxone
Fluoroquinolones,
e.g. ciprofloxacin
Typhoid fever
type
salmonellosis
(dysentery,
colitis)
Human-human
Fecal-oral
through food
or water
Salmonella typhi
Colourless colonies on
MacConkey agar
(No vaccine or
preventive drug)
Proper sewage
disposal
Food preparation
Good personal
hygiene
Fluid and
electrolyte
replacement for
severe diarrhea
Antibiotics (in
immunocompromi
sed to prevent
systemic spread)
Salmonellosis
with
gastroenteritis
and
enterocolitis
Fecal-oral
Food
contaminated
by fowl (e.g.
eggs), pets
and other
animals
Salmonella
typhimurium
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

29. Culture on
Hektoen agar or
other media for
intestinal
pathogens
Protection of
water and
food supplies
Vaccines are
in trial stage
Ciprofloxacin or
azithromycin
Bacillary dysentery/
Shigellosis
Fecal-oral
Flies
Contaminated
food or water
Shigella sonnei
Microscopy
showing strongly
positive
Gram stained cells
in grape-like
clusters
Positive Catalase
test and
coagulase test
Culture on
enriched media
producing deep
yellow, hemolytic
colonies
(no vaccine or
preventive
drug)
Barrier
precautions,
washing
hands and
fomite
disinfection in
hospitals
Incision and
drainage of
localized lesions
Nafcillin and
oxacillin
Vancomycin for
Methicillin
-resistant (MRSA)

Coagulase-positive
staphylococcal infections:
Localized skin infections
Diffuse skin infection (
Impetigo)
Deep, localized infections
Acute infective endocarditis
Septicemia
Necrotizing pneumonia
Toxinoses Toxic shock
syndrome
Staphylococcal food
poisoning
Human flora
on mucosae
in e.g.
anterior nares
and vagina,
entering
through
wound
Staphylococcus
aureus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

30. Microscopy showing strongly
positive Gram stained cells in
grape-like clusters
Positive Catalase test but
negative coagulase test
Novobiocin-sensitivity (S.
epidermidis)
Novobiocin-resistance (S.
saprophyticus)
Culture on enriched media
producing white, nonhemolytic
colonies
None Vancomycin Infections of
implanted
prostheses, e.g.
heart valves and
catheters
Human flora in
skin and
anterior nares
Staphylococcus
epidermidis
Microscopy showing
gram-positive, encapsulated
lancet-shaped diplococci
α-hemolysis on blood agar, bile-
soluble, optochin-sensitive
Positive Quellung reaction
23-serotype
vaccine for
adults (PPV)
Heptavalent
conjugated
vaccine for
children (PCV)
Penicillin G
Vancomycin
for resistant
strains
Acute
bacterial pneumonia
& meningitis in
adults
Otitis media and
sinusitis in
children
Respiratory
droplets
Often human
flora in
nasopharynx
(spreading in
immunocompro
mised)
Streptococcus
pneumoniae
laboratory diagnosis Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

31. Culture on
sheep blood agar
forming small,
opalescent
surrounded by
large zone of β-
hemolysis
Serology for ASO
Very bacitracin-
sensitive
No vaccine
Rapid antibiotic
treatment helps
prevent
rheumatic fever
Penicillin G
Macrolide, e.g.
clarithromycin or
azithromycin in
penicillin allergy
Drainage and
debridement for
Necrotizing
fasciitis
Streptococcal
pharyngitis
Scarlet fever
Rheumatic fever
Impetigo and
erysipelas
Puerperal fever
Necrotizing
fasciitis
Respiratory
droplets
Direct physical
contact with
impetigo lesions
Streptococcus
pyogenes
Culture on blood
or MacConkey
agar, enhanced
by TCBS
Positive oxidase
test
Preventing fecal
contamination of
water supplies
and food
Adequate food
preparation
Fluid and
electrolyte
replacement
e.g. doxycycline
to shorten
duration
Cholera Contaminated
water and food,
especially raw
seafood
Vibrio cholerae
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

32. Gram-negative
smear
If pneumonic,
culture from
aspirate on
MacConkey or
blood agar
Formalin-killed
plague vaccine
Minimize
exposure to
rodents and fleas
Streptomycin
primarily
Gentamicin
Tetracyclin
Supportive
therapy for shock
Plague:
Bubonic plague
Pneumonic
plague
Fleas from
animals
Ingestion of
animal tissues
Respiratory
droplets
Yersinia pestis
laboratory
diagnosis
Prevention Treatment Diseases Transmission Species
Species of human pathogenic bacteria

33. nucleus icosahedral non-enveloped adenovirus dsDNA Adenoviridae
icosahedral non-enveloped coxsackievirus,
hepatitis A virus, poliovirus,
rhinovirus
+ssRNA Picornaviridae
nucleus enveloped Herpes simplex, type 1,
Herpes simplex, type 2,
Varicella-zoster virus,
Epstein-barr virus,
Human cytomegalovirus,
Human herpesvirus, type 8
dsDNA Herpesviridae
nucleus icosahedral enveloped Hepatitis B virus dsDNA and
ssDNA
Hepadnaviridae
icosahedralenveloped Hepatitis C virus,
yellow fever virus,
dengue virus, West Nile virus
+ssRNA Flaviviridae
enveloped Human immunodeficiency
virus (HIV)
+ssRNARetroviridae
Replication
site
Virion shape envelopment Important species Baltimore
group
Family
Comparison table of clinically important virus families and species

34. nucleus spherical enveloped Influenza virus -ssRNA Orthomyxoviridae
spherical enveloped Measles virus, Mumps virus,
Parainfluenza virus,
Respiratory syncytial virus,
Human metapneumovirus
-ssRNA Paramyxoviridae
nucleusicosahedral non-enveloped Human papillomavirus dsDNA Papillomaviridae
helical, bullet
shaped
enveloped Rabies virus -ssRNA Rhabdoviridae
icosahedralenveloped Rubella virus +ssRNA Togaviridae
icosahedral enveloped Human bocavirus, Parvovirus
B19
ssDNA Parvoviridae
Replication
site
Virion shape envelopment Important species Baltimore
group
Family
Comparison table of clinically important virus families and species

35. The clinical characteristics of viruses may differ The clinical characteristics of viruses may differ
substantially among species within the same family:substantially among species within the same family:
Cell culture,
antibody
detection
None None Coxsackie infections fecal-oral,
droplet contact
Picornaviridae Coxsackievirus
virus
neutralization
hemagglutination
assay
ELISA
NoneNone acute febrile
pharyngitis
pharyngoconjunctival
fever
epidemic
keratoconjunctivitis
infantile
gastroenteritis
droplet contact
(mainly)
fecal-oral
venereal
direct contact
(ocular
infections)
adenoviridae adenovirus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

36. antibody detection Vaccine
immunoglobulin
(post-exposure
prophylaxis)
avoid food-
contamination
Immunoglobulin
(post-exposure
prophylaxis)
acute hepatitis fecal-oral Picornaviridae Hepatitis
A virus
viral antigen detection
antibody detection
nucleic acid detection
vaccine
immunoglobulin
(perinatal and
post-exposure
prophylaxis)
immunoglobulin
Adefovir
Entecavir
Pegylated
interferon alfa-2
Lamivudine
acute hepatitis
chronic hepatitis
hepatic cirrhosis
hepatocellular
carcinoma
All body fluids
(blood,
semen, saliva,
mother's milk
etc.)
Hepadnaviridae Hepatitis
B virus
Antibody detection
immunoflourescence
ELISA
Nucleic acid detection
None None infectious
mononucleosis
Burkitt
lymphoma
Saliva Herpesviridae Epstein-Barr
virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

37. The clinical characteristics of viruses may differ
substantially among species within the same family:
immunofluorescence
immunoperoxidase
nucleic acid
detection
None acyclovir
famciclovir
foscarnet
penciclovir
primary HSV-1
infection
(gingivostomatitis in
children, tonsillitis &
pharyngitis in adults,
keratoconjunctivitis)
latent HSV-1
infection (herpes
labialis, cold sores)
direct contact
with saliva
and lesions
Herpesviridae Herpes simplex
virus, type 1
antibody detection
nucleic acid
detection
None Pegylated
interferon
alfa-2
Ribavirin
acute hepatitis
chronic hepatitis
hepatic cirrhosis
hepatocellular
carcinoma
blood
(sexual)
FlaviviridaeHepatitis C virus
laboratory diagnosis Prevention Treatment Diseases Transmission Family Type

38. The clinical characteristics of viruses may differ substantially among
species within the same family:
antibody and nucleic
acid detection
Noneganciclovir
cidofovir
foscarnet
infectious
mononucleosis
Cytomegalic
inclusion disease
tears
urine
semen
saliva
vaginal
secretions
mother's milk
crosses
placenta
blood
Herpesviridae cytomegalovirus
cell culture
immunofluorescence
immunoperoxidase
nucleic acid
detection
contact-
avoidance
with lesions
safe sex
acyclovir
famciclovir
foscarnet
penciclovir
cidofovir
primary HSV-2
infection
latent HSV-2
infection
aseptic
meningitis
sexually
birth
Herpesviridae Herpes simplex
virus, type 2
laboratory
diagnosis
Prevention Treatme
nt
Diseases Transmission Family Type

39. The clinical characteristics of viruses may differ substantially among
species within the same family:
nucleic acid,
p24
antibody
detection
zidovudine
(perinatally)
blood product
screening
safe sex
HAART AIDS sexual
blood
mother's milk
Retroviridae HIV
Nucleic acid
and antibody
detection
Nonemany in
evaluation-
stage
Kaposi sarcoma
multicentric
Castleman
disease
primary
effusion
lymphoma
Herpesviridae Human
herpesvirus,
type 8
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

40. The clinical characteristics of viruses may differ substantially among
species within the same family:
antibody
detection
MMR vaccine None measles
postinfectious
encephalomye
litis
droplet contact Paramyxoviridae measles virus
Hemagglutination
assay
antigen detection
Influenza
vaccine
amantadine
rimantadine
amantadine
rimantadine
zanamivir
oseltamivir
influenza (
Reye
syndrome)
droplet contact Orthomyxoviridae Influenza virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

41. The clinical characteristics of viruses may differ substantially among
species within the same family:
Visual
inspection
Antigen
detection
Nucleic acid
detection
HPV vaccine
wart tissue
avoidance
safe sex
liquid nitrogen
laser
vaporization
cytotoxic
chemicals
interferon
cidofovir
direct contact
hyperplastic epithelial
lesions (common,
flat, plantar and
anogenital warts,
laryngeal papillomas,
epidermodysplasia
verruciformis) 55+
(hands/ feet) 30+
(anogenital/ some
are oral/ throat/
respiratory)
Malignancies for
some species (
cervical carcinoma,
squamous cell
carcinomas)
direct contact Papillomaviridae Human
papillomavirus
antibody
detection
MMR vaccineNone Mumps droplet contact Paramyxoviridae Mumps virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

42. The clinical characteristics of viruses may differ substantially among
species within the same family:
antibody
detection
MMR vaccine None measles
postinfectious
encephalomyelitis
droplet contact Paramyxoviridae measles
virus
Hemagglutination
assay
antigen detection
Influenza
vaccine
amantadine
rimantadine
amantadine
rimantadine
zanamivir
oseltamivir
influenza (Reye
syndrome)
droplet contact Orthomyxoviridae Influenza
virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

43. The clinical characteristics of viruses may differ substantially among
species within the same family:
Antibody
detection
None None croup
pneumonia
bronchiolitis
common cold
droplet contact Paramyxoviridae Parainfluenza
virus
Antibody
detection
None None croup
pneumonia
bronchiolitis
common cold
droplet contact Paramyxoviridae Parainfluenza
virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

44. The clinical characteristics of viruses may differ substantially among
species within the same family:
Histology
(postmortem)
Pre- and
postexposure
prophylaxis
Post-
exposure
prophylaxis
Rabies Animal bite
droplet
contact
Rhabdoviridae Rabies
virus
Antibody
detection
Polio vaccine NonePoliomyelitis fecal-oral Picornaviridae Poliovirus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

45. The clinical characteristics of viruses may differ substantially among
species within the same family:
Antibody
detection
MMR vaccine None German
measles
congenital
rubella
droplet
contact
Togaviridae Rubella virus
antibody and
antigen
detection
hand-washing
avoidance
palivizumab in
high risk
individuals
(ribavirin) bronchiolitis
pneumonia
influenza-
like
syndrome
severe
bronchiolitis
with
pneumonia
droplet
contact,
hand-to-
mouth
Paramyxoviridae Respiratory
syncytial
virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission

Family Type

46. The clinical characteristics of viruses may differ substantially among
species within the same family:
Cell culture
antigen and
nucleic acid
detection
Varicella
vaccine
varicella-zoster
immuneglobulin
Varicella:
acyclovir
famciclovir
valacyclovir
Zoster:
acyclovir
famciclovir
Varicella
herpes zoster
droplet contact Herpesvirida Varicella-zoster
virus
laboratory
diagnosis
Prevention Treatment Diseases Transmission Family Type

47. Mycosis
Mycosis is a condition in which fungi pass the
resistance barriers of the human or animal body
and establish infections. Mycoses can result
when the climate is hot and humid, and when
people live in crowded conditions. Some fungi
reproduce through tiny spores in the air. People
inhale those spores or they land on the skin.
Therefore, fungal infections often start in the
lungs or on the skin.

48. Disseminated fungal infectionsDisseminated fungal infections
CandidaCandida species are species are
important human important human
pathogens that are pathogens that are
best known for best known for
causing opportunist causing opportunist
infections in infections in
immunocompromised immunocompromised
hosts (e.g. transplant hosts (e.g. transplant
patients, AIDS patients, AIDS
sufferers, cancer sufferers, cancer
patients).patients).
Candida albicans at 200X
magnification.

49. Disseminated fungal infectionsDisseminated fungal infections
Aerosolized Aerosolized
AspergillusAspergillus spores are spores are
found nearly found nearly
everywhere so we are everywhere so we are
routinely and almost routinely and almost
constantly exposed to constantly exposed to
them. them.
Aspergillosis. H&E stain.

50. Disseminated fungal infectionsDisseminated fungal infections
Cryptococcus neoformansCryptococcus neoformans
can cause a severe can cause a severe
form of form of meningitismeningitis
and meningo-and meningo-
encephalitis in encephalitis in
patients with patients with HIVHIV
infection and infection and AIDSAIDS..
Cryptococcus. FNA specimen.
Field stain.

51. Disseminated fungal infectionsDisseminated fungal infections
Histoplasma capsulatumHistoplasma capsulatum
can cause can cause
histoplasmosishistoplasmosis in in
humans, dogs and humans, dogs and
cats. cats.
Histoplasmosis. PASD stain.

52. Disseminated fungal infectionsDisseminated fungal infections
Pneumocystis jiroveciiPneumocystis jirovecii
(or Pneumocystis (or Pneumocystis
carinii) can cause a carinii) can cause a
form of form of pneumoniapneumonia in in
people with weakened people with weakened
immune systemsimmune systems, ,
such as premature such as premature
children, the elderly, children, the elderly,
and and AIDSAIDS patients. patients.
P. jirovecii cysts in tissue

53. Protozoan infectionProtozoan infection
Examples of human Examples of human
diseases caused by diseases caused by
protozoa:protozoa:
MalariaMalaria
AmoebiasisAmoebiasis
GiardiasisGiardiasis
ToxoplasmosisToxoplasmosis
CryptosporidiosisCryptosporidiosis
TrichomoniasisTrichomoniasis
LeishmaniasisLeishmaniasis
Sleeping SicknessSleeping Sickness
DysenteryDysentery
Leishmania donovani, (a species of
protozoa) in a bone marrow cell

54. AmebiasisAmebiasis
Entamoeba histolyticaEntamoeba histolytica is is
an an anaerobicanaerobic parasitic parasitic
protozoanprotozoan, part of the , part of the
genusgenus EntamoebaEntamoeba. .
Predominantly infecting Predominantly infecting
humans and other humans and other
primates, primates, E. histolyticaE. histolytica is is
estimated to infect about estimated to infect about
50 million people 50 million people
worldwide.worldwide.
Entamoeba histolytica cyst

55. GardiasisGardiasis
Giardia lambliaGiardia lamblia
(synonymous with (synonymous with
Lamblia intestinalisLamblia intestinalis
and and Giardia Giardia
duodenalisduodenalis) is a ) is a
flagellatedflagellated protozoanprotozoan
parasiteparasite that colonises that colonises
and reproduces in the and reproduces in the
small intestine, small intestine,
causing causing giardiasisgiardiasis. .
Giardia cell, SEM

56. ToxoplasmosisToxoplasmosis
Toxoplasmosis is a Toxoplasmosis is a
parasitic diseaseparasitic disease caused by caused by
the the protozoanprotozoan
Toxoplasma gondiiToxoplasma gondii. The . The
parasite infects most parasite infects most
generagenera of of warm-bloodedwarm-blooded
animals, including humans, animals, including humans,
but the primary host is the but the primary host is the
cat familycat family. Animals are . Animals are
infected by eating infected infected by eating infected
meat, by ingestion of meat, by ingestion of fecesfeces
of a of a catcat that has itself that has itself
recently been infected, or recently been infected, or
by transmission from by transmission from
mother to fetus. mother to fetus.
T. gondii tachyzoites

57. HelminthsHelminths
Parasitic worms or helminths are a division of Parasitic worms or helminths are a division of
eukaryotic eukaryotic parasitesparasites that live inside their host. that live inside their host.
They are worm-like They are worm-like organismsorganisms that live and feed that live and feed
off living off living hostshosts, receiving , receiving nourishmentnourishment and and
protection while disrupting their hosts' protection while disrupting their hosts' nutrientnutrient
absorption, causing weakness and absorption, causing weakness and diseasedisease. .
Those that live inside the Those that live inside the digestive tractdigestive tract are are
called called intestinal parasitesintestinal parasites. They can live inside . They can live inside
humans as well as other animals. Approximately humans as well as other animals. Approximately
3 billion people globally are infected with 3 billion people globally are infected with
helminths.helminths.

58. CategorizationCategorization
Ascariasis,
dracunculiasis,
elephantiasis,
enterobiasis (pinworm),
filariasis, hookworm,
onchocerciasis,
trichinosis, trichuriasis
(whipworm)
Schistosomiasis, swimmer's
itch
Tapeworm infection Example
diseases in
humans
Lips, teeth, filariform
extremities, and
dentary plates
Oral sucker and ventral
sucker or acetabulum
Sucker or bothridia, and
rostellum with hooks
Attachment
organs
Cylindrical Unsegmented plane Segmented plane Shape
Nematodes
(roundworms)
Trematodes (flukes) Cestodes (tapeworms)

59. Cestoda (Cestoidea)Cestoda (Cestoidea)
Cestoda (Cestoidea) live Cestoda (Cestoidea) live
in the in the digestive tractdigestive tract of of
vertebratesvertebrates as adults, and as adults, and
often in the bodies of often in the bodies of
various animals as various animals as
juveniles. Several species juveniles. Several species
parasitiseparasitise humans after humans after
being consumed in being consumed in
underprepared meat such underprepared meat such
as pork (as pork (T. soliumT. solium), beef ), beef
((T. saginataT. saginata), fish (), fish (
DiphyllobothriumDiphyllobothrium spp.), spp.),
poor hygiene (poor hygiene (
HymenolepisHymenolepis spp. or spp. or
EchinococcusEchinococcus spp.). spp.).
Scolex (head) of Taenia solium, a
tapeworm.

60. TremotodesTremotodes
Schistosomiasis is a Schistosomiasis is a
parasitic diseaseparasitic disease caused caused
by several species of by several species of
tremotodestremotodes ("flukes"), a ("flukes"), a
parasitic wormparasitic worm of the of the
genus genus SchistosomaSchistosoma. The . The
urinaryurinary form of form of
schistosomiasis is schistosomiasis is
associated with increased associated with increased
risks for risks for bladder cancerbladder cancer in in
adults. Schistosomiasis is adults. Schistosomiasis is
the second most the second most
socioeconomically socioeconomically
devastating parasitic devastating parasitic
disease after disease after malariamalaria..
Skin vesicles on the forearm,
created by the penetration of
Schistosoma. Source: CDC

61. Nematodes Nematodes
A pinworm infection or A pinworm infection or
enterobiasis is a enterobiasis is a
human parasitic diseasehuman parasitic disease
and one of the most and one of the most
common childhood common childhood
parasitic wormparasitic worm infections infections
in the developed world. It in the developed world. It
is caused by infestation is caused by infestation
with the parasitic with the parasitic
roundworm roundworm
Enterobius vermicularisEnterobius vermicularis, ,
commonly called the commonly called the
human human pinwormpinworm..
Two pinworms

62. PrionPrion
A A prproteinaceous oteinaceous iinfectious particle, or nfectious particle, or prionprion, is an , is an
infectious agentinfectious agent composed primarily of composed primarily of proteinprotein, unlike , unlike
viruses which consist of two or three parts: a helical viruses which consist of two or three parts: a helical
molecule, protein coat and sometimes a viral wrapper.molecule, protein coat and sometimes a viral wrapper.
Prions are the cause of a number of diseases in a Prions are the cause of a number of diseases in a
variety of variety of mammalsmammals, including , including
bovine spongiform encephalopathybovine spongiform encephalopathy (BSE, also known as (BSE, also known as
"mad cow disease") in "mad cow disease") in cattlecattle and and
Creutzfeldt–Jakob diseaseCreutzfeldt–Jakob disease (CJD) in humans. In general (CJD) in humans. In general
usage, usage, prionprion refers to the refers to the theoretical unit of infectiontheoretical unit of infection. .
All known prion diseases affect the structure of the All known prion diseases affect the structure of the
brainbrain or other or other neuralneural tissue and all are currently tissue and all are currently
untreatable and universally fatal.untreatable and universally fatal.

63. Creutzfeldt–Jakob disease Creutzfeldt–Jakob disease
Creutzfeldt–Jakob Creutzfeldt–Jakob
diseasedisease or or CJDCJD is a is a
degenerativedegenerative
neurological disorderneurological disorder ( (
brainbrain diseasedisease) that is ) that is
incurable and invariably incurable and invariably
fatal. It is the most fatal. It is the most
common among the common among the
types of types of
transmissible spongiform encephalopathytransmissible spongiform encephalopathy
found in humans. found in humans.
Microscopic "holes" are
characteristic in prion-affected
tissue sections, causing the tissue
to develop a "spongy"
architecture.

64. Thank you for
your attention!