Rabies virus
? Shape,bullet
? Genome,-ssRNA
? enveloped virus
? CPE,Negri body
Structure of Rabies Virus
? 抵抗力不强,60?C 30min或 100?C
2min可灭活。可被强酸、强碱、乙醇、
乙醚、肥皂水、去垢剂等灭活。
? 在脑组织中室温或 4?C可持续 1－ 2周。
甘油中可保存数月。
Reservoir
? Urban forms,Dogs and
cats
? Sylvatic forms,Bats,foxes,
raccoons莞熊,wolves,
skunks臭鼬,coyotes丛林狼,
mongooses猫鼬,and biting
animals
Transmission
? By bite or scratch
? Via saliva
? Airborne ( bats)
BAT armadillo
Cat fox
raccoon dog
Rabies or hydrophobia
? Fever
? Dysphagia咽下困难
? Altered mental
status
? Excitement,
agitation
? Paralysis麻痹
? Hydrophobia恐水
? Hypersalivation
多涎
? Nausea,
vomiting恶心 ;作
呕
? Headache
? malaise不适
Laboratory diagnosis
? Diseased dog,viral antigen and
Negri body in brain tissue,
? Patient,IF assay,PCR,
Prevention and treatment
Prevention and treatment
? Bite Geographical area,type of animal,
severity and site of bite,
Animal
? Live - observe in cage,
If survives > 8 days,then NOT rabies,
Dead - brain
? - Negri bodies
- IFA
- virus isolation
Prevention and treatment
Man
Live - difficult diagnosis
- clinical picture,skin biopsy,corneal
impression (antibodies only appear
very late)
Dead - brain sent to Onderstepoort
"Negri bodies" in cytoplasm of brain
cells; immunofluorescence virus
isolation,
Human papillomavirus
(HPV)
Biological properties
? naked dsDNA virus
with 9 ORF
? belongs to
Papovaviridae
? more than 60 types
? artificial
cultivation un-
successful,
Transmission
? contact infection
? sexual infection
? congenital infection,
Pathogenesis
? Host-specific
? Tissue-specific,
Disease
? Cutaneous warts
? Epidermodysplasia verruciformis
? Mucosal HPV infections
? Cervical cancer and other cancers,
? A significant proportion of cancers is
associated with HPV infection,11% of all
cancers in women and 2% of all cancers in
men,
LIFE CYCLE OF HUMAN
PAPILLOMAVIRUS
?
Laboratory diagnosis
? - Cytology
- Histology
- Colposcopy in the case of genital HPV
infections,
- Electron microscopy,
? - Immunocytochemistry can detect major
capsid protein but are generally group
specific not type specific
- DNA detection techniques,This is the
only way to type HPVs.PCR
PARVOVIRUSES
Human parvovirus B19
DISTINCTIVE PROPERTIES
? Are small,naked viruses with
icosahedral nucleocapsids,
? Contain single-stranded DNA
and replicate in the nucleus,
? Include human parvovirus (B19)
and adenoassociated virus,a
defective virus of the
dependovirus genus that
requires adenovirus to replicate,
? Human pathogen,B19,has
tropism for red blood cell
progenitors
Human diseases associated with B19
parvovirus
Syndrome Host or condition Clinical features
Fifth diseases Children
Adilts
Cutaneous rash
Arthralgia-
arthrtis
Transient
aplastic crisis
Underlying
hemolysis
Severe acute
anemia
Pure red cell
aplasia
Immunodeficienci
es
Chronic anemia
Hydrops
fetails
Fetus Fatal anemia
EPIDEMIOLOGY
? These organisms are widely
distributed in nature,
? Enters the body through,
The respiratory tract
Blood transfusions
Vertically from mother,
DIAGNOSIS
PARVOVIRUS B-19 SEROLOGY
Serology Interpretation
IgG-
IgM-
No past infection
Patients susceptible to
infection
IgG+
IgM-
There has been a past
infection
Patient probably immune
IgG + or –
IgM
equivocal
Current or recent infection
Patient should be retested
in a few weeks
IgG+
IgM+
Ongoing or recent infection
Fetus may be at risk if
patient pregnant
IgG- (or
equivocal)
IgM+
Current infection
Patient should be retested
in a few weeks ? Direct detection of the viral DNA may be achieved
by PCR
Prevention and Treatment
? Immunological,no vaccines are
available
? Treatment,Commercial
immunoglobulin preparations
contain parvo B19 antibodies can
successfully eliminate the
infection in immunocompromised
patients