midterm examPOXVIRIDAE AND HERPES Flashcards
Largest and most complex of viruses that infect vertebrates, and is large enough to be seen under the light microscope
poxviridae
size of a poxviridae
200-450 nm
shape of a poxviridae
ovoid to brick with complex morphology
in poxviridae, Inside is a core structure shaped like a ____, and two
accompanying lateral bodies, so named after their location
in the virion
dumb bell
Family poxviridae contains two subfamilies
Chordopoxvirinae
Entomopoxvirinae
2 genus of Chordopoxvirinae
Orthopoxvirus
Molluscipoxvirus
Entomopoxvirinae is a poxviruses of ___
insects
Orthopoxvirus is a virus of
Variola, Cowpox, Vaccinia and Monkeypox
Replication of __ is unique among the DNA-containing
viruses, in that the entire multiplication cycle takes place within the
host cell cytoplasm
poxviruses
Cytopathology of poxviridae
produce eosinophilic inclusion bodies called
Guarnieri bodies and membrane hemagglutinins in infected cells
what is the inclusion bodies of poxviridae
guarnieri bodies
Causative agent of Smallpox
variola virus
2 subtypes of variola
variola major and minor
this type of variola caused the most severe disease (case fatality rate of
30%), occurred mainly in Asia
variola major
this type of variola is less severe disease (case fatality rate of 0.1%-2%)
variola minor
variola virus is Completely eradicated in
1980
All known stocks of variola are held at two WHO laboratories
- CDC (Atlanta, Georgia)
- State Center of Virology and Biotechnology (Koltsovo, Russia)
MOT of Variola Virus
Respiratory droplets, direct skin-to-skin contact, fomites
incubation period of variola virus
7-14 days
Clinical Manifestation of variola
fever, malaise, rash
starts from face then downward to trunk
and extremities
Recovery time of variola
2-3 weeks
Complications that variola may cause
pneumonia, encephalitis,
death
PREVENTION of variola
Vaccination-live attenuated virus vaccine made from Vaccinia Virus
indistinguishable from smallpox infection except that it lacks the same level of mortality and transmissibility
monkeypox
- Main reservoir of monkey pox
rodents
monkey fox are found in
found in the tropical rain forests of Africa
Clade I: Monkey pox virus
congo basin-high mortality rate
Clade II:I Monkey pox virus
west africa
Clade III: Monkey pox virus
2022 european/north american outbreak
MOT of monley pox
Close contact with infected animals/individuals, fomites,
transplacental
- Symptoms: skin rash or mucosal lesions which can lasts 2-4 weeks,
fever, headache, body aches, fatigue, swollen lymph nodes
monkey pox
LABORATORY DIAGNOSIS of monkey pox
- Clinical diagnosis can be difficult because other infections and
conditions can look similar - Diagnostic specimen: Skin, fluid, crusts, throat swab/anal swab if skin
lesions are absent - Detection of E9L gene and B5R gene through molecular techniques
explain the course of lesions caused by monkey pox
rashes typically first appears on the face. Beginning as macules, progressing to papules, to vesicles and then pustules
illness caused by monkey pox last for how many weeks
2-4 weeks
lesion progression of monkey pox
small, round changes in skin color
macules
lesion progression of monkey pox
slighltly elevated with no fluid
papules
lesion progression of monkey pox
containing a bubble of fluid
vesciles
lesion progression of monkey pox
containing purulent material consisting of necrotic inflammatory cells
pustules
lesions are seen on the udder and teats of cows and may be
transmitted to humans during milking.
Cowpox Virus
- Lesions in humans caused by cowpox virus usually appear on the
hands or fingers
Natural reservoir of cowpox seems to be a
rodent
__ used cowpox virus to develop the smallpox vaccine in
1796
Edward Jenner
Vaccinia Virus is the agent used for __ vaxx
smallpox
Lesions are small, pink, wart-like tumors
on the face, arms, back, and buttocks are
more frequent in children than in adults
causes single or small clusters of lesions
Molluscum Contagiosum Virus
Incubation period of molloscum contagiosum
1 week to 6 months
mot of Molluscum Contagiosum V
direct contact with an infected
person, sharing contaminated items
spread to other parts of their body by
touching or scratching a lesion and then
touching their body somewhere else called
autoinoculation
autoinoculation is seen in what virus we studied
Molluscum Contagiosum Virus
DIAGNOSIS of molluscum contangiosum
- Diagnosis can be done by clinical
appearance of the lesions - Electron microscopy to visualize virus
particles in skin tissue samples - PCR of genetic material
- Presence of Henderson-Petterson bodies
on keratinocytes
Transmitted from sheep to humans through human direct contact with infected sheep
ORF VIRUS
causes single or multiple nodules, usually on the hands
ORF virus
Nodules may be painful and accompanied by low-grade fever and node swelling
ORF VIRUS
ORF virus infections resolved ___ weeks without further complication except inoculation in the eye
4-6 weeks
diagnosis of orf virus
Direct examination of nodules, along with epidemiologic evidence of a recent history of contact with sheep or lambs
describe the characteristic of a herpesviridae
Enveloped icosahedral capsid, linear double
stranded DNA
size of a herpesviridae
120-300 nm
herpes means
to creep q
herpes’ virion consists of
4 components
nucleic acid core
capsid
tegument
envelope
3 known subfamilies of a herpesviridae
Alphaherpesvirinae
betaherpersvirinae
gammaherpesvirinae
Alphaherpesvirinae types
HSV type 1 and 2, VZV
Betaherpesvirinae types
CMV, HHV-6, HHV-7
Gammaherpesvirinae types
EBV, HHV-8
Hallmark characteristic of a herpesviridae
latency
herpesviridae’s reactivation is caused by various stimuli such as
fever, stress, UV exposure, axonal injury, immunosuppression
herpesviridae will form what inclusion bodies
cowdry type A intranuclear inclusion bodies
what the first human herpesvirus to be recognized
herpes simplex virus
what are the human herpes virus
herpes simplex virus types 1 and 2
varicella zoster virus
epstein barr virus
cytomegalovirus
human herpes viruses 6 and 7
HHV -8 (associated with kaposi sarcoma)
viruses under the alphaherpesvirinae
human herpes virus 1,2,3
viruses under the gammaherpesvirinae
human herpesvirus 4 and 8
viruses under the betaherpesvirinae
human herpes virus 5. 6, 7
this genus of herpesviridae that is the site of latency is neurons
human herpes virus 1 2 3
type of human herpesvirus that is the site of latency is the b cell
human herpesvirus 4
type of human herpesvirus that is the site of latency is the monocyte, lymphocyte
HHV 5
herpes simplex virus is an infection of either
skin and genitalia
type of HSV that is usually isolated from lesions in and around the mount and is transmitted by DIRECT CONTACT OR DROPLET SPREAD from cases or carriers
HSV type 1
type of HSV where the infection is above the waist
HSV type 1
type of HSV that is transmitted sexually or from a maternal genital infection to a new born
herpes simplex virus type 2
type of HSV wherein the infection is below the waist
HSV type 2
herpes simplex virus
Initially infect and replicate in __ and then establish
latent infection of the innervating neurons.
mucoepithelial cells
Skin and mucous membranes are the portals of entry in which the
virus also multiplies, causing lysis of cells and formation of vesicles.
herpes simplex virus
herpes simplex virus
After replication is under way in the skin or a mucous membrane,
virions travel to the __ via the sensory nerves supplying the
area
root ganglia
Cutaneous Infections of a HSV
most common site is the
face—on the cheeks,
chin, around the mouth or on the forehead;
Napkin rash
cutaneous infection of HSV
- Some sensitive persons, very minor stimuli,
like common cold, exposure to sun or even
mental strain or menses may bring on such
reactivation of
fever blister’ or herpes febrilis
an infection of the finger caused by the HSV
herpetic whitlow
an infection of the body cause by the hsv
herpes gladiatorum
Eczema herpeticum is an infection of
HSV (cutaneous )
Acute gingivostomatitis, herpetic
stomatitis, pharyngitis, tonsillitis and localized
lymphadenopathy may occur.
oral infection of HSV
Ophthalmic infection of HSV
Severe keratoconjunctivitis, follicular
conjunctivitis with vesicle formation on the lids,
dendritic keratitis or corneal ulcers or as vesicles
on the eyelids, corneal scarring and impairment
of vision.
Are known to increase
the risk of transmission of infection of herpes simplex virus with human
immunodeficiency virus (HIV).
genital herpetic ulcers
in make patients with hsv, The lesions typically develop
on the __ and
occasionally in the urethra
glans or shaft of the penis
In female patients with hsv, lesions may be seen on
the
vulva, vagina, cervix, perianal area, or inner
thigh
- : In patients of
both sexes, hsv may be seen in
Inguinal lymphadenopathy
this hsv is seen in homosexual patients
Herpetic proctitis:
diagnosis if HSV
rapid result but cannot distinguish
between HSV and VZV
electron microscopy of vesicle fluids
a direct detection of hsv that can distinguish between HSV and VZV
immunofluorescence of skin scrapings
a direct detection that is now used routinely for the diagnosis of herpes simplex encephalitis and other herpes simplex infections
PCR
type of HSV that is easy to cultivate
hsv 1 and 2
why do serology is not a useful way of detecting HSV in acute phase
it takes 1-2 weeks before the antibodies appear after infection
this the drug of choice for most situations at present for HSV
acyclovir
oral only, more expensive than acyclovir
Famciclovir and valacyclovir
Other older agents for HSV
__________
* These agents are highly toxic and is suitable for topical use for ophthalmic
infection only
– e.g. idoxuridine, trifluorothymidine, Vidarabine (ara-A).
causing Chicken Pox (Bulutong)-1° infection
varicella
2° infection of bulutong is called as
shingles caused by zoster
- Classic disease of childhood with the highest prevalence occurring in
the 4-10 years old age group
Varicella-Zoster (Virus)
varicella zoster virus is Highly communicable-attack rate of __% in close contacts
90
MOT of varicella zoster virus
Respiratory droplet, Direct contact with lesion
varicella-zoster virus gains entry via the respiratory tract and spreads to the lymphoid system
varicella-zoster virus
incubation period of varicella-zoster virus
14 dyas
VZV -
* Following the primary infection, the virus remains latent in the
___
sensory ganglia
Presents fever, lymphadenopathy. a widespread vesicular rash.
varicella
varicella
severe complications which may be life threatening include
viral pneumonia, encephalitis, and hemorrhagic chickenpox
The features are so characteristic that a diagnosis can usually be made on
clinical grounds alone.
varicella
varicella
Most common complication is secondary bacterial infection of the
vesicles
- __mainly affect a single area of the skin
Herpes Zoster
herpes zoster or shingles
- It may occur at any age but the vast majority of patients are more than ___ y/o
50 years of age
- Complications include for herpes zoster
opthalmic zoster
generalized zoster
ramsay hunt syndrome
TREATMENT for VZV
- Self-limiting
- Acyclovir
- For Herpes zoster: Famciclovir and Valacyclovir
PREVENTION for VZV
- Chicken pox
Live attenuated vaccine (2 doses)-Varivax®, ProQuad®
PREVENTION for VZV
zoster
: Zostavax, Shingrix (for adults > 50 y.o)
Prophylaxis for VZV
Passive immunization of Varicella-zoster immunoglobulin
(VZIg)
- Human herpesvirus 4 is also called as
epstein barr virus
M,OT of Epstein-Barr Virus (EBV)
saliva and sexual contact,
kissing disease is caused byb
epstein barr virus
epstein barr virus is common in
Common in younger children and sexually active adolescents
- Site of latency of epstein barr virus
memory B cells
CLINICAL MANIFESTATION of epstein barr virus
infectious mononucleosis
burkitt’s lymphoma
nasopharyngeal carcinoma
Lymphoproliferative disease and lymphoma in the immunosuppressed
x linked lymphoproliferative syndrome
chronic infectious mononucleosis
oral leukoplakia in AIDS patients
chronic interstitial pneumonitis in aids patients
symptoms of infectious mononucleosis
Fatigue, fever,
sore throat, swollen lymph
nodes and splenomegaly
TREATMENT AND PREVENTION for epstein barr virus
no antiviral drug
self limiting for 2-3 weeks
no vaxx
avoid sharing personal items like utensils, drinking glassesa etc
Has the largest genome of the human herpesvirus
cytomegalovirus
cytomegalovirus Replicates only in human cells such as
Fibroblasts, epithelial cells, granulocytes, macrophages and others
cytomegalovirus is Acquired from
blood, tissue and body secretions
MOT of cytomegalovirus in early stage
during pregnancy
during birth
after birth
MOT of cytomegalovirus in childhood
saliva (kissing)
MOT of cytomegalovirus in adult
sexual transmission
blood transfusion
organ transplantation
incubation period of CMV
3-6 weeks
Cytomegalovirus
* Due to the severity of the infection to the unborn, it is included for
pre-natal screening which is the test called
TORCH TEST
TORCH test stands for
T: Toxoplasmosis
O: Other infections (including syphilis and hepatitis B)
R: Rubella
C: Cytomegalovirus
H: Herpes simplex virus
TREATMENT AND PREVEVENTION for CMV for retinitis and pneumonia
ganciclovir
TREATMENT AND PREVEVENTION for CMV
- Ganciclovir-retinitis and pneumonia
- Valganciclovir
- Foscarnet
- Cidofovir
type of HHV that are ubiquitous and are
found worldwide.
HHV-6 and HHV-7
HHV 6 and 7
They are transmitted mainly through contact
with
saliva and through breast feeding
HHV-6 and HHV-7 infection are acquired
rapidly after the age of ____ months when the
effect of maternal antibody wears off.
4
Like other herpesviruses, HHV-6 and HHV-7
remains latent in the body after primary
infection and reactivates from time to time
true or false
true
HHV 6 : ____-fever and rash in
babies
Roseola Infantum
- Originally isolated from cells of Kaposi’s
sarcoma (KS)
hhv 8
HHV-8 DNA is found in almost __% of
cases of Kaposi’s sarcoma
100
MOT of HHV 8
sharing utensils, kissing or close
contact with infected individual, blood
transfusion, organ transplantation, needle
sharing, sexual transmission
Castleman’s
disease and primary effusion lymphomas
HHV 8