Transcript Varicella zoster - FM Faculty Web Pages

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Varicella-zoster virus is a herpesvirus which
causes varicella (chickenpox) and, after the
virus has remained latent in the body (virus
latency) and reactivates, herpes zoster
(shingles)
Serious complications that can occur: central
nervous system involvement, pneumonia,
secondary bacterial infections, and death
Varicella is highly infectious, attack rates in
susceptible contacts vary from 61%-100%
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After primary infection, the virus persists in
sensory nerve ganglia of the dorsal root and
then establishes latent infection in neuronal
cells.
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Varicella-zoster virus is 1 of the 8 herpesviruses
of the Herpesviridae family
The virus is a DNA a-herpesvirus with a
genome of approximately 125,000 bp that
encode 70 genes
During the primary lytic infection, the genes
are expressed sequentially
Sequential expression leads to the production
of groups of immediate to early non-structural
proteins, early non-structural proteins
enzymes, and late structural proteins
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The late structural proteins form a capsid
surrounding the DNA core, and a lipidcontaining envelope
The envelope of the virion is composed of
glycoproteins
After varicella-zoster has infected a cell, the
virus replicates in the nucleus
The incubation period of varicella is in the
range of 10-21 days
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The virus spreads by droplets and aerosols
from the nasopharynx 1-2 days before onset of
a rash, and from skin lesions during the first 57 days after appearance of a rash
The virus enters a susceptible host via the
mucosal surfaces of the respiratory tract
Several viral glycoproteins act together to stick
to mucosal cells which allows the virus to enter
and spread from cell to cell
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Heininger, Ulrich and Seward, Jane F.
Varicella. Basel, Switzerland: Division of
Pediatric Infectious Diseases and
Vaccinology, University Children’s
Hospital, 2006.
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The virus goes through 2 viraemic phases (the
virus enters the bloodstream and can then
affect the whole body)
Wikipedia, The Free Encyclopedia. Viremia. 19
January 2009. 1 April 2009.
<http://en.wikipedia.org/wiki/Viremia >.
The virus multiplies in regional lymph nodes
just before the first viraemic phase
The virus then multiplies further in
reticuloendothelial tissues
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The second viraemic phase occurs between 1021 days after the infection. This phase promotes
viral spread to the nasopharyngeal surfaces
and the skin, which causes the typical rash. The
vesicles contain a great amount of the virus,
and are believed to be the most important route
of viral transmission.
The virus is no longer contagious when all the
lesions have crusted.
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Older age and a compromised immune system
can be risk factors that are linked with the
severity of varicella disease and death
Video
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Heininger, Ulrich and Seward, Jane F.
Varicella. Basel, Switzerland: Division of
Pediatric Infectious Diseases and
Vaccinology, University Children’s Hospital,
2006.
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It is believed that VZV can spread in two ways
1: by release of enveloped virions into the
extracellular space, which occurs mainly in the
vesicular skin lesions that develop in disease
2: by cell-to-cell spread of infection, which does
not require enveloped virions.
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Gershon, Anne A. and Hambleton, Sophie.
Preventing Varicella-Zoster Disease. New
York: Department of Pediatrics, Columbia
University College of Physicians and
Surgeons, 2005.
<http://www.pubmedcentral.nih.gov/articler
ender.fcgi?artid=544176 >.
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VZV virons are spherical and 150-200 nm in
diameter.
Its DNA is a single, linear, double-stranded
molecule, 125,000 nt long.
The capsid is surrounded by a number of
loosely associated proteins called a tegument
Many of these proteins play critical roles in
initiating the process of virus reproduction in
the infected cell.
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Wikipedia, The Free Enycylopedia. VaricellaZoster Virus. 18 March 2009. 1 April 2009.
<http://en.wikipedia.org/wiki/Varicella_zo
ster_virus >.
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The epidemiology differs in temperate and
tropical climates
In most temperate climates, more than 90% of
the population are affected by the virus before
adolescence—in more tropical climates the
disease affects people later in life
This could be because of differences in
transmissibility of heat-labile varicella-zoster in
hot, humid conditions
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Heininger, Ulrich and Seward, Jane F.
Varicella. Basel, Switzerland: Division of
Pediatric Infectious Diseases and
Vaccinology, University Children’s Hospital,
2006.
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Although the immune system has many ways
to destroy virus-infected cells, varicella-zoster
virus has evolved several mechanisms to
reduce presentation of viral proteins to the
immune system and thereby evade detection.
Brunell, Philip A., Cohen, Jeffery I., Krause,
Philip R., Straus, Stephen E. Recent
Advances in Varicella-Zoster Virus Infection.
1 June 1999. 3 April 2009.
<http://www.annals.org/cgi/content/full/
130/11/922>.
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In the U.S., 9 out of 10 adults have had chickenpox
If you have had chickenpox, you can acquire
Shingles at any time with no warning, no way to
predict if you even would get it, or how severe
your case could be
Approximately 1 million cases of Shingles occur in
the U.S. every year, and almost half of these cases
occur in adults who are 60 years of age or older
1 out of every 2 people who live to age 85 will have
Shingles
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Increasing age
A weakened immune system which could be
caused by various things such as certain drugs
or cancer
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Shinglesinfo.com. New Jersey: Merck & Co.,
Inc., 2009. 8 April 2009.
< http://www.shinglesinfo.com/index.html
>.
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Chickenpox can strike at any age, but by ages 9
or 10 about 80-90% of American children have
already been infected.
Children living in rural areas and many
foreign-born children are less likely to be
immune
Because almost every case of chickenpox leads
to lifelong protection against future attacks,
adults account for less than 5% of all cases in
the United States.
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A case of chickenpox usually starts without
warning or only with a slight fever.
Within a few days or even hours, small red
spot begin to appear. After 12-24 hours these
spot tend to become itchy, fluid-filled bumps
called vesicles which begin to appear in crops
lasting 2-6 days.
Some people may only develop only a few
blisters, while in most cases the numbers tend
to reach between 250-500.
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Wells, Ken R. “Chickenpox”. The Gale
Encyclopedia of Medicine. Ed. Jacqueline L.
Longe. 3rd ed. Detriot: Gale, Online update,
2008. Vol 5.
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For Chickenpox, the virus enters the upper
respiratory tract and conjunctiva and replicates
at the site of entry.
New viruses are carried in blood and various
tissues. Here they replicate several more times.
The release of these viruses causes fever and
malaise. In 14-16 days after exposure, small,
irregular, rose-colored skin lesions appear.
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These lesions appear in cyclic crops over 2-4
days as the viruses go through cycles of
replication.
These lesions are often important portals of
entry for ordinary infections, especially with
Staphylococcus aureus (Staph Infection).
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Black, Jacuelyn. Microbiology: Principles and
Explorations. Arlington: John Wiley & Sons
Inc., 2008.
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Although chickenpox are considered a common,
childhood disease, it is also known to be fatal.
The virus can be known to invade and damage
cells that line small blood vessels and lymphatics.
Circulating blood clots and hemorrhages from
damaged blood vessels are common
Death from varicella pneumonia is due to
extensive blood vessel damage in the lungs and
the accumulation of erythrocytes and leukocytes in
alveoli.
Cells in the liver, spleen, and other organs also die
because of the extensive damage to the blood
vessels within them.
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Many children are hospitalized each year with
chickenpox or shingles. In the United States
alone, about 100 people die each year from
chickenpox.
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Black, Jacuelyn. Microbiology: Principles and
Explorations. Arlington: John Wiley & Sons
Inc., 2008.
Uzzell, Jennifer. “Putting a Stop to
Chickenpox”. Nursing 31.2 (Feb. 2001): 30-30.
Academic Search Premier. EBSCO. 4 April
2009.
http://ep.fmcc.edu:5001/login.aspx?direct=tru
e&db=aph&AN=4114743&site=ehost-live.
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Chickenpox is prevalent in industrialized
societies in the temperate zone.
Its incidence is highest between March and
April
The highest infection usually occurs between
ages 5 and 9
Shingles is most common amongst individuals
45+ years old.
Infection can be spread by respiratory
secretions and contact with moist lesions but
not from crusted lesions
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Study results reported by the Centers for
Disease Control and Prevention (CDC) indicate
that more than 90% of American adults are
immune to the chickenpox virus but, however,
are much more likely to suffer more dangerous
complications than children if infected.
More than half of all chickenpox deaths occur
among adults.
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Black, Jacuelyn. Microbiology: Principles and
Explorations. Arlington: John Wiley & Sons
Inc., 2008.
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Because chickenpox is a viral disease, antibiotics
are ineffective against it.
Applying wet washcloths or bathing in cool or
lukewarm water can help the itch.
4-8oz. Of baking soda or 204 cups of oatmeal also
help to relieve symptoms.
Calamine lotion also helps to reduce itchiness.
Fever and discomfort can be reduced by
medication that does not contain aspirin (aspirin
can increase the chances of developing Reye’s
Syndrome)
* Reye's syndrome primarily targets the brain and liver. Brain swelling and chemical changes in the
blood from liver damage affect the entire body. Drowsiness, confusion, seizures, coma, and in
severe cases, death may result.
Wells, Ken R. “Chickenpox”. The Gale
Encyclopedia of Medicine. Ed. Jacqueline L.
Longe. 3rd ed. Detriot: Gale, Online update,
2008. Vol 5.
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Chicken pox ( varicella) vaccine was first
licensed in Japan and Korea in 1988
The chicken pox vaccine was first introduced in
the US in 1995
Deaths went down 145-66 or has fallen 57% 90% overall
Has exceeded expectation
Szabo, Liz. "Chickenpox vaccine does a number on number of
cases.(LIFE)." USA Today. (Sept 2, 2008): 05D. Opposing Viewpoints
Resource Center. Gale. Fulton Montgomery CC Evans Lib - SUNY.
15 Apr. 2009
<http://find.galegroup.com/ovrc/infomark.do?&contentSet=IAC
Documents&type=retrieve&tabID=T004&prodId=OVRC&docId=
CJ184362210&source=gale&srcprod=OVRC&userGroupName=fm
cc&version=1.0>.
Doctors' Orders.(Your Time/Health)." Time. 165. 7 (Feb 14, 2005): 73.
Opposing Viewpoints Resource Center. Gale. Fulton Montgomery CC
Evans Lib - SUNY. 15 Apr. 2009
<http://find.galegroup.com/ovrc/infomark.do?&contentSet=IAC
Documents&type=retrieve&tabID=T003&prodId=OVRC&docId=
A128148201&source=gale&srcprod=OVRC&userGroupName=fm
cc&version=1.0>.
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Vaccination is recommended for adults and
children 1 year or older who do not have a history
of chickenpox, healthcare professionals, and those
who live and work in a crowded setting.
Because the vaccination contains a live virus, it is
not recommended for pregnant women, children
on steroids, and those with a generalized
malignancy.
The vaccine is known to provide 70-90% protection
against severe infection for an estimated 7-10
years.
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Live attenuated vaccine
Vaccine made from live chickenpox germs that
are weakened
Administrated by a shot given in the fatty
tissue
For children, adolescents and adults
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First dose 12-15 months of age
Second dose between 4-6 years old
Adults can get it at any time if they have not
already been vaccinated, get two doses
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About 20% of vaccine recipients experience
Discomfort of injection site
Fever
Mild rash
Risk of Transmission
Later Infection
upper respiratory infection.
Severe Side effects
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“Chickenpox Vaccine.” Carenotes. 2008.McKesson Health Solutions.Web.9.Apr.2009.
Dugdale,David. “Vaccination.” 19 June 2008. Web. 9.April.2009.
“Varicella virus (chickenpox) vaccine.” Cerner Multum. 1996. Web. 9. Apr.2009.
McNeil, Donald. “A Multitude of Vaccine Benefits, Yet Controversy
Persists.”19.June.2008. Web. 9. Apr.2008.
“Vaccine Information.” 2009. Centers for Disease Control and Prevention. Web.
9.Apr.2009
Pollack, Andrew. "Chickenpox Vaccine Cuts Deaths but Raises Questions on Shingles,
Experts Say.(National Desk)." The New York Times. (Feb 3, 2005 pA18 col 01 (24 col): A18.
Opposing Viewpoints Resource Center. Gale. Fulton Montgomery CC Evans Lib - SUNY. 16
Apr. 2009 <http://find.galegroup.com/ovrc/infomark.do?&contentSet=IACDocuments&type=retrieve&tabID=T004&prodId=OVRC&docId=A128041884&source=g
ale&srcprod=OVRC&userGroupName=fmcc&version=1.0
Uzzell, Jennifer. “Putting a Stop to Chickenpox”. Nursing 31.2 (Feb. 2001): 30-30.
Academic Search Premier. EBSCO. 4 April 2009.
http://ep.fmcc.edu:5001/login.aspx?direct=true&db=aph&AN=4114743&site=ehostlive
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Not immune and exposed should get shot
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Varicella Zoster Immune Globulin ( VZIG)
If mom develops chickenpox rash 5 days before
or 2 days after the birth of the baby, baby may
be given VZIG
If serious symptoms occur may be given
antiviral drug
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Being moderately to severely ill
Pregnant women, potentially pregnant, or trying
to become pregnant
Having a family history of weakened immune
system
Having an untreated, active tuberculosis
Receiving antibody containing blood products for
past 3-11 months
Medicines that effect immune system like steriods
Diseases that cause immune system to be
weakened –cancer, HIV/AIDS, Chemotherapy,
ETC.
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“Chickenpox (varicella) during
pregnancy.”Clinical reference
systems.2008.McKesson Health
Solutions.Web.9.Apr.2009.
“Chickenpox Vaccine.” Carenotes.
2008.McKesson Health
Solutions.Web.9.Apr.2009.
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In 1995, the American Academy of Pediatrics
began recommending that the varicella vaccine be
given to all children between 12-18 months.
Prior to the vaccine’s availability, an average of 50
children died from chickenpox and related
complications.
Today, 20 states require children to get vaccinated
before they can enter childcare or preschool.
Research shows that the vaccine’s effectiveness is
about 85% and offers excellent protection against
the disease even 8 years after it was given.
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“Preventing Chickenpox”. Scholastic Parent &
Child. 12.1 (Sept. 2004): 65-65. Academic Search
Premier. EBSCO. 4 April 2009.
http://ep.fmcc.edu:5001/login.aspx?direct=tru
e&db=aph&AN=14380524&site=ehost-live.
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In shingles, much like chickenpox, lesions appear
(most often rather painful) and are usually
confined to a small region of the body supplied by
a particular nerve.
Such eruptions arise from latent viruses acquired
during an earlier case of chickenpox.
During this period, the viruses can reside in
ganglia in the cranium and/or near the spine.
When reactivated, the viruses spread from a
ganglion along the pathway of its associated
nerve(s).
Before the painful lesions appear, a pain and/or
burning sensation of the skin may occur.
http://www.youtube.com/watch?v=7jeur
TCz1CI
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The obvious factor that will allow you to
realize you have Shingles is a
painful/blistering rash will appear usually on
only 1 side of your body
Before the rash develops, there will be burning,
itching, or tingling on your skin where the rash
will form
The rash lasts approximately 30 days
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These viruses damage nerve endings, cause
intense inflammation, and produce clusters of
skin lesions indistinguishable from chickenpox
lesions.
Symptoms range from mild itch to continuous,
severe pain and can include headache, fever,
and malaise.
Shingles is most severe in individuals with
malignancies or immune disorders.
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The latent virus is activated when cellmeditated immunity drops below a critical,
minimal level (ex: Spinal Cord trauma or
immunosuppression).
Release of newly replicated viruses increases
antibody production, but the antibodies may
fail to stop viral replication.
Recovery from shingles is usually complete.
Second and third cases can occur and depend
on the degree of development of cell-meditated
immunity and local interferon production.
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Scarring
Bacterial skin infections
Decrease or loss of vision or hearing
Paralysis on one side of your face
Muscle weakness
Long-term nerve pain, known as postherpetic
neuralgia, is the most common complication
that occurs after Shingles. For many people this
pain is very severe to the point where a clot
touching their skin is very painful.
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Statistics from the National Institute of Health
at nihseniorhealth.gov show that 50% of
Americans have had shingles by the time they
reach 80.
http://www.youtube.com/watch?v=SUYjb3Kwu8&NR=1
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Black, Jacuelyn. Microbiology: Principles and
Explorations. Arlington: John Wiley & Sons
Inc., 2008.
Ponti, Karlene. “Shingles is a serious and
common illness for those over 50: The illness,
caused by the Chickenpox Virus, stay in the
body and Reactivates Later”. McClatchyTribune Business News. 4 April 2009,
ABI/INFORM Dateline Database.
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Shingles is also called Herpes Zoster
Vaccine name is Zostavax
Like chicken poxs shingles are caused by
herpes zoster virus
Vaccine works by mimiking a shingles attack
but without pain
Zostavax roughly equivalent to 14 doses of
chicken pox vaccine
Strengthens body against virus
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Reducing chances of outbreak and severity of the
disease
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For people 60 and older
First vaccine in 30 years to be exclusively for
older people
First vaccine that keeps an infection in check
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Harris, Gardiner. “ Vaccine to Cut Risk of
Shingles in Older People Is
Approved.”2006.Web.9.Apr.2009
Dugdale,David. “Vaccination.” 19 June 2008.
Web. 9.April.2009.