Transcript Chickenpox (varicella)

CHICKENPOX
(VARICELLA)
Sarah Fisher
What is Chickenpox?
• Highly contagious disease
caused by Varicella Zoster Virus
(VZV)
• On of the most commonly
contracted childhood diseases
• Usually mild and not lifethreatening to otherwise healthy
patients
• Potentially severe in infants, adults
and others with impaired immune
systems
• Infections cause long-term
immunity—second infections are
rare
History
• 1500s: Believed to have
been first discovered by
Giovanni Fillipo in Italy
• 1600s: English physician
Richard Morton gave the
disease the name
“chickenpox” because he
believed it was a milder
version of smallpox
• 1700s: English physician
William Heberden became
the first physician to prove
that chickenpox and
smallpox were two
different diseases
History Cont.
• 1888: Relationship between Herpes Zoster and
chickenpox was suggested
• 1986: Complete DNA sequence of VZV was established
• 1995: FDA approved vaccine to immunize children and
other susceptible individuals against chickenpox
Transmission
• One of the most readily transmissible diseases
• Can be spread from person to person by:
• Direct contact with fluid from the blisters
• Direct contact with secretions from the respiratory tract
• Handling an infected person’s clothing or bedding
• Exposure to the coughing or sneezing of an infected person
(airborne)
• Touching or breathing in the virus particles that come from
chickenpox blisters
• Susceptibility is universal among those not previously
infected
• Greatest number of cases occur in the winter/early spring
Symptoms
• Symptoms usually start about two weeks after exposure
• Fever, tiredness, loss of appetite, headache, an itchy rash
• Rash generally starts as little red spots on the chest,
stomach or back and then spreads to the face
• Infected patient may only get a few spots, a large cluster or develop
hundreds of spots during the first 3-5 days of the rash
• Spots turn into clear, fluid-filled blisters and eventually turn to scabs
(2-4 days)
• Very contagious 1-2 days before rash appears and until
all blisters have formed scabs
Complications
• Not common in otherwise healthy people
• People with more severe risks for complications:
• Infants
• Adolescents
• Adults
• Pregnant women
• People with weakened immune systems because of illness or
medications
• 1/400 patients need hospitalization
• Approx. 90 deaths/year
Complications Cont.
• Serious complications include:
• Dehydration
• Pneumonia
• Bleeding problems
• Brain infection/inflammation
• Bacterial infects of the skin/soft tissues
• Blood stream infections (Sepsis)
• Toxic shock syndrome
• Bone infections
• Joint infections
• Chickenpox remains latent and may recur years later as
Herpes Zoster (shingles)
• Risk increases with age and for those with HIV
Prevention
• The best way to prevent
the disease is to get
vaccinated—98% percent
effective
• Children, adolescents and
adults should have two doses
• With the vaccine, it is still
possible to contract the
disease but it will be much
more mild with fewer blisters
and a mild or no fever
• Vaccine is required for
attendance in day care and
schools
Prevention Cont.
• If you have never had chickenpox, vaccinated or not, you
should stay away from any infected people
• Some newborn babies, any immune-deficient child and
any susceptible persons over 14 years of age who have
not been previously vaccinated may need a shot of
varicella zoster immune globulin (VZIG) to try and prevent
chickenpox contraction after exposure
Treatment
• Acetaminophen can be given to reduce fever
• Aspirin should not be given because it may cause Reye syndrome
• Calamine lotion, antihistamines and oatmeal baths can be
given to help reduce itching
• Acyclovir is a new drug now given to some patients within
the first day after rash onset to make the symptoms milder
Epidemiology
• Varicella is endemic in the US with seasonal fluctuation
• Between 150,000-200,000 cases are reported annually to
the CDC (1998)
• Highest attack rates are in children ages 509—60% of all
cases
Epidemiology Cont.
• By adulthood, 90-95% of the US population have
antibodies to varicella
• In the tropics, varicella occurs more often in adults so
immigrants from these areas are more likely to be
susceptible than the rest of the population at comparable
ages
Herpes Zoster (Shingles)
• Reactivation of latent varicella zoster virus (VZV)
• Associated with aging, immunosuppression, in-utero
exposure to varicella, and postnatal varicella (before 18
months)
• In the immunocompromised, zoster can disseminate,
causing generalized skin lesions, and central nervous
system (CNS), pulmonary, and hepatic involvement
Sources
• http://chickenpox.emedtv.com/chickenpox/history-of•
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chickenpox.html
http://www.cdc.gov/chickenpox/about/
http://www.idph.state.il.us/public/hb/hbchikpx.htm
http://wonder.cdc.gov/wonder/prevguid/p0000108/p00001
08.asp#head001002000000000
http://www.ncbi.nlm.nih.gov/pubmed/11867004