Chickenpox in Children, Adults and Pregnancy: What to do

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Chickenpox in Children, Adults and Pregnancy
What to do?

• Dr. Nayyar Raza Kazmi
• Community Pediatrics Project
• Department of Health, Government of NWFP

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BACKGROUND

• gt 90 of population infected by 15 yrs
• attack rates 90 for household contacts
• morbidity
• bacterial skin infections
• pneumonia
• encephalitis, post varicella cerebritis
• days from school/work
• hospitalizations (lt1)

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BACKGROUND

• risk of death
• lower for children than infants
• increases with age for adolescents/adults
• 30 for perinatally exposed infants
• 2/100,000 aged 1-14
• 2.7/100,000 aged 15-19
• 25.2/100,000 aged 30-49

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STRATEGIES

• Prevent infection?
• infection control
• passive vaccination (VZIG)
• active vaccination (live attenuated)
• Treat infection?
• who to treat?
• what to treat with?

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VARICELLA IN CHILDREN
Prevention Options -vaccination -school
omission Treatment Options -symptomatic -antivi
ral medications
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VARICELLA VACCINE Efficacy

• 96-100 seroconversion within 4-6 weeks post
  vaccination
• gt 90 with high titers after 20 years
• lt 2 breakthrough of varicella 2 years out
• attenuated disease
• Not available in Pakistan

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VARICELLA VACCINESide Effects

• fever (12)
• pain at site (2)
• rash at injection site (1.5)
• generalized rash (1.5)
• transmission of vaccine virus
• higher if vaccinees are immunocompromised

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WHO SHOULD BE VACCINATED?

• YES
• gt 1 year of age
• varicella susceptible
• no history of chicken pox
• no contraindications

• NO
• lt 1 year of age
• immunedeficient in household
• pregnancy
• mild natural chickenpox

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VARICELLA IN CHILDREN
Usually previously well children develop
malaise and low grade fever which rises once the
rash appears. The rash begins along the hairline
on face as macules which progresses to tiny
vesicles with surrounding erythema.(Dew drops on
rose petal appearance) . Rash then appears in
successive crops over the trunk and extremities.
They heal in 7-10 days. Sometimes hemorrhage may
occur within the vesicles which may be mistaken
as Meningococcemia.
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SCHOOL WITHDRAWALSThe Evidence

• contagious 1-2 days before the rash until all
  lesions crusted
• documented transmission of infection to
  classmates prior to rash (AJDC 1989-Brunell)

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ACYCLOVIR IN CHILDRENThe Evidence

• Balfour et al J Peds 1990 Dunkle et al NEJM
  1991
• RCT of 102 and 815 children
• acyclovir (20mg/kg/dose) qid vs placebo
• ?lesions, ?fever, ?itching
• no change in complications or titers

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ACYCLOVIR IN CHILDREN

• no serious adverse drug reactions noted
• cost of medications needs to be considered!!!!
• acyclovir is not routinely recommended for the
  treatment of chickenpox in healthy children

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PROPHYLACTIC ACYCLOVIR IN CHILDREN

• 40 mg/kg/day after exposure
• ? symptomatic cases with acyclovir vs placebo
  (16 vs 100) (Asano et al Pediatrics 1993)
• 79-85 still had serologic evidence of infection

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PROPHYLACTIC ACYCLOVIR IN CHILDREN

• ? severity if acyclovir given for two weeks (Suga
  et al Arch Dis Child 1993, PIDJ 1998)
• development of resistance is a concern
• routine acyclovir prophylaxis not recommended
  in otherwise healthy children

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VARICELLA IN HEALTHY ADULTS
38 yo healthy man with no previously
documented chicken pox develops fever and
vesicular rash 18 days after his son recovers
from chickenpox. Has lesions in mouth and
urethra and increasing cough.
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VARICELLA IN HEALTHY ADULTS

• ? incidence of pneumonia
• ?hospitalization rates (10)
• ?mortality compared to children
• ?time from work/school

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VARICELLA IN ADULTSThe Evidence

• RCTs in adults with acyclovir given within 24
  hours of onset
• 800mg qid x 5 days
• ? duration, ? severity of illness
• (Wallace et al An n Int Med 1992, Feder Arch
  Intern Med1990)
• No studies to date with valacyclovir or
  famciclovir

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VARICELLA IN PREGNANCY

• pregnancy alters cellular immunity needed to
  fight viral infections
• ? pneumonitis
• ?mortality
• ?maternal complications in 2nd and 3rd trimester
• premature labour/delivery, IUGR
• small risk of fetal infection

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VARICELLA IN PREGNANCY-What To Do?

• prevent infection
• VZIG
• infection control
• diagnose early
• treat infection

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VARICELLA IN PREGNANCY-The Evidence

• no evidence to suggest that maternal acyclovir
  prevents fetal infection
• no evidence of teratogenic effect of acyclovir at
  therapeutic doses
• high doses have in vitro effects

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VARICELLA IN PREGNANCY

• treat based on maternal status
• 800mg qid x 5 days
• IV therapy if pneumonia

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VARICELLA IN FETUS

• 2.2 transmission to fetus (1.2-4.9) (Pastuszak
  et al NEJM 1994)
• intrauterine infection more common in 1st
  trimester
• congenital infection
• scarring, limb deformities, cataracts, CNS
  involvement, chorioretinitis
• neonatal or childhood zoster (0.8 -1)

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VARICELLA IN NEONATES

• during maternal varicella 24 of fetuses get
  transplacentally infected
• critical times
• is 5 days before to 2 days after birth
• neonates lt 28 weeks gestation or lt1000gm
• 1st month of life if mother non-immune and in
  NICU, immunedeficiency etc
• infant mortality up to 30

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VARICELLA IN NEONATES
Infant born at full term following
uncomplicated delivery. Mother noticed to have
varicella lesions 2 days prior to delivery with
low grade fever. Infant is completely well with
no skin lesions, no fever etc.
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VARICELLA IN NEONATES The Evidence

• VZIG if peripartum maternal infection (Hanngren K
  et al Scand J Infect Dis 1985)
• attack rate still 51
• incubation period of 11 days
• attenuates infection (Miller et al. Lancet 1989 )
• ? mortality rate (1-2), ? lesions
• no literature regarding the use of acyclovir for
  prevention of disease in this group

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VARICELLA IN NEONATES

• Perinatal Exposure
• treat with acyclovir due to high mortality
• lt 4 weeks of age
• treat if mother is not immune, if infant born lt
  28 weeks gestation, lt 1000gm, sick in NICU
• no clinical trials to date however good studies
  with acyclovir in other neonatal infections