Chickenpox in Children, Adults and Pregnancy: What to do? Dr. Nayyar Raza Kazmi Community Pediatrics Project Department of Health, Government of NWFP Chicken Pox is a viral illness caused by the Varicella Zoster virus which is a DNA virus causing an eruptive fever in children and adults. Once attacked, the Immunity conferred in Life Long.

BACKGROUND > 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 (<1%)

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

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

VARICELLA IN CHILDREN Prevention Options -vaccination -school omission Treatment Options -symptomatic -antiviral medications

VARICELLA VACCINE: Efficacy 96-100% seroconversion within 4-6 weeks post vaccination > 90% with high titers after 20 years < 2% breakthrough of varicella 2 years out attenuated disease Not available in Pakistan

VARICELLA VACCINE: Side 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

WHO SHOULD BE VACCINATED? YES > 1 year of age varicella susceptible no history of chicken pox no contraindications NO < 1 year of age immunedeficient in household pregnancy mild natural chickenpox

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.

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

ACYCLOVIR IN CHILDREN The 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 * RCT Randomized Control Trial

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

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

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

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.

VARICELLA IN HEALTHY ADULTS  incidence of pneumonia hospitalization rates (10%) mortality compared to children time from work/school

VARICELLA IN ADULTS The Evidence RCT’s 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 Med;1990) No studies to date with valacyclovir or famciclovir

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

VARICELLA IN PREGNANCY-What To Do? prevent infection VZIG infection control diagnose early treat infection

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

VARICELLA IN PREGNANCY treat based on maternal status 800mg qid x 5 days IV therapy if pneumonia

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%)

VARICELLA IN NEONATES during maternal varicella 24% of fetuses get transplacentally infected critical times is 5 days before to 2 days after birth neonates < 28 weeks gestation or <1000gm 1st month of life if mother non-immune and in NICU, immunedeficiency etc infant mortality up to 30%

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.

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

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