Perinatal Varicella

By Rafat Mosalli MD FAAP FRCPCBy Rafat Mosalli MD FAAP FRCPC

Objectives

Perinatal varicella related diseases How common is it How to prevent Congenital and neonatal form Indication of VZIG Hospital isolation and precaution methods

for infected mother and exposed newborn.

Problem 1

You are called to assess a newborn that You are called to assess a newborn that his mother has a history of Chicken pox 3d his mother has a history of Chicken pox 3d prior to delivery, you will:prior to delivery, you will:

Isolate the baby and start VZIG as soon as Isolate the baby and start VZIG as soon as possible together with acyclovirpossible together with acyclovir

Isolate the baby and start treatment with Isolate the baby and start treatment with acycloviracyclovir

Isolated the baby and give VZIG onlyIsolated the baby and give VZIG only No treatment is indicated since the risk is No treatment is indicated since the risk is

low.low.

Problem 2

The type of isolation needed for the newborn The type of isolation needed for the newborn whose mother developed chickenpox whose mother developed chickenpox 5 5 days prior and days prior and 22 days post to delivery is: days post to delivery is:

1- Standard, contact and airborne 1- Standard, contact and airborne precaution.precaution.

2-only standard and airborne2-only standard and airborne

3- Only Contact.3- Only Contact.

4-No isolation is needed.4-No isolation is needed.

Problem 3; In regard to VZIG all true except:

1- VZIG does not prevent 100% of cases of 1- VZIG does not prevent 100% of cases of

neonatal varicella neonatal varicella 2- Best given within 96 hours of exposure2- Best given within 96 hours of exposure3- Not effective once active disease occurs3- Not effective once active disease occurs4- it is indicated for newborn with onset of 4- it is indicated for newborn with onset of

maternal varicella within 5 days prior maternal varicella within 5 days prior through 2 days following deliverythrough 2 days following delivery

5-VZIG may shorten the incubation period. 5-VZIG may shorten the incubation period.

Varicella Zoster Virus (VZV)

-Causes chicken poxand shingles

- Humans are the onlyknown reservoir

- Highly contagious- Transmission is bycontact or airborne

droplets

Epidemiology

Exposure to a household results in infection

in virtually all susceptible members Incubation period usually 14-16 days

Can range 10-21 days Patients are contagious from 2 days prior to

and 5 days after the onset of the rash Immunocompromised patients contagious for

duration of rash

Perinatal varicella related disease

Maternal VaricellaMaternal Varicella Congenital varicellaCongenital varicella Neonatal varicellaNeonatal varicella

Varicella and pregnancy

Varicella in pregnancy is relatively rare (5 per Varicella in pregnancy is relatively rare (5 per 10,000)10,000)

Severe form (maternal pneumonia ,congenital Severe form (maternal pneumonia ,congenital infection, abortion)infection, abortion)

IgG, IgM, and IgA are produced within IgG, IgM, and IgA are produced within 2 to 5 days2 to 5 days after infection ,The IgG crosses the placenta to after infection ,The IgG crosses the placenta to provide passive immunity to the fetus .provide passive immunity to the fetus .

All exposed pregnant women not having a history All exposed pregnant women not having a history of varicella of varicella should beshould be tested for antibody tested for antibody, , although most are immune although most are immune

Post-exposure pregnancy prophylaxis

(VZIG) is recommended within (VZIG) is recommended within 96 hours96 hours of exposure of a pregnant woman who is of exposure of a pregnant woman who is non-immune to VZV.non-immune to VZV.

VZIG is also recommended if it is not VZIG is also recommended if it is not possible to obtain antibody test results possible to obtain antibody test results within 96h.within 96h.

Post-exposure pregnancy prophylaxis

The dose recommended by the The dose recommended by the manufacturer is 125 U (1 vial) per 10 kg, manufacturer is 125 U (1 vial) per 10 kg, with a maximum of 625 U . with a maximum of 625 U .

No prospective studies evaluating the No prospective studies evaluating the efficacy of efficacy of VZIG or acyclovirVZIG or acyclovir for the for the prevention of congenital varicella.prevention of congenital varicella.

90% effective in preventing severe 90% effective in preventing severe varicella infection in exposed pregnant varicella infection in exposed pregnant women women

Varicella and pregnancy

Treatment for motherTreatment for mother : : Isolation, supportiveIsolation, supportive Monitor for pneumoniaMonitor for pneumonia oral acyclovir oral acyclovir (Class C drug by (Class C drug by

FDA)FDA) :administered at 24 hours after rash :administered at 24 hours after rash onsetonset

Early acyclovir has been used to limit the Early acyclovir has been used to limit the course of illness during pregnancy course of illness during pregnancy

2-Congenital Varicella

Caused by maternal infection in the 1st trimester to early 2nd trimester Greatest risk between 13-20 weeks

gestation Overall attack rate 1.2% Limb atrophy and scarring Chronic encephalopathy and corticalAtrophy, Chorioretinitis, micropthalmia,

cataract

Congenital Varicella

Prenatal diagnosis

Is difficult and invasive. Is difficult and invasive. Benefit/risk is lowBenefit/risk is low Noninvasive with ultrasound:Noninvasive with ultrasound:

cranial calcifications, porencephalic cysts, hepatic cranial calcifications, porencephalic cysts, hepatic calcifications ,echogenic bowel, ascites, calcifications ,echogenic bowel, ascites, hydrops, and polyhydramnios…hydrops, and polyhydramnios…

3-Neonatal Varicella

Transplacental exposure At risk when mother develops varicellafrom 5 days prior to 2 days after delivery Can manifest from 1-16 days after

delivery High risk for disseminated varicella Mortality rates as high as 30% Prognosis much better if lesions develop greater than 5 days after delivery

3-Neonatal varicella

of varying severity (mildof varying severity (mild systemic). systemic). Treatment with VZIG .Treatment with VZIG . VZIG does not prevent 100% of cases of VZIG does not prevent 100% of cases of

neonatal varicella neonatal varicella In one series : half of the infants who In one series : half of the infants who

received prophylaxis developed received prophylaxis developed chickenpox, though the severity of the chickenpox, though the severity of the infection was reduced infection was reduced

Nosocomial Transmission

Well documented in pediatric wards Rare in newborn nurseries

High risk infants: Premature infants (> 28 weeks gestation and

> 1000 grams) whose mother has no history of

varicella Premature infants (< 28 weeks gestation or

< 1000 grams) regardless of maternal history

Nursery control measures

-Siblings 14 years of age or less, check their -Siblings 14 years of age or less, check their immunization status. Siblings who have immunization status. Siblings who have not had chickenpox or the vaccine are not not had chickenpox or the vaccine are not allowed to visit, allowed to visit,

-Adult visitors who have been in contact with -Adult visitors who have been in contact with chicken pox(3 w) and/or unsure of their chicken pox(3 w) and/or unsure of their immune status must not visit until they are immune status must not visit until they are shown to be immune shown to be immune

Varicella Zoster ImmuneGlobulin (VZIG)

Provides passive immunity Not effective once active disease occurs Dosage: 125 units/10 kg Minimum dose: 125 units Maximum dose: 625 units Never administer intravenously Best given within 96 hours of exposure

Indications for VZIG (assumingsignificant exposure)

Susceptible pregnant women Newborn with onset of maternal varicella within

5 days prior through 2 days following delivery Hospitalized premature > 28 weeks gestation

and no maternal history of varicella Hospitalized premature < 28 weeks gestation or

<1000 grams regardless of maternal history

VZIG

Term infants exposed after 2 days of life areTerm infants exposed after 2 days of life are not at increased risknot at increased risk VZIG not indicatedVZIG not indicated All infants who receive VZIG should be inAll infants who receive VZIG should be in

strict isolationstrict isolation 50% of infants still develop varicella though50% of infants still develop varicella though

disease tends to be milderdisease tends to be milder VZIG may prolong incubation as long as 28 dVZIG may prolong incubation as long as 28 d

Isolation of the hospitalized patient

For Infected Mother:For Infected Mother: standard+ airborne+ contact precaution for standard+ airborne+ contact precaution for

a minimum 5d after the onset of the rash a minimum 5d after the onset of the rash till all lesions crusted.till all lesions crusted.

For neonates of infected mother:For neonates of infected mother: standard +airborne+ contact precaution till standard +airborne+ contact precaution till

21d if still hospitized(28 d if had IG)21d if still hospitized(28 d if had IG) For infant with congenital varicella:For infant with congenital varicella: No need for isolationNo need for isolation

Summary

Fortunately, varicella in pregnancy is Fortunately, varicella in pregnancy is relatively rare with only 1.2% Fetal attack relatively rare with only 1.2% Fetal attack rate ,nevertheless; complications rate ,nevertheless; complications (Maternal & fetal) can be severe. (Maternal & fetal) can be severe.

Treatment of neonatal form with VZIG .Treatment of neonatal form with VZIG . Remember the indications of VZIG.Remember the indications of VZIG.

The message for Obstetrician and internist

Prevention is Important:

Physicians caring for women have the Physicians caring for women have the

opportunity to prevent the complications of opportunity to prevent the complications of varicella by identifying and vaccinating varicella by identifying and vaccinating susceptible women.susceptible women.

With the introduction of the varicella With the introduction of the varicella vaccine and its efficacy, the rate of vaccine and its efficacy, the rate of varicella in pregnancy isvaricella in pregnancy is expected to expected to decrease dramatically.decrease dramatically.