varicella zoster virus

Varicella-Zoster Virus

Kaveh Haratian,Ph.D.

Medical Virologist

Department of Bacteriology and Virology

School of Medicine

Alborz University of Medical Sciences Oct 26, 2013


Varicella (chickenpox) acute, highly contagious viral disease with worldwide

distribution majority of annual costs*

80% to 85% of chickenpox : physician visits 85% to 90% of chickenpox : hospitalization most of which are related to productivity losses by

caregivers mainly a childhood disease

5 years of age : infection rate 50%

12 years of age : infection rate 90%

Health Canada. CCDR 1999;25(S5):1-29.


mostly a mild disorder in childhood

tends to be more severe in adults

It may be fatal

Neonates

Immunocompromised persons 4% to 13% of individuals who had previous varicella

infection : recurrences of varicella-like rash* The risk factors

young age (< 12 months) at first infection

a milder symptoms at first infection

*Hall S, et al. Pediatrics 2002;109:1068-73.


Fatality rates for varicella*

adults 30 deaths/100,000 cases

infants 7 deaths/100,000 cases

1-19 yr of age 1-1.5 deaths/ 100,000 cases

In the United States

adults account for only 5% of cases but for 55% of the approximately 100 chickenpox deaths each year

In Canada, from 1987 to 1996

70% of the 53 reported chickenpox deaths occurred in those > 15 years of age.

*Meyer PM, et al. J Infect Dis 2000;182:383-90. Preblud SR. Pediatrics 1981;68:14-7.

The pathogen

a double-stranded DNA virus : human herpesvirus-3 subfamily Alphaherpersvirinae

only one serotype is known

humans are the only reservoir VZV enters the host through the nasopharyngeal

mucosa, and almost invariably produces clinical disease in susceptible individuals

Following varicella, the virus persists in sensory nerve ganglia, from where it may later be reactivated to cause herpes zoster (Shingles)

Transmission

The virus is transmitted by

direct contact with the rash

Airborne respiratory droplets

vertical transmission (mother to baby) during pregnancy can transmit the virus for up to 48 hours before rash

appears and remains contagious until all spots crust over little genetic variation

no animal reservoir

visceral dissemination of the virus has occurred in 30% and mortality in 7% to 10% of these patients*

*Feldman S, et al. Pediatrics

1975;56:388.

Signs and symptoms

In healthy children

the disease is generally mild.

The illness usually appear 14–16 days after exposure

Incubation period 10-21 days

Prodromal symptoms : particularly in older children Low-grade fever preceding skin manifestations by 1-2 D 24-48 hr before rash

Mild abdominal pain

Mild cough and runny nose Mild headache

malaise or irritability

Signs and symptoms

red, itchy rash appear first on the scalp, face, trunk quickly turn into clear fluid-filled vesicles

24-48 hr later, clouding and umbilication of lesions

initial lesions are crusting, new crops form on trunk and then the extremities

Characteristics : various stages of evolution

oropharyngeal, vagina involvement : common

cornial involvement and serious ocular disease : rare

the average number of varicella lesion is about 300 lesions

<10 to >1,500 lesions Itching may range from mild to intense

Laboratory studies

unnecessary for diagnosis, obvious clinically

Immunohistochemical staining of skin lesion scrapings can confirm varicella A Tzanck smear : multinucleated giant cells

useful for high-risk patients who require rapid confirmation

not sufficiently sensitive or specific for varicella

more specific immunohistochemical staining of such scrapings, if available

Immunoglobulin M tests : not reliable, positive results indicate current or recent VZV activity

Redbook27th Ed;2006;711-725.

Immune response

Natural infection induces lifelong immunity to clinical varicella in almost all immunocompetent persons

Newborn babies of immune mothers are protected by passively acquired antibodies during their first months of life

Temporary protection of non-immune individuals can be

obtained by injection of varicella-zoster immune globulin

within 3 days of exposure

The immunity acquired in the course of varicella prevents

neither the establishment of a latent VZV infection, nor the possibility of subsequent reactivation as zoster.

Immune response

Antibody assays : indication of previous infection or response to vaccination less reliable as correlates of immunity, particularly to zoster failure to detect antibodies against VZV does not

necessarily imply susceptibility, as the corresponding cell-mediated immunity may still be intact

20% of persons aged 55–65 show no measurable cell-mediated immunity to VZV in spite

of persisting antibodies, and a history of previous varicella Zoster is closely correlated to a fall in the level of VZV-

specific T-cells

an episode of zoster will reactivate the specific T-cell response

High-risk groups

High risks of complications Newborns and infants whose

mothers never had chickenpox or the vaccine

Teenagers Adults Pregnant women

People whose immune systems are impaired by another disease or condition

People who are taking steroid medications for another disease or condition, such as asthma

People with the skin inflammation eczema

Complications of Varicella

herpes zoster (shingles) lifetime risk 15%-20% mainly affecting the

elderly and immunocompromised persons

secondary bacterial skin and soft tissue infections

otitis media bacteremia, pneumonitis osteomyelitis septic arthritis

endocarditis necrotizing fasciitis toxic shock-like syndrome hepatitis thrombocytopenia

hemorrhagic varicella cerebellar ataxia encephalitis severe invasive group A

streptococcal infection increases the risk 40-60 fold*

*Health Canada. CCDR 1999;25(S5):1-29. Davies HD, et al. N Eng J Med 1996;335:547-54.

Complications of Varicella

When compared with children, adults are

3 to 18 fold higher risk : admitted to hospital for varicella

11 to 20 fold higher : higher rates of complications such as pneumonia

1.1- to 2.7-fold higher : encephalitis* The risk factors identified in adults for varicella pneumonia

underlying chronic lung disease

Smoking** varicella pneumonia occurring in 3.4% to 9.3% of pregnant

women (no higher than in nonpregnant adults)*** High mortality *Choo PW, et al. J Infect Dis 1995;172:706-12

**Ellis ME, et al. Br Med J 1987;294:1002. ***Harger JH, et al. Obstet Gynecol 2002;100(2):260-65.

Neonatal varicella

can be a serious illness, depending upon

the timing of maternal varicella and delivery

If the mother develops varicella within 5 days before or 2 days after delivery acquires the virus transplacentally no protective antibodies

Prophylaxis or treatment is required with varicella-zoster immune globulin (VZIG) and acyclovir

Without these drugs, mortality rates 20% - 30%*

The primary causes of death are severe pneumonia and

fulminant hepatitis

*Derrick CW Jr, et al.South Med J 1998 Nov; 91(11): 1064-6.

Neonatal varicella

Onset of maternal varicella more than 5 days antepartum provides the mother sufficient time to manufacture and

pass on antibodies along with the virus. Full-term neonates : usually have mild varicella Treatment with VZIG is not recommended, but

acyclovir may be used, depending on individual circumstances

Derrick CW Jr, et al.South Med J 1998 Nov; 91(11): 1064-6.

Congenital varicella syndrome

gestational varicella : currently no evidence associated increase in spontaneous abortion, stillbirth, or prematurity transplacental or perinatal infection can have other serious

outcomes.

0.4% of live births when maternal infection occurred from conception through the 12th week of gestation

2% when infection occurred between the 13th and 20th week of gestation*

A smaller, prospective study of 347 women who had varicella during pregnancy found an overall congenital varicella syndrome rate of 0.4%**

*Enders G, et al. Lancet 1994;343:1547-50. **Harger JH, et al. Obstet Gynecol 2002;100(2):260-65.

Congenital varicella syndrome

maternal infection with chickenpox (maternal varicella

zoster) early during pregnancy (i.e., up to 20 weeks

gestation)

The range and severity of associated symptoms and

physical findings may vary greatly from case to case

depending upon when maternal varicella zoster infection occurred during fetal development

Stigmata of Varicella-Zoster Virus Fetopathy

Damage to Sensory Nerves

Cicatricial skin lesions

Hypopigmentation

Damage to Optic Stalk and Lens Vesicle

Microphthalmia

Cataracts

Chorioretinitis

Optic atrophy

Damage to Brain/Encephalitis Microcephaly

Hydrocephaly

Calcifications

Aplasia of brain

Damage to Cervical or Lumbosacral Cord Hypoplasia of an extremity

Motor and sensory deficits

Absent deep tendon reflexes

Anisocoria

Horner’s syndrome Anal/urinary sphincter dysfunction

Nelson, Textbook of Pediatrics.17th ed;246:973-977.

Type of exposure

Household

Playmate: face to face, indoor play

Hospital

Varicella : same 2-4 bed room, adjacent beds in a large ward

Zoster : intimate contact with a person deemed contagious

NB : mother had onset of chickenpox within 5 days

before delivery or within 2 days after delivery

VariZIG is indicated for susceptible people

Redbook27th Ed;2006;711-725.

Postexposure Immunization

Varicella vaccine

Susceptible people > 12 mo of age, including adults

As soon as possible within 72 hr and possibly up to

120 hr after varicella exposure

To prevent or modify disease

Recommendations of the Advisory Committee on Immunization Practices. MMWR 2006;55:209-210.

Chemoprophylaxis

If VariZIG is not available or > 96 hr after exposure

Oral Acyclovir (some experts recommend)

80 mg/kg/day divided 4 times/day for 7 days

Start on day 7-10 after varicella exposure

if vaccine is contraindicated

Susceptible immunocompromised adults Limited data on acyclovir as postexposure prophylaxis

in healthy children


Passive immunoprophylaxis

VZIG : cessation of manufacture,2005

VariZIG (Varicella-Zoster Immune Globulin)

125 U/10 kg IM, Maximum dose 625U

lessen the severity of the disease

Likelihood that the exposed person is susceptible to varicella

Probability that a given exposure to varicella or zoster will result in

infection

Likelihood that complications of varicella will develop if person

is infected

If VariZIG is not available, choose IGIV (Immune Globulin

Intravenous)


Passive immunoprophylaxis

VariZIG should be administered as soon as possible, but no later than 96 hours after exposure

Newborns whose mothers have chicken pox five days prior to two days after delivery

Children with leukemia or lymphoma who have not been vaccinated

Persons with cellular immunodeficiencies or other immune problems

Persons receiving drugs, including steroids, that suppress the immune system

Pregnant women


Candidates for Acyclovir or VariZIG

Immunocompromised children without Hx.of varicella

or varicella immunization

NB : mother had onset of chickenpox within 5 days

before delivery or within 2 days after delivery

Hospitalized preterm infants (GA 28 wks) whose

mother lack Hx or serology of varicella

Hospitalized preterm infants (GA < 28 wks or BW

< 1000gm) regardless Hx of varicella or zoster serostatus

Redbook27th Ed;2006;711-725.

Treatment

Healthy children

no medical treatment

antihistamine to relieve itching

IV Acyclovir (nucleoside analogues)

< 1 yr 30 mg/kg/day in 3 divided doses for 7-10 days > 1 yr 1500 mg/m2/day divided q 8 h for 7-10 days Immunocompromised patients Patients being treated with chronic corticosteroids

medications to shorten the duration of the infection

help reduce the risk of complications


Treatment Oral Acyclovir (Category B drug)

80 mg/kg/day divided in 4 doses for 5 days, Max dose 3200 mg/day (* some experts recommend)

Healthy people at increased risk of moderate to severe varicella

> 12 yr of age

Chronic cutaneous or pulmpnary disorders

Receiving long-term salicylate therapy

Receiving short, intermittent, or aerosonized courses of

corticosteroids

*Secondary household cases

(disease usually is more severe than in primary case)

*Pregnancy, especially during the second and third trimesters

*HIV-infected patients with relatively normal CD4+ T-lymphocytes

*Leukemia in whom careful follow-up


Treatment

Valacyclovir and Famciclovir

approved for use only in adults

Complicated cases

Hospitalization

skin infections and pneumonia : antibiotics encephalitis : antiviral drugs

Don't give Aspirin : Reye's syndrome.


http://www.mayoclinic.com/health/chickenpox/DS00053/DSECTION=5

Care of Hospital Exposure

Identify those who are susceptible: both personel and patients

immunocompromised patient

immunocompetent patient who:

< 6 month old without maternal history of chickenpox

> 6 month old with unimmunized/unvaccinated

All exposed susceptible patients should be discharged as soon as possible.

All susceptible patients who cannot be discharged should be placed in airborne and contact precaution from day 10-21 after exposure.(28 day who received VariZIG)

Redbook27th Ed;2006;711-725.

Care of Hospital Exposure

All susceptible exposed staff should be furloughed from

day 8-21 post exposure to an infectious patient. (28 day

who received VariZIG)

Serologic testing for immunity is not necessary for

personel who have been immunized

Immunizaed health care personel who develop

breakthough infection should be considered infectious

Varicella immunization is recommended for susceptible personnel if there are no contraindications to vaccine use

Redbook27th Ed;2006;711-725.

A Varicella Zoster outbreak among Thai healthcare workers

45 yrs-old, Thai woman, admitted to Thammasart

Hospital ICU because of CAP

Day 11, she develop chicken pox Healthcare workers IgG + IgG -

Hx of Varicella + 23 0

Hx of Varicella - 30 47

Sensitivity = 23/53 = 43%

Specificity = 17/17 = 100%

PPV = 23/23 = 100% NPV = 47/77 = 61%

Sereprevalence

•>90% adults seropositive (in general)

•History of Varicella 97-99% predictive of antibodies •Negative or uncertain history 79-93% seropositive

Apisarnthanarak A, et al. Infect Control Hosp Epidemio,2007

Isolation of the hospitalized patient

Standard precautions, airborne and contact precaution

Recommended for patients with varicella for a minimum of 5 days

after onset of rash and until all lesions are crusted

For exposed susceptible patients

Airborne and contact precautions from 10-21 days after exposure

to index patient (28 days for those who received VariZIG or IGIV)

For neonates born to mothers with varicella and, if still

hospitalized, should be continued until 21 or 28 days of age if they received VariZIG or IGIV Airborne and contact precautions

Redbook27th Ed;2006;711-725.

Who should get chickenpox vaccine?

all susceptible children and adults

A second dose catch-up varicella vaccination is recommended for

children, adolescents, and adults who previously had received only one dose

exposed to chickenpox may receive varicella vaccine within 3 days (72 hours) to 5 days (120 hours) prevent or diminish the severity of illness

National Foundation for Infectious Diseases.USA. August 2006

Who should get chickenpox vaccine? special consideration in Adults

not received the vaccine not already had chickenpox higher risk for exposure/transmission

College students Household contacts of immunocompromised persons Residents and staff in institutional settings Inmates and staff of correctional institutions International travelers Military personnel Nonpregnant women of childbearing age Teachers and day care workers Non-immune persons

National Foundation for Infectious Diseases.USA. August 2006

Prevention

The attack rate in unvaccinated susceptible children was 88%

The varicella vaccine is the best way to prevention CDC estimate complete protection from the virus for

nearly 90% Unvaccinated older children

7-13 yr receive two catch-up doses of the varicella vaccine

at least 3 mo apart > 13 yr

receive two catch-up doses of the varicella vaccine

at least 4 wks apart

CDC. MMWR 2005 Jul 29; 54(29): 717-21.

Prevention

Unvaccinated adults who've never had chickenpox but are at high risk of exposure

If you don't remember whether you've had chickenpox or the vaccine, a serum antibody test

If you've had chickenpox, you don't need the vaccine

CDC. MMWR 2005 Jul 29; 54(29): 717-21.

Varicella vaccine

Oka strain of VZV since 1974

a single dose of vaccine : seroconversion 95% optimal age for varicella vaccination is 12–24 months In Japan and several other countries

one dose of the vaccine : sufficient, regardless of age In the United States

two doses, four to eight weeks apart

Recommendation for adolescents and adults

after the first dose : seroconversion 78%

after the second dose : seroconversion 99%

Hall S, et al. Pediatrics 2002;109:1068-73

Asano Y, et al. Biken J 1980;23:157-61.

Varicella vaccine

Varicella outbreak in a day-care center

efficacy 100% in preventing severe disease

86% in preventing all disease

From the Japanese experience

immunity to varicella following vaccination lasts for at least 10–20 years

In the United States : routine vaccination Since 1995

70%–90% protection against infection

> 95% protection against severe disease 7–10 years after immunization*

*Clements DA, et al. Pediatr Infect Dis J 1999;18:1047-50. Vasquez M, et al. N Eng J Med 2001;344:955-60. Izurieta H, et al. JAMA 1997;279:1495-99.

Varicella vaccine

In immunocompromised persons, including patients with advanced HIV infection contraindication : fear of disseminated vaccine-induced

disease Vaccine safety

asymptomatic HIV-infected children with CD4 counts of more than 1,000 cell/μL

patients with leukaemia in remission or solid tumours before chemotherapy

uremic patients waiting for transplantation a killed varicella vaccine has been studied in VZV-positive

bone marrow transplant patients where a multiple-dose schedule has been reduce the severity of zoster

A Vaccine to prevent Herpes Zoster and Post-herpetic Neuralgia in older adults

Randomized, double-blind, placebo-controlled trial of an investigational live attenuated Oka/Merck VZV vaccine enrolled 38,546 adults 60 years of age or older burden of illness due to herpes zoster, a measure affected by the

incidence, severity, and duration of the associated pain and discomfort

secondary end point was the incidence of postherpetic neuralgia

Results > 95 % of the subjects continued in the study to its completion a median of 3.12 years of surveillance for herpes zoster. A total of 957 confirmed cases of herpes zoster

(315 among vaccine recipients and 642 among placebo recipients)

NEJM2005;352:2271-2284.

A Vaccine to prevent Herpes Zoster and Post-herpetic Neuralgia in older adults

107 cases of postherpetic neuralgia (27 among vaccine recipients and 80 among placebo recipients) were included in the efficacy analysis.

zoster vaccine reduced the burden of illness due to herpes zoster by 61.1% (P<0.001)

reduced the incidence of postherpetic neuralgia by 66.5% (P<0.001), and reduced the incidence of herpes zoster by 51.3% (P<0.001)

Reactions at the injection site were more frequent among vaccine recipients but were generally mild

Conclusions The zoster vaccine markedly reduced morbidity from

herpes zoster and postherpetic neuralgia among older adults

NEJM2005;352:2271-2284.

Breakthrough Varicella

Varicella in persons who have received the vaccine

less severe than the disease in unvaccinated individuals

3% to 4% per year after varicella vaccination 5% to 20% after household exposure to wild-type virus. The risk that vaccinated individuals with breakthrough

disease will infect others appears to correlate with the number of lesions that develop. > 50 lesions were equally as likely to transmit the

infection to household contacts < 50 lesions were only half as likely to transmit the

infection (J. Seward, Centers for Disease Control and Prevention, Atlanta: personal communication)

NEJM 2001;344:955-60. JAMA 1997;279:1495-99. Pediatrics 1999;104:561-63.

Comparison of severity of varicella

symptoms in naturally infected children and varicella vaccine recipients

Nagai T. Clin Virol 1997;25:271-81.

Vaccine associated adverse events

Varilix® GlaxoSmithKline

In children < 13 years of age In adolescents and adults

Adverse effects

local pain, redness and

swelling 11% - 22%

Varicella-like rash 1%

other rash types 10%

Reactions at the injection

site tended to be mild and transient Fever 11%

the first and second doses

local symptoms

12% and 16%

fever 29% and 20%

varicella-like rash

0.9% and 1.3%

Product monograph. Varilix®. GlaxoSmithKline, September 12, 2002.

Risk of clinical reactions of Oka strain varicella vaccine

Asano Y. J Infect Dis 1996;174Suppl3:S310-3.

Vaccine associated adverse events

In healthy children

27% : local swelling and redness at the site of injection < 5% : a mild varicella-like disease with rash within 4 wks rare occasions of mild zoster following vaccination

Since licensure and distribution of more than 10 million doses of vaccine in the United States, the Vaccine Adverse Event Reporting System (VAERS) reports of

encephalitis, ataxia

pneumonia

thrombocytopenia

arthropathy and erythema multiforme

These events may not be causally related and they occur at much lower rates than following natural disease

A tetravalent vaccine with the combined measles-mumps-rubella vaccine

Immune response

VZV IgG

Varicella vaccine MMRV vaccine

(ProQuad)

6 wks after dose 1 85.7% 91.2%

6 wks after dose 1 and

3 mos between doses

99.6% 99.2%

6 wks after dose 2

at age 4–6 yrs

99.4% 98.9%

1.Kuter B, et al. Pediatr Infect Dis J 2004;23:132–7. 2.Shinefield H, et al. Pediatr Infect Dis J 2005;24:665–9. 3.Reisinger KS, et al. Pediatrics 2006;117:265–72.

Humoral and cellular immune response among children aged 12 months–12 years measured at 6 weeks postvaccination, by vaccine type and vaccination schedule — United States, 1988–2002

Contraindications for Varicella vaccine

a history of anaphylactic reactions to any component of the vaccine including neomycin

pregnancy due to theoretical risk to the fetus

pregnancy should be avoided for 4 wks following vaccination

ongoing severe illness, and advanced immune disorders of any type except for patients with acute lymphatic leukaemia in

stable remission ongoing treatment with systemic steroids

for adults more than 20 mg/day

for children more than 1mg/kg/day

American Hospital Formulary Service (AHFS) Drug Information 1997, p.2653-2655.

Contraindications for Varicella vaccine

A history of congenital immune disorders in close family members is a relative contraindication both varicella-zoster immune globulin (VZIG) and antiviral

drugs are available should persons in the immunocompromised categories receive the vaccine by mistake

Administration of blood, plasma or immunoglobulin

< 5 mo before immunization or

3 wks afterwards

reduce the efficacy of the vaccine use of salicylates is discouraged for 6 wks following

varicella vaccination : risk of Reye syndrome American Hospital Formulary Service (AHFS) Drug Information 1997, p.2653-2655.

Between 1995 and 2004 : Researchers from the Centers for Disease Control and Prevention (CDC) and the Los Angeles Department of Health Services looked at data on 350,000 Californians > 11,000 people who developed chickenpox, almost

1,100 had been vaccinated The study also found that 8- to 12-year-olds who

contracted chickenpox after being vaccinated at least 5 years earlier were twice as likely to have "moderate or severe" cases than those who had gotten the vaccine less than 5 years before.

early on with just one dose may still develop chickenpox at an older age, when the illness may be more severe

Study : Single Dose of Varicella Vaccine Not Enough


Randomized clinical trial : compared the efficacy of 1 dose of vaccine with that of 2 doses

the cumulative rate of breakthrough varicella during a 10-year observation period

was 3.3-fold lower among children who received 2 doses than that among children who received 1 dose (2.2% and 7.3,respectively; p<0.001)

Breakthrough cases occurred occasionally in 0.8% of 2-dose vaccine recipients.

Kuter B, et al. Pediatr Infect Dis J 2004;23:132–7.


The majority of cases of breakthrough disease occurred 2–5 years

after vaccination; no cases were reported 7–10 years after vaccination

Of 16 children with breakthrough cases, three (19%) had >50 lesions.

The proportion of children with >50 lesions did not differ between the 1-dose and 2-dose regimens (p = 0.5).

In 2006, the CDC recommended

First dose at 12 - 15 mo of age a booster dose at 4 - 6 yr old

Kuter B, et al. Pediatr Infect Dis J 2004;23:132–7.

Category 1996 recommendations

1999 recommendations


Routine

childhood

schedules

1 dose

recommended at

age 12–18months

No change 2 doses recommended

• 1st dose at age 12–15 months

• 2nd dose at age 4–6 years

Adults and

adolescents

aged >13 years

2 doses, 4–8 weeks apart


No change

Recommended


Recommended for all

adolescents and adults

without evidence of immunity

Catch-up

vaccination 1 dose recommended for all susceptible

children aged 19

months–12 years

(i.e., those with no history of varicella or

vaccination)

No change 2nd dose recommended for all

persons who received 1 dose previously

Recommendations of the Advisory Committee on Immunization Practices (ACIP):MMWR,June 22, 2007 / Vol. 56 / No. RR-4

Category 1996 recommendations



HIV-infected

persons

Contraindicated

2 doses, 3 months

apart

Considered for

asymptomatic

or CDC N1 or A1

or CD4+ >25%

2 doses, 3 months

apart

Considered for

CD4+ >15%

Outbreak

control

vaccination

None Should be

considered

Recommended 2 dose

vaccination policy

Postexposure

vaccination

Vaccination

requirements

None

None

Recommended within 3–5 days

Recommended for

children without

evidence of immunity

attending child

care centers and

entering elementary

school

No change

Recommended for

children attending

child care centers,

students in all grade

levels and persons

attending college

Recommendations of the Advisory Committee on Immunization Practices (ACIP):MMWR,June 22, 2007 / Vol. 56 / No.

RR-4

Herpes Zoster

rash usually resolves within 14-21 days

Postherpetic neuralgia pain persisting at least 1 month after the rash has healed incidence increases dramatically with age

4% in aged 30-50 years 50% in older than 80 years

Immunocompetent host

all ages : same as Varicella in imunocompromised host > 12 yr : Acyclovir 4,000 mg/day in 5 divided doses for 5-7 days

Immunocompromised children < 12 yr : Acyclovir 60 mg/kg/day IV q 8 hr, for 7-10 days > 12 yr : Acyclovir 30 mg/kg/day IV q 8 hr, for 7 days

Redbook27th Ed;2006;711-725.

Herpes Zoster

the boosting of cell-mediated

immunity by exposure to wild-type varicella infection

reduces the risk of zoster in adults*

The adults with the most

contact with children had roughly one-fifth the zoster

risk of those with the least contact with children**

**Levine MJ, Vaccine 2000;18(25):2915-20.

*Solomon BA, et al. J Am Acad Dermatol 1998;38:763-65. Thomas SL, et al. Lancet. URL: 2 July, 2002.

Infantile zoster

Infantile zoster usually manifests within the first yr

The cause is maternal

varicella infection after the 20th week of gestation

commonly involves the thoracic dermatomes

NEJM1994 Mar 31; 330(13): 901-5.

Complications of Herpes Zoster

Postherpetic neuralgia

Ocular involvement with facial zoster

Meningoencephalitis

Cutaneous dissemination

Superinfection of skin lesions

Hepatitis/pneumonitis Peripheral motor weakness/segmental myelitis

Cranial nerve syndromes, particularly ophthalmic and facial (Ramsay Hunt syndrome)

Corneal ulceration

Guillain-Barré syndrome

Ann Neurol 1994; 35 Suppl: S4-8.

Isolation of the hospitalized patient

Immunocompromised patient who have zoster (localized

or disseminated) and immunocompetent patients with

disseminated zoster

Airborne and contact precautions for the duration of

illness

For immunocompetent patients with localized zoster

Contact precautions until all lesions are crusted

Redbook27th Ed;2006;711-725.

National Advisory Committee on Immunization. CCDR 2002;28(ACS-3):1-7.

Management of chickenpox in pregnancy

Management of significant exposure* to varicella zoster virus (VZV) during pregnancy

Immunoglobulin Interval (months)

HBIG

RIG

Measles prophylaxis

standard

immunocompromised

VZIG

Blood transfusion

Washed RBCs

RBCs, adenine saline added

Packed RBCs

Whole blood

Plasma and platelet

Replacement of immune deficiency (IVIG)

ITP

400 mg/kg

1,000 mg/kg

1,600-2,000 mg/kg

Kawasaki disease

3

4

5

6

5

0

3

5

6

7

8

8

10

11

11

THANK YOU

varicella zoster virus

Health & Medicine