Hsv ppt (2)
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HSV IN NEONATES
Overview
Introduction
Epidemiology
Patho-physiology
Risk Factor
Clinical features
Diagnosis
Treatment
Prognosis
Introduction - history
“Herpes” – from the Greek “to creep, crawl”
“Herpetic eruptions” were described as early as 100 AD
1960’s – HSV1 and HSV2 differentiated
Introduction
Herpes simplex virus(HSV) -ubiquitous, enveloped &
Ds- DNA virus
belongs to Herpesvirdae family
Man is the only Host
Two types HSV -1, 2
HSV-1- oral infections (gingivo-stomatitis and
pharyngitis)
HSV-2- genital herpes
- predominant cause of neonatal herpes
AVERY’S DISEASES
OF THE NEWBORN 19th
edition
HSV
Alfa-herpesviruses : eg Herpes Simplex Virus, Varicella
Zoster virus
Beta-herpesviruses : eg. Cytomegaloviruses
Gama-herpesviruses: eg. Epstein-Barr virus
Textbook of Microbiology 8th Edition Ananthanarayan and Paniker’s
Terminology-
Primary infection:- acquisition of HSV-1 or 2 without prior
exposure to either virus.No preformed antibodies.
Nonprimary infection:- acquisition of HSV 2 infection in an
individual with prior HSV-1 antibodies or vice-versa.
Reactivation:-it is the isolation of same type of virus from
genital lesions as that of pre-existing antibodies.
Nelson 20th
edition
uncommon but potentially fatal
>90% cases- maternal-fetal transmission
Incidence-1/ 3,000-5,000 live births, higher than
syphilis,rubella,toxoplasmosis and rubella
30% of mothers of affected infant - history of genital
herpes
Neonatal herpes
Epidemiology
worldwide prevalence of HSV 2 seropositivity- high (25% in
US)
Antibodies to HSV-2 -approximately 20% of pregnant women
5 % report a history of symptomatic infection
Infection Rate during pregnancy similar to non-pregnant
women,
often asymptomatic
Seroconversion rate in pregnant women- 2-3%
Transmission occur from asymptomatic patients shedding the
virus
Symptomatic and asymptomatic primary genital HSV
infections are associated with the preterm labor and LBW
infants American family physician neonatal Herpes Simplex Virus Infections volume65, november6/march15,2002
Factors influencing transmission of HSV to
neonate:-
type of maternal infection (higher for primary i.e.30% vs 2%)
maternal antibody status
mode of delivery(vaginal/caesarean section)
duration of rupture of membranes
type of HSV(1 or 2)
Pathophsiology
Viral infection begins at a cutaneous portal of entry.
Virus replicates locally, resulting in the death of the cell
inflammatory response herpetic vesicles and ulcers
Virus also enters nerve endings and spreads beyond the
portal of entry to sensory ganglia by intra-neuronal
transport
Many sensory neurons infected during initial infection
(latent infection)
Pathophysiology
Virus replicates in some sensory neurons
progeny virions send back to periphery
released from nerve endings
replicate further in skin or mucosal surface
Viremia, does not appear to play an important role in HSV
infections
in the immunocompetent host but can occur in neonates,
can result in dissemination of the virus to visceral organs
Pathogenesis of HSV infection in newborns – complicated, not well
understood
Risk factors
Transmission generally occurs during delivery, (may even occur with LSCS with intact fetal membranes)
The most common portals of entry - conjunctiva, mucosal epithelium of the nose and mouth, and breaks or abrasions in the skin that occur with scalp electrode use or forceps delivery.
Intraneuronal transport to the central nervous system -cause encephalitis
Hematogenous spread- to visceral organs and the brain
May occur intra- partum or post-natally
American family physician neonatal Herpes Simplex Virus Infections volume65, november6/march15,2002
Salient features of HSV
infection
The hallmarks of HSV infections are skin vesicles and shallow ulcers
Acute oropharegeal infections
Herpes labialis
Cutaneous infestations genital herpes
Ocular infestation
CNS manifestations
Infection in immunocopromised persons
Perinatal infection
VESICULAR LESIONS HSV
Clinical Features In Neonates
Pre term delivery, LBW
Congenital HSV infection (4%) rare entity and occurs
approximately in 1 in 300,000 deliveries.
Affected babies present with a triad :-
(1)cutaneous- scarring, rash, pigmentation, aplasia cutis
(2)opthalmologic- micropthalmia,chororetinitis,optic
atrophy
(3)neurologic- microcephaly, neurologic calcifications and
encephalomalacia.
American family physician neonatal Herpes Simplex Virus Infections volume65, november6/march15,2002
CLINICAL FEATURES
Presentation non specific
Three subtypes-
1) Disease localize to the skin, eye or mouth; (50%)
2) Encephalitis, with or without skin, eye or mouth involvement; (33%)
3) Disseminated infection that involves multiple sites, including the CNS, lung, liver, adrenals, skin, eye or mouth (17%)
Ocular manifestation
broad spectrum- ranging from mild superficial lesions involving the
external eye, to severe sight-threatening diseases of the inner eye-
Primary HSV keratitis – dendritic ulcers
Recurrent HSV keratitis
HSV conjunctivitis
Iridocyclitis, chorioretinitis and cataract
COMPLICATIONS-
Corneal complications range from epitheliopathy to frank
neurotrophic or metaherptic ulcers.
Long standing disciform keratitis- bullous keratopathy.
deep vascular stromal scarring include secondary lipid
keratopathy.
Finally, stromal inflammation may lead to visually significant
corneal scarring and irregular astigmatism.
Herpes simplex virus type 2 mediated acute retinal necrosis in a
pediatric population: case series and review
( Ruwan et al, Graefes Arch Clin Exp Ophthalmo (2013)
Retrospective, observational case series
CASES- patients (15 eyes) all aged upto21 years with ARN
resulting from HSV-2 and examined between 1995 and 2009. Mean
age of presentation was 11.7 years . Mean initial vision was 20/200
DIAGNOSIS- (PCR) of aqueous, vitreous, and serum, antibody
determination of serum and intraocular fluids, fundoscopic exam,
therapeutic trial of antivirals active against HSV-2, or a combination
thereof.
INTERVENTION- 11 pts received steroids, 14 received antiviral
therapy
RESULTS- mean final visual acuity 20/400, worsen in 5 eyes
-Anatomically, 14 of 15 eyes had healed or improved retinal
appearance.
CONCLUSIONS-In a pediatric population with ARN, HSV-2 should
be considered as the prime candidate. Prompt diagnosis may lead
to appropriate anti-viral therapy.
DIAGNOSIS
Hallmark of primary genital Herpes- multiple painful
vesicles in clusters on inflamed surface ass with pruritis,
dysuria, vaginal discharge and tender regional
lymphadenopathy
Clinical diagnosis should be confirmed by laboratory
test
Isolation of virus or viral DNA detection by polymerase
chain reaction (PCR) in CSF/blood
Viral culture –GOLD STANDARD
should include cultures of suspicious lesions as well as
eye and mouth swabs
AVERY’S DISEASES OF THE NEWBORN 19th edition
Diagnosis
When to suspect HSV in an infant??
all neonates who present in 1st mth of life with non- sp.
Symptoms
any vesicular rash upto 8 wks of age
body fluids – culture for HSV
Clinical and laboratory features of neonatal HSV
infection : A. chantel Caviness et al, Pediatric Infectious Disease Journal, 2008
Case control study to identify clinical and laboratory features of neonates with and without HSV infection admitted to Texas Children's Hospital during a 14-year period.
Univariate and multivariate analyses were performed to identify clinical and laboratory factors associated with neonatal HSV infection.
Forty cases and 160 comparison subjects were identified.
maternal primary HSV infection, maternal fever, vaginal delivery, prematurity, postnatal HSV contact, vesicular rash, hypothermia, lethargy, seizures, severe respiratory distress, hepatosplenomegaly, thrombocytopenia, elevated hepatic enzymes, and cerebrospinal fluid (CSF) pleocyosis and proteinosis, were found to be associated with neonatal herpes infection
Factors not associated were fever, total peripheral white blood cell count, and red blood cells in the CSF.
For neonates presenting without vesicular rash, maternal fever, respiratory distress requiring mechanical ventilation, and CSF pleocytosis were independently associated with HSV infection.
Treatment
The cornerstone of the treatment of neonatal HSV-
Parental Acyclovir
Dosage- 60 mg/kg/d in 3 div. doses iv x14 d for skin,
eyes, and mucous membrane inv.
-same dose for 21 days- CNS/ Disseminated
disease
High safety profile- non teratogenic
Selective against HSV infected cells
At the end of therapy CSF PCR should be done in all
the neonates, If positive, the therapy is continued till the
PCR comes negative.
Study states that detection of HSV in CSF after
completion of treatment has been associated with
poorer outcomes
American family physician neonatal Herpes Simplex Virus Infections volume65, november6/march15,2002
Treatment
Topical Trifluorothymidine, Vidarabine, and Idoxuridine-
herpes keratitis. Steroids - contraindicated
All primary episodes of genital HSV infections should be
treated (Aciclovir, Famciclovir, Valacyclovir) (ACOG)
MOA- inhibits viral replication
Prophylactic Acyclovir- considered in the third trimester
for women who have a primary episode of genital HSV
LSCS does not completely remove the risk of
transmission
Rupture of membranes for more than 4 to 6 hours
before delivery increases the risk.
HSV VACCINE
HSV 2 vaccine has been developed,but its efficacy in
previously sero positive individuals is not reported.
Currently no vaccine has proved to be effective.
Prevention of maternal HSV acquisition during pregnancy:-
- To screen all couples for HSV serology at 14 to 18 weeks of
gestation.
-Abstain from sexual contact in third trimester.
Prognosis
MORTALITY- skin, eyes and mouth- no mortality
- Encephalitis- 15%
-Disseminated disease-57%, even with
antiviral therapy
Long term morbidity is common in survivors and
includes -seizure, psychomotor retardation, spasticity,
blindness or learning disabilities
Take Home Message
HSV infection common in women of reproductive age
Can transmit infection even if asymptomatic
Can be contracted and transmitted to the fetus during
pregnancy/ postnatally
Varied presentation- mortality, morbidity varies