Laboratory Lab results are too important to go anywhere else.

Herpes Simplex Virus, Neonate Surface Screen

HSV, PCR, Culture, nucleic acid amplification, Neonatal, maternal, genital, shedding, intrapartum, postpartum, conjunctivae, mouth, nasopharynx, rectum

Test Codes

WARDE: HSVC, EPIC: LAB7086, Beaker: NHSVG

Department

Molecular Pathology

Specimen Collection Criteria

• Use a single swab to collect clinical “surface material” from the conjunctivae, mouth, nasopharynx and lastly the rectum.  If desired, a separate swab can be used for the rectum.

• Place the swab(s) into a single tube of viral transport media (UVT, UTM). MedSchenker Smart Transport Media (STM) is acceptable. *Please call the Molecular laboratory if you need the correct collection media sent.

Physician Office/Draw Specimen Preparation

• Maintain specimen refrigerated (2-8°C or 36-46°F) prior to transport.
• Do not freeze specimens. 

Preparation for Courier Transport

Transport: refrigerated (2-8°C or 36-46°F).

Rejection Criteria

• Frozen specimens.
• Specimens with gross bacterial contamination.
• Specimens not received in viral transport media.
• Specimens received in Ruhof media are not acceptable for HSV culture.

 

In-Lab Processing

Do not freeze specimens. Refrigerate (2-8°C or 36-46°F) specimens if testing will not be performed within 4 hours of the time of collection.

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

PCR Testing  
Royal Oak Clinical Molecular Pathology Laboratory.

Culture Testing  
Sent to Warde Medical Laboratory, Ann Arbor, MI.

Performed

PCR
Sunday – Saturday.
Results available within 24 hours (PCR). 

Culture
Monday – Saturday
Results available 3-6 days.

Reference Range

PCR – Negative.
Culture – Not Detected.

Test Methodology

Real-Time Polymerase Chain Reaction (PCR). Rapid Shell Vial Culture.

Interpretation

A negative result does not rule out HSV infection.

Clinical Utility

The American Academy of Pediatrics recommends performing newborn “surface cultures” when the mother has active herpes lesions.  Although virus culture is the preferred test method, nucleic acid amplification (i.e. PCR) is more sensitive and provides test results more rapidly. This test incorporates both PCR and culture testing, and is an optimal testing strategy in this clinical situation.

Clinical Disease

HSV infection of the newborn infant is acquired during 1 of 3 distinct times: intrauterine (in utero), intrapartum (perinatal), and postpartum (postnatal). The time of transmission of HSV-1 or HSV-2 for the overwhelming majority of infected infants (∼85%) is in the intrapartum period. An additional 10% of infected neonates acquire HSV-1 postnatally from either a maternal or nonmaternal source, and the final 5% are infected with HSV-2 or HSV-1 in utero.

Five factors known to influence transmission of HSV from mother to neonate are: (1) type of maternal infection (primary vs. recurrent), (2) maternal HSV antibody status, (3) duration of rupture of membranes, (4) integrity of mucocutaneous barriers (e.g. use of fetal scalp electrodes), (5) mode of delivery (cesarean vs. vaginal delivery). Infants born to mothers who have a first episode of genital HSV infection near term and are shedding virus at delivery are at much greater risk of developing neonatal herpes than are infants whose mothers have recurrent genital herpes.

The largest assessment of the influence of type of maternal infection on likelihood of neonatal transmission is a landmark study involving almost 60,000 women in labor who did not have clinical evidence of genital HSV disease, approximately 40,000 of whom had cultures performed within 48 hours of delivery. Of these, 121 women were identified who were asymptomatically shedding HSV and who had sera available for analysis. In this large trial, 57% of infants delivered to women with first-episode primary HSV infection developed neonatal HSV disease, compared with 25% of infants delivered to women with first-episode nonprimary infection and 2% of infants delivered to women with recurrent HSV disease. 

Epidemiology

Herpes simplex virus (HSV) infection of the neonate is an uncommon occurrence, with an estimated 1,500 cases diagnosed annually in the United States from a birth cohort of more than 4,000,000. In contrast, genital herpes infections in adults are very common. Between 1 in 4 and 1 in 5 adults in the United States has genital herpes caused by HSV type 2 (HSV-2). 

In addition, HSV type 1 (HSV-1) now accounts for at least 20% and, in some locales, more than 50% of cases of genital herpes in the United States. Therefore, managing infants potentially exposed to HSV at the time of delivery is not uncommon, and prevention of the devastating outcomes of neonatal HSV disease is paramount. 

Incubation Period

The incubation period ranges from 1 - 26 days and with a mean of 6 - 8 days.

Transmission

Transmission of HSV typically occurs through close personal contact.  HSV is shed during primary infection, during episodes of recurrent herpes, and periodically in the absence of any clinically apparent disease. Asymptomatic shedding is a significant source of virus transmitted to susceptible hosts, particularly neonates.

Reference

Clinical Report:  Guidance on Management of Asymptomatic Neonates Born to Women with Active Genital Herpes Lesions (American Academy of Pediatrics).  Pediatrics 2013:131(2):635-646.

CPT Codes

87529, 87252, 87253 if indicated.

Contacts

Last Updated

10/7/2023