Herpes Simplex Virus: The herpes simplex virus (HSV) (also known as cold sore, night fever, or fever blister) is a virus that manifests itself in two common viral infections, each marked by painful, watery blisters in the skin or mucous membranes (such as the mouth or lips) or on the genitals. The disease is contagious, particularly during an outbreak, and is at times incurable. An infection on the lips is commonly known as a “cold sore” or “fever blister”. These are sometimes confused with canker sores or aphthous ulcers, which have a similar appearance; these appear inside the mouth and are not caused by the herpes simplex virus. Orofacial infection (Generally HSV 1): Prodromal symptoms, Skin appears irritated, sore or cluster of fluid-filled blisters appear, Lesion begins to heal, usually without scarring.

Genital infection (Generally HSV 2): Prodromal symptoms, Itching in affected area, Sore appears, Lesion begins to heal, usually without scarring.

Herpes is contracted through direct skin contact (not necessarily in the genital area) with an infected person, and less frequently by indirect contact, in particular by sharing lip balm. The virus travels through tiny breaks in the skin or through moist areas, but symptoms may not appear for up to a month or more after infection. Transmission was thought to be most common during an active outbreak; however, in the early 1980s, it was found that the virus can be shed from the skin in the absence of symptoms. It is estimated that between 50% and 80% of new HSV-2 cases are from asymptomatic viral shedding. HSV asymptomatic shedding is believed to occur on 2.9% of days while on antiviral therapy, versus 10.8% of days without. Shedding is known to be more frequent within the first 12 months of acquiring HSV-2, and concurrent infection with HIV also increases the frequency and duration of asymptomatic shedding. Sex should always be avoided in the presence of symptomic lesions. Oral sex performed by someone with oral lesions or other symptoms should be avoided, to avoid transmission of HSV-1 to the partner’s genitals. Even without symptoms it is possible for transmission to occur. Many people still believe Herpes cannot be transmitted through oral sex. This is a dangerous myth.

Women are more susceptible to acquiring genital HSV-2 than men (11% of men and a little over double the number of women, 23%, carry HSV-2. On an annual basis, without the use of antiviral or condoms, the transmission risk from infected male to female is approximately 8-10%. This is believed to be due to the increased exposure of mucosal tissue to potential infection sites. Transmission risk from infected female to male is approximately 4-5% annually.


Methodology:
Taqman Real time PCR assay

Clinical Use:

  • HSV-1/HSV-2 testing May differentiate disease severity
  • Distinguishing between HSV-1 and HSV-2 in early stage disease with IgG may not be possible
  • Assist in HSV diagnosis and patient management
  • Identify HSV viral load quantitation for epidemiologic and prognostic purposes
  • Assess viral response to treatment as measured by changes in the HSV DNA levels
  • Detect and differentiate between type 1 and type 2 herpes simplex virus (HSV)
  • Patients with recurrent meningitis

Screening: Centers for Disease Control recommendations

  • Patient has AIDS & HIV-positive persons
  • Patient has recurrent meningitis
  • Infant has suspected neonatal herpes
  • Pregnant women
Performed:  Every day
Reported: 2-3 days

Specimen required: Bronchoalveolar lavage (BAL), CSF, Genital Swabs, ocular fluid, Lesion tissue, vesicle fluid Or Endocervical specimen. Serum, plasma Collect in: Lavender (EDTA), pink (K2EDTA), or serum separator .Stability collection to initiation of testing On Cells: Ambient: 4 hours; after separation from cells: Refrigerated: 48 hours; Frozen at -20°C: 72 hours; Frozen at -70°C: 4 months. Do not thaw avoid repeated freezing and thawing

Specimen Preparation: Separate serum or plasma from cells within 24 hours.

 

Storage/Transport Temperature: Frozen-20 0C. Refrigerate specimens at 2°C-4°C.

Unacceptable Conditions
:  Heparinized specimens, Hemolysis sample, Quantity not sufficient for analysis, specimen grossly contaminated, specimen too old, frozen whole blood specimen, specimen leaky or tube broken.

 

Interpretation: This test can quantitate/detect Herpes Simplex Virus DNA over the range 90-108 Copies/mL. However this does not mean that lower copies or higher copies cannot be detected. The lower copies can be detected in some cases. This is a limitation of the currently available extraction systems. The test is intended for use in conjunction with clinical presentation and other markers as an aid in assessing viral response to antiviral treatment as measured by change in HSV DNA levels. A negative result does not preclude the presence of HSV infection because results depend on adequate/proper patient sample storage and transportation. This test Rapid diagnostic for Infants with suspected neonatal herpes where cultures have been negative (eg, CSF nasopharyngeal aspirate).

Note: The test is intended for use in conjunction with clinical presentation and other laboratory markers as an indicator of disease prognosis.  This test is also used as an aid in assessing viral response to antiretroviral treatment as measured by changes in HSV DNA levels

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