2012-05-19
HSV (1/2)
All genetic information of every living body including infectious agents such as bacteria and viruses is encoded in the DNA molecule in the cell nucleus. Modern method of molecular biology, polymerase chain reaction (PCR), is used in the SORPO medical research center. The essence of PCR method: target fragments of the virus or human DNA in several hours are amplified millionfold, separated from other components, stained, identified and documented. It is accurate, quick and sensitive method.
Exceptional nature of PCR method:
•infectious agent is tested, but not body reaction to it;
•patient is not injured;
•disease could be identified in the very beginning;
•high sensitivity of the method: even small number of infectious agent allows identification of the disease;
•one specimen could be use for identification of multiple infectious agents.
There are two types of Herpes simplex virus: type 1 HSV causes Herpes simplex of lips, oral mucosa and skin; type 2 HSV causes genital herpes. It is extremely prevalent virus: antibodies to HSV-1 have 90%, ant to HSV-2 – about 20% of all adults. Humans usually catch HSV-1 in their childhood. Source of virus is patient with active or asymptomatic disease. HSV virus is an airborne infection or it could be transmitted through direct contact (kissing, during sexual intercourse, at delivery). Herpes viruses invade the body trough damaged mucosa of oral cavity, eye, and genital organs or through undamaged skin.
Onset of the disease could be asymptomatic or sporadic skin pustules occur. Initially skin (mucosa) redness and swelling occur; patient could feel itching, burning, tension and pain. Later papules filled with clear fluid, and painful ulcers develop following their rupture. Enlargement of lymphatic nodes and fever may occur. Acute period may be accompanied with common cold-like symptoms: fever, headache, back and muscle pain. Virus reproduces; it causes host’s immune reaction and invades peripheral sensory nerves and subsequently invades sensory ganglia of the central nervous system (CNS). Virus becomes inactive but remains in the body. Latent and non-reproducing viruses remain in the ganglia of spinal cord and may persist there for a relatively long time. When favorable conditions occur (common cold, overexposure of ultraviolet rays, hormonal disorders, stress or depressed mood), Herpes virus reactivates and invades sensory nerves again causing their damage and damaging surfaces they innervate. Symptoms of the disease usually are less pronounced comparing with initial disease, and this depends on individual immunity. Sometimes virus invades brain meninges or neurons and causes meningitis or encephalitis.
When HSV test using molecular PCR method is performed in SORPO laboratory it include both type 1 and type 2 HSV viruses; however, virus types are not identified. When virus is found in the material investigated, the result is being identified as “positive” (or “virus found”); when virus is not found, result is “negative”.
To perform tests using PCR method vaginal scraping in females and first void urine or urethral scraping in males are obtained.
Test duration – 2 days. Tests are performed on a daily basis.