الفهرس 
IntroductionOnly 14 pages are availabe for public view
Abstract
Herpes simplex virus (HSV) 1,2 are ubiquitous, enveloped and double stranded DNA viruses, which belong to the family of herpesviridae that consist of more than 80 distinct types of viruses that are found in nearly all kind of animals.
The life cycle of all herpesviruses in their natural host can be divided into lytic (resulting in the production of infectious progeny) and latent (dormant) infections. During a lytic infection the virus is replicated and newly synthesized particles are released into the surrounding medium. During a latent infection viral replication is suppressed, resulting in the formation of a quiescent state. The establishment of viral latency is a hallmark of all known herpesviruses.
Symptomatic disease caused by HSV-1 is typically limited to cold sores of the mouth and keratitis in the eyes. HSV-2, in contrast, is mostly responsible for genital lesions. However, both viruses are capable of causing lesions on same body sites and both can cause life- threatening diseases in immunocompromised individuals including newborns, patients with human immunodeficiency virus or patients undergoing immunosuppressive treatment.
HSV-2 is predominantly asymptomatic. Viral shedding in body secretions contributes to spread of infection to susceptible individuals, but the risk of transmission is highest during symptomatic periods.
The diagnosis and treatment of HSV encephalitis is crucial to rapidly control the disease and decrease the sequlae, while the recognition of genital herpes is important to prevent transmission and provide counseling. Thus, rapid and accurate laboratory diagnosis is important to guide management and institute appropriate therapy.
Testing for HSV-1 and -2 is accomplished through the use of light microscopy, viral culture, serology, and molecular methods. Historically, direct light microscopy of patient specimens was widely used due to its simplicity. However, the addition of viral culture greatly enhanced diagnostic sensitivity. Diagnostic sensitivity has further increased over time with the addition of modified culture methods and molecular assays.
The objective of this study was to compare the performance of the conventional PCR with those of conventional cell culture for the detection of HSV in dermal, genital, mouth, or other swab samples.
The study included 70 subjects. Their ages ranged from 2 to 58 years (35.79 ± 14.61). They were 7 (10.0%) males and 63 (90.0%) females.
Study participants were divided into two groups. group I included 50 patients with clinical manifestations suggestive of HSV 1, 2 infections attending Ain Shams University hospitals (ASUH). Seventeen orolabial, 33 genital swabs were collected from patients in this group. group II included 20 subjects who were apparently healthy or presenting to ASUH clinics with clinical manifestations other than herpes. Four orolabial, 16 genital swabs were collected from patients in this group.
Appropriate samples were collected and tested by both techniques. The sensitivity of the PCR technique was higher than tissue culture (100% versus 57.7%). However, the specificity of both techniques was the same (100%).
The results of both tests were affected by the stage of the lesion with the vesicular lesions giving the highest results.
The history of antiviral treatment affected the results of both tests. Only 7.7% of the samples gathered from patients with history of taking antiviral treatment gave positive results in tissue culture versus 26.9% of the samples that gave positive results in PCR.
In this study, it was obvious that the presence of symptoms of HSV alone had very low specificity (31.4%) compared to the true results.
The results of this study emphasized the fact of subclinical shedding of HSV where 5 of the 20 samples of the control group (25%) were positive by both PCR and tissue culture.
In conclusion, though tissue culture has its own advantages, conventional PCR could serve as a gold standard for the diagnosis of HSV infection.