Genital herpes notes for all types of medical field students by Sanju Sah.pptx

Genital herpes is a sexually transmitted infection caused by the herpes simplex virus (HSV). It results in painful blisters or sores on the genital and anal areas. The virus remains dormant in the body and can reactivate, causing recurrent outbreaks. Safe sexual practices and antiviral medications help manage symptoms and reduce transmission.

1. Genital herpes (HSV 1 and HSV 2) Prepared by SANJU SAH Public Health Microbiology St. Xavier’s College, Maitighar,Kathmandu

2. Introduction Genital herpes is an infection by herpes simplex virus 2 (HSV-2) of the genitals. Most people either have no or mild symptoms and thus do not know they are infected. When symptoms do occur, they typically include small blisters that break open to form painful ulcers. Flu-like symptoms may also occur. Onset is typically around 4 days after exposure with symptoms lasting up to 4 weeks. Once infected further outbreaks may occur but are generally milder . The disease is typically spread by direct genital contact with the skin surface or secretions of someone who is infected. This may occur during sex including oral sex. Active sores are not required for transmission to occur. HSV is classified into two types, HSV-1 and HSV-2. While historically mostly cause by HSV-2, genital HSV-1 has become more common in the developed world.

3. Structure

4. Introduction Diagnosis may occur by testing lesions using either PCR or viral culture or blood tests for specific antibodies . Efforts to prevent infection include not having sex, using condoms, and only having sex with someone who is not infected. Once infected, there is no cure. Antiviral medications may, however, prevent outbreaks or shorten outbreaks if they occur. The long term use of antivirals may also decrease the risk of further spread. In 2015 about 846 million people (12%) had genital herpes. Women are more commonly infected than men. Rates of disease caused by HSV-2 have decreased in the United States between 1990 and 2010 .

5. Sign and Symptoms In males, the lesions occur on the glans penis, shaft of the penis or other parts of the genital region, on the inner thigh, buttocks, or anus. In females, lesions appear on or near the pubis, clitoris or other parts of the vulva, buttocks or anus. Other common symptoms include pain, itching, and burning. Less frequent, yet still common, symptoms include discharge from the penis or vagina, fever, headache, muscle pain (myalgia), swollen and enlarged lymph nodes and malaise. Women often experience additional symptoms that include painful urination (dysuria) and cervicitis. Herpetic proctitis (inflammation of the anus and rectum) is common for individuals participating in anal intercourse . After 2–3 weeks, existing lesions progress into ulcers and then crust and heal, although lesions on mucosal surfaces may never form crusts . In rare cases, involvement of the sacral region of the spinal cord can cause acute urinary retention and one-sided symptoms and signs of myeloradiculitis (a combination of myelitis and radiculitis ): pain, sensory loss, abnormal sensations ( paresthesia ) and rash. Historically, this has been termed Elsberg Syndrome, although this entity is not clearly defined.

6. Table 1: Main clinical symptoms, manifestations and complications of genital herpes infections

7. Laboratory diagnosis Laboratory confirmation of the clinical diagnosis is necessary for estimating the potential infectivity during episodes of lesions, identifying persons at risk of transmitting infection subclinically , selecting women at future risk of transmitting the infection to the neonate and confirming the clinical diagnosis in those for whom antiviral therapy for HIV infection should be prescribed. Methods used for the diagnosis of HSV could be divided into direct detection of virus in material from lesions and serological diagnosis. Both virological detection and type-specific serological tests for HSV should be available in clinical settings that provide care for patients with STIs or those at risk for STIs . A] Sample Collection HSV-1 and HSV-2 can be recovered by swabbing mucocutaneous genital lesions and from previously involved mucocutaneous sites in patients with asymptomatic infection. For sample lesions collection, a small cotton, cotton-tipped, or Dacron swab on a wire shaft is used for viral culture as well as molecular biology.

8. Laboratory diagnosis contd.. Nylon flocked swabs may be preferred since their perpendicular nylon fibers act like a soft brush to allow the improved collection and release from patient samples although no formal validation for herpes positive samples has been performed yet . Calcium alginate swabs are toxic to HSV and therefore should not be used for virus isolation in cell culture . Samples used for diagnosis of genital herpes are: Male skin or mucus membrane lesion Male urethra Female skin or mucus membrane lesion Female urethra Cervix Vagina ( prepubertal girls) Urine Conjunctiva 9. Rectum

9. B] Microscopy I)Light Microscopy - Cells from the base of the lesion, or wiped from a mucous surface, or biopsy material, may reveal intranuclear inclusions. Infected cells may show ballooning and fusion. II) Electron Microscopy - Electron microscopy is not a sensitive tool for the detection of HSV, except in the case of vesicle fluids which often contain 108 or more particles per millilitre . However like light microscopy, electron microscopy cannot distinguish between different viruses.

10. C]Antigen detec tion Viral antigen from swab specimens can be detected using either direct immunofluorescence (DIF) or enzyme immunoassay (EIA ). Direct immunofluorescence: DIF could be classified as a rapid diagnostic test allowing type differentiation of genital herpes viruses . It can be valuable when testing high-prevalence populations, but when testing asymptomatic patients , the sensitivity may drop to less than 50% when compared with culture. The disadvantages of DIF are that it is time consuming, labour intensive and , compared to NAATs, has a suboptimal sensitivity. II) Antigen Capture enzyme immuoassay : The sensitivity of commercially available EIAs, when compared with that of viral isolation, is greater than or equal to 95% and with specificities ranging from 62% to 100% for symptomatic patients.

11. Laboratory Diagnosis contd.. The sensitivity of antigen capture EIAs may be higher than that of virus culture for typical presentations, but lower for cervical and urethral swabs. Most commercially available assays, however, do not differentiate between serotypes . D ) Viral isolation in cell culture Virus isolation in cell culture has been the cornerstone of HSV diagnosis over the past two decades in laboratories. Although HSV can be isolated from over 90% of vesicular or pustular lesions, the isolation rate from ulcerative lesions is only 70% and falls to 27% at the crusting stage. Delayed transport of samples to the laboratory and lack of refrigeration during transportation substantially affect the outcome of the testing. The characteristic cytopathic effect of HSV in tissue culture generally appears within 24–72 hours, but may take up to five days.

12. Laboratory Diagnosis contd.. Virus isolation in tissue culture roller tubes is slow and labour intensive, but has the advantage of demonstrating active infection within a clinical lesion and also allows virus typing and antiviral sensitivity testing . More rapid culture of HSV can be achieved by using shell vials or multiwell plates and centrifuging the specimen onto cell monolayers on coverslips. Commonly used cells include primary human fibroblasts and cell lines such as MRC-5, Vero cells, baby hamster kidney and rabbit kidney cells. Typing of HSV using cell culture can be performed directly on infected cell cultures using fluorescein isothiocyanate (FITC)- or immunoperoxidase-labelled type-specific monoclonal antibodies by DIF or by testing the cell supernatant by nucleic acid amplification tests (NAATs), with specifically designed primers . Storage of HSV isolates Isolates of HSV may be stored in 0.2 M sucrose in 0.02 M phosphate-buffered saline pH 7.2 (2SP medium) at –70 °С or in liquid nitrogen.

13. E ] Nucleic acid amplification tests HSV detection using polymerase chain reaction ( PCR) has been shown to be the test of choice in patients with genital herpes ulcers. The detection rates of the PCR assays were shown to be 11–71% superior to virus culture . Furthermore, compared with traditional PCR , real-time PCR allows detection and typing of HSV in a single reaction tube, is faster ( takes approximately two hours to perform), allows simplified conditions of performance and lowers the risk of cross-contamination . Use of NAATs for diagnosis ofmHSV also allows less strict sample transportation conditions, compared with those required for diagnosis by culture.

14. F ] Serological tests Serological tests detect antibodies to HSV in blood, which are indicative of ongoing latent infection. Both type- and non-type-specific antibodies to HSV develop during the first several weeks after infection and persist indefinitely. However, directly after infection there is a ‘window’ in which testing for antibodies will give a negative result. Serodiagnosis is useful for documenting newly acquired infections and for diagnosis in persons who present without lesions or with atypical lesions . Testing for HSV type-specific antibodies can also be used to diagnose HSV-2 infection in asymptomatic individuals, and other persons with undiagnosed HSV-2 infection.

15. Table 2: Recommended sampling site, type of sample and preffered diagnostic methods for genital herpes

16. Treatment Treatment with medication is effective in shortening the initial outbreak of the infection, lowers the chance that the infection will come back, and makes any later outbreaks less severe. There are similar antiviral drugs available for the treatment of genital herpes infection, These antiviral medications vary in cost and how often they should be taken. All should be taken for 7 to 10 days. The patient's doctor may extend the course of therapy if ulcers have not healed in 10 days. Examples of these antiviral medications include: acyclovir ( Zovirax ), famciclovir ( Famvir ), and valacyclovir (Valtrex ).

17. Treatment For preventing later genital herpes outbreaks, people with recurring infections also may benefit from the antiviral medications. Treatment is started when the recurrence first begins and continues for five days. For continuous prevention, individuals who have frequent outbreaks (generally over six recurrences per year) can control the outbreaks by taking medication every day. Acyclovir , famciclovir , and valacyclovir are all used to treat recurrent disease. This is known as suppressive therapy. Suppressive therapy has been shown to decrease the frequency of genital herpes recurrences in those who have frequent recurrences, and many individuals taking this treatment report no symptomatic outbreaks.