What is Herpes Simplex Virus?
Herpes Simplex Virus Type 2 is the usual causative virus for genital herpes. Although Herpes Simplex Virus Type 1 which usually cause “cold sore” on the oral-facial area can also cause genital herpes.
Herpes Simplex Virus is a sexually transmitted disease spread to skin to skin contact via genitalia to genitalia, mouth to genitalia, genitalia to anal and mouth to anal contact. A person with herpes may spread the herpes virus to the partner even when they do not have symptom, this is known as asymptomatic shedding of virus.
Clinical Presentation of Herpes Simplex Virus HSV
About 50% of people with Herpes Simplex Virus (HSV) may not have any symptoms at all but they can still spread the virus to their partners.
First episode of genital herpes can be divided into primary herpes and non-primary herpes infection. Primary herpes refer to the group of people with no prior exposure to either Herpes Simplex Virus Type 1 or Type 2. Non-primary genital herpes refer to people who have their first episode of genital herpes however they have herpes simplex virus type1 or 2 infections at other body sites before.
First episode of genital herpes is often severe, painful multiple grouped vesicles which will rupture into erosions and ulcer will occur over the genitalia area. These lesions can occur on the penis in male and the vagina and cervix in females. Other associated symptoms include painful urination (dysuria), genital discharge, fever, enlarged lymph nodes in the groin area and vague tingling, burning and itching sensation. Uncomplicated lesions will usually resolve in 2 to 4 weeks.
Recurrent attacks are often less severe than the first episode. Recurrences range from 5 to 10 attacks a year and they tend to occur more often in the first 2 years of infection. The grouped vesicles and ulcers will usually heal within 10 days. Immunosuppression states like patients with diabetes, renal patients, HIV patients and patients on immunosuppressant drugs like steroid are more susceptible to recurrence of herpes. Also genital herpes caused by herpes simplex type 1 tend to recur infrequently.
Other possible causes of genital ulcers that have to be excluded are syphilis and haemophilus ducreyi.
Confirmatory tests of Herpes Simplex Virus HSV
1.Viral isolation in cell culture: Viral typing of HSV into type 1 and 2 is possible. It is a sensitive and specific test to detect herpes simplex virus. However as the lesions heal, the sensitivity decreases
2.Tzanck smear test: This test is able to identify the giant cells from the lesions however it is not sensitive and only provides presumptive evidence of HSV.
3.PCR detection of nucleic acid: This is a highly sensitive test and can be used to type HSV into Type 1 or 2. However it is expensive and not widely used.
4.HSV antigen detection: This test via DFA or EIA techniques are insensitive tests that does not allow HSV typing also.
5.Type-specific serological tests (TSST): These tests are sensitive and specific. Type 1 and 2 Herpes Simplex virus have type specific glycoproteins gG1 in HSV1 and gG2 in HSV2 which can be tested individually allowing typing of HSV. These tests are useful for diagnosis, screening of partners and detection of unrecognized infections.
Treatment of Herpes Simplex Virus
General measures include cleaning the affected areas with normal saline and usage of oral or topical analgesics to control pain. If there is co-infection of bacteria origin, treatment should be commenced too.
Antiviral medicine has been in the market since the 1980s. These include acyclovir, valacyclovir and famiciclovir. These drugs are useful to aid recovery of each herpes episodes however they do not eradicate the virus from the person. They also do not reduce the subsequent recurrence of herpes episodes and do not affect the severity of the episode.
Treatment regime for first episode genital herpes
Antiviral treatment like oral acyclovir 400 mg 3 times daily is given for 5-10 days or famiciclovir 250 mg 3 times daily for 5-10 days or valacyclovir 500 mg/1 gram twice daily for 5-10 days. It will be more optimal if treatment is started within 2-3 days of the onset of the lesions. The duration of treatment depends on whether patient responds to treatment clinically.
Treatment regime for recurrent genital herpes
Recurrent episodes of genital herpes are often less severe than the first episode. Hence they can be managed by general and supportive measures like cleansing with normal saline and analgesics. Specific therapy with antiviral medications may not always be necessary.
For each episode of recurrence genital herpes, if antiviral treatment is necessary it should be started within 1 day of the attack. Medications given include oral acyclovir 400 mg 3 times daily/ 800 mg 2 times daily for 5 days or oral acyclovir 800 mg 3 times daily for 2 days or oral famiciclovir 125 mg twice daily for 5days/ 1 gram twice daily for 1 day or oral valacyclovir 500 mg twice daily/ 1000 mg once daily for 5 days.
For suppression daily therapy, oral acyclovir 400 mg twice daily or valacyclovir 1000 mg once daily or valacyclovir 500 mg twice daily or famiciclovir 250 mg twice daily. After treating for 9 to 12 months, stop the medications and observe if there is any recurrence. If recur then continue suppression therapy.
Treatment regime for HIV patients with Herpes Simplex Virus
HIV patients being immune-compromised are prone to herpes recurrence. Some patients may be resistant to acyclovir or famiciclovir or valacyclovir. In such cases then intravenous foscarnet or topical trifluridine/cidofovir may be used for treatment.
For treatment of each recurrent herpes episode, oral acyclovir 400 mg thrice daily for 7-10 days or oral famiciclovir 500 mg twice daily for 7-10 days or oral valacyclovir 1 gram twice daily for 7-10 days can be commenced.
To prevent recurrence, suppressive therapy can be started with oral famiciclovir 500 mg twice daily or valacyclovir 500 mg twice daily or acyclovir 400 mg- 800 mg twice to thrice daily.
Genital Herpes Simplex Virus in pregnancy
Transmission of herpes to the neonates occurs when mother has symptomatic genital herpes during delivery. The risk of transmission to neonate is higher (30-50%) from a mother with primary genital herpes during pregnancy as compared to mothers who have recurrent herpes or virus shedding during phase without symptoms. If the mother has premature rupture of membranes, the risk of transmission to the neonate is about 10%.
Anti-viral therapy like acyclovir, valacyclovir and famiciclovir are considered pregnancy category B drugs. So far, acyclovir has yet to cause any birth defects when used in first trimester. In life threatening HSV infection, intravenous acyclovir is used.
Acyclovir can be started when near term to reduce the rate of caesarean sections. Starting 6 weeks from delivery, weekly genital viral cultures are taken and tested for herpes. If positive, treatment is commenced.
If genital herpes lesions are present at labor, prepare for caesarean section within 6 hours from membrane rupture. Neonates should then be screened for HSV using cultures from the eyes, oral-pharynx and rectum area within 2 days from birth. If any of the culture is positive, treatment should be started immediately and baby should be closely monitored.
If there are no genital herpes lesions present at labor, mother can proceed with vaginal delivery. The vaginal and cervix of the mother should be swabbed for herpes. If positive, monitor baby and treat baby. If negative, no treatment is needed.
Follow up post herpes infection
Patients with herpes simplex virus should be educated on the disease, its transmission, treatment and also potential of recurrence. They should avoid sexual contact when they actively have herpes infection. They will also need to inform their partners of their disease. Women who are pregnant should inform their obstetricians early.
Sexual partners of patients with herpes should be counseled together with their partners. They should also look out for the symptoms and outbreaks and to seek treatment early.