Herpes. Transmission and viral shedding

Seroprevalence of herpes simplex virus type 1 and type 2 in Turkey

BACKGROUND

Herpes simplex virus (HSV) infections are among the most common infectious diseases in humans. The prevalence of herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) varies widely across the world. HSV-2 infection is the primary cause of genital herpes. It is highly prevalent in human populations in many parts of the world, and is the most common cause of genital ulcer disease worldwide. In spite of the large prevalence and growing incidence of herpes simplex infection (HSV-1 and HSV-2), relatively few data have been published regarding the seroprevalence of herpes simplex infection, while no data exist regarding the Turkish population.

METHODS

We aimed to investigate the prevalence of HSV-1 and HSV-2 in selected populations in Turkey. A cross-sectional study was conducted involving 2082 serum samples of 725 adults, 300 pregnant women, 200 blood donors, 483 sex workers and 110 patients with genital warts and 264 hotel staff in Istanbul, Turkey. All serum samples were assessed for HSV1 and HSV-2 IgG antibodies using an HSV-type specific, enzyme-linked immunosorbent assay (ELISA).

RESULTS

The prevalence of HSV-2 and HSV-1 antibodies was 4.8 and 85.3% in sexually active adults; 5.5 and 96% in blood donors; 5 and 98% in pregnant women, 17.3 and 93.6% in patients with genital warts; 8.3 and 97.3% in hotel staff; and 60% and 99% in sex workers.

CONCLUSION

These results confirm a higher prevalence of HSV infection than estimated, especially in high risk groups in Turkey. The high prevalence of HSV infection underlines the need for education among these populations.

Reducing the risk of transmitting genital herpes: advances in understanding and therapy

BACKGROUND

This review considers the epidemiology and impact of genital herpes, discusses how herpes simplex virus-2 (HSV-2) is transmitted, and reviews data on methods of reducing the risk of HSV transmission.

SCOPE

Information for the paper was identified through multiple PubMed searches. Information in the section on interventions was identified through PubMed searches using several pairs of key words (herpes and transmission, herpes and treatment, herpes and antiviral, herpes and valacyclovir, herpes and famciclovir, herpes and acyclovir, herpes and condom, herpes and clinical trial). The searches, conducted in January 2005, did not have date limits. Papers were selected for inclusion based on the author's judgment of their relevance to the topic of the review.

FINDINGS

An estimated 45 million persons in the United States have genital herpes infection, and new infections occur at a rate of approximately one million per year. Approximately 85% to 90% of infections are unrecognized and therefore undiagnosed. Individuals with genital HSV-2 infection shed virus during asymptomatic periods as well as symptomatic periods. In fact, transmission frequently occurs during periods of asymptomatic viral shedding. Asymptomatic viral shedding (1) occurs in the majority of patients with genital HSV-2 infection; (2) accounts for approximately one third of the days of viral shedding; (3) occurs regardless of duration of infection but is most frequent during the first year after infection; (4) occurs more than 7 days before or after a symptomatic recurrence 50% of the time; and (5) does not differ significantly when comparing patients with 1 to 12 annual recurrences to those with no recurrences. A recently published study of discordant couples counseled on safe sex practices found that once daily suppressive therapy with valacyclovir reduced the risk of transmission of HSV-2 in heterosexual immunocompetent adult couples discordant for HSV-2 infection. In an 8-month study, daily valacyclovir compared with placebo reduced the risk of acquisition of symptomatic genital HSV-2 infection by 75% (2.2% placebo vs. 0.5% valacyclovir; hazard ratio = 0.25; p = 0.008). The overall risk of acquisition of HSV-2 infection (defined via laboratory-confirmed symptoms or seroconversion) was reduced by 48% (3.6% placebo vs. 1.9% valacyclovir hazard ratio = 0.52; p = 0.04). The most common adverse events in the study were headache, nasopharyngitis, and upper respiratory infection.

CONCLUSION

Daily suppressive therapy is recommended as a therapeutic option for HSV-2 seropositive individuals at risk of transmitting HSV-2. Because no intervention completely protects against transmission of HSV, infected individuals and their partners should be counseled to use safer sex practices, including the use of condoms.

Prevention of genital herpes in a guinea pig model using a glycoprotein D-specific single chain antibody as a microbicide

Background

Genital herpes (GH) is a recurrent sexually transmitted infection (STI) that causes significant morbidity and is also the major source of herpes simplex virus (HSV) in cases of neonatal herpes. Vaccination is a current goal which has had limited success so far in preventing GH and microbicides offer an attractive alternative. Treatment of primary disease cannot prevent establishment of latent infections and thus, cannot prevent subsequent recurrent disease. Recently, many of the molecular events leading to entry of HSV into cells have been elucidated, resulting in the description of a number of herpesvirus entry mediators (HVEMs) that interact with HSV glycoprotein D (gD) on the surface of virions. Described here is a strategy for interrupting the spread of HSV based on interfering with these interactions. The hypothesis addressed in the current report was that single chain antibody variable fragments (scFv) that interrupt associations between gD and HVEMs would not only prevent infection in vitro but could also be used as microbicides to interfere with acquisition GH.

Results and Conclusions

Here we show that a scFv derived from a particular hybridoma, DL11, not only inhibits infection in vitro but also prevents development of GH in a guinea pig model when applied intravaginally in an inert vehicle. Comparison of different anti-gD single chain antibodies supported the hypothesis that the activity of DL11-scFv is based on its ability to disrupt the associations between gD and the two major receptors for HSV, nectin-1 and HveA. Further, the results predict that bacterial expression of active single chain antibodies can be optimized to manufacture inexpensively a useful microbicidal product active against HSV.

Gynecologic infections

The scope of gynecologic infections presenting to the emergency department is quite diverse. This article presents an update on the current literature for vaginitis, cervicitis, pelvic inflammatory disease, tubo-ovarian abscesses, the Fitz-Hugh-Curtis syndrome, herpes, and syphilis. Inadequate identification or treatment of these diseases can result is significant morbidity or mortality for the patient and for the fetus.

Current treatments and perceptions of genital herpes: a European-wide view

A European panel of physicians reviewed the current treatments and perceptions of recurrent genital herpes (GH) across the continent. The panel consisted of specialists in dermatology and venereology from France, Finland, Germany, Italy, Norway, Spain, Sweden and the UK. A wide variety of factors that influence GH management were considered, including different health delivery systems, funding and cultural differences. The poor awareness of GH among both the general public and physicians was highlighted. The effectiveness of GH management was then examined from a patient's viewpoint, including the confirmation of the diagnosis, information and counselling about GH, as well as prescriptions for treatment. It was agreed that both physicians and patients often feel uncomfortable about discussing the disease, and that a European-wide effort is needed to re-educate patients and physicians about GH. The panel identified clear and unmet needs to manage a patient with clinical recurrences and to attempt to reduce the risk of GH transmission. Finally, resiquimod, an immune response modifier, was considered as a potential treatment option for GH.