Age-specific prevalence of infection with herpes simplex virus types 2 and 1: a global review

Differential induction of innate anti-viral responses by TLR ligands against Herpes simplex virus, type 2, infection in primary genital epithelium of women

Genital epithelial cells (GECs) are the first line of mucosal defense against sexually transmitted infections. We exploited the ability of GECs to mount innate immune responses, by using TLR ligands to induce anti-viral activity against Herpes simplex virus, type 2 (HSV-2). Primary cultures of GECs were grown to confluent, polarized monolayers and found to express different levels of mRNA for TLR1-10. Innate anti-viral responses against HSV-2 infection were determined following treatment with eight different TLR ligands. HSV-2 replication was significantly inhibited following treatment with ligands for TLR3, 5 and 9, while lipo-polysaccharide (LPS), a TLR4 ligand, failed to provide any protection. Biologically active interferon-beta and nitric oxide production by GECs correlated with anti-viral activity. Following treatment with TLR3 ligand Poly I:C, inflammatory cytokines were upregulated. Poly I:C treatment led to activation of downstream transcription factors including interferon regulatory factor-3 (IRF-3) and NFkappaB. Anti-viral responses induced by TLR ligands in GECs may provide a unique alternative to topical microbicides by enhancing body's own mucosal innate defense mechanisms against sexually transmitted viruses.

Progressive hypertrophic genital herpes in an HIV-infected woman despite immune recovery on antiretroviral therapy

Most HIV-infected individuals are coinfected by Herpes simplex virus type 2 (HSV-2). HSV-2 reactivates more frequently in HIV-coinfected individuals with advanced immunosuppression, and may have very unusual clinical presentations, including hypertrophic genital lesions. We report the case of a progressive, hypertrophic HSV-2 lesion in an HIV-coinfected woman, despite near-complete immune restoration on antiretroviral therapy for up to three years. In this case, there was prompt response to topical imiquimod. The immunopathogenesis and clinical presentation of HSV-2 disease in HIV-coinfected individuals are reviewed, with a focus on potential mechanisms for persistent disease despite apparent immune reconstitution. HIV-infected individuals and their care providers should be aware that HSV-2 may cause atypical disease even in the context of near-comlpete immune reconstitution on HAART.

Seroprevalence and risk factors associated with herpes simplex virus infection among pregnant women

OBJECTIVES

To estimate the type-specific seroprevalence and identify the risk factors associated with herpes simplex virus (HSV)-2 infection in pregnant women in Bucharest, Romania.

METHODS

A prospective survey was conducted in 452 subjects, aged 15-39 years, at the Elias Hospital, during the years 2004-2005. We evaluated serum IgG anti-bodies to HSV-1 and HSV-2 using the HerpeSelect ELISA test. All subjects completed an epidemiological questionnaire.

RESULTS

Seroprevalence was 87.3% and 15.1% for HSV-1 and HSV-2, respectively. The risk factors for HSV-2 infection were lower level of education and a greater number of sexual partners. Elementary school and high-school graduates were 6.28 and 2.26 times more exposed than University graduates. Having 2-3 partners and more than three partners was associated with 2.43 and 4.26 times the risk of acquiring HSV-2, compared with having one partner.

CONCLUSIONS

In pregnant women, HSV-1 seroprevalence was higher than in Western Europe but similar to that in Eastern Europe. HSV-2 seroprevalence was within European ranges. Both were lower than in the USA. Risk factors for HSV-2 infection may lead to prevention programs.

Vaginal microbicides: where are we and where are we going?

The epidemic of HIV has catalyzed the need for safe and effective prevention methods, particularly for women. Vaginal microbicides have been targeted because these methods can be controlled by women themselves. Microbicides have focused on preventing HIV as well as other sexually transmitted infections, because the acquisition of HIV is enhanced by the presence of many infections. Although many products show promise in preclinical trials, safety remains paramount. The importance of safety was exemplified by the nonoxynol-9 studies which showed actual harm. This experience catalyzed the development of criteria that should be used as safety standards in trials, including immune markers of the cervical epithelium, and colposcopy standards. Unfortunately, immune markers are in their infant stages of development and reliability and validity checks remain large challenges. There have been four recent phase IIb/III trials that had disappointing results. However, these trials offer an opportunity to develop new preclinical models and biomarkers. The search for new microbicides remains critical. Current microbicides in trials can be categorized into vaginal defense enhancers (which help maintain the vaginal pH or facilitate the colonization of vaginal lactobacilli); surfactants (or detergents) which disrupt viral membranes; HIV entry inhibitors; and HIV reverse transcriptase inhibitors. Even with a good product, acceptance by both partners will be essential for its success, and lack of acceptance is often not evident until large trials are completed.

Herpes simplex virus type 2 trends in relation to the HIV epidemic in northern Malawi

OBJECTIVES

It is unclear whether the high prevalence of herpes simplex virus type 2 (HSV-2) found in much of Africa predates the HIV epidemic or is, to some extent, a consequence of it. HSV-2 prevalence trends in a rural African community were assessed over a period in which HIV prevalence rose sharply, and antenatal clinic (ANC) surveillance was explored as a method of estimating community HSV-2 prevalence.

METHODS

HSV-2 seroprevalence was determined among community controls seen for case-control studies of mycobacterial disease in Karonga district, Malawi, in 1988-90, 1998-2001 and 2002-5, and in women attending ANC as part of surveillance for HIV in 1999-2000. Over this period HIV prevalence rose from 4% to 12%.

RESULTS

HSV-2 prevalence in all periods increased sharply with age and was higher in women than in men. After excluding migrants, there was no evidence of change in HSV-2 prevalence in the different periods. Women in the ANC group had lower HSV-2 prevalence than those in the community, but the ANC prevalence was a good approximation to the combined male and female prevalence for the same age group.

CONCLUSIONS

This study suggests that HSV-2 was already widespread before the HIV epidemic and has not been greatly influenced by it. It also demonstrates that ANC surveillance may be useful for estimating community HSV-2 prevalence.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Ocular HSV-1 latency, reactivation and recurrent disease

Ocular infection with HSV-1 continues to be a serious clinical problem despite the availability of effective antivirals. Primary infection with HSV-1 can involve ocular and adenaxial sites and can manifest as blepharitis, conjunctivitis, or corneal epithelial keratitis. After initial ocular infection, HSV-1 can establish latent infection in the trigeminal ganglia for the lifetime of the host. During latency, the viral genome is retained in the neuron without producing viral proteins. However, abundant transcription occurs at the region encoding the latency-associated transcript, which may play significant roles in the maintenance of latency as well as neuronal reactivation. Many host and viral factors are involved in HSV-1 reactivation from latency. HSV-1 DNA is shed into tears and saliva of most adults, but in most cases this does not result in lesions. Recurrent disease occurs as HSV-1 is carried by anterograde transport to the original site of infection, or any other site innervated by the latently infected ganglia, and can reinfect the ocular tissues. Recurrent corneal disease can lead to corneal scarring, thinning, stromal opacity and neovascularization and, eventually, blindness. In spite of intensive antiviral and anti-inflammatory therapy, a significant percentage of patients do not respond to chemotherapy for herpetic necrotizing stromal keratitis. Therefore, the development of therapies that would reduce asymptomatic viral shedding and lower the risks of recurrent disease and transmission of the virus is key to decreasing the morbidity of ocular herpetic disease. This review will highlight basic HSV-1 virology, and will compare the animal models of latency, reactivation, and recurrent ocular disease to the current clinical data.

Biomedical interventions to prevent HIV infection: evidence, challenges, and way forward

Intensive research efforts for more than two decades have not yet resulted in an HIV vaccine of even moderate effectiveness. However, some progress has been made with other biomedical interventions, albeit on the basis of inconsistent levels of evidence. The male condom, if used correctly and consistently, has been proven in observational studies to be very effective in blocking HIV transmission during sexual intercourse; and, in three randomised trials, male circumcision was protective against HIV acquisition among men. Treatment of sexually transmitted infections, a public health intervention in its own right, has had mixed results, depending in part on the epidemic context in which the approach was assessed. Finally, oral and topical antiretroviral compounds are being assessed for their role in reduction of HIV transmission during sexual intercourse. Research on biomedical interventions poses formidable challenges. Difficulties with product adherence and the possibility of sexual disinhibition are important concerns. Biomedical interventions will need to be part of an integrative package that includes biomedical, behavioural, and structural interventions. Assessment of such multicomponent approaches with moderate effects is difficult. Issues to be considered include the nature of control groups and the effect of adherence on the true effectiveness of the intervention.

Herpes simplex virus seroprevalence among children, adolescents and adults in Greece

The aim was to study the type-specific seroprevalence of Herpes simplex virus (HSV)-1 and HSV-2 infections and the associated risk factors in children, adolescents and adults in Greece. A total of 1867 serum samples from children, adolescents and adults of both genders aged from 0 to 60 years were collected from three large hospital-referral centres in Athens. All sera were tested for type-specific antibodies to HSV-1 and HSV-2 using HerpeSelect IgG ELISA tests (Focus Diagnostics Cypress, Cal, USA). Overall age-adjusted seroprevalence of HSV-1 and HSV-2 was 72.0% and 10.2%, respectively. HSV-1 seropositivity was low in children up to nine years of age, increased sharply in adolescence, and was higher in females than males in each group surveyed. HSV-2 seropositivity was low (0.8%) below 20 years of age and increased to a maximum prevalence of 18.7% in men and 22.7% in women. Multivariate risk factor analyses indicated that HSV-1 seropositivity was associated with socioeconomic indicators (e.g. lower educational level, residency outside greater Athens), whereas HSV-2 was associated with sexual behavioural factors (e.g. being divorced, greater number of lifetime sexual partners). HSV-2 risk factor profiles were similar in women and in men. This first large seroprevalence study in Greece showed a high age-standardized HSV-1 seropositivity after adolescence and a relatively low age-standardized HSV-2 seroprevalence from birth to 60 years of age. Dual seropositivity to HSV-1 and HSV-2 was low (0.6%) in females under 20 years of age, suggesting that the potential use of an HSV-2 prophylactic vaccine in adolescents could reduce the spread of HSV-2 infection.

Blocking antibody access to neutralizing domains on glycoproteins involved in entry as a novel mechanism of immune evasion by herpes simplex virus type 1 glycoproteins C and E

Herpes simplex virus type 1 (HSV-1) glycoprotein C (gC) blocks complement activation, and glycoprotein E (gE) interferes with IgG Fc-mediated activities. While evaluating gC- and gE-mediated immune evasion in human immunodeficiency virus (HIV)-HSV-1-coinfected subjects, we noted that antibody alone was more effective at neutralizing a strain with mutations in gC and gE (gC/gE) than a wild-type (WT) virus. This result was unexpected since gC and gE are postulated to interfere with complement-mediated neutralization. We used pooled human immunoglobulin G (IgG) from HIV-negative donors to confirm the results and evaluated mechanisms of the enhanced antibody neutralization. We demonstrated that differences in antibody neutralization cannot be attributed to the concentrations of HSV-1 glycoproteins on the two viruses or to the absence of an IgG Fc receptor on the gC/gE mutant virus or to enhanced neutralization of the mutant virus by antibodies that target only gB, gD, or gH/gL, which are the glycoproteins involved in virus entry. Since sera from HIV-infected subjects and pooled human IgG contain antibodies against multiple glycoproteins, we determined whether differences in neutralization become apparent when antibodies to gB, gD, or gH/gL are used in combination. Neutralization of the gC/gE mutant was greatly increased compared that of WT virus when any two of the antibodies against gB, gD, or gH/gL were used in combination. These results suggest that gC and gE on WT virus provide a shield against neutralizing antibodies that interfere with gB-gD, gB-gH/gL, or gD-gH/gL interactions and that one function of virus neutralization is to prevent interactions between these glycoproteins.

A replication-competent, neuronal spread-defective, live attenuated herpes simplex virus type 1 vaccine

Herpes simplex virus type 1 (HSV-1) produces oral lesions, encephalitis, keratitis, and severe infections in the immunocompromised host. HSV-1 is almost as common as HSV-2 in causing first episodes of genital herpes, a disease that is associated with an increased risk of human immunodeficiency virus acquisition and transmission. No approved vaccines are currently available to protect against HSV-1 or HSV-2 infection. We developed a novel HSV vaccine strategy that uses a replication-competent strain of HSV-1, NS-gEnull, which has a defect in anterograde and retrograde directional spread and cell-to-cell spread. Following scratch inoculation on the mouse flank, NS-gEnull replicated at the site of inoculation without causing disease. Importantly, the vaccine strain was not isolated from dorsal root ganglia (DRG). We used the flank model to challenge vaccinated mice and demonstrated that NS-gEnull was highly protective against wild-type HSV-1. The challenge virus replicated to low titers at the site of inoculation; therefore, the vaccine strain did not provide sterilizing immunity. Nevertheless, challenge by HSV-1 or HSV-2 resulted in less-severe disease at the inoculation site, and vaccinated mice were totally protected against zosteriform disease and death. After HSV-1 challenge, latent virus was recovered by DRG explant cocultures from <10% of vaccinated mice compared with 100% of mock-vaccinated mice. The vaccine provided protection against disease and death after intravaginal challenge and markedly lowered the titers of the challenge virus in the vagina. Therefore, the HSV-1 gEnull strain is an excellent candidate for further vaccine development.

The high prevalence of herpes simplex virus type 1 DNA in human trigeminal ganglia is not a function of age or gender

The purpose of this study was to determine the presence and copy numbers of herpes simplex virus type 1 (HSV-1) DNA in human trigeminal ganglia (TG) with respect to age, gender, and postmortem interval (PMI). Human TG (n = 174, obtained from the Oregon Brain Bank, with data on age, gender, and PMI) were analyzed for HSV-1 DNA copies (HSV-1 DNA polymerase gene) by using real-time PCR. We found that 89.1% (131/147) of subjects and 90.1% (155/174) of TG contained HSV-1 DNA. The copy numbers of HSV-1 DNA in the positives ranged from very high (>10(6)) to very low (5). These data confirm and strengthen our previous findings that subjects were positive for HSV-1 DNA in tears (46/50; 92%) and saliva (47/50; 94%). These TG data and tear and saliva data demonstrated considerable variability in copy numbers of HSV-1 DNA per subject. Statistical analysis showed no significant relationship between gender and copy number, age and copy number, or PMI and copy number for each pair of variables. A factorial analysis of gender, age, and PMI with respect to copy number also showed no statistical significance. This is the first study that provides statistical analysis that documents that the prevalence of HSV-1 DNA in the human TG is not a function of either gender or age.

[Genital herpes and HSV transmission in HIV patients]

There is a bidirectional relationship between HSV-2 and HIV-1, both at the cellular level, as well as regarding transmission and even progression of HIV-1 infection. There is clear evidence that anti-herpetic therapy reduces the plasma and mucosal HIV-1 viral load, as well as transmission. Serologic testing for HSV-2 in patients with an increased HIV-1 risk, coupled with a better understanding of the interaction between the viruses and appropriate anti-herpetic suppression therapy could both reduce the HIV-1 transmission rate and help the individual with an HIV infection.

Genital herpes has played a more important role than any other sexually transmitted infection in driving HIV prevalence in Africa

Background

Extensive evidence from observational studies suggests a role for genital herpes in the HIV epidemic. A number of herpes vaccines are under development and several trials of the efficacy of HSV-2 treatment with acyclovir in reducing HIV acquisition, transmission, and disease progression have just reported their results or will report their results in the next year. The potential impact of these interventions requires a quantitative assessment of the magnitude of the synergy between HIV and HSV-2 at the population level.

Methods and Findings

A deterministic compartmental model of HIV and HSV-2 dynamics and interactions was constructed. The nature of the epidemiologic synergy was explored qualitatively and quantitatively and compared to other sexually transmitted infections (STIs). The results suggest a more substantial role for HSV-2 in fueling HIV spread in sub-Saharan Africa than other STIs. We estimate that in settings of high HSV-2 prevalence, such as Kisumu, Kenya, more than a quarter of incident HIV infections may have been attributed directly to HSV-2. HSV-2 has also contributed considerably to the onward transmission of HIV by increasing the pool of HIV positive persons in the population and may explain one-third of the differential HIV prevalence among the cities of the Four City study. Conversely, we estimate that HIV had only a small net impact on HSV-2 prevalence.

Conclusions

HSV-2 role as a biological cofactor in HIV acquisition and transmission may have contributed substantially to HIV particularly by facilitating HIV spread among the low-risk population with stable long-term sexual partnerships. This finding suggests that prevention of HSV-2 infection through a prophylactic vaccine may be an effective intervention both in nascent epidemics with high HIV incidence in the high risk groups, and in established epidemics where a large portion of HIV transmission occurs in stable partnerships.

The role of chemokines during herpes simplex virus-1 infection

Herpes simplex virus-type 1 is among the most prevalent and successful humans pathogens. Although infection is largely uncomplicated in the immunocompetent human host, HSV-1 infection can cause blinding corneal disease, and individuals with defects in innate or adaptive immunity are susceptible to herpes simplex encephalitis. Chemokines regulate leukocyte trafficking to inflamed tissues and play a crucial role in orchestrating the immune response to HSV-1 infection. In this review we will focus on the pathways that induce chemokine expression during HSV-1 infection and the implications of chemokine signaling on control of viral replication.

[Herpes serology for genital herpes]

The epidemiology of genital herpes is changing. The seroprevalence of HSV-2 infections is increasing, while HSV-1 is an increasingly common cause of herpetic ulcerations. The reference examination provides direct diagnosis after viral isolation in a cell culture or genome amplification. Herpes serology is indicated principally if direct examination is negative and in the absence of lesions. Non-type-specific serology detects antibodies common to HSV-1 and HSV-2. Its specificity and sensitivity are excellent, and it is approved as a reimbursable laboratory procedure. It cannot specify the viral type involved. Type-specific serology can distinguish between anti-HSV-1 and anti-HSV-2 antibodies. Currently available kits have a sensitivity and specificity, depending on the population studied, of 90 to 100%. It is not approved as a reimbursable laboratory procedure. HSV-1-specific serology cannot diagnose old HSV-1 genital infections, but seropositivity for HSV-2 generally suffices to diagnose HSV-2 genital herpes. The indication for type-specific serology must be discussed according to clinical context. The value of non-type-specific serology is limited.

Human herpes simplex labialis

Humans are the natural host for eight of more than 80 known herpes viruses. Infections with herpes simplex virus type 1 (HSV-1) are ubiquitous worldwide and highly transmissible. Herpes simplex labialis (HSL) is the best-recognized recrudescent infection of the lips and perioral tissues caused by HSV-1. Facial lesions of HSL may be unsightly, frequent outbreaks unpleasant, and the infection itself more severe locally and systemically in immunocompromised people. This article highlights the pathogenesis, clinical presentation, diagnostic features and management issues for HSL.

Seroprevalences of herpes simplex virus type 2, five oncogenic human papillomaviruses, and Chlamydia trachomatis in Katowice, Poland

Herpes simplex virus type 2 (HSV-2), human papillomaviruses (HPVs), and Chlamydia trachomatis are the most common pathogens causing sexually transmitted infections (STIs). There is limited information about the prevalences of these STIs in Poland. Here, we estimated the occurrence of immunoglobulin G (IgG) antibodies against HSV-2, HPV, and C. trachomatis in 199 blood donors and 110 patients of both genders attending an STI clinic in Katowice in southern Poland. The seroprevalences of HSV-2 were 5% for blood donors and 14% in the STI cohort. The seroprevalences of the five potentially oncogenic HPV types 16, 18, 31, 35, and 51 were 15%, 7%, 5%, 5%, and 17%, respectively, in blood donors and 37%, 8%, 12%, 5%, and 21%, respectively, in the STI cohort. The majority of HPV-infected individuals showed antibodies against more than one type, i.e., had been infected with multiple HPV types. Anti-C. trachomatis IgG antibodies were detected in 6% of blood donors and 13% of individuals attending the STI clinic. The relatively high prevalence of HPV-51 may have implications for future vaccine programs, as the newly introduced HPV vaccines are based on the potentially oncogenic HPV types 16 and 18.

Selective ablation of virion host shutoff protein RNase activity attenuates herpes simplex virus 2 in mice

The virion host shutoff (vhs) protein of herpes simplex virus (HSV) has endoribonuclease activity and rapidly reduces protein synthesis in infected cells through mRNA degradation. Herpes simplex virus 1 (HSV-1) and HSV-2 vhs mutants are highly attenuated in vivo, but replication and virulence are largely restored to HSV-2 vhs mutants in the absence of a type I interferon (IFN) response. The role of vhs in pathogenesis and the hindrance of the type I IFN response have classically been examined with viruses that completely lack vhs or express a truncated vhs protein. To determine whether RNase activity is the principal mechanism of vhs-mediated type I IFN resistance and virulence, we constructed a HSV-2 point mutant that synthesizes full-length vhs protein lacking RNase activity (RNase(-) virus). Wild-type and mutant HSV-2 vhs proteins coimmunoprecipitated with VP16 and VP22. vhs protein bearing the point mutation was packaged into the virion as efficiently as the wild-type vhs protein. Like a mutant encoding truncated vhs, the RNase(-) virus showed IFN-dependent replication that was restricted compared with that of the wild-type virus. The RNase(-) virus was highly attenuated in wild-type mice infected intravaginally, with reduced mucosal replication, disease severity, and spread to the nervous system comparable to those of the vhs truncation mutant. Surprisingly, in alpha/beta interferon (IFN-alpha/beta) receptor knockout mice, the vhs RNase mutant was more attenuated than the vhs truncation mutant in terms of disease severity and virus titer in vaginal swabs and central nervous system samples, suggesting that non-enzymatically active vhs protein interferes with efficient virus replication. Our results indicate that vhs enzymatic activity plays a complex role in vhs-mediated type I IFN resistance during HSV-2 infection.

Third trimester antiviral prophylaxis for preventing maternal genital herpes simplex virus (HSV) recurrences and neonatal infection

BACKGROUND

Genital herpes simplex virus (HSV) infection is one of the most common viral sexually transmitted infections. The majority of women with genital herpes will have a recurrence during pregnancy. Transmission of the virus from mother to fetus typically occurs by direct contact with virus in the genital tract during birth.

OBJECTIVES

To assess the effectiveness of antenatal antiviral prophylaxis for recurrent genital herpes on neonatal herpes and maternal recurrences at delivery.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 4), MEDLINE (January 1966 to February 2007) and EMBASE (January 1974 to February 2007; handsearched conference proceedings; reviewed bibliographies of all relevant articles for further references; and contacted experts in the field.

SELECTION CRITERIA

Randomized controlled trials which assessed the effectiveness of antivirals compared to placebo or no therapy, on neonatal herpes and maternal disease endpoints among pregnant women with genital herpes.

DATA COLLECTION AND ANALYSIS

Two authors independently applied study selection criteria and extracted data.

MAIN RESULTS

Seven randomized controlled trials (1249 participants) which met our inclusion criteria compared acyclovir to placebo or no treatment (five trials) and valacyclovir to placebo (two trials). The effect of antepartum antiviral prophylaxis on neonatal herpes could not be estimated. There were no cases of symptomatic neonatal herpes in the included studies in either the treatment or placebo groups. Women who received antiviral prophylaxis were significantly less likely to have a recurrence of genital herpes at delivery (relative risk (RR) 0.28, 95% confidence interval (CI) 0.18 to 0.43, I(2 )= 0%). Women who received antiviral prophylaxis were also significantly less likely to have a cesarean delivery for genital herpes (RR 0.30, 95% CI 0.20 to 0.45, I(2) = 27.3%). Women who received antiviral prophylaxis were significantly less likely to have HSV detected at delivery (RR 0.14, 95% CI 0.05 to 0.39, I(2) = 0%).

AUTHORS' CONCLUSIONS

Women with recurrent genital herpes simplex virus should be informed that the risk of neonatal herpes is low. There is insufficient evidence to determine if antiviral prophylaxis reduces the incidence of neonatal herpes. Antenatal antiviral prophylaxis reduces viral shedding and recurrences at delivery and reduces the need for cesarean delivery for genital herpes. Limited information exists regarding the neonatal safety of prophylaxis. The risks, benefits, and alternatives to antenatal prophylaxis should be discussed with women who have a history and prophylaxis initiated for women who desire intervention.

The prevalence of human herpesvirus 6 in human sensory ganglia and its co-occurrence with alpha-herpesviruses

Human herpesvirus 6 (HHV-6) persists in the central nervous system, but its prevalence in the peripheral nervous system, a preferred latency site for herpesviruses, has not been studied. Using nested polymerase chain reaction (PCR), the authors determined the distribution of HHV-6 in human sensory ganglia. HHV-6 was present in 30% of trigeminal, 40% of geniculate, 25% of vestibular, and 55% of dorsal root ganglia. It co-occurred with alpha-herpesviruses (herpes simplex virus type 1 or varicella-zoster virus) in 91% of the ganglia. As HHV-6 positivity did not depend on the presence of inflammatory cells, known to harbor the virus, HHV-6 probably resides in the ganglia themselves.

An HSV-1 gD mutant virus as an entry-impaired live virus vaccine

HSV-1 glycoprotein D (gD) interacts with HVEM and nectin-1 cell receptors to initiate virus entry. We prepared an HSV-1 strain with mutations in the gD gene at amino acid residues 3 and 38 by changing alanine to cysteine and tyrosine to cysteine, respectively (A3C/Y38C). These mutations were constructed with the intent of evaluating infection in vivo when virus enters by HVEM but not nectin-1 receptors and were based on prior reports demonstrating that purified gDA3C/Y38C protein binds to HVEM but not to nectin-1. While preparing a high-titered purified virus pool, the cysteine mutation at position 38 reverted to tyrosine, which occurred on two separate occasions. The resultant HSV-1 strain, KOS-gDA3C, had a single amino acid mutation at residue 3 and exhibited reduced entry into both HVEM and nectin-1 expressing cells. When tested in the murine flank model, the mutant virus was markedly attenuated for virulence and caused only mild disease, while the parental and rescued viruses produced much more severe disease. Thirty days after KOS-gDA3C infection, mice were challenged with a lethal dose of HSV-1 and were highly resistant to disease. The KOS-gDA3C mutation was stable during 30 passages in vitro and was present in each of 3 isolates obtained from infected mice. Therefore, this gD mutant virus impaired in entry may represent a novel candidate for an attenuated live HSV-1 vaccine.

Inhibitory effect of essential oils against herpes simplex virus type 2

Essential oils from anise, hyssop, thyme, ginger, camomile and sandalwood were screened for their inhibitory effect against herpes simplex virus type 2 (HSV-2) in vitro on RC-37 cells using a plaque reduction assay. Genital herpes is a chronic, persistent infection spreading efficiently and silently as sexually transmitted disease through the population. Antiviral agents currently applied for the treatment of herpesvirus infections include acyclovir and its derivatives. The inhibitory concentrations (IC50) were determined at 0.016%, 0.0075%, 0.007%, 0.004%, 0.003% and 0.0015% for anise oil, hyssop oil, thyme oil, ginger oil, camomile oil and sandalwood oil, respectively. A clearly dose-dependent virucidal activity against HSV-2 could be demonstrated for all essential oils tested. In order to determine the mode of the inhibitory effect, essential oils were added at different stages during the viral infection cycle. At maximum noncytotoxic concentrations of the essential oils, plaque formation was significantly reduced by more than 90% when HSV-2 was preincubated with hyssop oil, thyme oil or ginger oil. However, no inhibitory effect could be observed when the essential oils were added to the cells prior to infection with HSV-2 or after the adsorption period. These results indicate that essential oils affected HSV-2 mainly before adsorption probably by interacting with the viral envelope. Camomile oil exhibited a high selectivity index and seems to be a promising candidate for topical therapeutic application as virucidal agents for treatment of herpes genitalis.

Risk factors for herpes simplex virus type 2 and HIV among women at high risk in northwestern Tanzania: preparing for an HSV-2 intervention trial

OBJECTIVES

To determine prevalence of and risk factors for herpes simplex virus type 2 (HSV-2) and HIV among women being screened for a randomized, controlled trial of HSV suppressive therapy in northwestern Tanzania.

METHODS

Two thousand seven hundred nineteen female facility workers aged 16 to 35 were interviewed and underwent serological testing for HIV and HSV-2. Factors associated with HSV-2 and HIV in women aged 16 to 24 were examined using logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

HSV-2 seroprevalence was 80%, and HIV seroprevalence was 30%. Among women aged 16 to 24, both infections were significantly and independently associated with older age, being a bar worker, working at a truck stop, and having more lifetime sexual partners. HSV-2 infection was also associated with lower socioeconomic status, increased alcohol intake, younger age at first sex, inconsistent condom use, and vaginal douching. There was a strong association between the 2 infections after adjustment for other factors (OR = 4.22, 95% CI: 2.6 to 6.9).

CONCLUSIONS

Female facility workers in northwestern Tanzania are vulnerable to HSV-2 and HIV infections. Programs designed to increase safer sexual behavior and reduce alcohol use could be effective in reducing HSV-2 incidence and, in turn, HIV infection. This is a suitable population for an HSV suppressive therapy trial.

Use of commercial enzyme immunoassays to detect antibodies to the herpes simplex virus type 2 glycoprotein G in a low-risk population in Hanoi, Vietnam

Sera from 1,238 Vietnamese women in Hanoi were tested for herpes simplex virus type 2 (HSV-2). HSV-2 prevalence was 2.0%. The Kalon and Biokit assays showed significantly higher concordance to Western blotting data than did the Focus assay (P < 0.01). Screening by Focus and then retesting with Kalon/Biokit of positive samples can reduce falsely positive results significantly (P < 0.01).

CD8 T cell control of HSV reactivation from latency is abrogated by viral inhibition of MHC class I

In humans, herpes simplex virus (HSV) establishes latency in sensory nerve ganglia from where it periodically reactivates, whereas in murine models, the virus efficiently establishes latency but rarely reactivates. HSV inhibits MHC class I antigen presentation to CD8 T cells efficiently in humans but poorly in mice, and whether this is a crucial determinant of HSV's ability to reactivate in humans remains uncertain. To test this, we generated a panel of recombinant HSVs that inhibit presentation by murine MHC class I mimicking the effect in humans. Antigen-specific CD8 T cells prevent the in vivo reactivation of wild-type HSV. Despite their presence in the ganglia of latently infected mice, CD8 T cells do not prevent the reactivation of recombinant HSVs that inhibit murine MHC class I in mice. These findings suggest that efficient inhibition of MHC class I by HSV is a key factor in its ability to reactivate in humans.

Herpes simplex virus type 2 seroprevalence in Korea: rapid increase of HSV-2 seroprevalence in the 30s in the southern part

To determine the characteristics of seroprevalence of herpes simplex virus type 2 (HSV-2) infection among Korean people, a cross-sectional study was conducted on three groups in 2004. The three groups consisted of the general public who visited public health centers, commercial sex workers (CSWs), and human immunodeficiency virus (HIV)-infected persons. Among the general public, HSV-2 seroprevalence rates for age under the 20s, in the 20s, 30s, 40s and the above 22.6%, 32.7% and 32.3%, respectively, which showed rapid increase of the rate in the 30s (p<0.0001). In case of the above of 19 yr old, women (28.0%) was higher than men (21.7%) (p<0.0001). The rate of CSWs (81.6%) was about 10 times higher than that of general women. In case of HIV-infected men (47.6%), the figure was about 2-3 times higher than that of general men. The low rate in the teens and the 20s proved that it is essential to develop sexually transmitted infections (STIs) prevention programs of education and publicity for them as a precaution measure. This study is the first major study of its kind on HSV-2 and would provide basic data for prevention of STIs including information about target groups subject to vaccination program.

The neurotropic herpes viruses: herpes simplex and varicella-zoster

Herpes simplex viruses types 1 and 2 (HSV1 and HSV2) and varicella-zoster virus (VZV) establish latent infection in dorsal root ganglia for the entire life of the host. From this reservoir they can reactivate to cause human morbidity and mortality. Although the viruses vary in the clinical disorders they cause and in their molecular structure, they share several features that affect the course of infection of the human nervous system. HSV1 is the causative agent of encephalitis, corneal blindness, and several disorders of the peripheral nervous system; HSV2 is responsible for meningoencephalitis in neonates and meningitis in adults. Reactivation of VZV, the pathogen of varicella (chickenpox), is associated with herpes zoster (shingles) and central nervous system complications such as myelitis and focal vasculopathies. We review the biological, medical, and neurological aspects of acute, latent, and reactivated infections with the neurotropic herpes viruses.

Human immunodeficiency virus-1 infection correlates strongly with herpes simplex virus-2 (genital herpes) seropositivity in South African and United States blood donations

BACKGROUND

In South Africa, human immunodeficiency virus-1 (HIV-1) infection correlates with herpes simplex virus-2 (HSV-2; genital herpes) seropositivity in genitourinary disease clinic attendees. HSV-2 infection may be a marker for risk behavior and/or directly facilitate HIV-1 transmission. The rate of HSV-2 infection in HIV-infected South African and US blood donations was assessed, and whether the infections were correlated in donors screened and found negative for high-risk behavior by predonation interview was questioned.

STUDY DESIGN AND METHODS

A total of 625 South African and 393 US HIV-1-infected repository samples previously characterized for longstanding or recent HIV-1 infection were tested with two commercially available HSV-2-specific assays. The prevalence of HSV-2 antibodies in South Africa was further assessed in 106 HIV-1-infected and 106 HIV-1-negative donors matched for sex, race, and donation history, as well as 200 random HIV-1-negative donors.

RESULTS

A total of 52.2 percent of US and 69.3 percent of South African HIV-1-infected donations were HSV-2-seropositive. Age, race, and sex were independent risk factors for HSV-2 antibody prevalence in HIV-1-infected South African donors, who were more likely to be HSV-2 antibody-reactive than random HIV-1-negative donors (72.6% vs. 8.5%: odds ratio [OR], 28.6; 95% confidence interval [CI], 14.5-55) or matched donors (71.6% vs. 19.6%: OR, 10.3; 95% CI, 5.4-19.8). HIV-1 infection and HSV-2 seropositivity correlated in white and black populations when analyzed by age group.

CONCLUSIONS

HIV-1 infection correlates strongly with HSV-2 seropositivity in US and South African blood donors. Our data describe the characteristics of HSV-2 antibody testing as a surrogate marker for HIV-1 infection and support a facilitating role for HSV-2 infection in HIV-1 transmission.

Human herpes simplex virus infections: epidemiology, pathogenesis, symptomatology, diagnosis, and management

Eight of the more than 80 known herpesviruses are human pathogens. Human herpes simplex virus (HSV) is a contagious infection with a large reservoir in the general population. It has a potential for significant complications in the immunocompromised host. In addition, psychological distress caused by the negative stigma associated with genital herpes and visible facial lesions in those experiencing frequent outbreaks renders it a challenging clinical dilemma. This article reviews the epidemiology, pathogenesis, and diagnostic features of HSV infections, providing the clinician with an up-to-date understanding of the available management strategies for mucocutaneous HSV-induced disease.

HIV-1/HSV-2 co-infected adults in early HIV-1 infection have elevated CD4+ T cell counts

INTRODUCTION

HIV-1 is often acquired in the presence of pre-existing co-infections, such as Herpes Simplex Virus 2 (HSV-2). We examined the impact of HSV-2 status at the time of HIV-1 acquisition for its impact on subsequent clinical course, and total CD4+ T cell phenotypes.

METHODS

We assessed the relationship of HSV-1/HSV-2 co-infection status on CD4+ T cell counts and HIV-1 RNA levels over time prior in a cohort of 186 treatment naïve adults identified during early HIV-1 infection. We assessed the activation and differentiation state of total CD4+ T cells at study entry by HSV-2 status.

RESULTS

Of 186 recently HIV-1 infected persons, 101 (54%) were sero-positive for HSV-2. There was no difference in initial CD8+ T cell count, or differences between the groups for age, gender, or race based on HSV-2 status. Persons with HIV-1/HSV-2 co-infection sustained higher CD4+ T cell counts over time (+69 cells/ul greater (SD = 33.7, p = 0.04) than those with HIV-1 infection alone (Figure 1), after adjustment for HIV-1 RNA levels (-57 cells per 1 log(10) higher HIV-1 RNA, p<0.0001). We did not observe a relationship between HSV-2 infection status with plasma HIV-1 RNA levels over time. HSV-2 acquisition after HIV-1 acquisition had no impact on CD4+ count or viral load. We did not detect differences in CD4+ T cell activation or differentiation state by HSV-2+ status.

DISCUSSION

We observed no effect of HSV-2 status on viral load. However, we did observe that treatment naïve, recently HIV-1 infected adults co-infected with HSV-2+ at the time of HIV-1 acquisition had higher CD4+ T cell counts over time. If verified in other cohorts, this result poses a striking paradox, and its public health implications are not immediately clear.

Rise in seroprevalence of herpes simplex virus type 1 among highly sexual active homosexual men and an increasing association between herpes simplex virus type 2 and HIV over time (1984-2003)

Objectives Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) are both highly prevalent. The rate of genital HSV-1 transmission is reportedly increasing over time. HSV-2 is considered to be an important risk factor for HIV transmission. We therefore studied changes in the HSV-1 and HSV-2 prevalence in a large cohort of men who have sex with men (MSM) over a 20-year time period. Methods Among 1847 HIV-infected and HIV-uninfected MSM participating in the Amsterdam Cohort Studies, seroprevalence of HSV-1 and HSV-2 was determined and prevalence rate ratios (PRR) and 95% confidence intervals were calculated. Results Between 1984 and 2003 the HSV-1 and HSV-2 prevalence decreased among HIV-uninfected MSM (P < 0.001), but remained stable among HIV-infected MSM. HSV-1 prevalence increased among men with at least 200 sexual partners over lifetime (PRR: 1.49, P < 0.001). The association between HIV infection and HSV-2 became stronger over time (PRR: 3.45, P < 0.001). Conclusions Seroprevalence of HSV-1 and HSV-2 remained high among HIV infected MSM from 1984 to 2003. The association of HIV and HSV-2 increased during the HIV epidemic. Since the proportion of sexual transmission of HSV-1 is rising, it is important to study the potential role of HSV-1 as risk factor for HIV acquisition.

Seroprevalence of herpes simplex virus type 1 in children in the United States

OBJECTIVES

To describe HSV-1 seroprevalence in children in the United States and to examine factors associated with herpes simplex virus type 1 (HSV-1) infection in children.

STUDY DESIGN

Sera samples available from 2989 children age 6 to 13 years who participated in the National Health and Nutrition Examination Surveys (NHANES) 1999-2002 were tested for HSV-1 antibodies using a type-specific immunodot assay. HSV-1 seroprevalence in children age 12 to 13 years was compared with that reported in an earlier survey (NHANES 1988-1994).

RESULTS

Overall, HSV-1 seroprevalence in children age 6 to 13 years was 31.1% (95% confidence interval [CI], 28.6% to 33.9%). Seroprevalence increased with age, from 26.3% in 6- to 7-year-olds to 36.1% in 12-to 13-year-olds, and varied by race/ethnicity, birthplace, and poverty level. Among US-born children age 12 to 13 years, the point estimate of HSV-1 seroprevalence was lower in NHANES 1999-2002 than in NHANES 1988-1994 (34.3% vs 38.1%), but the differences were not statistically significant.

CONCLUSIONS

HSV-1 is a common infection in US children, with more than 25% infected by age 7. Race/ethnicity, birthplace, and poverty level are predictors for HSV-1 infection in children.

Early acquisition of herpes simplex virus type 1 antibodies in children—A longitudinal serological study

BACKGROUND

Herpes simplex virus type 1 (HSV-1) infections are commonly acquired in childhood, asymptomatically or as a symptomatic infection. However, little is known about the time of HSV seroconversion during infancy and early childhood.

OBJECTIVE

To investigate the acquisition of IgG-antibodies to HSV in infants and children.

STUDY DESIGN

A longitudinal study, using type-specific HSV-1 and herpes simplex virus type 2 (HSV-2) enzyme-linked immunosorbent assays on sera collected from the mother and from their child at the age of 3, 5, 6, 12, 13 and 30 months.

RESULTS

The maternal seroprevalences for HSV-1 was 65% and for HSV-2 19%. A gradual loss of maternal antibodies was seen, with few infants having detectable HSV-1 antibodies at the age of 1 year. A more rapid decline was registered for HSV-2 antibodies. A small number of new HSV-1 infections occurred in 3-5-month olds and more than half of the new infections were detected before the age of 13 months. At the age of 30 months, 30% of the children were HSV-1 antibody positive.

CONCLUSION

Seroconversion to HSV-1 commonly occurs already during infancy, suggesting that HSV-1 is transmitted primarily from parent to child.

Asymptomatic shedding of herpes simplex virus (HSV) in the oral cavity

OBJECTIVE

The aim of this study was to investigate the rate of herpes simplex virus (HSV) shedding from the oral cavity, because recent studies suggest that shedding is more frequent than originally reported. Factors that could influence the rate and duration of shedding from the oral cavity were examined.

METHODS

Existing epidemiologic data from 22 reports of HSV shedding from more than 3,500 individuals were analyzed with regard to demographics, frequency of sampling, and methodologic assays.

RESULTS

HSV-1 was more likely to be detected than HSV-2 in the oral cavity of asymptomatic persons (7.5 odds ratio, 95% confidence interval 4.4-12.8; P < .0001). The rate of shedding was highly variable among individuals, ranging from none to 92% of days tested, and occurred in seropositive and seronegative individuals. In cell culture studies, the rate of detection on a single day was 6.3%. Polymerase chain reaction studies provided a different picture. HSV-1 DNA was present in 97 of 180 patients (53.9%) at multiple visits, with a rate of daily detection of 33.3%. The mean duration of shedding was between 1 and 3 days, but more than 3 days in about 10% of patients.

CONCLUSIONS

At least 70% of the population shed HSV-1 asymptomatically at least once a month, and many individuals appear to shed HSV-1 more than 6 times per month. Shedding of HSV-1 is present at many intraoral sites, for brief periods, at copy numbers sufficient to be transmitted, and even in seronegative individuals. The dental implications of these findings are discussed.

Asymptomatic shedding of HSV-1 in patients undergoing oral surgical procedures and attending for noninvasive treatment

Oral surgery and stress can trigger and/or increase asymptomatic shedding of herpes simplex virus type-1 (HSV-1) into human saliva. In this investigation we examined the frequency of HSV-1 shedding in 32 patients undergoing an oral surgery procedure compared with 40 control patients attending for noninvasive treatment. Control patients comprised 18 migraine patients and 22 patients with temporomandibular (TMD) joint problems. Nested-PCR was carried out on oral rinses collected from each patient prior to treatment and 7 days post-treatment. Fifty-two of sixty-one seropositive patients were positive for HSV-1 DNA in one or both oral rinses. The frequencies of HSV-1 shedding for the oral surgery and control patients were 84.6% and 85.7% respectively. Seropositive patients who started shedding after treatment were significantly higher in oral surgery patients (46.2%) compared to control patients (34.3%). Shedding of HSV-1 in the oral cavity is not only increased by direct surgical trauma, but also appears to be common in migraine and TMD patients attending for general dental treatment. Thus pain or pain-induced stress as well as anxiety associated with dental treatment may also be a risk factor for asymptomatic shedding in specific seropositive patients attending for dental treatment.

Herpes simplex virus type 2 (HSV-2) infection in women attending an antenatal clinic in the South Pacific island nation of Vanuatu

OBJECTIVE

The objective of this study was to estimate the prevalence and correlates of herpes simplex virus type 2 infection in women in an antenatal clinic in the South Pacific island nation of Vanuatu.

STUDY DESIGN

A prevalence survey of sexually transmitted infections of pregnant women attending an antenatal clinic at Vila Central Hospital was conducted in 1999-2000. Serum samples were tested for HSV-1 and HSV-2 antibodies by enzyme-linked immunosorbent assay. Results for other sexually transmitted infections and demographic and obstetric variables were analyzed for their association with HSV-2 serostatus.

RESULTS

HSV-2 serum antibody results were obtained on 535 women and HSV-1 results on 134. The seroprevalence of HSV-2 was 30% and HSV-1 was 100%. On multivariate analysis, the independent predictors of HSV-2 infection were age, marital status, and trichomoniasis.

CONCLUSIONS

HSV-2 was common in this sample of sexually active women in Vanuatu. This is the first study of HSV in Vanuatu and one of very few studies in the Pacific region.

Cutting edge: recombinant Listeria monocytogenes expressing a single immune-dominant peptide confers protective immunity to herpes simplex virus-1 infection

The vast majority of the world's population is infected with HSV. Although antiviral therapy can reduce the incidence of reactivation and asymptomatic viral shedding, and limit morbidity and mortality from active disease, it cannot cure infection. Therefore, the development of an effective vaccine is an important global health priority. In this study, we demonstrate that recombinant Listeria monocytogenes (Lm) expressing the H-2K(b) glycoprotein B (gB)(498-505) peptide from HSV-1 triggers a robust CD8 T cell response to this Ag resulting in protective immunity to HSV infection. Following challenge with HSV-1, immune-competent mice primed with recombinant Lm-expressing gB(498-505) Ag were protected from HSV-induced paralysis. Protection was associated with dramatic reductions in recoverable virus, and early expansion of HSV-1-specific CD8 T cells in the regional lymph nodes. Thus, recombinant Lm-expressing Ag from HSV represents a promising new class of vaccines against HSV infection.

Longitudinal study of herpes simplex virus type 2 infection using viral dynamic modelling

OBJECTIVES

Rates of reactivation of herpes simplex virus type 2 (HSV-2) change over time and these changes affect transmission and clinical management strategies. We conducted a longitudinal study of HSV-2 infection to quantify rates of change in HSV-2 reactivation, mucosal shedding and recurrences of genital lesions, using a newly available model of HSV within-host dynamics.

METHODS

A cohort of 18 women was studied at two time periods spaced 2 years apart. The cohort provided daily mucosal swabs for HSV PCR analysis for 10 weeks during each time period and recorded recurrences in diaries. We fit the model of HSV dynamics to the mucosal shedding data using Bayesian methods to produce estimates of HSV reactivation, shedding and longitudinal rates of change. The model was validated using a separate group of 67 individuals.

RESULTS

According to the viral dynamic modelling results, rates of HSV-2 reactivation from latency in the ganglia varied >10-fold among the women, and were estimated to be > or = 10% higher than rates of mucosal shedding episodes for many individuals. The mucosal shedding associated with each reactivation typically lasted 1-3 days. Reactivation frequency was estimated to be declining by three reactivations a year on average. The median number of recurrences, based on patient diaries, declined from 6.8 per year to 2.1 per year over the 2-year period.

CONCLUSIONS

Rates of HSV-2 reactivation, shedding and recurrence generally decline over time but remain high in some individuals 4-5 years after primary infection. Viral dynamic modelling provides quantification of HSV infection that cannot be obtained by other methods.