Serologic analysis of first-episode nonprimary genital herpes simplex virus infection. Presence of type 2 antibody in acute serum samples

G, Ballesteros P. P, Valenzuela L. G, Roncone D. E. Tumor-like presentation of herpetic cervicitis: A case report

The case of a 20-year-old immunocompetent woman with necrotizing cervicitis of the cervix caused by a primary infection with herpes simplex virus type 2 is presented, along with its respective evolution in images. Cervical cancer was included in the differential diagnoses, but biopsies ruled out malignancy and laboratory tests demonstrated the viral etiology of the cervical inflammation. After initiating specific treatment, the cervical lesions completely healed within 3 weeks. This case highlights the need to consider herpes simplex infection in the differential diagnosis of cervical inflammation and tumor formation. Additionally, it provides images that can aid in diagnosis and allow for the observation of its clinical evolution.

Diagnosis and Treatment of Sexually Transmitted Infections: A Review

IMPORTANCE

Approximately 1 in 5 adults in the US had a sexually transmitted infection (STI) in 2018. This review provides an update on the epidemiology, diagnosis, and treatment of gonorrhea, chlamydia, syphilis, Mycoplasma genitalium, trichomoniasis, and genital herpes.

OBSERVATIONS

From 2015 to 2019, the rates of gonorrhea, chlamydia, and syphilis increased in the US; from 1999 to 2016, while the rates of herpes simplex virus type 1 (HSV-1) and HSV-2 declined. Populations with higher rates of STIs include people younger than 25 years, sexual and gender minorities such as men and transgender women who have sex with men, and racial and ethnic minorities such as Black and Latinx people. Approximately 70% of infections with HSV and trichomoniasis and 53% to 100% of extragenital gonorrhea and chlamydia infections are asymptomatic or associated with few symptoms. STIs are associated with HIV acquisition and transmission and are the leading cause of tubal factor infertility in women. Nucleic acid amplification tests have high sensitivities (86.1%-100%) and specificities (97.1%-100%) for the diagnosis of gonorrhea, chlamydia, M genitalium, trichomoniasis, and symptomatic HSV-1 and HSV-2. Serology remains the recommended method to diagnose syphilis, typically using sequential testing to detect treponemal and nontreponemal (antiphospholipid) antibodies. Ceftriaxone, doxycycline, penicillin, moxifloxacin, and the nitroimidazoles, such as metronidazole, are effective treatments for gonorrhea, chlamydia, syphilis, M genitalium, and trichomoniasis, respectively, but antimicrobial resistance limits oral treatment options for gonorrhea and M genitalium. No cure is available for genital herpes. Effective STI prevention interventions include screening, contact tracing of sexual partners, and promoting effective barrier contraception.

CONCLUSIONS AND RELEVANCE

Approximately 1 in 5 adults in the US had an STI in 2018. Rates of gonorrhea, chlamydia, and syphilis in the US have increased, while rates of HSV-1 and HSV-2 have declined. Ceftriaxone, doxycycline, penicillin, moxifloxacin, and the nitroimidazoles are effective treatments for gonorrhea, chlamydia, syphilis, Mycoplasma genitalium, and trichomoniasis, respectively, but antimicrobial resistance limits oral therapies for gonorrhea and Mycoplasma genitalium, and no cure is available for genital herpes.

Pathogenesis and virulence of herpes simplex virus

Two of the most prevalent human viruses worldwide, herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2, respectively), cause a variety of diseases, including cold sores, genital herpes, herpes stromal keratitis, meningitis and encephalitis. The intrinsic, innate and adaptive immune responses are key to control HSV, and the virus has developed mechanisms to evade them. The immune response can also contribute to pathogenesis, as observed in stromal keratitis and encephalitis. The fact that certain individuals are more prone than others to suffer severe disease upon HSV infection can be partially explained by the existence of genetic polymorphisms in humans. Like all herpesviruses, HSV has two replication cycles: lytic and latent. During lytic replication HSV produces infectious viral particles to infect other cells and organisms, while during latency there is limited gene expression and lack of infectious virus particles. HSV establishes latency in neurons and can cause disease both during primary infection and upon reactivation. The mechanisms leading to latency and reactivation and which are the viral and host factors controlling these processes are not completely understood. Here we review the HSV life cycle, the interaction of HSV with the immune system and three of the best-studied pathologies: Herpes stromal keratitis, herpes simplex encephalitis and genital herpes. We also discuss the potential association between HSV-1 infection and Alzheimer's disease.

Genital Herpes: Insights into Sexually Transmitted Infectious Disease

Etiology, transmission and protection: Herpes simplex virus-2 (HSV-2) is a leading cause of sexually transmitted infections with recurring manifestations throughout the lifetime of infected hosts. Currently no effective vaccines or prophylactics exist that provide complete protection or immunity from the virus, which is endemic throughout the world. Pathology/Symptomatology: Primary and recurrent infections result in lesions and inflammation around the genital area and the latter accounts for majority of genital herpes instances. Immunocompromised patients including neonates are susceptible to additional systemic infections including debilitating consequences of nervous system inflammation. Epidemiology, incidence and prevalence: More than 500 million people are infected worldwide and most reported cases involve the age groups between 16-40 years, which coincides with an increase in sexual activity among this age group. While these numbers are an estimate, the actual numbers may be underestimated as many people are asymptomatic or do not report the symptoms. Treatment and curability: Currently prescribed medications, mostly nucleoside analogs, only reduce the symptoms caused by an active infection, but do not eliminate the virus or reduce latency. Therefore, no cure exists against genital herpes and infected patients suffer from periodic recurrences of disease symptoms for their entire lives. Molecular mechanisms of infection: The last few decades have generated many new advances in our understanding of the mechanisms that drive HSV infection. The viral entry receptors such as nectin-1 and HVEM have been identified, cytoskeletal signaling and membrane structures such as filopodia have been directly implicated in viral entry, host motor proteins and their viral ligands have been shown to facilitate capsid transport and many host and HSV proteins have been identified that help with viral replication and pathogenesis. New understanding has emerged on the role of autophagy and other innate immune mechanisms that are subverted to enhance HSV pathogenesis. This review summarizes our current understanding of HSV-2 and associated diseases and available or upcoming new treatments.

Clinical assessment of assays for diagnosis of herpes simplex infection

It is becoming increasingly clear that the herpes simplex viruses (HSVs) 1 and 2 constitute a major, global, public health problem, particularly as genital herpes is implicated in the causation of a significant percentage of onwards transmission of the HIV virus. A major factor in the transmission of HSV is that most carriers are unaware of their diagnosis. In the last few years, the development of nucleic acid amplification technology and type-specific antibody serology to test for HSV-1 and -2 has contributed significantly to the accurate diagnosis of these infections. Despite guidance to the contrary, there is still much use of less sensitive tests such as viral culture and antibody testing based on crude antigen. It is essential that we use the most sensitive and specific diagnostic tests if we are to curb this epidemic.

Epidemiology, clinical presentation, and antibody response to primary infection with herpes simplex virus type 1 and type 2 in young women

BACKGROUND

Herpes simplex virus infections type 1 (HSV-1) and type 2 (HSV-2) are common, but the epidemiology of HSV disease is changing.

METHODS

HSV-seronegative women, aged 18-30 years, who were in the control arm of the HERPEVAC Trial for Women were followed for 20 months for primary HSV infections.

RESULTS

Of the 3438 evaluable participants, 183 became infected with HSV: 127 (3.7%) with HSV-1 and 56 (1.6%) with HSV-2. The rate of infection for HSV-1 (2.5 per 100 person-years) was more than twice that for HSV-2 (1.1 per 100 person-years). Most infections (74% of HSV-1 and 63% of HSV-2) occurred without recognized signs or symptoms of herpes disease. The HSV-2 infection rate was 2.6 times higher in non-Hispanic black participants than in Hispanics and 5.5 times higher than in non-Hispanic whites (P < .001), while the HSV-1 infection rate was 1.7 times higher in non-Hispanic whites than non-Hispanic blacks. Younger participants (18-22 years) were more likely to acquire HSV-1 infections and less likely to develop recognized disease than older participants. Overall, 84% of recognized disease cases were genital. No differences were noted in the clinical manifestations of genital HSV-1 vs genital HSV-2 disease. The clinicians' assessment that cases were caused by HSV was good when they assessed cases as clinically confirmed or unlikely (validated in 83% and 100% of cases, respectively).

CONCLUSIONS

HSV-1 is now more common than HSV-2 as a cause of oral and genital mucosal infections in young women, but there are important age and race differences.

Persistent genital herpes simplex virus-2 shedding years following the first clinical episode

BACKGROUND

Patients with newly acquired genital herpes simplex virus 2 (HSV-2) infection have virus frequently detected at the genital mucosa. Rates of genital shedding initially decrease over time after infection, but data on long-term viral shedding are lacking.

METHODS

For this study, 377 healthy adults with history of symptomatic genital HSV-2 infection collected anogenital swabs for HSV-2 DNA polymerase chain reaction for at least 30 consecutive days.

RESULTS

Time since first genital herpes episode was significantly associated with reduced genital shedding. Total HSV shedding occurred on 33.6% of days in participants <1 year, 20.6% in those 1-9 years, and 16.7% in those ≥10 years from first episode. Subclinical HSV shedding occurred on 26.2% of days among participants <1 year, 13.1% in those 1-9 years, and 9.3% in those ≥10 years from first episode. On days with HSV detection, mean quantity was 4.9 log₁₀ copies/mL for those <1 year, 4.7 log₁₀ copies/mL among those 1-9 years, and 4.6 log₁₀ copies/mL among those ≥10 years since first episode.

CONCLUSIONS

Rates of total and subclinical HSV-2 shedding decrease after the first year following the initial clinical episode. However, viral shedding persists at high rates and copy numbers years after infection, and therefore may pose continued risk of HSV-2 transmission to sexual partners.

New concepts in understanding genital herpes

Herpes simplex virus (HSV)-2 is a lifelong infection that causes recurrent genital ulcers and, rarely, disseminated and visceral disease. HSV-1 infection is an increasingly important cause of genital ulcers. HSV infections are the most common cause of genital ulcers in adults, but acquisition and chronic infection are more commonly asymptomatic than symptomatic. Both the symptomatic and asymptomatic forms of HSV are of clinical consequence for several reasons. HSV-2 infection enhances HIV-1 acquisition and transmission. In addition, sexual and perinatal transmission can occur during asymptomatic viral shedding. Perinatal transmission is of particular concern because neonatal HSV infection results in severe morbidity to the newborn. Antiviral medicines are effective for limiting recurrence duration and decreasing transmission likelihood, although no available intervention completely prevents transmission. This fact highlights the importance of laboratory diagnostics for this lifelong infection, and the need for an HSV vaccine.

Genital herpes

Genital herpes is the main cause of genital ulcers worldwide; the prevalence of herpes simplex virus (HSV) type 2 infections in the general population ranges from 10% to 60%. Most genital herpes is caused by HSV-2, although HSV-1 accounts for about half of new cases in developed countries. The risk of HIV acquisition is three times higher in people with HSV-2. Neonatal herpes is an uncommon but serious complication of genital herpes. Most genital HSV-2 infections are unrecognised and undiagnosed; infected individuals, even with mild symptoms, shed HSV, and can infect sexual partners. Since clinical diagnosis is neither sensitive nor specific, virological and type-specific serological tests should be used routinely. Oral antiviral drugs for HSV infections are safe and effective and can be used both to treat episodes and to prevent recurrences. Antiviral treatment of the infected partners and condom use reduce the risk of sexual transmission of HSV-2.

Predictors of Herpes Simplex Virus Type 2 Antibody Positivity Among Persons With No History of Genital Herpes

BACKGROUND

The demographic, historical, and behavioral factors that predict a positive herpes simplex virus type 2 (HSV-2) antibody test in persons without a history of genital herpes have not been well-defined.

METHODS

Individuals (age 14-30 years) without a history of genital herpes completed a questionnaire and were offered free HSV-2 antibody testing. Factors from the questionnaire were correlated with the HSV-2 antibody result.

RESULTS

Univariate analysis showed that female gender was significantly associated with positive test results. In gender-specific, multiple logistic regression models, a positive HSV-2 antibody test among men was associated with older age, non-white race, and a history of sexually transmitted disease (STD). Gender-specific symptom scores from the questionnaire were not predictive in either gender, but the gender-common symptom score was marginally predictive of a positive HSV-2 antibody test in women. Among women, older age, non-white race, and STD history predicted a positive test.

CONCLUSIONS

Among young persons with no history of genital herpes who agreed to HSV-2 antibody testing, increasing age, non-white race, and a history of an STD were predictors of a positive test. A history of frequent pain, itching, burning, and rashes in the anogenital region was marginally associated with positive HSV-2 tests in women. These results might help guide selective use of HSV-2 antibody screening.

Development and use of a type-specific antibody avidity test based on herpes simplex virus type 2 glycoprotein G

OBJECTIVES

It is difficult to discriminate between lesions resulting from recently acquired versus established genital herpes simplex virus type 2 (HSV-2) infection. Methods not based on history or serum IgM status are needed.

GOAL

Our goal was to use type-specific gG-2 antibody avidity determinations based on HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA) to identify new infections.

STUDY

Sera (N = 168) from 71 patients with first-episode genital herpes and 45 sera from 21 patients with recurrent episodes were tested.

RESULTS

Median avidity increased from 30.2 in sera drawn </=6 weeks to 54.9 >6 weeks after infection (P <0.001). Patients with recurrent episodes and established HSV-2 infections (median, 6.1 years' duration) had higher avidity antibodies (median, 92.7; range, 55.1-100) than patients after first episodes (median, 33.7; range, 6.4-73.9; P <0.001).

CONCLUSION

Avidity testing based on HerpeSelect ELISA could be a cost-effective method to identify patients with new HSV-2 infections.

Longitudinal reliability of focus glycoprotein G-based type-specific enzyme immunoassays for detection of herpes simplex virus types 1 and 2 in women

Serologic assays that utilize herpes simplex virus (HSV) type-specific glycoproteins G-1 (HSV-1) and G-2 (HSV-2) to discriminate between antibodies against HSV-1 and HSV-2 are sensitive and specific. However, the high rates of seroreversion, defined as the change in an individual's antibody status from positive to negative over time, previously reported in longitudinal evaluations of glycoprotein G type-specific tests suggests that their use in HSV acquisitional studies would be problematic. To further explore the reliability of the glycoprotein G-based serologic tests, we evaluated HSV-1 and HSV-2 enzyme immunoassays from Focus Technologies in a longitudinal cohort of 1207 young women from Pittsburgh, Pa. On enrollment of the women in the study, HSV-1 and HSV-2 antibodies were detected in 46.6 and 24.9% of the women, respectively. Among the women with at least three visits, 3.4% (15 of 447) of those who were HSV-1 antibody positive had a subsequent negative result while fewer than 1% (2 of 227) of those who were HSV-2 antibody positive seroreverted. The median of mean positive index values for women who seroreverted to HSV-1 antibody was lower than that for women who remained seropositive (1.25 versus 7.06; P < 0.001). Similarly, the median of mean positive index values for women whose HSV-2 antibody status reverted from positive to negative was lower than that for those women who did not serorevert (1.83 versus 7.46; P = 0.02). Comparative Western blot analysis demonstrated that the lower positive index values, seen more often among the HSV seroreverters, often signified false-positive immunoassay results. Overall, the seroreversion rates were low; the use of glycoprotein G-based serologic tests for the measurement of HSV-1 and HSV-2 antibodies in incidence studies therefore appears warranted.

Serological testing for herpes simplex virus (HSV)-1 and HSV-2 infection

Serological tests for herpes simplex virus (HSV) that can accurately distinguish between HSV-1 and HSV-2 are now commercially available. These tests detect antibodies to HSV glycoproteins G-1 and G-2, which evoke a type-specific antibody response. Focus Technologies produces the HerpeSelect-1 and HerpeSelect-2 enzyme-linked immunosorbent assay tests and the HSV-1 and HSV-2 HerpeSelect1/2 Immunoblot. Diagnology has marketed POCkit-HSV-2, a point-of-care test for HSV-2 that allows blood from a finger stick to be tested in a clinic. These tests can be used to confirm a genital herpes diagnosis, establish diagnosis of HSV infection in patients with atypical complaints, identify asymptomatic carriers, and identify persons at risk for acquiring HSV. Potential settings for use of these tests include sexually transmitted disease clinics, prenatal clinics, and clinics that care for patients with human immunodeficiency virus. Patient interest in HSV serological tests appears high.

Detection of herpes simplex virus type 2-specific immunoglobulin G antibodies in African sera by using recombinant gG2, Western blotting, and gG2 inhibition

Sera (n = 781) from four African countries were used to determine the prevalence of herpes simplex virus type 2 (HSV-2) antibodies by using the HerpeSelect HSV-2 enzyme-linked immunosorbent assay (ELISA; Focus Technologies) and Western blotting (WB). Also, an HSV inhibition assay was developed to evaluate the discordant sample results between HerpesSelect and WB. The seroprevalence of HSV-2 ranged from 17% in the South African panel to nearly 70% in panels from Kenya, Uganda, and Zimbabwe. Overall, HerpeSelect was 100% sensitive and 88% specific compared to WB and 100% sensitive and 96% specific compared to the inhibition assay. There was 100% concordance among all three assays for samples from South Africa and Zimbabwe. The discordant results occurred in samples from Kenya and Uganda.

Sorting out the new HSV type specific antibody tests

This review will delineate performance characteristics and limitations, as far as they are known, of the new glycoprotein G based, type specific HSV serologies. Several of these tests have been FDA approved in the United States for use in adults. With the departure of Gull/Meridian from the HSV serology market, it is important for clinicians to understand the sources and claims of the remaining type specific tests. Moreover, inaccurate tests using crude antigen preparations remain on the market. These tests are identified based on product insert information provided by company representatives.

First episodes of genital herpes in a Swedish STD population: a study of epidemiology and transmission by the use of herpes simplex virus (HSV) typing and specific serology

OBJECTIVES

To determine the proportion of herpes simplex virus type 1 (HSV-1) and HSV type 2 (HSV-2) in first episodes of genital herpes. To evaluate the use of HSV specific serology for classifying first episodes of genital herpes and for defining HSV serostatus in the patients' sexual partners.

METHODS

108 consecutive patients with first episodes of genital herpes seen at three STD clinics in Sweden from 1995 to 1999 were included in the study. HSV culture and typing were performed and serum was tested for antibodies against a type common HSV antigen and a type specific HSV-2 antigen, glycoprotein G2 (gG2). A structured interview including questions about sexual behaviour and sexual partners was taken. "Steady" partners were offered a blood test for HSV serology and counselling.

RESULTS

Of 108 patients, 11 had a negative HSV culture. Of the 97 who were HSV culture positive, 44% (43/97) were typed as HSV-1 and 56% (54/97) as HSV-2. For 86 of these 97 patients, HSV serology from the initial visit was available. Of 52 primary infections, thus initially seronegative, 64% were HSV-1 infections and of 19 female primary infections 16 (84%) were HSV-1. In 17% the first episode of genital herpes corresponded to the first clinical recurrence of an infection acquired earlier in life. There was a significant correlation between having orogenital sex and being infected with HSV-1 and also a history of labial herpes in the partner. Only 20% of partners of patients with an HSV-2 infection had a history of genital herpes.

CONCLUSIONS

Almost half of first episodes of genital herpes are caused by HSV-1. In young women with a primary genital infection, HSV-1 is much more frequent than HSV-2. Besides HSV typing, we found specific HSV serology of value for classifying first episodes and for diagnosing a subclinical HSV-2 infection in partners. Anamnestic data supported the suggestion that the orogenital route of transmission was common in genital HSV-1 infections.

A prospective study of new infections with herpes simplex virus type 1 and type 2. Chiron HSV Vaccine Study Group

BACKGROUND AND METHODS

Herpes simplex virus (HSV) infections are endemic, but the clinical characteristics of newly acquired HSV type 1 (HSV-1) and HSV type 2 (HSV-2) infections in adults have not been rigorously defined. We monitored 2393 sexually active HSV-2-seronegative persons for clinical and serologic evidence of new HSV infection. Of the participants, 1508 were seropositive for HSV-1 and 885 were seronegative. Charts were reviewed in a blinded manner for classification of those with genitourinary or oropharyngeal symptoms. Charts were also reviewed for all 174 persons with HSV seroconversion.

RESULTS

The rates of new HSV-1 and HSV-2 infections were 1.6 and 5.1 cases per 100 person-years, respectively. Of the 155 new HSV-2 infections, 57 (37 percent) were symptomatic, 47 of which (82 percent) were correctly diagnosed at presentation. Among the 74 patients given a clinical diagnosis of genital HSV-2 during the study, 60 were given a correct diagnosis and 14 were given an incorrect diagnosis of genital herpes, for a ratio of true positive results to false positive results of 4:1. Among the 98 persons with asymptomatic HSV-2 seroconversion, 15 percent had genital lesions at some time during follow-up. Women were more likely than men to acquire HSV-2 (P<0.01) and to have symptomatic infection. Previous HSV-1 infection did not reduce the rate of HSV-2 infection, but it did increase the likelihood of asymptomatic seroconversion, as compared with symptomatic seroconversion, by a factor of 2.6 (P<0.001). Of the 19 new HSV-1 infections, 12 were symptomatic. The rates of symptomatic genital HSV-1 infection and oropharyngeal HSV-1 infection were the same (0.5 case per 100 person-years).

CONCLUSIONS

Nearly 40 percent of newly acquired HSV-2 infections and nearly two thirds of new HSV-1 infections are symptomatic. Among sexually active adults, new genital HSV-1 infections are as common as new oropharyngeal HSV-1 infections.

Clinical course of patients with serologic evidence of recurrent genital herpes presenting with signs and symptoms of first episode disease

BACKGROUND AND OBJECTIVES

The care of patients with first episode and recurrent genital herpes differs with respect to therapy and source partner evaluation. Of 498 persons who presented with what appeared by history and symptoms to be a first episode of genital herpes, we identified 41 who had serologic evidence of remotely acquired herpes simplex virus 2 (HSV-2) infection.

GOALS

To define the natural history of these individuals with previously unrecognized HSV-2 and to evaluate if any clinical or historical features could differentiate these people from persons with true first episode infection.

STUDY DESIGN

Observational cohort study.

RESULTS

Clinical overlap existed in the frequency of local symptoms, fever, and size of genital lesions between those with remotely acquired versus recently acquired genital herpes. The frequency of new sexual partners and recent sexual history were also similar in the two groups. However, on follow-up, the lesions of persons with remotely acquired HSV-2 healed more rapidly and subsequently recurred less frequently than those of true primary HSV-2.

CONCLUSIONS

Even in a referral clinic with experienced clinicians, almost 10% of persons who are judged to have first episode genital herpes have evidence of remotely acquired HSV-2, suggesting that clinical differentiation of first episode genital herpes from previously acquired infection is difficult. Type-specific serologic testing assists the clinician in correctly classifying the infection and determining the potential source partner.

Limits in reliability of glycoprotein G-based type-specific serologic assays for herpes simplex virus types 1 and 2

Type-specific serologic assays for herpes simplex virus (HSV) types 1 and 2 based on glycoprotein G-1 (gG-1) (HSV-1) and gG-2 (HSV-2) discriminate between antibodies against HSV-1 and HSV-2. We previously developed a Western blot assay using gG-1 and gG-2 expressed in baculovirus, performed extensive validation studies, and determined that it was both sensitive and specific for type-specific detection of HSV antibody. Here we report that, among a cohort of Thai military recruits, the serostatus of some individuals changed from positive to negative over time (6.6% among those ever positive for HSV-1, and 14.9% among those ever positive for HSV-2). We tested a subset of these specimens in three other gG-based assays: an enzyme-linked immunosorbent assay, an immunoblot strip assay, and a Western blot assay. Positive-to-negative shifts occurred in every assay; the frequency of the shifts ranged from 6. 1% to 21.2% of the specimen sets tested. There was only limited agreement among the assays concerning which individuals lost reactivity. This inaccuracy, exhibited by all of the assay protocols, was not predicted by validation studies employing specimens from cross-sectional studies and was most pronounced in HSV-2 testing. This argues for the inclusion of serial blood specimens in serologic assay validation procedures.

Genital herpes: review of the epidemic and potential use of type-specific serology

Prevention of genital herpes simplex virus (HSV) infections is desirable from both a public health standpoint and the patient's perspective. A key factor in the spread of genital herpes infections is the high proportion of undiagnosed infections. Persons with subclinical or unrecognized infections are best diagnosed by accurate, type-specific antibody tests. Unfortunately, these tests are only now becoming widely available. The use of current, conventional (non-type-specific) serologic tests for diagnosis of herpes infections has resulted in confusion and misdiagnosis of patients. This review provides recent information on the epidemiology of genital herpes infections, describes the importance of subclinical herpes infection and shedding, summarizes the status of HSV type-specific serologic assays being developed, and provides indications for using such assays.

Role of type specific herpes simplex virus serology in the diagnosis and management of genital herpes

OBJECTIVES

To investigate the indications for the use of a type specific antibody test for herpes simplex virus in a department of genitourinary medicine in the United Kingdom.

METHOD

Retrospective analysis of case records of 127 patients who accepted the test during a 20 month period.

RESULTS/CONCLUSION

The test contributed to patient management in 79% of patients with recurrent genital ulceration of unknown cause. It was also useful for counselling a number of patients with initial episodes of disease and the asymptomatic partners of some patients when the partners were shown to possess antibodies specific to herpes simplex virus type 2. When evaluating sexual partners, the test was difficult to interpret if an isolate from the index case had not been typed. Access to viral typing may therefore be a greater priority than serological testing. As adverse psychological sequelae may follow the identification of an asymptomatic chronic infection, guidelines for the use of a type specific serological test are proposed.

Management of genital herpes

Oral acyclovir is the therapy of choice for treatment of first-episode genital herpes, for suppression of frequently recurrent genital herpes, and, in selected patients, for episodic treatment of recurrent genital herpes. Topical acyclovir therapy is relatively or totally ineffective and is therefore discouraged. Indications for intravenous acyclovir therapy of mucocutaneous HSV infections include patients hospitalized with severe first-episode genital herpes and immunocompromised patients who have severe infections or who cannot swallow the oral preparation. The most promising investigational drugs are the oral prodrugs valaciclovir and famciclovir. Famciclovir is licensed in the U.S. for treatment of zoster but not for treatment of mucocutaneous genital herpes. When used for episodic therapy of recurrent genital herpes, both famciclovir and valaciclovir effectively reduce the duration of viral shedding, lesion healing times, and the duration of symptoms. Suppressive therapy with famciclovir has also been shown to be effective in reducing the frequency of episodes in women with frequently recurring genital herpes. Although these drugs can be given less frequently than oral acyclovir, there is yet no clear indication that they are more effective or better tolerated than oral acyclovir.

Automated microneutralization: method and comparison with western blot for type-specific detection of herpes simplex antibodies in two pregnant populations

A novel method for the detection of microneutralization was compared to Western blot for detection of type-specific antibodies to herpes simplex virus in two pregnant patient populations in Vancouver. From an unselected group of women in labor in a tertiary care obstetric hospital (426) and another group of women specially referred for assessment of genital herpes in pregnancy (195) 20 and 88%, respectively, were seropositive for herpes simplex virus type 2 antibodies by Western blot. During the study period, 93 (48%) of the high-risk group were culture positive for HSV-2 and all but one case was verified serologically by Western blot. Therefore, the sensitivity for Western blot in this high seroprevalence group was 99%. The false-negative case had longstanding recurrent infection and on retest was found to be a laboratory error. For microneutralization, type-specificity was especially difficult to distinguish among patients with mixed viral type patterns. Comparing microneutralization to Western blot as the gold standard, sensitivity, specificity, positive and negative predictive values were 84, 78, 97 and 40% respectively, for the referred group and 73, 82, 51 and 92%, respectively, for the unselected group. Poor negative and positive predictive values for the referred group and unselected populations, respectively, demonstrate that microneutralizations are not clinically acceptable for type-specific antibody detection. By contrast, serology by Western blot is very sensitive and apparently highly specific.

Detection of immunoglobulin M antibodies to glycoprotein G-2 by western blot (immunoblot) for diagnosis of initial herpes simplex virus type 2 genital infections

Western blots (immunoblots) for the detection of immunoglobulin M (IgM) antibodies specific for herpes simplex virus type 1 (HSV-1) and HSV-2 in patients' sera were developed. The locations of the type-specific glycoprotein G (gpG-2) of HSV-2 (92- and 140-kDa forms) and glycoprotein C of HSV-1 (gpC-1), which carries mostly type-specific antigenic epitopes, were checked with specific monoclonal antibodies. Western blot assays for IgM antibody to gpC-1 or gpG-2 were performed after depletion of IgG by precipitation with anti-human IgG. In patients with primary HSV-2 genital infections, seroconversion of IgM and IgG antibodies to both the 92- and 140-kDa forms of gpG-2 was observed, although both antibodies appeared in convalescent-phase serum after the first week. IgM and IgG antibodies to low-molecular-size polypeptides (40 to 65 kDa) were the first antibodies observed in patients with primary infection, but these antibodies were cross-reactive with HSV-1 and HSV-2. However, in patients with recurrent HSV-2 infections, IgG antibodies to both forms of gpG-2 and the low-molecular-size polypeptides were found no matter how early after onset the patient was bled, and IgM to gpG-2 did not appear. In patients with nonprimary initial genital HSV-2 infections, IgG antibody to HSV-1 was demonstrated in the first serum specimen, and HSV-2-specific IgM was found in 39% of the serum specimens. Hence, the Western blot assay can be used to test for IgM antibody to gpG-2, allowing for the retrospective diagnosis of inital HSV-2 infections and its use as a supplementary test to the gpG-2 IgG enzyme-linked immunosorbent assays developed elsewhere. In contrast, IgM antibody to gpG-2 is not usually detected in patients with recurrent HSV-2 infections.

Laboratory techniques in the diagnosis of herpes simplex infection

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The reliability of serological tests for the diagnosis of genital herpes: a critique

The reliability and limitations of the currently used routine tests for herpes simplex virus type 2 (HSV-2) antibody in Australia are reviewed. Six case reports illustrate the clinical dangers of overinterpretation of the currently available kits and the need for a readily available specific HSV-2 antibody test. In Sydney, HSV-2 causes approximately 85% of primary genital herpes and > 95% of recurrent genital herpes. Due to the extensive serological cross-reactivity between HSV-1 and HSV-2, currently available "type specific" commercial assays cannot reliably distinguish between the 2. Isolation of herpes simplex virus (HSV) or detection of HSV antigen in vesicle fluid is the preferred diagnostic test but may be overlooked or patients may have no visible lesions. The only accurate techniques for detecting HSV-2 specific antibody are the Western blot assay and an enzymatic immunoassay using glycoprotein G (gG-2), a component of the HSV-2 envelope. These tests, which still are restricted to research laboratories can be used to accurately identify people with previous exposure to HSV-2 (IgG) or to diagnose primary infection where virus isolation has not been performed or is impossible. Current commercially available antibody tests may have extensive cross-reactivity.

Herpes simplex virus infection in pregnancy

Genital infections in pregnancy caused by herpes simplex virus types 1 and 2 are a difficult management problem. Both primary and recurrent genital herpes can range from severe, extensive ulceration to asymptomatic virus shedding. Although neonatal herpes is a well recognized complication of symptomatic maternal primary genital infection at the time of delivery, most cases are associated with asymptomatic virus shedding and absence of a history of genital herpes. Neonatal herpes may also be acquired in utero and in the postnatal period. The diagnosis of herpes simplex infection is made most reliably by virus isolation or antigen detection from samples obtained from clinically apparent lesions. Serology is useful for diagnosing primary herpes, and newer serological techniques allow the detection of HSV-2 specific antibodies. Strategies to prevent neonatal herpes are limited by the failure of currently available diagnostic tests to rapidly detect women in labour who are at risk of transmitting herpes, by the absence of proven antenatal screening tests for HSV, and by transmission of herpes to neonates from asymptomatic mothers. The most useful current strategy is careful examination of the vulva and cervix for herpes lesions in women coming to labour. Caesarean section is indicated in women with clinically apparent genital herpes at delivery. Effective and safe antiviral agents are available for treatment of maternal and neonatal herpes.

The diagnosis of recent herpes simplex virus type 2 genital infections by the simplex-2 test

The prevalence of complement-fixing (CF) antibody against the AG-4 early antigen of herpes simplex virus (HSV) type 2 (HSV-2) was determined in patients with culture confirmed HSV-2 genital herpes and control groups using a commercial HSV-2 early antigen (Simplex-2; Gene Link Australia Ltd). Eighty seven per cent of 39 sera collected between 14 and 28 days after confirmed primary and recurrent HSV-2 infection were positive. In acute sera collected between 2-10 days after onset the Simplex-2 test was negative in all 90 patients with presumed primary infection but positive in 53% of 230 sera from recurrent infection. A specificity of 90-94.5% was obtained by testing 36 patients with recent proven HSV-1 infection and 331 control group patients. The Simplex-2 test may be useful in some cases of culture-negative, clinically suspected genital HSV-2 lesions only when sera are collected between 14-28 days after primary and recurrent infection. Its lack of specificity makes it unsuitable for the routine diagnosis of recent HSV-2 infection in the general population.

Comparison of the Western immunoblot assay and a glycoprotein G enzyme immunoassay for detection of serum antibodies to herpes simplex virus type 2 in patients with AIDS

Herpes simplex virus type 2 (HSV-2) seroprevalence in 68 patients with AIDS was 77% by Western blot (immunoblot) and 44% by glycoprotein G-2 immunoassay. Each of 16 patients with culture-proven HSV-2 infection was positive by Western blot versus 8 by glycoprotein G-2 immunoassay. No differences in age, race, duration of AIDS, acyclovir usage, or HSV-1 seroprevalence were found to explain differences in sensitivity.

Highly sensitive enhanced chemiluminescence immunodetection method for herpes simplex virus type 2 Western immunoblot

Three Western blot (immunoblot) methods for detecting antibodies to herpes simplex virus type 2 were compared: (i) nitrocellulose blots with 4-chloro-1-naphthol immunostaining (4CN-WB); (ii) polyvinylidene difluoride (PVDF) blots with 3,3',5,5'-tetramethylbenzidene immunostaining (TMB-WB); and (iii) PVDF blots with enhanced chemiluminescence (ECL-WB). TMB-WB was 10-fold more sensitive than 4CN-WB, while ECL-WB was as much as 500-fold more sensitive.

Neonatal herpes simplex virus infection in relation to asymptomatic maternal infection at the time of labor

BACKGROUND AND METHODS

To define the risk factors associated with neonatal acquisition of herpes simplex virus (HSV) infection, we prospectively obtained HSV cultures from the cervix and external genitalia of 15,923 pregnant women in early labor who were without symptoms or signs of genital HSV infection. Follow-up of the women with positive cultures for HSV and their HSV-exposed infants included serologic tests and serial cultures for HSV.

RESULTS

HSV was isolated from 56 of the women (0.35 percent), 18 of whom (35 percent) had serologic evidence of a recently acquired, subclinical first episode of genital HSV infection, and 34 of whom (65 percent) had reactivation of HSV. Neonatal HSV developed in 6 of 18 infants (33 percent) born to the women with a first episode of genital HSV, and in 1 of 34 infants (3 percent) born to the women with reactivation of HSV (P less than 0.01); neonatal HSV also occurred in three of the infants born to the 15,867 women with negative cultures. Neonatal HSV-2 occurred in 1 of 4 infants born to mothers seronegative at delivery for both HSV-1 and HSV-2, in 4 of 12 infants exposed to HSV-2 whose mothers had only HSV-1 antibodies at delivery, and in none of the infants born to 31 women who were HSV-2-seropositive. An increased risk of neonatal HSV was associated with exposure to viral shedding from the cervix and the use of fetal-scalp electrodes.

CONCLUSIONS

Of the asymptomatic women who shed HSV in early labor, about a third have recently acquired genital HSV, and their infants are 10 times more likely to have neonatal HSV than those of women with asymptomatic reactivation of HSV. The presence of maternal antibodies specific to HSV-2 but not HSV-1 appears to reduce the neonatal transmission of HSV-2. Further studies are necessary to determine whether screening and prophylactic treatment are warranted for infants of HSV-2-seronegative mothers who shed HSV-1 or HSV-2 in early labor.

Genital herpes simplex virus infections

There has been a dramatic increase in patient visits to physicians for evaluation and treatment of genital herpes infections. This has resulted in part from an increase in genital herpes infections, particularly severe, first-episode genital herpes infections in adults without prior HSV-1 infection. Virus culture remains the most sensitive and specific method for diagnosis, and use of viral cultures is encouraged. Type-specific antibody tests have been employed in studies documenting the role of asymptomatic shedding of HSV in transmission of genital infections, the role of genital HSV in transmission of HIV, the predominance of asymptomatic and unrecognized infections in those infected with HSV-2, and the presence of past asymptomatic or unrecognized acquisition of HSV-2 in 25% of persons presenting with first-episode genital herpes. Unfortunately, commercially available serologic tests do not reliably differentiate between antibody to HSV-1 and HSV-2. Recent studies suggest that the annual risk of transmission from a sexual partner with genital herpes is about 10% in heterosexual couples. Currently, promotion of "safe sex" is the only available approach for prevention of transmission. However, ongoing research is focused on the development of an effective vaccine. Acyclovir should be used routinely in persons with first-episode genital herpes, but careful evaluation is needed in persons with recurrent genital herpes to determine whether episodic or suppressive treatment is indicated. Acyclovir should also be used routinely for episodic or suppressive treatment of HSV infections in persons with AIDS. Additional antiviral agents are needed for more effective suppressive therapy and for treatment of ACV-resistant HSV infections in the immunocompromised host.

Detection of asymptomatic initial herpes simplex virus (HSV) infections in animals immunized with subunit HSV glycoprotein vaccines

The evaluation of herpes simplex virus (HSV) vaccine efficacy will require methods to detect asymptomatic acquisition of HSV infection and to assess the risk of recurrences in these patients. HSV-infected vaccinees should develop antibodies to HSV polypeptides not included in subunit vaccines. Sera from 57 HSV glycoprotein-vaccinated guinea pigs that had asymptomatic initial infections after genital HSV type 2 challenge were collected after vaccination but before HSV challenge and again 30 days after HSV challenge to determine the antibody response to HSV polypeptides. Antibodies to nonvaccine HSV polypeptides were detected in sera collected after viral challenge from 32 (56%) of these 57 animals. Twenty-six (81%) of the 32 animals with detectable antibody developed recurrent disease; however, recurrences also developed in 11 (44%) of the remaining 25 that did not show detectable antibody to nonvaccine HSV polypeptides. The magnitude of vaginal viral shedding during the initial disease period following challenge was significantly lower in animals that did not develop antibody to nonvaccine polypeptides compared with those that did develop antibody (area under the viral shedding curve, 5.2 +/- 3.2 versus 18.1 +/- 5.8; P less than 0.0001) . These data suggest that detection of antibody to nonvaccine HSV polypeptides will identify the majority (70%) of initially asymptomatic vaccinees that develop recurrent disease but that latency can be established even with markedly reduced levels of viral replication that did not induce a detectable antibody response.

Genital herpes. How to relieve patients' physical and psychological symptoms

Genital herpes simplex virus is being encountered at an increasing rate by the primary care physician. Recurrences of this disease create not only medical but psychological and social problems, of which the physician must be aware. Although acyclovir (Zovirax) has become a useful palliative tool, compassion, sensitivity, and understanding are essential in the treatment of this disease. Physician-provided education is still currently the thrust for prevention.

Humoral antibody response in patients with herpes genitalis: analysis of factors influencing the pattern of disease

An investigation was made of the diagnosis of herpes genitalis, the prediction of virus type and the likelihood and frequency of clinical and asymptomatic recurrences in relation to a history of herpes labialis, the virus type isolated from genital lesions and the humoral antibody status against HSV 1 and 2. Diagnosis of herpes genitalis correlated negatively with mean neutralising antibody levels against HSV type 1 and type 2 but positively with the variance of neutralising antibody levels in sequential sera. Virus type in patients with initial episodes was best predicted by initial and mean type 2 antibody levels and in patients with recurrent disease by the ratio of type 1 to type 2 antibody by radioimmune assay. The likelihood and frequency of clinical and asymptomatic recurrences was higher in patients where HSV type 2 was isolated. The likelihood of recurrences in patients with initial episodes was related to high initial neutralising antibody levels against type 2 and to low primary antibody responses against type 1 while frequency of recurrences was best related to low initial antibody levels against type 1 in combination with high levels against type 2. These data will be useful in diagnosis of herpes genitalis. Prediction of the likelihood and frequency of clinical and asymptomatic recurrences will facilitate advice concerning prognosis and risk factors to patients and their consorts.

Comparison of Western blot (immunoblot) and glycoprotein G-specific immunodot enzyme assay for detecting antibodies to herpes simplex virus types 1 and 2 in human sera

Sera from patients with culture-proven genital herpes infections were tested for herpes simplex virus type 1 (HSV-1)- and HSV-2-specific antibodies by both a Western blot (immunoblot) technique (WBA) and immunodot enzyme assays (IEAs) specific for HSV-1 or HSV-2 glycoprotein G (gG). Of 137 serum samples tested, none was mistyped by either WBA or IEA. Both tests were most sensitive with sera obtained at least 21 days after onset of primary HSV-2 infections or sera drawn during recurrent HSV-2 genital episodes: 75 of 76 (99%) such serum samples were positive for HSV-2 antibody by WBA and 73 of 76 (96%) were positive by IEA. Of sera drawn earlier than 21 days from onset of primary genital HSV-2, antibodies to HSV-2 were detected in 25% by WBA and 8% by IEA. In patients with culture-proven primary genital HSV-1 infection, WBA detected antibodies to HSV-1 proteins in 16 of 17 (94%) serum samples drawn at least 21 days after onset of primary genital HSV-1 infection, compared with 9 of 17 (53%) serum samples tested for gG-1 by IEA. Both WBA and IEA are accurate and sensitive tests for HSV-2 antibody in patients convalescing from a first episode or having symptomatic or asymptomatic recurrent genital herpes. WBA was more sensitive than IEA in detecting seroconversion following primary HSV-1 genital herpes, although both assays may miss persons undergoing early seroconversion to HSV-2.

Use of densitometric analysis for interpreting HSV serologies based on Western blot

Western blot assays have been described for detecting antibodies to herpes simplex virus (HSV). A predominance of antibody binding to either the HSV-1 or the HSV-2-containing blot has been reported to indicate infection with HSV-1 or HSV-2, respectively. By densitometry, differential binding of total antibody on HSV-1 versus HSV-2 strips can be expressed as a ratio. To determine the clinical correlation of these ratios, sera from 81 patients with culture-proven oral or genital herpes were tested by Western blot (WB) and densitometry. Binding ratios accurately identified patients with primary HSV-2 infections. However, ratios on sera with HSV-1 antibody or dual antibody status showed considerable overlap. Densitometry was shown to amplify and clarify the band corresponding to the HSV-2 specific glycoprotein gG-2 and was useful, in this respect, for detecting HSV-2 antibody in the presence of HSV-1 antibody. Sera from 52 patients with asymptomatic HSV-1, HSV-2 or dual infection were also tested by WB. Typing results were confirmed by cross-adsorption of sera ("adsorption blot assay"). Ratios of HSV-2 to HSV-1 binding were higher in asymptomatic versus symptomatic patients with dual antibody (P less than 0.01). Ratios for those with HSV-1 or HSV-2 antibody types were not affected by disease expression.

Detection of asymptomatic herpes simplex virus infections after vaccination

Twenty-two volunteers seronegative for antibodies to herpes simplex virus (HSV) were enrolled in a trial to determine tolerance and immunogenicity of an HSV-2 glycoprotein subunit vaccine. Vaccine was administered at days 0, 28, and 140, and sera were obtained on days 0, 7, 14, 21, 28, 35, 49, 56, 140, 147, and 365 for determination of HSV neutralizing antibody activity and antibody-dependent cell cytotoxicity (ADCC). Sera were also tested by immunoprecipitation of radiolabeled HSV-2-infected cell proteins and polyacrylamide gel electrophoresis to identify the viral proteins which elicited antibody responses in vaccine recipients. After vaccination two male volunteers presented with atypical first-episode genital herpes: patient 1 with a culture-negative genital lesion at day 53 and patient 3 with urethritis at day 68. Seroconversion to wild-type viral proteins not present in the vaccine was detectable by radioimmunoprecipitation-polyacrylamide gel electrophoresis within 10 days in both patients. Two additional volunteers, one a sex contact of patient 1, seroconverted asymptomatically to nonvaccine proteins during the trial. All four vaccine breakthrough patients were indistinguishable from the other volunteers in the time required to develop neutralizing and ADCC antibodies, in the titer of these antibodies, and the time to seroconversion to gB and gD vaccine proteins. However, only one of the four breakthrough patients had antibodies to g80 (a complex of gC-2 and gE) after vaccination as compared with 15 of the other 18 volunteers (P = 0.05). Neither neutralizing antibody nor ADCC titers consistently identified acquisition of wild-type viral infection; therefore, protein-specific serologies were required to detect wild-type antibodies in these four patients. These data underscore the importance of using serologic assays which will distinguish naturally acquired infection from the immune response to vaccination.

Type specificity of complement-fixing antibody against herpes simplex virus type 2 AG-4 early antigen in patients with asymptomatic infection

We evaluated the type specificity of complement-fixing (CF) antibody against the AG-4 early antigen of herpes simplex virus (HSV) type 2 (HSV-2) by comparing a commercial AG-4 CF kit (Simplex-2; Gene Link Australia, Inc., Princeton, N.J.) with quantal microneutralization (MN) and absorption-Western blotting in testing sera from patients with and without a history of genital herpes. Sera characterized as HSV type 1 (HSV-1) or HSV-2 positive or negative by MN were selected and tested by CF, and those with discordant results were further analyzed for specific antibodies by absorption with HSV-1 or HSV-2 antigen and Western blotting with heterologous HSV proteins. A total of 34 of 42 (81%) sera HSV-2 positive by MN, 19 of 43 (44%) sera HSV-1 positive by MN, and 0 of 19 sera negative by MN were positive by CF. Absorption-Western blotting showed that 12 of 18 (67%) sera HSV-1 positive by MN but positive by CF had no HSV-2-specific antibody and that all 7 sera HSV-2 positive by MN but negative by CF had HSV-2-specific antibody. When MN and absorption-Western blotting data were combined to analyze patients with no history of genital herpes, 7 of 19 (37%) with no HSV-2-specific antibody were positive by CF, and 7 of 27 (26%) with HSV-2-specific antibody were negative by CF. The positive and negative predictive values for the CF test were 78 and 75%, respectively, in this group. The presence of antibody to the HSV AG-4 antigen does not discriminate sufficiently between HSV-1- and HSV-2-infected patients to be of value in predicting HSV-2 infection in the absence of symptomatic disease.