Raising the consciousness for identifying and controlling viral STDs: fears and frustrations--Thomas Parran Award Lecture

Herpes Simplex Virus Type 2 (HSV-2) Western Blot Confirmatory Testing Among Men Testing Positive for HSV-2 Using the Focus Enzyme-Linked Immunosorbent Assay in a Sexually Transmitted Disease Clinic

OBJECTIVE

The objective of this study was to define the positive predictive value (PPV) of the Focus herpes simplex virus type 2 (HSV-2) enzyme-linked immunosorbent assay (ELISA) in a low HSV-2 prevalence population and to develop a new test interpretation algorithm.

METHODS

HSV-2 Western blots were performed on sera from male sexually transmitted disease clinic patients testing HSV-2 ELISA-positive and used to define a new class of indeterminate HSV-2 ELISA result. HSV-2 Western blots were then prospectively performed on sequential sera with indeterminate HSV-2 ELISAs.

RESULTS

Ninety-one (84%) of 108 HSV-2 ELISA-positive sera tested HSV-2 Western blot-positive. Western blot positivity was more common in men without herpes simplex virus type 1 (HSV-1) antibody than in those with HSV-1 antibody (93% vs 76%, P = 0.02) and in men with a history or clinical evidence of genital lesions (88% vs 80%, P = 0.30). Selectively raising the ELISA index value defining HSV-2 positivity from >1.1 to >or=3.0 either among HSV-1-positive men or among those without a history or clinical evidence of genital lesions increased the PPV to >or=93%. Prospective evaluation of an algorithm incorporating HSV-1 serostatus found that 11 of 70 persons with indeterminate HSV-2 ELISAs were Western blot-positive.

CONCLUSIONS

Clinicians should consider selectively using a higher index value to define Focus ELISA HSV-2 positivity based on either HSV-1 serostatus or clinical circumstances.

Gynecologic infections

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

Time course of seroconversion by HerpeSelect ELISA after acquisition of genital herpes simplex virus type 1 (HSV-1) or HSV-2

BACKGROUND

HerpeSelect HSV-1 and HSV-2 ELISAs are glycoprotein G-based, type-specific antibody detection tests that are approved by the US Food and Drug Administration for diagnosis of genital herpes.

GOAL

The goal was to determine seroconversion times by means of HerpeSelect ELISAs.

STUDY DESIGN

Four-hundred thirteen sera from 113 patients with recently acquired genital herpes were tested by HerpeSelect ELISAs and Western blot (WB). Thirty-one patients had primary genital HSV-1 (group 1), 56 had primary HSV-2 (group 2), and 26 had prior HSV-1 antibodies and newly acquired HSV-2 (group 3).

RESULTS

Median interval from onset of symptoms to seroconversion was 25 days, as determined by HerpeSelect HSV-1, versus 33 days by WB for group 1; 21 days by HerpeSelect HSV-2 versus 40 days by WB (group 2; P = 0.0005); and 23 days by HerpeSelect HSV-2 ELISA versus 47 days by WB (group 3; P = 0.02). In long-term follow-up, transient reversion to HerpeSelect negativity occurred in 3 of 31 HSV-1-infected subjects (10%) and in 2 of 82 HSV-2-infected subjects (2%).

CONCLUSION

Seroconversion to HSV-2 was determined faster by HerpeSelect than by WB.

Genital herpes serotesting: a study of the epidemiology and patients' knowledge and attitude among STD clinic attenders in Coventry, UK

OBJECTIVES

To examine the seroprevalence and correlates of antibodies to herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2), and to assess patients' knowledge and attitude towards genital herpes infection and its serotesting, before and after counselling.

METHODS

A cross sectional study among genitourinary medicine (GUM) clinic attenders in Coventry, a UK metropolitan city. Participants were asked to complete a self administered questionnaire before and after counselling. Patients were counselled before testing and after receiving the result. A commercially available enzyme immunoassay (EIA) was used to identify HSV-1 and HSV-2 antibodies (Gull/Meridian EIA).

RESULTS

223 patients participated in the study (97% of eligible patients). Overall, prevalence of HSV-2 antibody was 43/216 (20%) (19/103, 18% for males and 24/113 (21%) for females, p=0.61) while prevalence of HSV-1 antibody was 129/215 (60%) (60% for both sexes, p=0.91). In the multivariate analysis HSV-2 seropositivity was higher among black people and those with a history of genital herpes. HSV-1 seropositivity was independently associated with less education, increased years of sexual activity (between 14-25 years), and history of cold sores. The majority of patients wanted this serotesting to be available in the clinic (204/222 (92%) before and 216/218 (99%) after counselling, p=0.0003) and 97% accepted the test when offered. Only three patients regretted having the test and four patients contacted the department within 6 months of receiving the results for more counselling.

CONCLUSION

The vast majority of the study population not only wanted to be tested, but accepted the test when offered. HSV-2 infection is common and largely unrecognised among our study population. The psychological impact of introducing type specific HSV serological testing in a clinical setting seems to be minimal. Counselling could improve patients' awareness of the infection and the acceptability of the test and its results.

Dichotomy of glycoprotein g gene in herpes simplex virus type 1 isolates

Herpes simplex virus type 1 (HSV-1) encodes 11 envelope glycoproteins, of which glycoprotein G-1 (gG-1) induces a type-specific antibody response. Variability of the gG-1 gene among wild-type strains may be a factor of importance for a reliable serodiagnosis and typing of HSV-1 isolates. Here, we used a gG-1 type-specific monoclonal antibody (MAb) to screen for mutations in the immunodominant region of this protein in 108 clinical HSV-1 isolates. Of these, 42 isolates showed no reactivity to the anti-gG-1 MAb. One hundred five strains were further examined by DNA sequencing of the middle part of the gG-1 gene, encompassing 106 amino acids including the immunodominant region and epitope of the anti-gG-1 MAb. By phylogenetic comparisons based on the sequence data, we observed two (main) genetic variants of the gG-1 gene among the clinical isolates corresponding to reactivity or nonreactivity to the anti-gG-1 MAb. Furthermore, four strains appeared to be recombinants of the two gG-1 variants. In addition, one strain displayed a gG-1-negative phenotype due to a frameshift mutation, in the form of insertion of a cytosine nucleotide. When immunoglobulin G reactivity to HSV-1 in sera from patients infected with either of the two variants was investigated, no significant differences were found between the two groups, either in a type-common enzyme-linked immunosorbent assay (ELISA) or in a type-specific gG-1 antigen-based ELISA. Despite the here-documented existence of two variants of the gG-1 gene affecting the immunodominant region of the protein, other circumstances, such as early phase of infection, might be sought for explaining the seronegativity to gG-1 commonly found in a proportion of the HSV-1-infected patients.

Adolescent girl's coping with an STD. Not enough problem solving and too much self-blame

STUDY OBJECTIVE

Approximately three million teenagers are infected with an STD each year. The ways in which an adolescent girl copes with an STD may have implications for future risk and for psychological adjustment. The purpose of the current study was to compare whether coping with an STD was similar to coping with other stressors.

SETTING

Urban, hospital-based adolescent medicine clinic.

DESIGN AND PARTICIPANTS

Sixty-seven girls with a mean age of 15.9 (sexual debut was 13.8) yr completed the KIDCOPE in response to both an STD acquisition and an interpersonal stressor within the previous 6 months.

RESULTS

Problem solving was used less often, and self-blame was used more often, in response to an STD acquisition. Frequency of use of self-blame was not correlated with perceived helpfulness.

CONCLUSIONS

These findings suggest that clinicians need to help adolescent girls manage STD acquisition from the perspective of problem solving rather than self-blame.

Use of a glycoprotein G-based type-specific assay to detect antibodies to herpes simplex virus type 2 among persons attending sexually transmitted disease clinics

BACKGROUND

Most genital herpes simplex virus type 2 (HSV-2) infections are unrecognized, thus, strategies to reduce the sexual transmission of HSV-2 are partly dependent on serologic screening.

GOAL

To define performance characteristics of the Gull/ Meridian glycoprotein G-based HSV-2 enzyme-linked immunosorbent assay among sexually transmitted disease clinic attendees and correlates of test acceptance.

STUDY DESIGN

The cross-sectional study was conducted during two periods. Serologic testing was offered at a US $15 charge during the first period and at no charge during the second period. Sera were tested by a type-specific glycoprotein G enzyme-linked immunosorbent assay and Western blot analysis, with the latter test used as the reference standard.

RESULTS

Acceptance of HSV-2 testing was associated with free testing (odds ratio, 7.5; 95% CI, 6.0-9.9), older age, and white race. Sensitivity of the HSV-2 assay was 80.5% and specificity was 98.5%. The HSV-2 positive and negative predictive values were 95.8% (95% CI, 91.6-98.0%) and 92.2% (95 % CI, 89.6 -94.2%), respectively. Antibodies to HSV-2 were detected in 25.9% of 606 persons with no history of genital herpes.

CONCLUSION

Acceptance of HSV-2 serologic testing was cost sensitive. In this high-prevalence population, the positive predictive value of the enzyme-linked immunosorbent assay was sufficient to warrant its use without a confirmatory test. This assay could be useful in the screening of sexually active adults to detect unrecognized HSV-2 infection.

Comparison of a monoclonal antibody-blocking enzyme-linked immunoassay and a strip immunoblot assay for identifying type-specific herpes simplex virus type 2 serological responses

Detection of herpes simplex virus type 2 (HSV-2)-specific antibodies by a monoclonal antibody (MAb)-blocking enzyme-linked immunoassay (EIA) was compared with detection by a strip immunoblot assay (SIA) in a sexually transmitted disease (STD) clinic population. The study population consisted of 1,683 genitourinary medicine clinic attendees (582 women and 1,101 men). Sera were tested for the presence of HSV-2 antibody by use of the blocking EIA, in which binding of the MAb AP-1 to HSV-2 glycoprotein G-2 (gG-2) is blocked by HSV-2-specific antibody. The Chiron RIBA HSV-1 and -2 strip immunoassay (SIA) utilizes HSV-1- and HSV-2-specific or cross-reactive antigens immobilized on nitrocellulose strips (HSV gB-1 and HSV gG-1 peptide bands specific for HSV-1 antibody, HSV-2 gG-2 band specific for HSV-2 antibody, and HSV gD-2 band cross-reactive for HSV-1 and HSV-2 antibodies). A total of 1,612 sera were tested by MAb-blocking EIA for HSV-2 antibody and by SIA for HSV-1 and HSV-2 antibodies. By EIA, 541 (33.6%) sera were positive for HSV-2 antibody and 1,068 sera were negative for HSV-2 antibody; 3 sera gave equivocal results. HSV-2 antibody was detected in 555 (34.4%) sera by SIA; 144 (26%) of these sera possessed only HSV-2 antibody, and 411 (74%) sera contained both HSV-1 and HSV-2 antibodies. SIA detected HSV-1 antibody in 1,155 (71.6%) sera; 744 (64%) of these sera contained HSV-1 antibody alone. Sixteen sera contained antibody against HSV but could not be typed by SIA. A total of 512 sera were positive for HSV-2 antibody by both the EIA and SIA. We concluded that the blocking EIA and SIA showed a high level of agreement in detecting HSV-2 antibody in this population. In contrast to the SIA, the blocking EIA is a useful tool for large epidemiological studies, though the SIA proved to be slightly more sensitive once sera with discrepant results were further tested.

A monoclonal blocking EIA for herpes simplex virus type 2 antibody: validation for seroepidemiological studies in Africa

A competitive type-specific enzyme-linked immunosorbent assay (ELISA) for herpes simplex virus type 2 (HSV-2) antibody was developed using an infected cell antigen and a monoclonal antibody to glycoprotein G-2. This assay has been validated for use for epidemiological studies using a large panel of sera collected in rural Uganda and a panel of 143 sera characterised previously by Western blotting, the 'gold standard' for HSV type-specific serology. This evaluation was found to have a sensitivity of 96% and a specificity of 91% in comparison with Western blot on 143 sera from clinic patients. The ELISA had a sensitivity of 93% and a specificity of 91% in comparison with Western blot on 495 sera collected in Uganda. The assay showed good reproducibility and a low percentage of sera gave equivocal results, indicating its suitability for epidemiological studies.

Glycoprotein G of herpes simplex virus type 1: identification of type-specific epitopes by human antibodies

Serological diagnosis of herpes simplex virus (HSV) infections requires assays based on antigens that expose type-specific determinants. This study was designed to outline the B-cell epitopes of the type-specific glycoprotein G-1 (gG-1) of HSV type 1 (HSV-1), by investigating the reactivity of human anti-gG-1 antibodies, purified from 21 HSV-1-isolation-proven patient sera, to cellulose-bound synthetic peptides spanning the entire gG-1 sequence. The epitope mapping demonstrated that these antibodies bound preferentially to antigenic determinants that localized to regions with a high degree of amino acid similarity to the corresponding glycoprotein in HSV-2, gG-2. In spite of this, the purified anti-gG-1 antibodies were found to be non-reactive to native gG-2 antigen, as well as to overlapping gG-2 peptides, thus supporting the role of gG-1 as a prototype HSV-1 type-specific antigen. One immunodominant region, delimited by amino acids 112-127, reacted with all purified anti-gG-1 antibodies and may be of interest for the further development of a peptide-based HSV-1 type-specific seroassay.

Public Health Strategies to Prevent Genital Herpes: Where Do We Stand?

At least 25% of the United States population has overt or subclinical genital herpes simplex virus (HSV) infection, and herpes probably is the sexually transmitted disease of greatest concern to sexually active persons, aside from AIDS. In addition to its direct clinical and psychosexual complications, genital herpes is an important determinant of sexual transmission of HIV. Genital herpes is usually transmitted by persons with subclinical infection, whether entirely asymptomatic or with unrecognized symptoms. Although the composition and efficacy of a national genital herpes prevention program are in debate, clinicians should adopt a public health perspective in managing patients to help prevent transmission. Specific approaches include accurate diagnosis of genital ulcer disease by routine use of virologic tests for HSV; use of type-specific serologic tests to diagnose subclinical HSV infection in patients' sex partners and others at high risk; counseling patients to recognize symptoms and defer sex with uninfected partners when symptomatic; and serologic testing and counseling of pregnant women and their partners to prevent neonatal herpes. Antiviral chemotherapy may be effective in preventing herpes-related cesarean sections, and its efficacy in preventing sexual transmission of HSV is under study.

College students' knowledge and perceptions of genital herpes

Given the rising prevalence of herpes simplex virus type 2 (HSV-2) and the lack of accurate information about STDs in general, it is important to understand specific aspects of knowledge and attitudes regarding genital herpes acquisition among college students. This study examined the knowledge and attitudes regarding HSV-2 among college students by recruiting subjects (n=518) from an undergraduate psychology class to complete a questionnaire. The percentage of students answering individual knowledge items correctly ranged from 67% to 99%. The media was a common source of information, and almost one-third of the students anticipated that their care provider would think negatively of them should they acquire the disease. There were gender differences in care-seeking behaviour, knowledge, and attitudes, with females having a more negative view of themselves if they acquired the disease. This study pointed to the challenges in ensuring accurate knowledge about genital herpes that will encourage preventive behaviours without causing undue alarm or shame.

Prevention agenda for genital herpes

Few meeting participants envisioned a prevention and control program on the scale or scope of CDC's programs to prevent HIV infection, syphilis, gonorrhea, and chlamydial infection, but all agreed that the virtual absence of public health interventions to prevent genital herpes is no longer appropriate in light of evolving epidemiologic knowledge and other research advances. The ultimate scope of a national genital herpes prevention effort will depend in part on the results of the recommended research agenda, which probably will evolve over the better part of a decade. Numerous other STD prevention partners will also need to contribute to this effort and help to determine the makeup of future programs. Substantial new fiscal resources will be required both to implement the proposed research agenda and, depending on the results, to undertake the prevention efforts indicated by those studies. Competing STD prevention priorities and other national health needs will influence the availability of those resources. The consultants' meeting and the research and program activities summarized above are described in more detail in the full meeting report, which is posted on the Division's web site (www.cdc.gov/nchstp/dstd/dstdp.html) or may be requested directly from the Division. DSTDP is interested in receiving comments and suggestions about herpes prevention.