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.     

Detection of herpes simplex virus type 2-specific antibody with glycoprotein G.

A recently described herpes simplex virus (HSV) type 2 (HSV-2)-specific glycoprotein (gG-2) was purified on an immunoaffinity column prepared with monoclonal antibody. This purified antigen was used in an immunodot enzymatic assay on nitrocellulose paper for the detection of HSV-2 antibodies in human serum. The test was very sensitive in that HSV-2 antibodies were detected in the convalescent sera of 132 of 134 patients with recurrent genital infections in which HSV-2 had been isolated earlier. Antibodies to gG-2 were detected in 17% of sera obtained within 10 days after the onset of a primary HSV infection and in 95% of sera obtained more than 10 days after onset. The specificity of the immunodot assay was demonstrated by testing sera from 245 HSV-seronegative adults, 344 children, 29 nuns, and 13 patients with primary genital HSV-1 infections. None of these 631 sera was reactive with the gG-2 antigen. When compared with a microneutralization test, the immunodot assay was found to be more specific in detecting HSV-2 antibodies. Reproducibility of the gG-2 assay, obtained by retesting 391 sera, was 95%. Thus, this assay has the sensitivity, specificity, and reproducibility necessary for the measurement of HSV-2 antibodies in seroepidemiological studies.     

A novel glycoprotein for detection of herpes simplex virus type 1-specific antibodies

A novel herpes simplex virus type 1 (HSV-1)-specific glycoprotein reactive with monoclonal antibody H1379 was purified by affinity chromatography. This glycoprotein, provisionally designated as gG-1, forms two sets of bands with molecular weights of 40-44,000 and 60-88,000. When used in an immunodot enzymatic assay, gG-1 reacted strongly with rabbit antisera to HSV-1, but not with sera hyperimmune to HSV-2. Specificity of the assay was further established by the lack of reactivity of convalescent sera collected from 20 patients with primary genital HSV-2 infections, and from 100 sero-negative individuals. In contrast, antibodies to gG-1 were detected in 9 of 10 patients with primary HSV-1 infection, and in 63/67 patients with culture-positive, recurrent oral or genital HSV-1 infection. Reproducibility of the gG-1 immunodot assay for HSV-1 antibody detection was 96%. Serological assay with purified gG-1, done in parallel with the assay using purified gG-2 described in an earlier report, provides simple and reliable methods to detect type-specific HSV-1 and HSV-2 antibodies for seroepidemiological studies.     

ELISA for detection of IgG and IgM antibodies to HSV-1 and HSV-2 in human sera

A rapid, enzyme-linked immunoassay (ELISA) was applied to identify and measure specific IgG and IgM antibodies to herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). Detergent solubilized infected cells and mock-infected cells were used as antigens in the assay. Identification of type-specific antibodies was achieved by a competition assay in which clinical sera mixed with HSV-1 or HSV-2 antigens were assayed for reactivity to identical antigens coating wells of polystyrene microtiter plates. Reactivity and the specificity of the reactive immunoglobulin class was quantitated using biotinylated goat anti-IgG and biotinylated goat anti-IgM. Five paired sera from patients with diagnosed herpes simplex genital infections and one human anti-HSV-1 reference serum were tested with this assay and results were compared to results previously obtained using a complement fixation test and micro-SPRIA. The results indicate that the ELISA is a specific, sensitive and simple test which confirms the herpes simplex virus infection history of patients.     

Secreted portion of glycoprotein g of herpes simplex virus type 2 is a novel antigen for type-discriminating serology

The secreted portion of glycoprotein G (sgG-2) of herpes simplex virus type 2 (HSV-2) was evaluated as a novel antigen in an enzyme-linked immunosorbent assay (ELISA) format for detection of type-specific immunoglobulin G (IgG) antibodies in HSV-2-infected patients. The results were compared with those obtained by a commercially available assay, the HerpeSelect 2 ELISA (the FOCUS2 assay). Five different panels of sera were analyzed: panel A consisted of 109 serum samples from patients with a culture-proven HSV-1 infection that were Western blotting (WB) negative for HSV-2; panel B consisted of 106 serum samples from patients with a culture-proven recurrent HSV-2 infection that were WB positive for HSV-2; panel C consisted of 100 serum samples with no detectable IgG antibodies against HSV-1 and HSV-2; panel D consisted of 70 HSV-2 negative "tricky" serum samples containing antinuclear IgG antibodies or IgM antibodies against other viruses or bacteria; and panel E consisted of consecutive serum samples from 21 patients presenting with a first episode of HSV-2-induced lesions. When sera in panels A to C were analyzed, the sgG-2 ELISA and the FOCUS2 assay both showed sensitivities and specificities of >or=98%. In total, among the samples in panel D, 13 serum samples (19%) were false positive by the FOCUS2 assay and 1 serum sample (1.4%) was false positive by the sgG-2 ELISA. When the sera in panel E were analyzed, the sgG-2 ELISA detected seroconversion somewhat later than WB or the FOCUS2 assay did. We conclude that sgG-2 induces an HSV-2 type-specific antibody response and can be used for type-discriminating serology.     

Performance of a novel test for IgM and IgG antibodies in subjects with culture-documented genital herpes simplex virus-1 or -2 infection

Novel tests (BioPlex) for herpes simplex virus-1 (HSV-1) and HSV-2 IgG were compared with HerpeSelect HSV-1 and HSV-2 ELISAs for type-specific IgG. The sensitivity and specificity of BioPlex HSV-1 IgG were 94% (84/89) and 96% (119/124), respectively, with unselected sera, while the sensitivity and specificity of BioPlex HSV-2 IgG were 92% (109/118) and 98% (95/97), respectively. BioPlex IgM was compared with Diamedix IgM against sera from patients with culture-documented genital herpes. The test results were concordant in 81% of sera from HSV-1 patients and in 90% of sera from HSV-2 patients. Use of BioPlex IgM in addition to BioPlex IgG tests increased HSV-2 seroconversion detection from 47% of subjects to 70%. Use of Diamedix IgM in addition to Focus IgG ELISA increased HSV-2 detection from 40% of subjects to 70%. IgM was detected by BioPlex in 63% of sera from patients with early HSV-2 infection (< 30 days) and in 59% of sera by Diamedix. IgM was also detected in a large proportion of sera from subjects with established HSV-2 infection (33% by BioPlex and 29% by Diamedix). Addition of IgM testing substantially increased the ability to detect seroconversion early in infection. IgM is an indicator of recent infection only in subjects who lack detectable IgG.     

Use of a fragment of glycoprotein G-2 produced in the baculovirus expression system for detecting herpes simplex virus type 2-specific antibodies

Fragments of glycoprotein G (gG-2(281-594His)), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1(t26-189His)), and glycoprotein D of HSV-1 (gD-1(1-313)), were expressed in the baculovirus expression system to develop an assay for the detection of HSV-1 and HSV-2 type-specific antibodies. The expression of the gG-1(t26-189His) and gG-2(281-594His) fragments was analyzed by Western blotting using monoclonal antibodies LP10 and AP1, respectively. The molecular masses of the major products of gG-1(t26-189His) and the fragment of gG-2(281-594His) were 36 to 39 kDa and 64 to 72 kDa, respectively. Human sera positive for HSV-1 reacted with gG-1(t26-189His), sera positive for HSV-2 reacted with the gG-2(281-594His) fragment, and sera positive for both types reacted with gG-1(t26-189His) and gG-2(281-594His) in Western blotting. The human sera recognized polypeptides of gG-2(281-594His) with molecular masses of 57 to 67 and 120 to 150 kDa and additional faint bands of 21, 29, and 45 kDa. The recombinant gG-1(t26-189His) and the recombinant gG-2(281-594His) fragment were used as type-specific antigens for the detection of HSV-1- and HSV-2-specific antibody responses in human sera, respectively. As type-common antigens, an extract of HSV-1-infected Vero cells and recombinant gD-1(1-313) were used. An enzyme-linked immunosorbent assay to detect type-specific antibodies was developed, and the sensitivity and specificity were evaluated by comparison with commercial tests by using sera obtained from different sources. The sensitivity and specificity were 91.5 and 95.5%, respectively, compared to the Gull assay. The gG-2(281-594His) fragment can be obtained in relatively large quantities at low cost.     

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.     

Evaluation of three glycoprotein G2-based enzyme immunoassays for detection of antibodies to herpes simplex virus type 2 in human sera

Three new glycoprotein G-based enzyme immunoassays (ETI-HSVK-G 2, Sorin Diagnostics Biomedica [assay A]; HSV Type 2 Specific IgG ELISA, Gull Laboratories, Inc. [assay B]; Cobas Core HSV-2 IgG EIA, Roche [assay C]) for the detection of herpes simplex virus (HSV) type 2 (HSV-2)-specific antibodies were evaluated. By testing sera from 25 individuals with culture-proven HSV-2 infection, the assays showed a sensitivity of 96%. The specificities, evaluated with sera from 70 HSV antibody-negative children, 75 HSV antibody-positive children, and 69 HSV antibody-negative adults, were 100% for assay A, 96.2% for assay B, and 97.8% for assay C, respectively. Discrepant results by any of the three assays, i.e., reactivity of a specimen in only one or two assays, occurred with similar frequencies for HSV-seronegative individuals as well as HSV-seropositive children and adults. For sera with discrepant results, the positive reactivity was mostly low. Thus, for determination of the prevalence of HSV-2 antibodies, only concordantly positive results were considered. On the basis of the results obtained with sera from 41 adults with culture-proven HSV-1 infection and from 173 HSV-antibody-positive pregnant women, the HSV-2 seroprevalence was 9. 8%. The results show that the new glycoprotein G2-based enzyme immunoassays are useful tools for the detection of type-specific HSV-2 antibodies. However, if only one assay is performed, careful interpretation of the results is indicated, especially if the exhibited reactivity is low, and for determination of the definitive HSV-2 serostatus, confirmatory assays may still be necessary.     

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.     

Detection of herpes simplex virus type-specific antibodies by an enzyme-linked immunosorbent assay based on glycoprotein G

In order to develop a simple and quantitative method to detect herpes simplex virus (HSV) type-specific antibodies, the usefulness of an enzyme-linked immunosorbent assay (ELISA) using HSV glycoprotein G (gG) captured on a plate by monoclonal antibodies as antigen was studied. The gG1- and gG2-specific IgG antibody activities were measured by the ELISA for 54 sera which had been collected from culture-proven genital herpes patients and pre-characterized by an immunodot assay using purified gG antigens. Thirty control sera without antibodies against the HSV whole antigens were also included. In comparison with the immunodot assay as standard, the sensitivities of the ELISA were 88.9% (32/36) for HSV-1 antibody and 89.2% (33/37) for HSV-2 antibody and the specificities were both 100%. Sera taken within a few months after primary infection tended to give false negative results. The HSV type-specific ELISA based on easy-to-prepare gG antigens might be useful to help improve the serological assessment of HSV infections. J. Med. Virol. 53:319–323, 1997. © 1997 Wiley-Liss, Inc.     

Prevalence of antibodies to herpes simplex virus 2 among homosexual men either positive or negative for human immunodeficiency viruses in Slovakia

We determined the prevalence of antibodies to herpes simplex virus 2 (HSV-2, HSV-2 antibodies) in sera of homosexual men either positive for human immunodeficiency virus 1 (HIV-1, HIV+, a group of 27 sera) or negative for HIV-1 and HIV-2 (HIV-, a group of 52 sera) in Slovakia. Antibodies to HSV-2 glycoprotein G-2 (gG-2, gG-2 antibodies) were determined by a double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and immunoblot analysis. We found that 40% of HIV+ and 23% of HIV- homosexual men were positive for the gG-2 antibodies, what is 3.6 and 2.1 times higher incidence, respectively, than that in the control heterosexual population (Bystrická et al., Acta Virol. 42, 319-324, 1998). Identification of individuals infected with genital herpes among HIV+ and HIV- homosexual men should be succeeded by antiviral therapy in order to prevent transmission of HSV-2 and HIV as well in this community.     

Human serum antibody response inCampylobacter jejuni enteritis as measured by enzyme-linked immunosorbent assay

An ELISA for detection of IgG, IgA, and IgM antibody using an acid-glycine extract from Campylobacter jejuni as antigen was developed. To determine the value of this assay for the diagnosis of acute Campylobacter jejuni infections, the IgG, IgA, and IgM immune response against Campylobacter jejuni was investigated at various timepoints after infection in patients with culture-proven infection. A total of 112 sera from 46 patients and 78 sera from a control group were tested. All but one of the 46 patients with culture-proven Campylobacter jejuni enteritis developed IgG antibodies against Campylobacter jejuni. IgA and IgM ELISA both showed 97% specificity, and sensitivity of 63% and 30% respectively. IgG antibody titers generally remained at a constant level for more than 50 days, whereas IgA and IgM antibody titers declined more rapidly to normal values within 30 to 50 days after onset of clinical symptoms. Detection of Campylobacter jejuni specific IgA antibodies in a single serum sample provided the most useful assay for serological diagnosis of Campylobacter jejuni enteritis. The presence of Campylobacter jejuni specific IgM antibodies was the sole diagnostic criterion in three cases. Serological diagnosis of Campylobacter jejuni enteritis should therefore include both IgA and IgM antibody determination.     

The use of peptides from glycoproteins G-2 and D-1 for detecting herpes simplex virus type 2 and type-common antibodies.

BACKGROUND: identification and discrimination of latent herpes simplex virus (HSV) infection relies on antibody identification. The inclusion of synthetic peptides with HSV glycoproteins provides means for stable and discriminatory assays for population studies. OBJECTIVE: to determine whether virus-specific synthetic peptides might identify HSV type 2 (HSV-2) antibodies in the presence of the cross-reactive and more common HSV type 1 (HSV-1) antibodies. STUDY DESIGN: the capacity of synthetic peptides as HSV antigens was analyzed in enzyme immunoassay (EIA) using well characterized human serum cohorts. The HSV peptide assays were evaluated in comparison with two commercial HSV-2 assays. RESULTS: a combination of two C-terminal HSV-1 glycoprotein D (gD-1) peptides detected type-common HSV immunoglobulin G (IgG) with high sensitivity (95%) and specificity (93%). Peptides derived from the C-terminus of HSV-2 glycoprotein G (gG-2) had a high HSV-2 type-specificity. Inclusion of both gD-1 and gG-2 peptides gave a sensitivity for human anti-HSV-2 IgG that was similar to that of assays including different amounts of native gG-2. With western blotting as a standard, the sensitivity of the peptide assay ranged between 86% for HSV-2 seropositive persons and 61% for HSV-2 seroconverters. Addition of a small amount of native gG-2 to the peptide assay tended to increase the specificity. CONCLUSION: HSV gG and gD peptides show promise as type-specific and type-common HSV antigens. These peptides are more stable and reproducibly prepared than native or recombinant glycoproteins and may be considered for inclusion in future HSV serodiagnostic assays.     

Seroprevalence of herpes simplex virus types 1 and 2 in HIV-infected and uninfected homosexual men in a primary care setting.

BACKGROUND: Genital herpes is usually caused by herpes simplex virus type 2 (HSV-2), with infections often being unrecognised by patients and/or clinicians. HSV-2 infections may be a risk factor for the transmission of human immunodeficiency virus (HIV) infection. Reliable tests for type-specific HSV antibodies are now readily available. OBJECTIVES: To determine the seroprevalence of HSV-1 and -2 in HIV-seronegative gay men in a primary care setting in Melbourne, Australia, and to compare it with the rate in HIV-infected gay men. To assess the utility in a clinical setting of a type-specific HSV enzyme linked immunosorbent assay (ELISA) as compared with western blot. STUDY DESIGN: We recruited a total of 300 HIV-seronegative homosexual men attending for HIV antibody testing, and HIV-infected men attending for CD4 lymphocyte count and viral load estimation. The subjects completed a questionnaire, and sera were sent for total IgG HSV testing and testing by Gull type-specific HSV ELISA assay. Selected serum samples were retested by western blotting and the results analysed. RESULTS: In total, 168 HIV-antibody negative men and 132 HIV-antibody positive men were recruited. Of all subjects, 73.3% had HSV-1 antibodies. This proportion did not differ between HIV-seronegative and seropositive men (P=0.48). About twenty percent of HIV-seronegative men and 61% of HIV-seropositive men had antibodies to HSV-2 (P<0.0001); 75.6% of HIV-seronegative men with antibodies to HSV-2 gave no history of genital herpes, as did 66.7% of HIV-seropositive men. Overall, in using the type-specific ELISA (Gull) assay, false negative, false positive or equivocal results were obtained in 33/300 (11%) of samples tested compared with western blot. CONCLUSIONS: High rates of HSV-2 infection were found in homosexual males, with the rate for HIV-seropositive men being over twice that for HIV uninfected men. Most subjects were not aware of their infection with HSV-2. HIV-infected individuals were also older and had higher numbers of sexual partners, but we were unable to unambiguously establish that these variables contributed to the difference in HSV-2 seroprevalence rates. The Gull type-specific assay for HSV antibodies has significant problems with sensitivity and specificity at a discrepancy rate of 11%. Caution is advised in using this type-specific commercial assay for clinical purposes.     

Performance of immunoglobulin G (IgG) and IgM enzyme-linked immunosorbent assays using a West Nile virus recombinant antigen (preM/E) for detection of West Nile virus- and other flavivirus-specific antibodies

Focus Technologies developed an indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and a mu-capture IgM ELISA for the detection of West Nile virus (WNV)-specific antibodies based on a WNV preM/E protein recombinant antigen. Normal and disease state serum panels were used to assess the performance characteristics of the two WNV ELISA kits. Totals of 807 and 1,423 sera were used to assess the IgG ELISA and IgM ELISA kits, respectively. The Focus Technologies IgG ELISA had a sensitivity of 97.6% and a specificity of 92.1% (excluding non-WNV flavivirus sera). The comparative method for WNV IgG may lack sensitivity in detecting IgG in early WNV infection, so the specificity of the Focus IgG ELISA may be higher than 92.1%. When sera from patients either infected with or vaccinated against other flaviviruses were tested on the WNV IgG assay, 35% of the sera reacted as positive for WNV IgG. Yellow fever and Japanese encephalitis vaccinees were less reactive in the IgG ELISA than St. Louis and dengue fever patients. The Focus Technologies IgM ELISA had a sensitivity and a specificity of 99.3% (excluding the non-WNV flavivirus sera). The overall cross-reactivity for the IgM ELISA to flavivirus sera was 12%, with 31% of St. Louis encephalitis patients found to be WNV IgM positive and no yellow fever vaccinees found to be WNV IgM positive. In a selected population of 706 sera, 15 false-positive WNV IgM sera were identified. The use of a background subtraction method for the IgM ELISA eliminated all 15 false-positive results, giving a specificity of 100% for the Focus IgM ELISA.     

Discrimination of antibody to herpes B virus from antibody to herpes simplex virus types 1 and 2 in human and macaque sera

The antigenic cross-reactive characteristics of herpes B virus and herpes simplex virus (HSV) type 1 (HSV-1) and HSV-2 are responsible for false-positive diagnoses by serological assays in humans and macaques. In the present study, we developed a fluorometric indirect enzyme-linked immunosorbent assay (ELISA) with recombinant herpes B virus glycoprotein D (gD) and HSV-1 and HSV-2 gG (gG-1 and gG-2, respectively) to discriminate between the three primate herpesvirus infections. The secreted form of gD, gDdTM, was used to detect antibody to herpes B virus gD. Sera positive for herpes B virus, HSV-1, and HSV-2 showed specific reactions to gD, gG-1, and gG-2, respectively. Sera collected from humans and rhesus macaques were investigated for the presence of antibodies to the recombinant proteins of the three herpesviruses. The results suggested that the approach is able to discriminate between herpes B virus and HSV infections. The ELISA was also found to be able to detect infections with multiple primate herpesviruses and may have the potential to identify a subsequent infection in individuals that have already been infected with another herpesvirus. In addition, we found evidence of a greater cross-reactivity of herpes B virus with HSV-1 than with HSV-2. It is suggested that the ELISA with the recombinant antigens is useful not only for the serodiagnosis of primate herpesvirus infections but also for elucidation of the seroprevalence of herpesviruses in humans and primates.     

Seroprevalence Study of Herpes Simplex Virus Type 2 among Pregnant Women in Germany Using a Type-Specific Enzyme Immunoassay

 In a German seroepidemiological study to determine the proportion of pregnant women infected with herpes simplex virus type 2 (HSV-2) and at risk of transmitting the infection to the newborn during delivery, IgG antibodies to HSV-2 in 1999 sera collected from pregnant women in 1996–1997 were measured using an automated type-specific enzyme immunoassay (Cobas Core HSV-2 IgG EIA; Roche Diagnostics, Switzerland). The seroprevalence of HSV-2 was 8.9%, and control studies with a type-common HSV assay measuring antibodies to HSV-1 and HSV-2 revealed that 20.7% of pregnant women were seronegative for HSV antibodies and are therefore at risk of acquiring primary genital HSV infection of either type.     

Evaluation of confirmatory strategies for detection of type-specific antibodies against herpes simplex virus type 2

In this study, the optimal combination of three commercial glycoprotein G-2 (gG-2)-based herpes simplex virus type 2 (HSV-2) type-specific enzyme-linked immunosorbent assays (Euroimmun anti-HSV-2 immunoglobulin G [IgG] ELISA [Eu2], Gull HSV-2-specific IgG ELISA [Gu2], and Radim HSV-2 IgG ELISA [Ra2]) and one gG-2-based HSV-2-specific immunoblot (Euroimmun anti-HSV-1/HSV-2 gG Western blot [EuW]) was determined with regard to diagnostic performance and cost efficiency. Two hundred fifty serum samples were included in this study, 194 of which were from female prostitutes. When a formal primary "gold standard" was defined based on majority agreement of the commercial tests, with EuW being decisive in stand-off situations, the sensitivity and specificity of the assays in the samples from prostitutes were as follows: Eu2, 100 and 89.22%; Gu2, 94.44 and 96.08%; Ra2, 61.18 and 95.10%; and EuW, 98.90 and 100%. The most cost-effective confirmatory strategy in the samples from prostitutes was screening with Eu2, retesting positive and equivocal samples with Gu2, and resolving the remaining discordant results with EuW (estimated additional costs per sample, 79.02%; sensitivity, 100%; positive predictive value, 96.81%). Applying a self-developed gG-2-independent assay to the discordant and concordant negative samples in the samples from prostitutes suggested that the primary gold standard may have missed six HSV-2-positive samples. In conclusion, confirmatory strategies based on commercial gG-2-dependent seroassays result in an increase in the specificity of HSV-2-specific serology. However, further improvement of the sensitivity of current HSV-2-specific serology may require the additional exploitation of the gG-2-independent type-specific antibody response.     

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.