Asymptomatic herpes simplex virus shedding and Russian roulette

Seroprevalence of HSV-1 and HSV-2 in Barbados

Type-specific enzyme-linked immunosorbent assays, based upon recombinant glycoprotein G (gG), were used to detect antibodies to HSV-1 and HSV-2, in a small Caribbean island population. A blinded serosurvey was performed on samples from 184 blood donors, 122 pregnant women, and 120 HIV-positive patients. The seroprevalence of HSV-1 and HSV-2 was 81% and 34%, respectively, in blood donors, 84% and 40% in the antenatal population and 89% and 77% in the HIV-positive group. As expected the majority of adults were seropositive against HSV-1. However, the HSV-2 seroprevalence was significantly higher in HIV-infected adults than in the other groups. These findings support the need for prospective epidemiological studies in this population.

Challenges in genital herpes simplex virus management

Development of serologic assays to detect antibodies to herpes simplex virus (HSV) glycoproteins (g)G1 and (g)G2 has allowed accurate definition of the seroprevalence of HSV-2 worldwide. Studies from all continents indicate epidemic proportions of HSV-2 infection. In the United States, 1 in 5 sexually active adults is infected. In Africa and the Caribbean, HSV prevalence is higher. Since the development of the acyclic nucleoside derivatives acyclovir, famciclovir, and valacyclovir, treatment of mucocutaneous HSV is a practice of everyday medical care. Yet, despite effective drugs, there is widespread discontent by clients and providers about care of patients with genital herpes. Much of this relates to transmission complexities and the varied natural history of the infection. However, over time, most patients adjust to their disease and the medical and psychosocial complications. Recent studies show condoms reduce transmission, providing an important tool for counseling the patient with newly diagnosed genital herpes.

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.

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.