Sensitivity and specificity of herpes simplex virus-2 serological assays among HIV-infected and uninfected urban Ugandans.

Herpes simplex virus type 2 (HSV-2) is a risk factor for HIV-1 infection. We characterized HSV-2 serology assay performance in HIV-positive and HIV-negative Africans. Serostatus for HSV-2 and HIV-1 was determined in 493 serum specimens stored from a community HSV-2 prevalence survey in Kampala, Uganda. HSV-2 serology by Focus HerpeSelect ELISA, Biokit HSV-2 rapid assay and Kalon HSV-2 was compared with HSV-2 Western blot (WB) according to HIV-1 serostatus. Sensitivity/specificity was: 99.5%/70.2% for Focus, 97.0%/86.4% for Biokit and 97.5%/96.2% for Kalon. Focus with Biokit confirmation improved sensitivity/specificity (99.4%/96.8%, respectively). Use of a higher Focus index value cut-off of 2.2 instead of 1.1 increased specificity from 70.2% to 92.4%. Kalon had higher specificity than Focus (P < 0.001). Of commercially available HSV-2 serological assays, Kalon alone, or Focus ELISA followed by Biokit confirmation perform best. Improved HSV-2 assays are needed for HSV-2 and HIV-1 public health activities in Africa.

Time-resolved phosphorescence of tyrosine, tyrosine analogs, and tyrosyl residues in oxytocin and small peptides.

We present the time-resolved phosphorescence of oxytocin, two oxytocin derivatives, vasopressin and a series of compounds that serve as models for free tyrosine. One of the oxytocin derivatives, desaminodicarbaoxytocin, has the disulfide bridge replaced by an ethylene bridge, and lacks the N-terminus. Similar to the reported fluorescence decays of tyrosine in these peptides, the phosphorescence decays generally are not single exponentials, but can be fit as biexponentials. The decay times for the oxytocin peptides are shorter than for desaminodicarbaoxytocin or the model compounds, and this we attribute to enhanced spin-orbit coupling due to the presence of sulfur. We measured the phosphorescence decay of the model cyclic pentapeptide that contains tyrosine and compared it to that observed for the same cyclic pentapeptide in which tyrosine is replaced by tryptophan. We also report the phosphorescence of 2-tryptophan-oxytocin, and deamino-2-tryptophan-oxytocin in which biexponential phosphorescence decay is also observed.

Risk factors for HIV-1 shedding in semen.

Semen is the body fluid most commonly associated with sexual transmission of human immunodeficiency virus type-1 (HIV-1). Because the male genitourinary tract is distinct immunologically from blood, compartment-dependent factors may determine HIV-1 shedding in semen. To identify these factors, the authors obtained 411 semen and blood specimens from 149 men seen up to three times. Seminal plasma was assayed for HIV-1 RNA and semen was cocultured for HIV-1 and cytomegalovirus (CMV), which may up-regulate HIV-1 replication. The best multivariate model for predicting a positive semen HIV-1 coculture included two local urogenital factors, increased seminal polymorphonuclear cell count (odds ratio (OR) = 12.6 for each log10 increase/mL, 95% confidence interval (CI) 12.2, 134.5) and a positive CMV coculture (OR = 3.0, 95% CI 1.2, 7.7). The best multivariate model for predicting semen HIV-1 RNA included two systemic host factors, CD4+ cell counts <200/microliter (OR = 3.0, 95 percent CI 1.3, 6.9) and nucleoside antiretroviral therapy (monotherapy: OR = 0.5, 95% CI 0.3, 1.0; combination therapy: OR = 0.4, 95% CI 0.2, 0.9), and a positive CMV coculture (OR = 1.7, 95% CI 1.0, 3.0). Thus, both systemic and local genitourinary tract factors influence the risk of semen HIV-1 shedding. These findings suggest that measures of systemic virus burden alone may not predict semen infectivity reliably.

Association between culturable human immunodeficiency virus type 1 (HIV-1) in semen and HIV-1 RNA levels in semen and blood: evidence for compartmentalization of HIV-1 between semen and blood.

Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 (HIV-1) to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments. Evidence for viral compartmentalization was suggested by earlier studies that noted the poor correlation between blood and seminal virus load, phenotype, and genotype. Further support for this viral compartmentalization was based on the following observations between semen and blood: lack of association between culturability of virus in semen and viral RNA level in blood, discordant distribution of viral phenotypes, discordant viral RNA levels, a weak correlation between viral RNA level in semen and CD4 cell count in blood, differences in the biologic variability of viral RNA levels, and differences in the virus load response to antiretroviral therapy.

Immune responses elicited by recombinant vaccinia-human immunodeficiency virus (HIV) envelope and HIV envelope protein: analysis of the durability of responses and effect of repeated boosting.

Previous studies indicate that immunization with recombinant (r) vaccinia-human immunodeficiency virus type 1 (HIV-1) gp160 and boosting with baculovirus-derived HIV-1 rgp160 results in stronger cellular and antibody responses than those following either vaccine alone. The durability of immunity over 1 year was evaluated in 12 recipients. Both cellular and binding antibody responses remained detectable but diminished, and neutralizing antibodies were absent. To boost immunity, rgp160 was given again 1 year after the initial boost. Reboosting elicited strong HIV-specific lymphoproliferative responses. Binding antibody levels also rose dramatically, and the magnitude of the peak responses was significantly greater following the 2-year than following the 1-year boost. However, neutralizing antibody titers were low (1:10-1:20) and detected in only 4 of 12 persons. Moreover, persistent CD8+ cytolytic responses were not induced. Thus, although repeated rgp160 boosting after vaccinia-envelope priming can augment selected immune components, an altered regimen may be necessary to achieve protective long-term immunity to HIV-1.

Acute infection of Macaca nemestrina by human immunodeficiency virus type 1.

The pigtail macaque (Macaca nemestrina) has a marked sensitivity to infection by simian immunodeficiency virus and human immunodeficiency virus type 2 (HIV-2). On this basis, we previously studied this species' susceptibility to HIV-1 and demonstrated infection in six macaques inoculated with either cell-associated HIV-1 or cell-free virus alone. This report expands upon our initial in vitro and in vivo findings. Five laboratory-adapted and one primary clinical strain of HIV-1 replicated in vitro in human and M. nemestrina peripheral blood mononuclear cells (PBMCs). Replication was enhanced when CD4+ purified PBMCs were infected and inhibited when PBMC cultures were treated with zidovudine. All six macaques demonstrated HIV-1 infection of PBMCs from 2 to 8 weeks after inoculation but nearly all PBMC cultures were negative from weeks 10 to 40. Polymerase chain reaction showed HIV-1 gag DNA in the PBMCs of all infected macaques, including times when the macaques were culture negative. All macaques developed and maintained antibodies to gag and envelope HIV-1 proteins from week 4 after inoculation through the period of observation. Five macaques showed neutralizing antibody. These findings suggest that M. nemestrina can be infected by cell-free and cell-associated HIV-1. This model of acute HIV-1 infection may help in evaluating the pathogenesis of HIV-1 replication and candidate vaccines and therapies.

Underestimation of HSV-2 seroprevalence in a high-risk population by microneutralization assay.

BACKGROUND: Complement independent neutralizing antibody assays (CINA) have been used in seroepidemiologic studies and in diagnostic laboratories to distinguish between antibodies to herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). The accuracy of CINA has not been rigorously tested against protein-specific typing assays, such as Western blot. GOAL OF THIS STUDY: To determine the ability of CINA to identify HSV-2 antibodies alone or in the presence of HSV-1 antibodies. STUDY DESIGN: Sera from randomly selected women at the Seattle King County Sexually Transmitted Disease Clinic were tested by CINA and Western blot. RESULTS: Of 521 women tested, 81% had HSV antibodies by Western blot and 76% had neutralizing antibodies. Of 220 sera with HSV-2 antibodies by Western blot, 106 (48%) were serotyped correctly by CINA. Of the women studied, 140 (27%) had type-indeterminate neutralizing antibodies; 55 of these sera (39%) had antibody only to HSV-1 by Western blot. CONCLUSION: The seroprevalence of HSV-2 in an STD clinic population was seriously underestimated by CINA.

Comparison of diploid fibroblast and rabbit kidney tissue cultures and a diploid fibroblast microtiter plate system for the isolation of herpes simplex virus.

We evaluated the relative sensitivities of two cell systems (rabbit kidney [RK] and human diploid fibroblast [DF; human embryonic tonsil]) in standard tube cultures versus DF cells in a 48-well microtiter plate system for the detection of both symptomatic and asymptomatic herpes simplex virus (HSV) infection. At least one system isolated HSV in 111 of 809 specimens (13.7%). HSV was isolated in RK tube cultures from 110 specimens (99%), in DF tube cultures from 91 specimens (82%), and in DF microtiter plates from 95 specimens (86%). The frequency of HSV isolation varied with the anatomic site and the presence or absence of a herpetic lesion. The sensitivities of the three culture systems remained similar whether the specimens were obtained from lesions or whether the specimens were taken to determine if asymptomatic excretion of HSV was present. While RK tube cultures were more sensitive than DF tube cultures, the DF microtiter plate system was as sensitive as DF tube cultures and its use is supported as a cheaper and less labor-intensive method for the detection of HSV.

Treatment of primary first-episode genital herpes simplex virus infections with acyclovir: results of topical, intravenous and oral therapy.

Three double-blind, placebo-controlled evaluations of acyclovir were performed in first-episode genital herpes infections. In one trial intravenous acyclovir or saline was administered in hospital over 5 days. In the other two trials, 10-day courses of oral, or 7-day courses of topical acyclovir and respective placebos were followed up in the outpatient department. Regular assessments included staging examinations, culture of lesions and blood and serum analyses. No patient discontinued medication because of an adverse reaction, although one quarter of topically treated patients complained of local irritation on application. The placebo-controlled evaluations indicate that, if given within the first 7 days after the onset of lesions, topical, intravenous and oral acyclovir are useful in shortening the course of first-episode primary genital herpes. The clinical and virological effects of intravenous and oral acyclovir were more marked than those of topical treatment in the reduction of viral shedding; the time to complete healing of lesions; and in the reduction of new lesion formation. Systemic preparations of acyclovir also decreased the symptoms of herpes simplex virus urethritis and intravenous acyclovir those of herpes simplex virus cervicitis. Neither systemic treatment, however, was effective in delaying or reducing the frequency of subsequent recurrences, which may be related to the development of early ganglionic infection. Despite this, acyclovir treatment is a significant advance in the management of primary genital herpes.