Herpes simplex virus seroprevalence and risk factors in 2 Canadian sexually transmitted disease clinics

Stacking the odds: Multiple sites for HSV-1 latency

A hallmark of herpes simplex virus (HSV) infection is the establishment of latent virus in peripheral sensory ganglia of the latently infected host. We and others originally reported that the latency-associated transcript (LAT) is the only abundantly expressed viral gene in neurons within trigeminal ganglia (TG) of a latently infected host. Here, we investigated the possible contribution of various cells [i.e., B cells, dendritic cells (DCs), fibroblasts, glial cells, innate lymphoid cells (ILCs), macrophages, microglia, monocytes, natural killer cells, neurons, neutrophils, and T cells] isolated from TG of latently infected mice. Our results demonstrated that all of these cell types contain LAT, with DCs, neurons, and ILCs having the most LAT⁺ cells. These results suggest that HSV-1 can establish a quiescent/latent infection in a subset of nonneuronal cells, which enhances the chances that the virus will survive in its host.

Blocking HSV-1 glycoprotein K binding to signal peptide peptidase reduces virus infectivity in vitro and in vivo

HSV glycoprotein K (gK) is an essential herpes protein that contributes to enhancement of eye disease. We previously reported that gK binds to signal peptide peptidase (SPP) and that depletion of SPP reduces HSV-1 infectivity in vivo. To determine the therapeutic potential of blocking gK binding to SPP on virus infectivity and pathogenicity, we mapped the gK binding site for SPP to a 15mer peptide within the amino-terminus of gK. This 15mer peptide reduced infectivity of three different virus strains in vitro as determined by plaque assay, FACS, and RT-PCR. Similarly, the 15mer peptide reduced ocular virus replication in both BALB/c and C57BL/6 mice and also reduced levels of latency and exhaustion markers in infected mice when compared with control treated mice. Addition of the gK-15mer peptide also increased the survival of infected mice when compared with control mice. These results suggest that blocking gK binding to SPP using gK peptide may have therapeutic potential in treating HSV-1-associated infection.

Signal peptide peptidase (SPP) and HSV-1 glycoprotein K (gK) are essential genes in the host and virus, respectively. SPP and gK genes are both highly conserved. Previously we reported that gK binding to SPP is important for virus infectivity in vitro and in vivo. In this study we have identified the gK binding site to SPP and have shown that a gK peptide that blocks gK binding to SPP can block HSV-1 infectivity in vitro and in vivo using different strains of virus and mice. Thus, the ability of this peptide to block gK binding to SPP may be a useful tool to control HSV-1-induced eye disease in patients with herpes stromal keratitis (HSK).

Loss of ICP22 in HSV-1 Elicits Immune Infiltration and Maintains Stromal Keratitis Despite Reduced Primary and Latent Virus Infectivity

Purpose

We previously have reported that ICP22, an immediate early gene of herpes simplex virus type 1 (HSV-1), binds to the CD80 promoter to suppress CD80 expression in antigen-presenting cells, leading to reduced T-cell function and protection. In contrast, overexpression of CD80 exacerbates corneal scarring (CS) in ocularly infected mice. In this study we tested the hypothesis that the absence of ICP22 could increase disease severity.

Methods

To test our hypothesis, BALB/c mice were ocularly infected after corneal scarification with a recombinant HSV-1 lacking the ICP22 gene with its parental wild-type (WT) virus (KOS) as a control. Virus replication in the eye, CS, angiogenesis, latency, and reactivation between ICP22 null virus and WT KOS were determined. In addition, expression of IL-2, IL-4, IFN-γ, IFN-α, granzyme A, granzyme B, and perforin by CD4 and CD8 T cells in corneas of infected mice on days 3, 5, 7, 10, 14, 21, and 28 postinfection were determined by flow cytometry.

Results

We found similar levels of eye disease and angiogenesis in mice following corneal scarification and ocular infection with the ICP22 null virus or parental WT virus despite reduced virus replication in the eye and reduced latency and reactivation in mice ocularly infected with ICP22 null virus. The similar level of eye disease in ICP22 null virus- and WT virus-infected mice correlated with expression of various proinflammatory cytokines that infiltrated the eye after HSV-1 infection.

Conclusions

Our study identified a critical role for ICP22 in HSV-1 pathogenicity and suggests that HSV-1-associated CS is more dependent on host immune responses to infection than to virus replication in the eye. Thus, HSV-1 as means of survival uses ICP22 as a mechanism of immune escape that protects the host from increased pathology.

The Latency-Associated Transcript Inhibits Apoptosis via Downregulation of Components of the Type I Interferon Pathway during Latent Herpes Simplex Virus 1 Ocular Infection

The herpes simplex virus (HSV-1) latency-associated transcript (LAT) has been shown to inhibit apoptosis via inhibiting activation of proapoptotic caspases. However, the mechanism of LAT control of apoptosis is unclear, because LAT is not known to encode a functional protein, and the LAT transcript is found largely in the nucleus. We hypothesized that LAT inhibits apoptosis by regulating expression of genes that control apoptosis. Consequently, we sought to establish the molecular mechanism of antiapoptosis functions of LAT at a transcriptional level during latent HSV-1 ocular infection in mice. Our results suggest the following. (i) LAT likely inhibits apoptosis via upregulation of several components of the type I interferon (IFN) pathway. (ii) LAT does not inhibit apoptosis via the caspase cascade at a transcriptional level or via downregulating Toll-like receptors (TLRs). (iii) The mechanism of LAT antiapoptotic effect is distinct from that of the baculovirus inhibitor of apoptosis (cpIAP) because replacement of LAT with the cpIAP gene resulted in a different gene expression pattern than in either LAT+ or LAT- viruses. (iv) Replacement of LAT with the cpIAP gene does not cause upregulation of CD8 or markers of T cell exhaustion despite their having similar levels of latency, further supporting that LAT and cpIAP function via distinct mechanisms.IMPORTANCE The HSV-1 latency reactivation cycle is the cause of significant human pathology. The HSV-1 latency-associated transcript (LAT) functions by regulating latency and reactivation, in part by inhibiting apoptosis. However, the mechanism of this process is unknown. Here we show that LAT likely controls apoptosis via downregulation of several components in the JAK-STAT pathway. Furthermore, we provide evidence that immune exhaustion is not caused by the antiapoptotic activity of the LAT.

CCR2+ migratory macrophages with M1 status are the early-responders in the cornea of HSV-1 infected mice

Complex interactions between HSV-1 and infiltrating immune cells play important roles in establishing localized, acute virus replication as well as chronic latent infection. The extent and duration of initial virus replication are the key determinants of subsequent pathologic inflammatory responses and therefore, the accumulation of immune cell populations at this time point is a key target for prevention. Therefore, we evaluated the role of various immune cell infiltrates between 1 h and 28 days post-infection (PI) using mice infected with virulent HSV-1 strain McKrae without corneal scarification. The effect of corneal scarification on immune cell infiltrates was also determined. We first determined the activation status and origin of macrophage infiltrates as early as 1 h PI. We found a sharp increase in the total macrophage population after 12 h PI, that was primarily due to infiltration of CCR2⁺ migratory macrophages, mostly in M1 status (MHC II⁺). The number of CCR2^- resident macrophages, mostly unpolarized (M0), increased gradually over time and peaked at 48 h PI. Interestingly, some of the resident macrophages gained an M2-like phenotype (CD206^Low), which peaked at 12 h PI, concurrent with M1 macrophage infiltration. From 1–7 days PI, infiltration of various immune cells correlated strongly with HSV-1 replication, with neutrophils showing the biggest increase, and NKT cells the biggest decrease, after infection. The presence of geographical ulcer did not correlate with increased infiltration, while mice with corneal scarring had significantly more immune cell infiltration than those without corneal scarring. Overall, we showed time-dependent infiltration of various immune cells in the eye of HSV-1 infected mice. Initial infiltration of macrophages followed by infiltration of T cells at later times PI demonstrates the importance of targeting macrophages rather than other immune cells type, for therapeutic treatment of HSV-1.

Role of Herpes Simplex Virus Type 1 (HSV-1) Glycoprotein K (gK) Pathogenic CD8+ T Cells in Exacerbation of Eye Disease

HSV-1-induced corneal scarring (CS), also broadly referred to as Herpes Stromal Keratitis (HSK), is the leading cause of infectious blindness in developed countries. It is well-established that HSK is in fact an immunopathological disease. The contribution of the potentially harmful T cell effectors that lead to CS remains an area of intense study. Although the HSV-1 gene(s) involved in eye disease is not yet known, we have demonstrated that gK, which is one of the 12 known HSV-1 glycoproteins, has a crucial role in CS. Immunization of HSV-1 infected mice with gK, but not with any other known HSV-1 glycoprotein, significantly exacerbates CS, and dermatitis. The gK-induced eye disease occurs independently of the strain of the virus or mouse. HSV-1 mutants that lack gK are unable to efficiently infect and establish latency in neurons. HSV-1 recombinant viruses expressing two additional copies of the gK (total of three gK genes) exacerbated CS as compared with wild type HSV-1 strain McKrae that contains one copy of gK. Furthermore, we have shown that an 8mer (ITAYGLVL) within the signal sequence of gK enhanced CS in ocularly infected BALB/c mice, C57BL/6 mice, and NZW rabbits. In HSV-infected “humanized” HLA-A^*0201 transgenic mice, this gK 8mer induced strong IFN-γ-producing cytotoxic CD8⁺ T cell responses. gK induced CS is dependent on gK binding to signal peptide peptidase (SPP). gK also binds to HSV-1 UL20, while UL20 binds GODZ (DHHC3) and these quadruple interactions are required for gK induced pathology. Thus, potential therapies might include blocking of gK-SPP, gK-UL20, UL20-GODZ interactions, or a combination of these strategies.

Prevalence of Sexually Transmitted Viral and Bacterial Infections in HIV-Positive and HIV-Negative Men Who Have Sex with Men in Toronto

Background

Hepatitis B (HBV), hepatitis C (HCV) and other sexually transmitted infections (STIs) have been associated with HIV transmission risk and disease progression among gay men and other men who have sex with men (MSM), but the frequency and distribution of STIs in this community in Canada has not been extensively studied.

Methods

We recruited MSM living with and without HIV from a large primary care clinic in Toronto. Participants completed a detailed socio-behavioural questionnaire using ACASI and provided blood for syphilis, HIV, HBV and HCV, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), and human cytomegalovirus (CMV) serology, urine for chlamydia and gonorrhea, and a self-collected anal swab for human papillomavirus (HPV) molecular diagnostics. Prevalences were expressed as a proportion and compared using chi-square.

Results

442 MSM were recruited, 294 living with HIV and 148 without. Active syphilis (11.0% vs. 3.4%), ever HBV (49.4% vs. 19.1%), HCV (10.4% vs. 3.4%), HSV-2 (55.9% vs. 38.2%), CMV (98.3% vs. 80.3%) and high-risk (HR) anal HPV (67.6% vs. 51.7%) infections were significantly more common in men living with HIV. Chlamydia and gonorrhea were infrequent in both groups. Regardless of HIV infection status, age and number of lifetime male sexual partners were associated with HBV infection and lifetime injection drug use with HCV infection.

Conclusions

Syphilis and viral infections, including HBV, HCV, HSV-2, CMV, and HR-HPV, were common in this clinic-based population of MSM in Toronto and more frequent among MSM living with HIV. This argues for the implementation of routine screening, vaccine-based prevention, and education programs in this high-risk population.

First HSV-1 non primary genital herpes in two patients

First HSV-1 genital episodes in HSV-2 infected patients however, had never been demonstrated until the 2 cases we observed. This scarcity could reflect the lower impact of HSV-2 on western populations but questions the existence of cross-protection between viral types.

Inhibitors of signal peptide peptidase (SPP) affect HSV-1 infectivity in vitro and in vivo

Recently we have shown that the highly conserved herpes simplex virus glycoprotein K (gK) binds to signal peptide peptidase (SPP), also known as minor histocompatibility antigen H13. In this study we have demonstrated for the first time that inhibitors of SPP, such as L685,458, (Z-LL)2 ketone, aspirin, ibuprofen and DAPT, significantly reduced HSV-1 replication in tissue culture. Inhibition of SPP activity via (Z-LL)2 ketone significantly reduced viral transcripts in the nucleus of infected cells. Finally, when administered during primary infection, (Z-LL)2 ketone inhibitor reduced HSV-1 replication in the eyes of ocularly infected mice. Thus, blocking SPP activity may represent a clinically effective and expedient approach to the reduction of viral replication and the resulting pathology.

Seroprevalence of HSV-1 and HSV-2 antibodies in Canadian women screened for enrolment in a herpes simplex virus vaccine trial

Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) infections continue to be among the most common and unrecognized sexually transmitted infections in the world. Although treatable, HSV-1 and HSV-2 infections remain incurable. Hence, there is interest in the development of a vaccine to prevent genital herpes. As part of a multicentre, randomized, placebo-controlled trial to test such a vaccine, healthy women 18-30 years were enrolled as volunteers in several Canadian centres between 2005 and 2007. This study reports the seroprevalence of HSV-1 and HSV-2 antibodies in this group. A total of 2694 adult female volunteers in Canada with no known history of herpes simplex were screened for HSV antibodies using Western blot assay (the gold standard for diagnosis of HSV) for potential participation in a randomized, double-blind efficacy field trial of a herpes simplex vaccine. This trial provides a unique opportunity to examine the prevalence of antibodies to HSV-1 and of antibodies to HSV-2 in women with no known history of herpes simplex infection. The prevalence of antibodies to HSV-1 and to HSV-2 is compared with that found in previous Canadian studies that focused on a more general population. The overall seroprevalence of antibody to HSV-1 was 43%; that of HSV-2 was 2.5% and seropositivity to both was 2%. The prevalence of antibody to both HSV-1 and to HSV-2 increased with age. Seronegativity to both HSV-1 and HSV-2 was 56% in participating centres with populations under 250,000 and 46% in participating centres with populations over 250,000. Significant racial differences in seropositivity to HSV-1 and to HSV-2 were noted. The likelihood of participants being seropositive to HSV-1 and to HSV-2 was found to increase with age and to positively correlate with the population of the city in which they resided. Hypotheses are proposed to account for differences in racial seropositivity to HSV-1 and to HSV-2.

Genital herpes in Canada: Deciphering the hidden epidemic

INTRODUCTION

Genital herpes (GH) is the most common cause of genital ulceration, but is not reportable in Canada. Research in the United States has found that less than 10% of seropositive persons reported a diagnosis of GH. The present article investigates the rates of diagnosed cases of GH in Canada from 2002 to 2007.

METHODS

Primary case diagnosis data on GH for the period between 2002 and 2007 were obtained from the Canadian Disease and Therapeutic Index, a proprietary database maintained by Intercontinental Medical Statistics (IMS) Health Canada. Of the 45,000 to 49,000 office-based physicians in Canada, IMS Health collected diagnosis-specific prescription diaries from a sample of 652, stratified according to geographic region and representing all major specialties, during this period.

RESULTS

Between 2002 and 2007, there were approximately 84,398 to 122,456 medically attended GH cases annually in Canada. Approximately 74% to 93% of these diagnosed cases made one physician visit per year. The annual rate of medically attended GH cases ranged from 261.2 per 100,000 population to 386.6 per 100,000 population.

DISCUSSION

The present report is the first time that administrative data have been used to estimate the annual rate of medically attended GH cases in Canada. The data include both incident and prevalent cases and are likely an underestimate of the actual number of cases because they only represent diagnosed cases presenting for medical care. Further seroepidemiological and clinical research studies would be helpful to assess the burden of infection and to plan appropriate diagnostic, treatment and preventive counselling services.

INTRODUCTION

Genital herpes (GH) is the most common cause of genital ulceration, but is not reportable in Canada. Research in the United States has found that less than 10% of seropositive persons reported a diagnosis of GH. The present article investigates the rates of diagnosed cases of GH in Canada from 2002 to 2007.

METHODS

Primary case diagnosis data on GH for the period between 2002 and 2007 were obtained from the Canadian Disease and Therapeutic Index, a proprietary database maintained by Intercontinental Medical Statistics (IMS) Health Canada. Of the 45,000 to 49,000 office-based physicians in Canada, IMS Health collected diagnosis-specific prescription diaries from a sample of 652, stratified according to geographic region and representing all major specialties, during this period.

RESULTS

Between 2002 and 2007, there were approximately 84,398 to 122,456 medically attended GH cases annually in Canada. Approximately 74% to 93% of these diagnosed cases made one physician visit per year. The annual rate of medically attended GH cases ranged from 261.2 per 100,000 population to 386.6 per 100,000 population.

DISCUSSION

The present report is the first time that administrative data have been used to estimate the annual rate of medically attended GH cases in Canada. The data include both incident and prevalent cases and are likely an underestimate of the actual number of cases because they only represent diagnosed cases presenting for medical care. Further seroepidemiological and clinical research studies would be helpful to assess the burden of infection and to plan appropriate diagnostic, treatment and preventive counselling services.

Using centralized laboratory data to monitor trends in herpes simplex virus type 1 and 2 infection in British Columbia and the changing etiology of genital herpes

OBJECTIVES

Understanding the regional epidemiology of genital Herpes Simplex Virus (HSV) infections is important for clinical and public health practice, due to the increasing availability of type-specific serologic testing in Canada and the contribution of genital HSV-2 infection to ongoing HIV transmission. We used centralized laboratory data to describe trends in viral identifications of genital HSV in BC and assess the utility of these data for ongoing population surveillance.

METHODS

Records of viral identifications (1997-2005) were extracted from the Provincial Public Health Microbiology & Reference Laboratory database. Classification as genital or other site was based on documented specimen site. We conducted a descriptive analysis of trends over time, and calculated odds of HSV-1 infection among individuals with genital herpes.

RESULTS

Of 48,183 viral identifications, 56.8% were genital, 10.0% were peri-oral and 9.1% cutaneous; site was unknown for 22.9%. Among genital identifications, HSV-1 infection was more likely in females, younger age groups, and later time periods. The proportion of genital herpes due to HSV-1 increased over time from 31.4% to 42.8% in BC.

CONCLUSIONS

Our analysis of population-level laboratory data demonstrates that the proportion of genital herpes due to HSV-1 is increasing over time in BC, particularly among women and younger age groups; this has implications for clinical practice including the interpretation of type-specific serology. Provincial viral identification data are useful for monitoring the distribution of genital HSV-1 and HSV-2 infections over time. Improving clinical documentation of specimen site would improve the utility of these data.

CD11c controls herpes simplex virus 1 responses to limit virus replication during primary infection

CD11c is expressed on the surface of dendritic cells (DCs) and is one of the main markers for identification of DCs. DCs are the effectors of central innate immune responses, but they also affect acquired immune responses to infection. However, how DCs influence the efficacy of adaptive immunity is poorly understood. Here, we show that CD11c(+) DCs negatively orchestrate both adaptive and innate immunity against herpes simplex virus type 1 (HSV-1) ocular infection. The effectiveness and quantity of virus-specific CD8(+) T cell responses are increased in CD11c-deficient animals. In addition, the levels of CD83, CD11b, alpha interferon (IFN-α), and IFN-β, but not IFN-γ, were significantly increased in CD11c-deficient animals. Higher levels of IFN-α, IFN-β, and CD8(+) T cells in the CD11c-deficient mice may have contributed to lower virus replication in the eye and trigeminal ganglia (TG) during the early period of infection than in wild-type mice. However, the absence of CD11c did not influence survival, severity of eye disease, or latency. Our studies provide for the first time evidence that CD11c expression may abrogate the ability to reduce primary virus replication in the eye and TG via higher activities of type 1 interferon and CD8(+) T cell responses.

The diagnosis of genital herpes - beyond culture: An evidence-based guide for the utilization of polymerase chain reaction and herpes simplex virus type-specific serology

Accurate identification of persons with genital herpes is necessary for optimal patient management and prevention of transmission. Because of inherent inaccuracies, clinical diagnosis of genital herpes should be confirmed by laboratory testing for the causative agents herpes simplex virus type 1 (HSV-1) and HSV type 2 (HSV-2). Further identification of the HSV type is valuable for counselling on the natural history of infection and risk of transmission. Laboratory methods include antigen detection, culture, polymerase chain reaction (PCR) and conventional and type-specific serology (TSS). PCR has, by far, the greater sensitivity and should be the test of choice for symptomatic cases. HSV-2 TSS is indicated for patients with genital lesions in whom antigen detection, culture or PCR fail to detect HSV, and for patients who are asymptomatic but have a history suggestive of genital herpes. HSV-2 TSS is further indicated for patients infected with HIV. HSV-2 TSS along with HSV-1 TSS may be considered, as appropriate, in evaluating infection and/or immune status in couples discordant for genital herpes, women who develop their first clinical episode of genital herpes during pregnancy, asymptomatic pregnant women whose partners have a history of genital herpes or HIV infection, and women contemplating pregnancy or considering sexual partnership with those with a history of genital herpes. The above should be performed in conjunction with counselling of infected persons and their sex partners.

Prospects for Developing an Effective Vaccine Against Ocular Herpes Simplex Virus Infection

One of the hallmarks of herpes simplex virus (HSV) infection is the establishment of a lifelong latent infection accompanied by periods of recurrent disease. Primary HSV infections or repeated clinical recurrences do not elicit immune responses capable of completely preventing recurrences of endogenous virus. It is therefore questionable if vaccination approaches that seek to mimic the immune response to natural infection will reduce infection or disease due to an exogenous viral challenge. Approaches to the induction of protective responses by altering or enhancing both innate and adaptive immunity, using novel vaccines specifically tested in models of HSV infections of the eye, such as recombinant viral vaccine vectors and DNA vaccines, are detailed in this review.

Seroprevalence and factors associated with herpes simplex virus type 2 among HIV-negative high-risk men who have sex with men from Rio de Janeiro, Brazil: a cross-sectional study

BACKGROUND

Herpes simplex virus type 2 (HSV-2) is the leading cause of genital ulcer disease in developing countries, including Brazil, and is especially prevalent among men who have sex with men (MSM). HSV-2 infection represents a risk factor for the acquisition and transmission of other sexually transmitted diseases. The goal of the present cross-sectional study was to estimate HSV-2 seroprevalence and to determine the factors associated with HSV-2 seropositivity in HIV-negative high-risk MSM from Rio de Janeiro, Brazil.

METHODS

Stored sera were tested to estimate HSV-2 seroprevalence, while socio-demographic and sexual behavior data were used to measure associations between risk factors and HSV-2 seropositivity. Using the Poisson regression model with robust variance, prevalence ratios (PR) were used to estimate de degree of association between risk factors and HSV-2 seropositivity in bivariate and multivariate analyses.

RESULTS

Seroprevalence of HSV-2 was of 45.7% (184 out of 403). Factors independently associated with HSV-2 seroprevalence in the multivariate model were: older age (>or= 26 years, PR: 1.41 95% Confidence Interval: 1.11-1.78), non-white race (PR: 1.32 95%CI: 1.06-1.64), positive serology for syphilis (PR: 1.65 95%CI: 1.33-2.05), positive serology for hepatitis B (PR: 1.25 95%CI: 0.99-1.57), stable male partner in the past 6 months (PR: 1.42 95%CI: 1.12-1.79), and unprotected anal sex with a stable female partner (PR: 1.46 95%CI: 1.05-2.04) in the 6 months preceding the cross-sectional assessment.

CONCLUSION

The present study made evident a high prevalence of HSV-2 infection in a sample of HIV-negative high-risk MSM from Rio de Janeiro. This finding indicates the need and urgency for implementing integrated programs for the prevention of HSV-2 and other sexually transmitted diseases, and, in particular, programs targeting high-risk MSM.

Seroprevalence of herpes simplex virus-1 and -2 in attendees of a sexually transmitted infection clinic in Singapore

BACKGROUND

We studied the seroprevalance of HSV (herpes simplex virus)-1 and HSV-2 in outpatient attendees of a sexually transmitted infection (STI) clinic in Singapore and examined their knowledge and attitudes towards HSV infection.

METHODS

Two hundred male and 200 female participants were recruited in the study. Questionnaires were administered and blood samples were taken and analysed using the HerpeSelect 1 and 2 enzyme-linked immunosorbent assay (ELISA) IgG assays (type-specific serological tests).

RESULTS

HSV-1 was positive in 223 (55.8%) individuals, negative in 175 (43.8%) and indeterminate in two (0.5%), whereas HSV-2 was positive in 114 (28.5%) individuals, negative in 284 (71.0%) and indeterminate in two (0.5%). The seroprevalance of HSV-2 was 26% and 31% in males and females, respectively. The correlation between a previous history of cold sores and HSV-1 infection was poor. On univariate analysis, there was a significant association with age, marital status and years of sex (P < 0.05) but after adjusting for confounders, none of the variables were significantly associated with HSV-2 seroprevalance. Most of the respondents (65.8%) were aware that herpes is an STI, whereas only half of them were aware of the possibility of asymptomatic transmission.

CONCLUSION

Although HSV-2 is a common infection among STI clinic attendees in Singapore, there is an unsatisfactory level of knowledge among the attendees about HSV infection and public education programs should be introduced to address this.

Human immunodeficiency virus test-seeking motivation in blood donors, Sao Paulo, Brazil

BACKGROUND AND OBJECTIVE

Previous studies have shown that volunteer, community-recruited donors have a higher prevalence of human immunodeficiency virus (HIV) infection in São Paulo, Brazil, than replacement donors. One hypothesis which may explain this unexpected finding is that some individuals donate blood because they are seeking HIV testing. The objective of this study was to characterize test-seeking blood donors and to determine whether they are at higher risk for HIV infection compared with other donors.

MATERIALS AND METHODS

Subjects presenting for blood donation were asked to participate in a study assessing their motivations (including test seeking) to donate, as measured by perceiving donation as a means to obtain infectious disease test results. Participants completed the standard blood bank predonation screening questions plus our additional survey, and were tested for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphocytotrophic virus (HTLV) I/II, syphilis and Chagas' disease. As a result of anticipated low statistical power to directly measure the association between test-seeking motivation and HIV infection, we tested for herpes simplex virus type 2 (HSV-2) as a marker of sexual risk for HIV. Our survey includes accepted donors as well as persons whose risk-behaviour histories would result in their exclusion from donation according to routine screening procedures.

RESULTS

Of 1,720 potential blood donors randomly selected and approached, 1,600 (93.0%) participated. Overall, 141 (8.8%) were classified as test seekers; 15.6% of these were HSV-2 positive. The proportion of test seekers was the same among community-recruited and replacement donors. Test seekers had a higher prevalence of HSV-2 [adjusted odds ratio (AOR) 1.66; 95% confidence interval (CI): 1.06-2.59] adjusting for age, gender and prior donation. The association was significant among community-recruited blood donors whose previous donation was more than 1 year ago (i.e. 'lapsed donors') (AOR 2.55; 95% CI: 1.20-5.44). Test seekers were not more likely to be rejected from blood donation as a result of health reasons, self-reported HIV risk-related behaviour, or by their own confidential unit exclusion. We found no difference in HSV-2 prevalence between persons accepted for donation (15.7%) and those rejected because of self-reported sexual risk (16.7%).

CONCLUSIONS

We did not detect a difference in the proportion of test seekers across different types of blood donors; however, we did detect an association between HSV-2 infection and test seeking, especially among community-recruited lapsed blood donors. Of note, questions on test-seeking behaviour detected donors with increased prevalence of HSV-2, but the self-reported sexual risk behaviours currently used for deferral criteria did not. Incentives to get tested at sites other than blood banks may decrease the residual risk of HIV in the blood supply.