Human herpesvirus 8 primary infection occurs during childhood in Cameroon, Central Africa

Novel gamma-2-herpesvirus of the Rhadinovirus 2 lineage in gibbons

We obtained 475 nucleotides of the DNA polymerase gene of a novel human herpesvirus 8 homolog sequence in a gibbon. The finding of this new gibbon virus, which clusters with a related chimpanzee virus in the rhadinovirus 2 genogroup, suggests the existence of a novel γ-2-herpesvirus in humans.

Human herpesvirus 8: an update

The discovery of human herpesvirus 8 (HHV-8) has opened a new field in the biology and in the clinical definition of HHV-8-associated diseases. Various aspects of epidemiology, laboratory diagnosis and treatment of HHV-8 infection are still controversial. This review will summarise the most recent findings on the modalities of viral transmission in geographic areas where the virus is endemic as compared with those where the infection is sporadic. The studies on the interactions between HHV-8 and Epstein-Barr virus in the promotion of tumorigenesis will be then emphasised. This review will finally address the problems still open in the laboratory diagnosis and in the definition of antiviral drug susceptibility of HHV-8. Solving satisfactorily these issues will be necessary to better understand the epidemiology of HHV-8 infection, to reduce the risk of viral transmission, the progression of infected hosts to HHV-8-related malignancies and to achieve more active treatment options for these clinical conditions.

Human herpesvirus 8 seroconversion in Kenyan women by enzyme-linked immunosorbent assay and immunofluorescence assay

BACKGROUND

Human herpesvirus 8 (HHV-8) antibody tests vary in reported sensitivity and specificity, depending on the population tested and the assay.

OBJECTIVE

The purpose of this study was to compare the ability to detect seroconversion to HHV-8 in a cohort of HHV-8 seronegative female commercial sex workers in Kenya using three tests: HHV-8 viral lysate-based enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay for HHV-8 lytic antigens (IFA-lytic) and IFA for latent nuclear antigens (IFA-LANA).

STUDY DESIGN

By ELISA, 16 women from a prospective cohort of commercial sex workers were identified as seroconverting to HHV-8. A total of 124 post-enrollment samples from these 16 women as well as the enrollment samples were tested for HHV-8 antibodies by all three assays to monitor seroconversion.

RESULTS

Of 16 women with apparent seroconversion by ELISA, 8 had a rise in IFA-lytic titers either concomitant with or prior to the first positive ELISA sample and no initial LANA by IFA. Five of the 16 women were IFA-LANA positive at entry, indicating prior infection with HHV-8. Three women had no evidence of seroconversion by either IFA-lytic or IFA-LANA and two of these three had increased ELISA reactivity concomitant with HIV-1 infection.

CONCLUSIONS

Conversion from a negative to a positive ELISA result for HHV-8 antibody indicated seroconversion in only half of the study cohort of 16 women when IFA-lytic and IFA-LANA results were considered. The IFA-lytic assay was more sensitive than ELISA for early antibody responses. The IFA-LANA was positive in some women who had neither IFA-lytic nor ELISA antibodies suggesting it may be a marker for latent infections. Presumptive identification of incident HHV-8 infection by ELISA screening followed by IFA-lytic testing to confirm the positive test and IFA-LANA to rule out prior infection provides the most accurate documentation of HHV-8 seroconversion.

Infections and other causes of death in HIV-infected children in Africa

The human immunodeficiency virus (HIV) pandemic has dramatically reversed improvements in infant mortality and child survival in sub-Saharan Africa. However, accurate information on the specific causes of HIV-related morbidity and mortality arising from vertical transmission is infrequent and is constrained in resource-poor settings by infrastructure and local access to health care. Such knowledge is essential to improve clinical management of HIV-infected children in Africa. In this review, a global overview of the clinical aspects of HIV infection in children is given. Factors influencing HIV disease progression, morbidity and mortality are discussed from studies on a cohort of HIV-infected children that were followed at an orphanage in Nairobi between 1999 and 2001. These parameters are contrasted with available data on HIV-infected children residing in community settings in Africa.

A Model to Estimate Risk of Infection with Human Herpesvirus 8 Associated with Transfusion from Cross‐Sectional Data

In cross-sectional studies of infectious diseases, the data typically consist of: age at the time of study, status (presence or absence) of infection, and a chronology of events possibly associated with the disease. Motivated by a study of how human herpesvirus 8 (HHV-8) is transmitted among children with sickle cell anemia in Uganda, we have developed a flexible parametric approach for combining current-status data with a history of blood transfusions. We model heterogeneity in transfusion-associated risk by a child-specific random effect. We present an extension of the model to accommodate the fact that there is no gold standard for HHV-8 infection and infection status was assessed by a serological assay. The parameters are estimated via maximum likelihood. Finally, we present results from applying various parameterizations of the model to the Ugandan study.

Comparison of human herpesvirus 8 and Epstein-Barr virus seropositivity among children in areas endemic and non-endemic for Kaposi's sarcoma

Human herpesvirus 8 (HHV-8) is the etiologic agent of Kaposi's sarcoma (KS). Several studies indicate horizontal HHV-8 transmission among children in areas where KS is endemic, but few studies have assessed acquisition of HHV-8 by children in low seroprevalence areas. Antibody screening was carried out for HHV-8 and Epstein-Barr virus (EBV) on 787 serum specimens from children living in two areas where HHV-8 is not endemic, the United States (US) and Germany, and on 184 specimens from children living in a KS-endemic area (Nigeria). For children in the US and Germany, the results showed low HHV-8 seroprevalence rates (3-4%). However, US children aged 6 months to 5 years had higher HHV-8 antibody titers than did 6-17-year-old children (P < 0.01), a finding consistent with more recent infections being detected in the younger children. Compared with seroprevalence rates and antibody titers in US and German children, those in Nigerian children were significantly higher, and seroprevalence increased with age. There was no evidence of cross-reactivity between assays for HHV-8 and EBV, despite the genetic similarity of these two herpesviruses. The data indicate that HHV-8 transmission among children where HHV-8 is not endemic occurs, but is uncommon. The findings also suggest that HHV-8 antibodies, as measured by current tests, may not persist for long periods in populations at low risk for KS and that vertical transmission is rare, although longitudinal studies are necessary to address directly these issues.

Molecular epidemiology of Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 strains from Russian patients with classic, posttransplant, and AIDS-associated Kaposi's sarcoma

We report the molecular characterization of 38 new Kaposi's sarcoma-associated herpesvirus (KSHV) strains from Russian patients with either classic (25 cases), epidemic/AIDS-associated (7 cases), or posttransplant/immunosuppressed patients (6 cases), or Kaposi's sarcoma (KS). While a complete sequence of the K1 gene (870 bp) was obtained from 30 strains, only partial sequences of the hypervariable regions VR1 (372 bp) and/or VR2 (381 bp) of the K1 gene were obtained from eight strains of KS paraffin blocks. Sequence comparison and phylogenetic studies indicate that the novel KSHV strains belong to either the A subtype (28 cases) or the C subtype (10 cases). Within the 28 strains of A subtype, 24 (86%) belong to the large A' subgroup, mostly A1 and A1' clades, and 4 belong to the A" subgroup, mostly A3 clade. Within the 10 strains of subtype C, 4 were of C' subgroup, and 6 of the C". Some molecular variants of subtype A' were observed, with 3 strains exhibiting an insertion of a single amino acid at the position 65 and 2 strains (both from AIDS-KS) with an unique deletion of 17 amino acids in the VR2 region. Polymerase chain reaction-based subtyping of the K14.1 genomic region indicated that most (23/32) of the novel strains belonged to the P subtype. The results indicate that despite a wide genetic diversity of A and C K1 subtypes of KSHV strains present in Russia, most are closely related and belong to the A1 or A1' molecular clades suggesting a common origin. This study also expands the data regarding the absence of any correlation between a K1 molecular subtype and a specific KS type (classic, epidemic, or posttransplant), as well as between the K1 and K14.1 molecular subtypes.

Human herpesvirus-8 infection in pregnancy and labor: Lack of evidence of vertical transmission

To investigate whether vertical transmission of the human herpesvirus 8 (HHV-8) may occur during pregnancy or at delivery, we enrolled 295 women recruited attending the Division of Obstetrics and Gynecology of a University Teaching of Rome Tor Vergata, S. Eugenio Hospital. The study population was divided in two groups: 245 pregnant women who underwent amniocentesis for genetic screening at 16-18 weeks gestation (group 1) and 50 women at the childbirth (group 2). Maternal blood was obtained from all women. Amniotic fluid (group 1) and cord blood (group 2) were obtained at midtrimester and at delivery, respectively. The presence of anti-HHV-8 antibodies in serum samples was investigated by an immunfluorescence assay. All amniotic fluids, maternal blood, and cord blood samples from HHV-8 seropositive women were tested for the presence of HHV-8 DNA sequences by the polymerase chain reaction. Thirty women, 27 of the group 1 and three of the group 2, were found to have anti-HHV-8 antibodies. Two neonates of the three seropositive mothers of the group 2 had anti-HHV-8 antibodies in cord blood. HHV-8 DNA sequences were detected in the blood of one woman of the group 2. None of the amniotic fluid and cord blood samples had detectable HHV-8 DNA sequences. This study suggests that vertical transmission of HHV-8 is unlikely or, at least, very rare.

Correlates of human herpes virus-8 and herpes simplex virus type 2 infections in Northern Cameroon

The association between sexual activity and human herpes virus-8 (HHV-8) infection has been established, but the mode of acquisition is still unclear. Blood samples from 238 individuals from Northern Cameroon were tested to evaluate the incidence of herpes simplex virus-2 (HSV-2), human immunodeficiency virus (HIV), Treponema pallidum, and HHV-8 infections and to identify their possible association. The presence of HSV-2 antibodies was associated significantly with gender, age, and HIV, HHV-8 antilatent, and T. pallidum antibodies, but not with HHV-8 antilytic antibodies. In a multivariate model older age, female gender, seropositivity for HIV, for HHV-8 latent antigens and for T. pallidum were associated independently with seropositivity for HSV-2. HSV-2-seropositive individuals had significantly higher titers of antibodies to both lytic (P = 0.019) and latent (P = 0.021) HHV-8 antigens. These results suggest that HSV-2 infection can contribute to sexual transmission of HHV-8 infection.

Human Herpesvirus 8 Infection Among Various Population Groups in Southern Israel

OBJECTIVE

To compare the prevalence of antibodies to human herpesvirus 8 (HHV-8) or Kaposi sarcoma-associated herpesvirus among Israeli and Ethiopian subjects.

METHODS

Serum samples were obtained from 98 Israeli Jewish students aged 18-30 years, 100 HIV-1-seronegative Ethiopian immigrants to Israel of the same age, and 100 HIV-1-seronegative Ethiopian children 1-12 years old upon their arrival in southern Israel. Plasma samples were obtained from 3 hospitalized patients with multicentric Castleman disease (MCD) as positive controls. All serum samples were tested for antibodies to both latent and lytic antigens. Antibodies to the lytic antigens and the latency-associated nuclear antigen (LANA) of HHV-8 were detected by enzyme linked immunosorbent assay and by immunofluorescence assay. HHV-8 DNA from serum or plasma samples was detected by polymerase chain reaction analysis.

RESULTS

Antibodies to HHV-8 LANA were detected in 2.9% of the Israeli subjects aged 18-30 years and in 26% of the Ethiopian subjects from both age groups tested. Antibodies to the lytic antigens were detected in all 3 MCD patients, in 4% of the Ethiopian children, and in 2% of the 18- to 30-year-old Ethiopians. No antibodies to the lytic antigens were detected in the Israeli students. HHV-8 DNA was detected in all 3 MCD patients and in 2 of 4 of the Ethiopian children positive for the lytic antigens.

CONCLUSIONS

HHV-8 is highly prevalent in Ethiopian immigrants to Israel as compared with Israeli students. Antibodies to HHV-8 in Ethiopia are acquired before puberty. The results of this study indicate the association of HHV-8 with MCD, as has been documented by many other researchers.

Human herpesvirus 8: current issues

Although human herpesvirus 8 (HHV-8) is the etiologic agent of Kaposi sarcoma (KS), there are no formal guidelines for the clinical management of HHV-8 infection. In patients infected with human immunodeficiency virus (HIV), highly active antiretroviral therapy (HAART) is the best tool for the prevention of KS. In patients who have undergone transplantation, KS is often managed by curtailing immunosuppressive therapies, despite the potential adverse consequences for graft survival. Interventions related to HHV-8 infection might improve the management of KS in immunocompromised patients. However, knowledge from HHV-8 research cannot yet be translated into clinically useful interventions. Achieving clinical utility will require the commercial development of diagnostic tools currently available only in research settings and the evaluation of potential interventions. Such interventions might include the use of HHV-8 diagnostics to identify patients at high risk and to aid in the early detection of KS, prophylaxis with antiherpes drugs to prevent KS, treatment of KS with antiherpes drugs, and donor/recipient screening for organ transplantation.

Epidemiology of AIDS-related malignancies an international perspective

Patients with HIV infection are at increased risk for developing Kaposi's sarcoma, non-Hodgkin's lymphoma, and several other cancers. The relative risks for the most common epithelial cancers in the general population--lung, breast, colon/rectum, stomach, liver, and prostate--are not increased substantially in people with AIDS, however. Accumulating data suggest that HIV-infected patients also are at increased risk for developing Hodgkin's lymphoma, cervical carcinoma in situ (CIS), other anogenital neoplasms (invasive cancer and CIS), leiomyosarcoma, and conjunctival squamous cell carcinoma. There is inconclusive evidence, however, with regard to HIV infection being associated with invasive cervical cancer, testicular seminoma, or hepatocellular carcinoma. Notably, other viral infections have been implicated in the etiology of many of these conditions. The introduction of highly active antiretroviral therapy (HAART) has decreased the incidence of AIDS-associated cancers in Western countries, but less than 1% of AIDS patients are receiving HAART in the HIV epicenter of sub-Saharan Africa. Further therapeutic advances that extend survival with HIV infection with varying reconstitution of immune competence may lead to additional alterations in cancer risk.

Kaposi's sarcoma in Uganda: risk factors for human herpesvirus 8 infection among blood donors

Human herpesvirus 8 (HHV-8) is etiologically linked to Kaposi's sarcoma, a common cancer in Uganda. The authors assessed HHV-8 seroprevalence, risk factors for infection, and HHV-8 assays in a cross-sectional study of Ugandan blood donors. Of 3,736 specimens, the authors selected 203 reactive for HIV, hepatitis B surface antigen (HBsAg), or syphilis, and, randomly, 203 nonreactive specimens. For HHV-8 testing, the authors used two peptide-based enzyme-linked immunosorbent assays (EIAs), ORFK8.1 and ORF65, and an immunofluorescence assay (IFA). Specimens reactive in at least two assays or on IFA alone were considered HHV-8-seropositive. Prevalence estimates were weighted to account for the sampling scheme. Overall HHV-8 seroprevalence was 40%. HHV-8 seroprevalence was higher among HBsAg-positive donors (53%) than HBsAg-negative donors (39%; p =.02) and higher among HIV-positive donors (63%) than HIV-negative donors (39%; p <.001). HHV-8 seroreactivity showed no trend with age. Kappa values for assay concordances were 0.68 (ORFK8.1 EIA and IFA), 0.37 (ORF65 EIA and K8.1 EIA), and 0.29 (ORF65 EIA and IFA). The association between HHV-8 and HBsAg positivity and the lack of association between HHV-8 and age point to primarily nonsexual HHV-8 transmission during childhood. The association with HIV indicates sexual transmission may also occur. The role of ORF65 EIA in testing specimens from Africa warrants further evaluation.

Molecular genetics of Kaposi's sarcoma-associated herpesvirus (human herpesvirus-8) epidemiology and pathogenesis

Kaposi's sarcoma had been recognized as unique human cancer for a century before it manifested as an AIDS-defining illness with a suspected infectious etiology. The discovery of Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, in 1994 by using representational difference analysis, a subtractive method previously employed for cloning differences in human genomic DNA, was a fitting harbinger for the powerful bioinformatic approaches since employed to understand its pathogenesis in KS. Indeed, the discovery of KSHV was rapidly followed by publication of its complete sequence, which revealed that the virus had coopted a wide armamentarium of human genes; in the short time since then, the functions of many of these viral gene variants in cell growth control, signaling apoptosis, angiogenesis, and immunomodulation have been characterized. This critical literature review explores the pathogenic potential of these genes within the framework of current knowledge of the basic herpesvirology of KSHV, including the relationships between viral genotypic variation and the four clinicoepidemiologic forms of Kaposi's sarcoma, current viral detection methods and their utility, primary infection by KSHV, tissue culture and animal models of latent- and lytic-cycle gene expression and pathogenesis, and viral reactivation from latency. Recent advances in models of de novo endothelial infection, microarray analyses of the host response to infection, receptor identification, and cloning of full-length, infectious KSHV genomic DNA promise to reveal key molecular mechanisms of the candidate pathogeneic genes when expressed in the context of viral infection.

Pathogenesis of Kaposi's sarcoma

Kaposi's sarcoma (KS) is a disease characterized by proliferative vascular lesions, which almost invariably contain the KS-associated herpesvirus (KSHV), also called human herpesvirus 8. KSHV is a lymphotrophic and angiotrophic herpesvirus, whose genome encodes several proteins involved in proliferation, antiapoptotic functions, and inflammation. Most KS spindle cells express latent KSHV genes, but a few express lytic genes, which might be involved in angiogenic and paracrine mechanisms that contribute to KS pathogenesis. A number of tissue culture and mouse models have been established, but a comprehensive system that accurately portrays KS pathogenesis still does not exist.

Viral coinfections among African children infected with human immunodeficiency virus type 1

City-dwelling children from Kenya who were infected with human immunodeficiency virus type 1 (HIV-1) were tested for coinfection with cytomegalovirus (CMV), human T cell lymphotropic viruses 1 and 2, Kaposi sarcoma-associated herpesvirus (KSHV), or hepatitis B, C, and G viruses. All children were found to be coinfected with CMV, whereas 5% had hepatitis G virus coinfection and 15% had KSHV coinfection. A protective role for hepatitis G virus cannot be excluded but likely affects only a minority of HIV-1-infected African children.

Human herpesvirus 8 infection

Human herpesvirus 8, also known as Kaposi sarcoma-associated herpesvirus, is etiologically associated with Kaposi sarcoma and other rare malignancies. Human herpesvirus 8 infection is common in certain areas of Africa and Italy, but occurs in only 0% to 15% of adult populations in North America and Europe. Reports of human herpesvirus 8 prevalence of 3% to over 50% among children in Central Africa, Brazil, and South Texas suggest that horizontal transmission of human herpesvirus 8 occurs among children. Primary human herpesvirus 8 infection in immunocompetent children is associated with a fever and maculopapular rash.

Review of the distribution of Kaposi's sarcoma-associated herpesvirus (KSHV) in Africa in relation to the incidence of Kaposi's sarcoma

In the years before human immunodeficiency virus (HIV) infection, the incidence of Kaposi's sarcoma varied markedly across the African continent, and it was a disease primarily affecting men. In contrast, the evidence reviewed here shows that the causal virus-Kaposi's sarcoma associated herpesvirus (KSHV)-is prevalent in many African countries, including places where Kaposi's sarcoma was almost unknown before HIV, and that it is as common in women as in men. Therefore, the geographical distribution of Kaposi's sarcoma in Africa before the spread of HIV and its predominance as a disease affecting men are not a simple reflection of the distribution of KSHV. Since the epidemic of HIV in Africa, Kaposi's sarcoma has become relatively more frequent in women, and the incidence has increased in countries where it was previously rare, but where KSHV is prevalent, as well as in countries where it was already common. These changes point to a role for other (as yet unknown) factors in the aetiology of Kaposi's sarcoma that may have the most effect in the absence of concurrent HIV infection.

Transmission of human herpesvirus 8 by sexual activity among adults in Lagos, Nigeria

BACKGROUND

Human herpesvirus 8 (HHV-8) infection is common in Africa, but prevalence varies geographically. Studies in Europe and America suggest spread through homosexual contact, but evidence of heterosexual spread is inconsistent. We examined the association between HHV-8 and markers of risky sexual activity in Nigeria.

METHODS

The study subjects included an adult referent population at relatively low risk of HIV infection, patients attending a sexually transmitted disease (STD) clinic, and female commercial sex workers (CSW). Sera were collected between 1991 and 1994 to study the epidemiology of retroviruses and STD in Lagos, Nigeria. Residual samples were tested for HHV-8 antibodies using a K8.1 enzyme immunoassay and for antibodies to syphilis, chancroid, herpes simplex virus 2, HIV-1/2, and HTLV-1. Associations were sought using chi square tests and logistic regression.

RESULTS

Overall, HHV-8 prevalence was 26.5% in 2002 study subjects, being higher among CSW and STD patients (31% in each) than in the referent population (19%). HHV-8 prevalence in women was approximately half that in men in both the referent and the STD populations. Increasing age and STD were each associated with HHV-8-seropositivity in men and women, and among women being a CSW was also a risk factor. HHV-8 antibodies were more frequently detected in those with laboratory evidence of STD in each group. Having at least one STD was associated with having HHV-8 antibodies.

CONCLUSION

The higher prevalence of HHV-8 antibody in groups with multiple sexual partners and the association with STD among individuals both support the sexual transmission of HHV-8 in African adults.

Tracking familial transmission of Kaposi's sarcoma-associated herpesvirus using restriction fragment length polymorphism analysis of latent nuclear antigen

Intra-familial transmission of Kaposi's sarcoma associated herpesvirus (KSHV) is likely to occur in geographical regions where KSHV infection is highly endemic. Transmission has been studied previously indirectly using serological techniques, however direct documentation of specific transmission routes has yet to be reported. The internal repeat domain (IRD) of the KSHV opening reading frame (ORF) 73 was shown previously to exhibit restriction-fragment length polymorphism (RFLP). Analysis of such polymorphism was undertaken using nested ORF 73 IRD PCR products derived from the blood and mouth rinse samples of individuals in Malawian family groups. The resulting RFLP patterns were unique to an individual and could be compared between family members. In three of eight families studied, identical RFLP patterns were recovered from family members; in the remaining five families, dissimilar RFLP patterns were revealed. Results from RFLP analysis were compared to sequencing data recovered from family members for the first variable region of the hypervariable KSHV ORF K1. Patterns of intra- and extra-familial transmission inferred from ORF K1 sequencing data were corroborated mainly using ORF 73 IRD RFLP analysis.

Human herpesvirus 8, Kaposi's sarcoma, and associated conditions

HHV-8 is a recently identified human herpes virus that can produce tumors, most often in immune compromised hosts. The virus is most closely associated with Kaposi's sarcoma, but is also clearly associated with primary effusion lymphomas and multicentric Castleman's disease. The prevalence of HHV-8 infection varies considerably, but is highest among men who have sex with men and others with histories of sexually transmitted diseases and high numbers of lifetime sexual partners. HHV-8 is shed in saliva, and less commonly in genital secretions. Treatment of HHV-8 associated diseases includes reversal of immune compromise either via discontinuation of immunosuppressives or immune reconstitution via antiretroviral regimens. Specific antiviral drug inhibit HHV-8 replication, and can result in responses in certain HHV-8-associated conditions.

Laboratory diagnosis of human herpesvirus 8 infection in humans

Human herpesvirus 8 (HHV-8) is causally associated with Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. Serological and molecular biology assays are used to investigate the biology of this virus in different populations and diseases. Serological assays are mainly used to study the prevalence of the viral infection and to predict the diagnosis of Kaposi's sarcoma and other HHV-8-associated cancers. The appearance of antibodies against lytic antigens precedes the appearance of antibodies against latent antigens, probably explaining the lower sensitivity of assays based on latent HHV-8 antigens. The lack of international reference serum panels is presently the major bottleneck for further progress in the field of HHV-8 serology. Molecular biological assays are an absolute requirement for both the diagnosis and the follow-up of HHV-8 infection. Qualitative methods have been particularly useful to elucidate the mode of transmission and the causal association between HHV-8 and HHV-8-associated diseases. Quantitative methods have become an essential tool to monitor the progression of the infection and the effects of antiviral therapies. This review analyzes the performance of the different serological and molecular biological assays available at present. The main conclusion is that more research is needed to define the most useful laboratory tests for the diagnosis of HHV-8 infection and to establish the clinical role of such tests.

Human herpesvirus 8 seroprevalence in an STD clinic in Paris: a study of 512 patients

BACKGROUND

Human herpesvirus 8 (HHV-8) is thought to be possibly sexually transmitted in some populations, but few data are available on this mode of transmission. GOAL The goal was to study HHV-8 seroprevalence in patients attending a sexually transmitted disease (STD) clinic and to search for predictive factors of HHV-8 seropositivity.

STUDY DESIGN

Five hundred twelve consecutive patients attending the STD clinic of Hôpital Saint-Louis (Paris) were tested for HHV-8 antibodies (immunofluorescence assay using two cell lines, BCP-1 and ISI n. butyrate [3 mmol/l]). A standardized questionnaire was used to obtain demographic, behavioral, and clinical data. Predictive factors of HHV-8 seropositivity were considered in univariate and multivariate analysis with use of logistic regression models.

RESULTS

In testing of the patients for HHV-8 antibodies, 67/512 (13.1%) tested positive: 53/346 (15.3%) of men and 14/166 (8.4%) of women ( = 0.03). The predictive factors of HHV-8 seropositivity for men were the country of origin (Central Africa, odds ratio [OR]: 7.5; North Africa, OR: 5.5), homosexuality (OR: 3.7), and visiting prostitutes (OR: 7.1). For women they were country of origin (Central Africa, OR: 8.3) and presence of HSV-2 antibodies (OR: 6.5, tendency).

CONCLUSION

Our study does not show clear relationships between HHV-8 seropositivity and sexual behavior, apart from homosexuality, but visiting prostitutes (for men) and HSV-2 seropositivity (for women) could be subtle clues supporting the hypothesis of heterosexual transmission.

Correlates of human herpesvirus 8 seropositivity among heterosexual men in Kenya

BACKGROUND

Several studies have suggested that sexual transmission of human herpesvirus 8 (HHV-8) occurs among homosexual men in developed countries. However, few studies have examined heterosexual HHV-8 transmission, especially among African populations in which HHV-8 is endemic.

OBJECTIVES

To determine the seroprevalence and correlates of HHV-8 infection among heterosexual African men.

DESIGN

Cross-sectional study.

METHODS

Participants were 1061 men enrolled in a prospective cohort study of risk factors for HIV-1 acquisition among trucking company employees in Mombasa, Kenya. Stored frozen sera from the study baseline visit were tested for antibodies to HHV-8 by whole-virus lysate ELISA.

RESULTS

HHV-8 seroprevalence was 43%. In multivariate logistic regression analysis, HHV-8 infection was independently associated with older age [for men aged 30-39 years: odds ratio (OR), 1.5; 95% confidence interval (CI), 1.1-2.0; for men aged > or = 40 years: OR, 1.7; 95% CI, 1.1-2.7, compared with men aged < 30 years], Christian religion (OR, 1.6; 95% CI, 1.2-2.1), being uncircumcised (OR, 1.5; 95% CI, 1.0-2.2), and ever having syphilis (OR, 2.2; 95% CI, 1.4-3.5). Ever having used condoms was associated with decreased likelihood of infection (OR, 0.7; 95% CI, 0.6-1.0). Seropositivity was not significantly related to other sexual behaviors characterized or to HIV-1 status.

CONCLUSIONS

HHV-8 seropositivity is common in this population and increases with age, suggesting on-going transmission during adulthood. Infection was more common among men who were uncircumcised or who had ever had syphilis and was less common among those who had ever used condoms, suggesting that sexual factors may play a role in HHV-8 transmission. Prospective studies of HHV-8 acquisition in heterosexual African populations are needed to demonstrate whether safer sexual practices can reduce transmission.

[Epidemiology of human herpes virus 8 (HHV-8) or the herpes virus associated with Kaposi's sarcoma (KSHV)]

Human herpesvirus 8 (HHV-8), also called Kaposi's sarcoma-associated herpesvirus (KSHV), is not a ubiquitous virus. In countries with a low viral seroprevalence (< 5% in adult general population) as the USA, Northern Europe and Asia, the infection concerns essentially homosexual men. In this latter population, the viral transmission seems to occur during sex. In endemic countries (HHV-8 seroprevalence between 10-70% in the adult general population) as in the Mediterranean basin (Italy, Greece), and Africa (East and Central Africa), men, women and children are infected. In these countries, HHV-8 seroprevalence increases with age and often reaches adult rates before the end of puberty. Viral transmission, in general endemic populations, seems to occur from mother to child and between sibs whereas heterosexual transmission appears to concern essentially groups at risk for sexual transmitted diseases. Saliva is a major reservoir of HHV-8.

Detection of human herpesvirus 8 DNA in serum from blood donors with HHV-8 antibodies indicates possible bloodborne virus transmission

Human herpesvirus 8 (HHV-8) is associated with Kaposi's sarcoma. There is a high seroprevalence of HHV-8 in several African countries, but the transmission route is not known definitively. In this study 174 serum samples from blood donors in Tanzania were examined by immunofluorescence assays detecting antibodies to latent and lytic HHV-8 antigens. Real-time polymerase chain reaction was used for detection and quantification of HHV-8 DNA in serum. In all, 83/174 (48%) of the subjects had antibodies to latent or lytic antigens. Forty (23%) had antibodies to both antigens and of those eight (20%) had detectable HHV-8 DNA in serum. HHV-8 DNA load correlated with antibody titres to lytic, but not latent, HHV-8 antigens. This supports the usefulness of anti-lytic antibodies in HHV-8 serology and suggests that transmission of HHV-8 by blood contact could be of importance in this region.

[Human herpesvirus-8 detection in Kaposi's sarcoma, multiple myeloma, and lymphoproliferative syndromes occurring in immunocompetent and immunocompromised patients]

BACKGROUND

The purposes of this study were: to study the presence of human herpesvirus-8 (HHV-8) in different Kaposi's sarcoma (KS) epidemiological groups, multiple myeloma (MM), and immunodeficiency-associated lymphoid proliferations; to investigate the potential sexual transmission of HHV-8 by analyzing its presence in women from the general population, human immunodeficiency virus (HIV) seropositive women, and prostitutes; and to establish a reliable and efficient PCR strategy for the detection of HHV-8.

PATIENTS AND METHODS

HHV-8 detection was performed by PCR and positive cases were confirmed by automatic bi-directional sequencing. We selected 25 KS, 70 immunodeficiency associated non-Hodgkin's lymphomas (NHL), 30 HIV-positive Hodgkin's lymphomas (HL), and 2 primary effusion lymphomas (PEL). Bone marrow aspirates were available from 41 MM, 9 monoclonal gammopathies of undetermined significance and 24 patients with other disorders. Bone marrow dendritic cell cultures from 12 MM patients were also performed. Cells from cervical, anal, and oral cavity scrapes were examined for the presence of HHV-8 in 40 control women, 10 HIV-seropositive women, and 20 HIV-seronegative prostitutes. Serologic tests were also performed.

RESULTS

HHV-8 was specifically detected in 100% KS and PEL, and in 5.7% immunodeficiency associated NHL. All cases of HIV-HL and MM were HHV-8 negative. Antibodies against HHV-8 were found in 10% of control women, 10% HIV-positive women, and 25% prostitutes. Only 1 sample was positive for HHV-8 by PCR.

CONCLUSIONS

HHV-8 is associated with all epidemiological forms of KS; HHV-8 does not contribute to the pathogenesis of MM, and this virus is not ubiquitous in the human population. Seroprevalence of HHV-8 is increased in prostitutes, although this may partially be attributed to the geographical origin. For a reliable PCR detection of HHV-8, it is necessary to target different regions of the viral genome and to sequence amplification products.

A seroprevalence study of human herpesvirus type 8 (HHV8) in eastern and Central Africa and in the Mediterranean area

Human herpes virus type 8 (HHV8) is the major determinant of Kaposi's sarcoma (KS), a neoplasm with wide geographic variations in incidence rates. To assess the prevalence of HHV8 infection among populations with differing rates of KS, we used sera from 1,402 persons (Central Africa: Cameroon, n = 293, age range: 5-40; eastern Africa: Uganda, n = 315, age range: 1-64: Mediterranean area: Egypt, n = 236, age range: 13-19: Italy, blood donors n = 134, age range: 20-67: Italy. HIV seroconverters n = 424, age range: 16-65). Serum samples were tested for antibodies to lytic and latent antigens of HHV8 using two immunofluorescence assays. HHV8 prevalence was evaluated according to geographic area, gender and age groups. Overall, the highest prevalence of HHV8 lytic antigens (47.5%) was recorded among children and adults in Africa. Approximately 40% of children and adolescents from Egypt and of Italian HIV-positive persons (39.9%) were HHV8 seropositive. In eastern and Central Africa and in Egypt, no differences emerged between males and females for both types of HHV8 antibodies. Conversely, Italian females were at lower HHV8 risk than their male counterparts. Moreover the prevalence of HHV8 infection tended to increase with age. This investigation partially confirms that HHV8 infection mirrors incidence rates of KS. The high prevalence of HHV8 infection in newborns, children and adolescents in Egypt, in eastern and in Central Africa strongly suggests the existence of transmission modes other than sexual.

High prevalence of human herpesvirus 8 (HHV-8) infection in south Texas children

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus, is etiologically associated with Kaposi's sarcoma and other rare malignancies. HHV-8 infection is common in certain areas of Africa and Italy, but occurs in only 0-15% of populations in North America and Europe. The epidemiology and prevalence of HHV-8 infection among children in the United States has not been determined, but is assumed to be low based on limited studies. The objective of this study was to determine the seroprevalence and possible risk factors of HHV-8 infection in children living in south Texas. Questionnaire data were collected and HHV-8 serologic tests were performed from a consecutive, non-probability sample of 123 healthy children (ages 4-13 years) attending general pediatric clinics in south Texas. Serum was tested for HHV-8 antibodies by latent immunofluorescence assay and ORF65 enzyme-linked immunosorbent assay confirmed by immunoblot. HHV-8 prevalence and 95 percent confidence intervals were calculated using standard epidemiologic methods. Logistic regression was used to assess independent risk factors associated with HHV-8 seropositivity. The overall prevalence of HHV-8 infection was 26%. No statistically significant associations were exhibited between HHV-8 prevalence and the variables under study. The prevalence of HHV-8 infection among children in south Texas, particularly among those under the age of 12 years, indicates that non-sexual transmission of this virus is likely to occur among this population. Future investigations of larger study samples will be necessary to develop an understanding of specific routes and risk factors of HHV-8 transmission among children in south Texas.

Mixed patterns of transmission of human herpesvirus-8 (Kaposi's sarcoma-associated herpesvirus) in Malawian families

To study transmission patterns of human herpesvirus-8 (HHV-8) (Kaposi's sarcoma-associated herpesvirus) in families in Malawi, nucleotide sequences derived from two hypervariable loci of the HHV-8 genome, the V1 and V2 regions of open reading frame K1 (K1/V1 and K1/V2, respectively), were amplified from blood and mouth rinse samples of 22 patients with treated and untreated Kaposi's sarcoma (KS) and their first-degree relatives (n=67). In patients with KS, vincristine therapy was significantly associated with non-detectability of circulating, but not oral, K1/V1 DNA. Intra-familial K1/V1 phylogenetic comparisons of eight families were possible. Both identical and non-identical sequences were observed between family members, suggesting transmission of HHV-8 along both intra- and extra-familial transmission routes.

Spectrum of Kaposi's sarcoma-associated herpesvirus, or human herpesvirus 8, diseases

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), discovered in 1994, is a human rhadinovirus (gamma-2 herpesvirus). Unlike other human herpesviruses (herpes simplex virus, Epstein-Barr virus, varicella-zoster virus, cytomegalovirus, HHV-6, and HHV-7), it is not widespread in the general population and has many unique proteins. HHV-8 is strongly associated with all subtypes of Kaposi's sarcoma (KS), multicentric Castleman's disease, and a rare form of B-cell lymphoma, primary effusion lymphoma. In addition, HHV-8 DNA sequences have been found in association with other diseases, but the role of the virus in these diseases is largely unconfirmed and remains controversial. The seroprevalence of HHV-8, based on detection of latent and lytic proteins, is 2 to 5% in healthy donors except in certain geographic areas where the virus is endemic, 80 to 95% in classic KS patients, and 40 to 50% in HIV-1 patients without KS. This virus can be transmitted both sexually and through body fluids (e.g., saliva and blood). HHV-8 is a transforming virus, as evidenced by its presence in human malignancies, by the in vitro transforming properties of several of its viral genes, and by its ability to transform some primary cells in culture. It is not, however, sufficient for transformation, and other cofactors such as immunosuppressive cytokines are involved in the development of HHV-8-associated malignancies. In this article, we review the biology, molecular virology, epidemiology, transmission, detection methods, pathogenesis, and antiviral therapy of this newly discovered human herpesvirus.

AIDS-related malignancies

Cancer remains a significant burden for human immunodeficiency virus (HIV)-infected individuals. Most cancers that are associated with HIV infection are driven by oncogenic viruses, such as Epstein-Barr virus, Kaposi's sarcoma-associated herpesvirus and human papillomavirus. Gaining insight into the epidemiology and mechanisms that underlie AIDS-related cancers has provided us with a better understanding of cancer immunity and viral oncogenesis.

Reactivation and role of HHV-8 in Kaposi's sarcoma initiation

Kaposi's sarcoma (KS) is an angioproliferative disease occurring in several clinical-epidemio-logic forms but all associated with infection by the human herpesvirus-8 (HHV-8). At least in early stages, KS is a reactive disease associated with a state of immune dysregulation characterized by CD8+ T-cell activation and production of Th1-type inflammatory cytokines (IC) that precedes lesion development. In fact, evidence indicates that IC can trigger lesion formation by inducing the activation of endothelial cells that leads to adhesion and tissue extravasation of lymphomonocytes, spindle cell formation, and angiogenesis, and HHV-8 reactivation that, in turn, leads to virus spread to all circulating cell types and virus dissemination into tissues. Due to virus escape mechanisms and deficient immune responses toward HHV-8, virus reactivation and spread are not controlled by the immune system but induce immune responses that may paradoxically exacerbate the reactive process. The virus is recruited into "activated" tissue sites where it finds an optimal environment for growth. In fact, viral load is very low in early lesions, whereas almost all spindle cells are infected in late-stage lesions. Although early KS is a reactive process of polyclonal nature that can regress, in time and in the presence of immunodeficiency, it can progress to a true sarcoma. This is likely due to the long-lasting expression of HHV-8 latency genes in spindle cells associated with the deregulated expression of oncogenes and oncosuppressor genes and, for AIDS-KS, with the effects of the HIV-1 Tat protein.

HHV-8 infection: a model for reactivation and transmission

The rapid pace of knowledge about HHV-8 since its discovery has been one of the most exciting aspects of medical virology in the last decade. As outlined in this review, the discovery by Drs Chang and Moore of this virus has opened up a broad field of biology with interesting contrasts between current epidemiological data for Kaposi's sarcoma and the cell biology of this gamma herpesvirus. In particular, we summarise the paucity of virological data supporting genital sites of replication and emphasise detection of HHV-8 in the oropharynx. Hopefully continued study will address many of the critical questions that exist today regarding how this infection is transmitted and acquired.

Vertical transmission of Kaposi's sarcoma-associated herpesvirus

Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.

Seroprevalence of Kaposi's sarcoma-associated herpesvirus infection among blood donors from Texas

PURPOSE

Kaposi's sarcoma-associated herpesvirus (KSHV), a gammaherpesvirus recently discovered among AIDS patients with Kaposi's sarcoma, is a potential candidate for screening in blood and plasma donors. While a number of studies have assessed KSHV infection among U.S. blood donors, larger-scale population-based studies would be necessary to develop more refined estimates of the magnitude and variation of KSHV infection across different geographic regions of the U.S. blood supply. The goal of the present study, therefore, was to determine the seroprevalence of KSHV infection and to assess demographic correlates of KSHV infection among south Texas blood donors.

METHODS

KSHV infection was determined using specific serologic assays that measure antibodies to KSHV latent and lytic antigens.

RESULTS

The overall seroprevalence of KSHV in Texas blood donors (15.0%) is substantially higher than previously reported among blood donor and general population samples in the United States. This high rate of KSHV infection persisted across most of the sociodemographic subgroups under study but was particularly elevated among participants with less than a high school education. The infection rate also increased linearly with age.

CONCLUSIONS

The elevated infection rate reported in the present study suggests that screening methods to detect KSHV infection in blood donors should be considered. In view of the etiologic role of KSHV for several malignancies, it would be important for future studies to directly assess the risk of KSHV transmission via blood transfusion.

A novel gamma 2-herpesvirus of the Rhadinovirus 2 lineage in chimpanzees

Old World monkeys and, recently, African great apes have been shown, by serology and polymerase chain reaction (PCR), to harbor different gamma2-herpesviruses closely related to Kaposi's sarcoma-associated Herpesvirus (KSHV). Although the presence of two distinct lineages of KSHV-like rhadinoviruses, RV1 and RV2, has been revealed in Old World primates (including African green monkeys, macaques, and, recently, mandrills), viruses belonging to the RV2 genogroup have not yet been identified from great apes. Indeed, the three yet known gamma2-herpesviruses in chimpanzees (PanRHV1a/PtRV1, PanRHV1b) and gorillas (GorRHV1) belong to the RV1 group. To investigate the putative existence of a new RV2 Rhadinovirus in chimpanzees and gorillas we have used the degenerate consensus primer PCR strategy for the Herpesviral DNA polymerase gene on 40 wild-caught animals. This study led to the discovery, in common chimpanzees, of a novel gamma2-herpesvirus belonging to the RV2 genogroup, termed Pan Rhadino-herpesvirus 2 (PanRHV2). Use of specific primers and internal oligonucleotide probes demonstrated the presence of this novel gamma2-herpesvirus in three wild-caught animals. Comparison of a 1092-bp fragment of the DNA polymerase obtained from these three animals of the Pan troglodytes troglodytes subspecies, one from Gabon and the two others from Cameroon, revealed <1% of nucleotide divergence. The geographic colocalization as well as the phylogenetic "relationship" of the human and simian gamma2-herpesviruses support the model according to which herpesviruses have diversified from a common ancestor in a manner mediating cospeciation of herpesviruses with their host species. By demonstrating the existence of two distinct Rhadinovirus lineages in common chimpanzees, our finding indicates the possible existence of a novel human gamma2-herpesvirus belonging to the RV2 genogroup.

Prevalence and distribution of HHV-8 in different subpopulations, with and without HIV infection, in Spain

OBJECTIVE

To estimate the seroprevalence of HHV-8 in several Spanish subpopulations with different risk levels of acquiring HIV-1 infection and from different geographical regions.

DESIGN

Cross-sectional seroprevalence study.

METHODS

A total of 1699 serum samples from blood donors (613), children under the age of 12 years (100), injecting drug users (IDU) (382), heterosexuals attending a sexually transmitted disease (STD) clinic (273) and homosexual men attending a STD clinic or a HIV-based hospital unit (331) were analysed for anti-HHV-8 antibodies. The presence of antibodies against HHV-8 was tested with an indirect immunofluorescence assay (IFA). A subsample of HHV-8-positive samples was also tested for antibody titre against HHV-8.

RESULTS

The overall seroprevalence of antibodies against HHV-8 for the blood donor population was 6.5% (7.0% in Andalusia, 8.0% in Catalonia and 4.5% in the Basque Country). None of the children tested positive for HHV-8. The HHV-8 prevalence was 86.7% in HIV-positive homosexual men and 28.0% in HIV-negative homosexual men (P < 0.001). Of heterosexual men attending STD clinics, 17.2% tested positive for HHV-8; 11.5% of IDU tested positive for HHV-8. HHV-8 antibody titres by groups parallel the distribution of HHV-8 prevalence. No association between HHV-8 antibody titres and CD4 cell count or HIV viral load was identified.

CONCLUSIONS

The HHV-8 prevalence among blood donors in Spain is higher than in Northern Europe and the USA, but is similar to that in Northern Italy. The distribution of HHV-8 is compatible with a sexually transmitted agent. The distribution of HHV-8 correlates with that of Kaposi's sarcoma but factors other than HHV-8 seem to explain the Kaposi sarcoma distribution.

Blood-borne and sexual transmission of human herpesvirus 8 in women with or at risk for human immunodeficiency virus infection

BACKGROUND

Human herpesvirus 8 (HHV-8), the causal agent of Kaposi's sarcoma, is transmitted sexually among homosexual men, but little is known of its transmission among women. Although HHV-8 has been detected in blood, there has been no clear evidence of blood-borne transmission.

METHODS

We identified risk factors for HHV-8 infection in 1295 women in Baltimore, Detroit, New York, and Providence, Rhode Island, who reported high-risk sexual behavior or drug use. HHV-8 serologic studies were performed with two enzyme-linked immunosorbent assays.

RESULTS

In univariate analyses, HHV-8 was associated with black race, Hispanic ethnic background, a lower level of education, and infection with syphilis, the human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV). The risk of seropositivity for HHV-8 increased with the frequency of injection-drug use (P<0.001); HHV-8 seroprevalence among the women who used drugs daily was three times that among women who never injected drugs. Among the women with a low risk of sexual transmission, HHV-8 seroprevalence was 0 percent in those who had never injected drugs and 36 percent in those who had injected drugs (P<0.001). However, injection-drug use was linked less strongly to HHV-8 infection than to infection with HBV or HCV. In a multivariate analysis, independent predictors of HHV-8 seropositivity included HIV infection (odds ratio, 1.6; 95 percent confidence interval, 1.1 to 2.2), syphilis infection (odds ratio, 1.8; 95 percent confidence interval, 1.1 to 2.8), and daily injection-drug use (odds ratio, 3.2; 95 percent confidence interval, 1.4 to 7.6).

CONCLUSIONS

Both injection-drug use and correlates of sexual activity were risk factors for HHV-8 infection in the women studied. The independent association of HHV-8 infection with injection-drug use suggests that HHV-8 is transmitted through needle sharing, albeit less efficiently than HBV, HCV, or HIV.

Seroepidemiology and molecular epidemiology of Kaposi's sarcoma-associated herpesvirus among Jewish population groups in Israel

BACKGROUND

The incidence of classic Kaposi's sarcoma among Jews in Israel is among the highest in the developed world. Kaposi's sarcoma-associated herpesvirus (KSHV or human herpesvirus 8) is causally linked to Kaposi's sarcoma. Very little is known about the prevalence of KSHV in the Middle East or about the modes of transmission in Mediterranean countries.

METHODS

From 1992 through 1995, sera were obtained from 1648 adults who had tested positive for hepatitis B virus (HBV) surface antigen 20 years earlier at blood donations; sera were also obtained from 2403 of their family members. All sera were tested for anti-KSHV antibodies with the use of an indirect immunofluorescence assay. To analyze the effects of various factors on the risk of KSHV infection for both the HBV-positive cohort and their families, logistic regression for cluster data and generalized estimating equations were used. All statistical tests were two-sided.

RESULTS

Among family members, the seroprevalence of antibodies against KSHV was 9.9% (95% confidence interval [CI] = 8.7% to 11.1%); among the former blood donors who had tested positive for hepatitis B, it was 22% (95% CI = 19.9% to 24.1%). Overall, the best predictor of KSHV status was the place of birth. The most important risk factors found for both husband and wife to test KSHV positive were their own places of birth and their spouse's seropositivity. For a child to test positive, the most important risk factor was maternal seropositivity.

CONCLUSIONS

The crude prevalence rate of KSHV among the Jewish population in Israel is 9.9%. Important routes of KSHV transmission in the families studied are spouse to spouse and mother to child. The presence of KSHV in Jews in Israel of all ethnic origins and their high incidence of reported Kaposi's sarcoma suggest that KSHV was introduced into the Jewish population prior to the major Diaspora.

Prevalence of Kaposi sarcoma-associated herpesvirus compared with selected sexually transmitted diseases in adolescents and young adults in rural Rakai District, Uganda

BACKGROUND

Kaposi sarcoma-associated herpesvirus (KSHV) is transmitted by routes such as homosexual intercourse and is associated with HIV infection in industrialized countries. However, there is little information about its transmission in developing countries where Kaposi sarcoma is an endemic disease.

GOAL

To examine KSHV seroprevalence in young adults in a general, rural Ugandan population, and to compare this prevalence with rates of known sexually transmitted infections.

STUDY DESIGN

The seroprevalence of KSHV was compared with the epidemiology of sexually transmitted diseases in 523 sexually active subjects aged 15 to 29 years who were randomly selected from a general population cohort in rural Rakai District, Uganda. Participants provided in-home interview data and specimens. Sera were tested for KSHV using immunofluorescence assay and immunoblot for lytically expressed recombinant KSHV ORF65.2. Sera were also tested for HIV type 1, herpes simplex virus type 2, and syphilis.

RESULTS

The prevalence of KSHV was significantly higher in participants 15 to 19 years compared with older persons 25 to 29 years (45.0% and 36.1%, respectively; adjusted odds ratio, 0.48; 95% CI, 0.28-0.82). In contrast, herpes simplex virus type 2 and HIV type 1 prevalence increased with age. Kaposi sarcoma-associated herpesvirus serostatus was not associated with HIV type 1, syphilis, herpes simplex virus type 2, or number of sexual partners. Homosexual and anal intercourse were reported by less than 1% of participants.

CONCLUSIONS

Kaposi sarcoma-associated herpesvirus does not appear to be a heterosexually transmitted infection in rural Uganda.

Molecular epidemiology of human herpesvirus 8 in africa: both B and A5 K1 genotypes, as well as the M and P genotypes of K14.1/K15 loci, are frequent and widespread

We have studied 52 new HHV8 strains by sequencing the complete hypervariable K1 gene and genotyping the K14.1/K15 loci located at both sides, respectively, of the viral genome. The samples originated from 49 patients with Kaposi's sarcoma (KS; 32 patients), multicentric Castleman's disease (MCD; 12 patients), or primary effusion lymphoma (PEL; 5 patients). Among these patients, 32 were of African origin (West and Central African countries and Creoles from French Guiana) and the 17 others were mostly French homosexuals. Comprehensive phylogenetic studies allowed the identification of distinct groups within the three already known main subtypes. Interestingly, two new sequences that did not cluster within a known subtype or group could be considered as prototypes of early/ancient variants of the C subtype and A/C set, respectively. Among the 32 African strains, the majority were either of the B subtype (13 cases) or of the A5 group (11 cases), indicating that this latter genotype is frequent and widespread in Africa. In contrast, a subtype C strain infected most of the 17 other patients. PCR-based genotyping of the K14.1/K15 loci revealed an overall predominance of P subtype, except in the A5 and B K1 groups, in which the P and M alleles were equally represented. The implications of these data on the evolution and spread of HHV8 among human African populations are discussed.