Seroprevalence of human herpesvirus 8 among injection drug users in San Francisco

The association between injection drug use and human herpesvirus 8 (HHV-8) was examined to investigate bloodborne transmission of the virus. In all, 1905 injection drug users (IDUs) enrolled in a cross-sectional study were tested for K8.1 antibodies to HHV-8 lytic antigen. Logistic regression was used to adjust for demographic and sexual behavior variables. HHV-8 seroprevalence was 10% among women, 10% among heterosexual men, and 23% among men who have sex with men. In adjusted analyses, HHV-8 seroprevalence increased with longer duration of injection drug use for each of these groups (P = .01, P = .03, and P = .049 for trend, respectively). HHV-8 infection is relatively common among IDUs in San Francisco, and longer duration of injection drug use is associated with an increase in the risk of HHV-8 infection that is not explained by sexual behavior or demographic differences. These results are consistent with the occurrence of bloodborne transmission of HHV-8 among IDUs.     

Human herpesvirus 8: seroprevalence and correlates in prostitutes in Mombasa,Kenya

Human herpesvirus 8 (HHV-8) infection is very prevalent in sub-Saharan Africa, but the role of sexual transmission has not been well characterized. HHV-8 seroprevalence and correlates were evaluated in a cohort of female prostitutes in Mombasa, Kenya. Between February 1993 and January 2000, stored plasma samples taken from 736 women were tested, by whole-virus ELISA assay, for the presence of HHV-8 antibodies; of these 736 women, 633 were included in the analysis of correlates of HHV-8 infection; and, of these 633, 44.1% were seropositive for HHV-8 antibodies. In univariate analysis, age, years of education, years of prostitution, workplace, hormonal contraception, intrauterine-device use, alcohol consumption, syphilis, and gonorrhea were all significantly associated with the presence of HHV-8 antibodies. In a multivariate model, older age, fewer years of education, and 2 markers of high-risk sexual behavior-namely, alcohol consumption and gonorrhea-were each independently associated with HHV-8 seropositivity. These results suggest that heterosexual transmission may contribute to acquisition of HHV-8 infections in this African population of prostitutes.     

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.     

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.     

Serologic evidence of human herpesvirus 8 transmission by homosexual but not heterosexual sex.

Epidemiologic studies link Kaposi's sarcoma with a sexually transmitted agent. Human herpesvirus 8 (HHV-8) is likely to be that agent, but routes of transmission are poorly described. A seroepidemiologic study was conducted to determine whether HHV-8 is transmitted sexually between heterosexuals. Sera from 2718 patients attending a sexually transmitted disease (STD) clinic were tested for antibodies to HHV-8 and herpes simplex virus type 2 (HSV-2). Information on sex partners in the previous 12 months and past STDs were obtained by questionnaire. Relationships between possible risk factors and HHV-8 infection were assessed by logistic regression. Overall, seroprevalence of HHV-8 was 7.3%. Independent risk factors for HHV-8 in the whole group were homo/bisexuality and birth in Africa and, among homo/bisexual men, a history of syphilis and HSV-2 and human immunodeficiency virus seropositivity. Among heterosexuals there was no evidence for sexual transmission; the only independent risk factor for HHV-8 seropositivity was birth in Africa.     

Human herpesvirus-8 infection and oral shedding in Amerindian and non-Amerindian populations in the Brazilian Amazon region

BACKGROUND: Human herpesvirus type 8 (HHV-8) is hyperendemic in Amerindian populations, but its modes of transmission are unknown. METHODS: Antibodies against either HHV-8 lytic antigen or HHV-8 latency-associated nuclear antigen (LANA) were detected, by immunofluorescence assays, in 339 Amerindians and 181 non-Amerindians from the Brazilian Amazon. Serological markers of oro-fecal (hepatitis A), parenteral (hepatitis B and C), and sexual (herpes simplex virus type 2 and syphilis) transmission were measured by specific ELISAs. Salivary HHV-8 DNA was detected by use of a nested polymerase chain reaction assay and was sequenced. RESULTS: Antibodies against either lytic antigen or LANA were detected in 79.1% of Amerindians and in 6.1% of non-Amerindians (adjusted seroprevalence ratio [SR], 12.63 [95% confidence interval {CI}, 7.1-22.4]; P<.0001). HHV-8 seroprevalence increased with age among Amerindians (P(Trend) < .001) and already had high prevalence in childhood but was not sex specific in either population. The 2 populations did not differ in seroprevalence of oro-fecal or parenteral markers, but seroprevalence of markers of sexual transmission was lower among Amerindians. HHV-8 DNA in saliva was detected in 47 (23.7%) of 198 HHV-8 seropositive Amerindians. Detection of HHV-8 DNA decreased with age (P(Trend) < .04) and was more common in men (SR, 2.14 [95% CI, 1.3-3.5]; P=.003). A total of 36 (76.6%) of the 47 saliva HHV-8 DNA samples were sequenced, and all clustered as subtype E. CONCLUSION: The data support the hypothesis of early acquisition and horizontal transmission, via saliva, of HHV-8 subtype E in Amerindian populations.     

Risk factors for human herpesvirus 8 infection in a cohort of drug users in the Netherlands, 1985-1996

To elucidate the mode of human herpesvirus 8 (HHV-8) transmission in a population of Amsterdam drug users, HHV-8 seroprevalence and seroincidence were determined in 1179 drug users in the Amsterdam Cohort Studies (1985-1996). Risk factors for HHV-8 infection were examined. Serum samples were screened with an enzyme immunoassay by using HHV-8 lytic capsid (open-reading frame [ORF] 65) and latent nuclear (ORF73) antigens; positive results were confirmed by Western blot and immunofluorescence assay. Seroprevalence (men, 3.4%; women, 1.4%) and seroincidence (men, 0.08; women, 0.05/100 person-years) were low in this study. Infections with human immunodeficiency virus (HIV) type 1, hepatitis B virus (HBV), and hepatitis C virus (HCV), but not HHV-8, were associated with injection drug use (IDU). Independent risk factors for HHV-8 seropositivity were homosexual contacts and Mediterranean nationality for men and sexual contact with bisexual men, absence of a steady partner, and unprotected commercial sex for women. Unlike HIV-1, HBV, or HCV infection, HHV-8 infection is uncommon in Amsterdam drug users, as is HHV-8 transmission through IDU.     

Human herpesvirus 8 in Brazilian Amerindians: a hyperendemic population with a new subtype

Human herpesvirus 8 (HHV-8) epidemiology in Brazilian Amerindians was studied. Use of an immunofluorescence (IFA) test for latent antibody demonstrated that the prevalence of HHV-8 in 781 Amerindians of diverse tribes (overall, 53% prevalence) was not related to language group or sex but rather increased gradually from 41% in children <10 years of age to 65% in adults >/=30 years of age. In IFA-positive subjects, HHV-8 DNA was detected in 3 (16%) of 19 mononuclear cell samples from peripheral blood and in 1 of 16 saliva samples. The sequences of conserved ORF22 and K6 genes were typical of HHV-8, but the variable K1 gene sequences were only 70%-75% identical to other known HHV-8 strains. Thus, a new HHV-8 subtype, E, is hyperendemic in Brazilian Amerindians, although Kaposi's sarcoma has not been reported. Transmission is probably oral rather than sexual. The limited genetic pool in isolated groups may permit more frequent transmission of a virus with a low prevalence in heterogeneous populations.     

Human serum antibodies to a major defined epitope of human herpesvirus 8 small viral capsid antigen

The major antibody-reactive epitope of the small viral capsid antigen (sVCA) of human herpesvirus 8 (HHV-8) was defined by use of overlapping peptides. Strong IgG reactivity was found among approximately 50% of 44 human immunodeficiency virus-positive or -negative patients with Kaposi's sarcoma and 13 subjects who were seropositive by immunofluorescence assay (IFA) for the latent HHV-8 nuclear antigen. Only 1 of 106 subjects seronegative for both lytic and latent HHV-8 antigens and 10 of 81 subjects IFA-seropositive only for the lytic HHV-8 antigen had strong IgG reactivity to this epitope. Among 534 healthy Swedish women, only 1.3% were strongly seropositive. Comparison of the peptide-based and purified sVCA protein-based ELISAs found 55% sensitivity and 98% specificity. However, only 1 of 452 serum samples from healthy women was positive in both tests. In conclusion, the defined sVCA epitope was a specific, but not very sensitive, serologic marker of active HHV-8 infection. Such infection appears to be rare among Swedish women, even with sexual risk-taking behavior.     

Risk factors for human herpesvirus 8 infection among adults in the United States and evidence for sexual transmission

BACKGROUND: Human herpesvirus 8 (HHV-8) causes Kaposi sarcoma. In the United States, transmission routes for HHV-8 are uncertain. METHODS: The National Health and Nutrition Examination Survey III sampled individuals from the US general population (1988-1994). We used enzyme immunoassays (EIAs) to measure HHV-8 antibodies (K8.1 and open reading frame [ORF] 73 antigens) in 13,894 surveyed adults. HHV-8 seroprevalence was examined according to sexual history and viral coinfection markers. RESULTS: Overall, seroprevalence was low when a highly specific cutoff was used (K8.1, 1.6%; ORF73, 1.5%) but was higher when a less-specific cutoff was used (K8.1, 7.1%; ORF73, 7.4%). When the more-specific approach was used, K8.1 seroprevalence was similar in men and women. Men who have sex with men (MSM) had a higher K8.1 seroprevalence (8.2%). Among other men, K8.1 seroprevalence was marginally associated with duration of heterosexual activity (P=.1) and was positively associated with the lifetime number of sex partners (P=.04) and with coinfections with hepatitis B virus (6.1% vs. 1.2% without coinfection; P<.001) and herpes simplex virus 2 (2.7% vs. 1.0%; P=.003). Among women, K8.1 seroprevalence was not significantly related to duration of sexual activity, the lifetime number of sex partners, or viral coinfections. The ORF73 EIA revealed similar but less clear-cut patterns. CONCLUSIONS: Among men, HHV-8 transmission may occur through sexual activity, particularly sex with other men. No evidence was observed for heterosexual transmission to women.     

Human herpesvirus 8 infection and Kaposi's sarcoma among human immunodeficiency virus-infected and -uninfected women

Little is known about the epidemiology of human herpesvirus 8 (HHV-8) infections among women. A cross-sectional study was conducted of HHV-8 infection among human immunodeficiency virus (HIV)-infected and high-risk HIV-uninfected women. Serological tests with noninduced (latent) and induced (lytic) HHV-8 antigens were used to detect infection among 2483 participants of a multisite cohort. Reactivity to latent antigen was present in 4.1% and to induced antigens in 12.0% of women. Seven of 8 women who reported Kaposi's sarcoma had HHV-8 antibodies. Among HIV-positive women, HHV-8 infection was associated with use of crack, cocaine, or heroin (76% vs. 65%; P<.001), past syphilis (29% vs. 20%; P<.001), an injection drug-using male sex partner (61% vs. 53%; P=.014), black race (P=.010), and enrollment site (P=.015). In multivariate analysis, HIV infection, older age, past syphilis, black race, and enrollment site were independently associated with HHV-8 infection. In this cohort of North American women, HHV-8 infection was associated with HIV infection, drug use, and risky sexual behavior.     

Human herpesvirus 8 infection within families in rural Tanzania

Human herpesvirus 8 (HHV-8) infection is common in Africa. We examined the distribution of HHV-8 within families in rural Tanzania to determine routes of spread. HHV-8 infection was assessed by measuring antibody reactivity with a K8.1 (lytic-phase antigen) immunoassay. The prevalence increased from 3.7% (1/27) among infants to 58.1% (36/62) among children aged 3-4 years and 89.0% (65/73) among adults aged > or =45 years. Women with HHV-8-seropositive husbands had a 7-fold risk for infection (odds ratio [OR], 6.9; 95% confidence interval [CI], 1.9-25.3). HHV-8 seropositivity in children was associated with having at least 1 seropositive first-degree relative (OR, 14.7; 95% CI, 5.9-43.1), a seropositive mother (OR, 7.4; 95% CI, 3.2-16.8), a seropositive father (OR, 4.8; 95% CI, 2.3-10.1), or a seropositive next-older sibling (OR, 4.2; 95% CI, 1.9-9.4). Our data are consistent with the occurrence of HHV-8 transmission within families, from mothers and other relatives to children via nonsexual routes and between spouses via sexual routes.     

Diagnosis and epidemiology of human herpesvirus 8 infection

There is consensus that human herpesvirus 8 (HHV-8) is a necessary, albeit not sufficient, causal agent of Kaposi's sarcoma (KS). In the past several years, there have been rapid advances in our understanding of HHV-8 infection. In diagnosis, antibody detection is more sensitive than nucleic acid-based techniques. While initial serologic assays have proven useful in epidemiologic work, their application to individual patient diagnosis is problematic. The major aspects of the epidemiology of HHV-8 infection have been described, but many questions remain. For example, it is not known why there are distinct differences in worldwide distribution, with high prevalence throughout Africa and the Middle East, moderate prevalence in the Mediterranean, and low prevalence in the United States and Northern Europe. There is more than one mode of transmission, and the importance of the type of transmission varies by region. In the United States and Northern Europe, sexual transmission among homosexual men is the most common route of spread, but the specific sexual act(s) responsible are not clear. In high prevalence areas, nonsexual horizontal transmission during childhood is dominant. While saliva is the likely conduit for transmission in highly endemic areas, the precise mechanism for person-to-person spread-and whether this is preventable-is not understood.     

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.     

Human herpesvirus type 8 in HIV-infected patients with interstitial pneumonitis

OBJECTIVES: The new human herpesvirus type 8 (HHV-8) has been detected in all types of Kaposi's sarcomas, as well as in body-cavity lymphomas and Castleman's disease. Recently, HHV-8 has also been associated with encephalitis in HIV-positive and HIV-negative patients. Interstitial pneumonitis, combined with detection of HHV-8 in non HIV-infected patients, indicates a pathogenetic role of HHV-8 in unexplained lung diseases. We have studied two HIV-infected patients, with otherwise unexplained interstitial pneumonitis for the presence of HHV-8. METHODS: Lung biopsies of both patients were investigated for HHV-8 sequences. A nested PCR method was used for amplification of HHV-8 DNA fragments, and the nature of the amplification products was confirmed by Southern blot hybridization. In addition, we used an in situ hybridization technique and immunohistochemical staining for detection of HHV-8 infected cells. RESULTS: Amplification of HHV-8 DNA fragments was seen with template DNA from lung biopsies of both cases and the appropriate positive controls, but not with negative controls. In situ hybridization and immunohistochemical staining demonstrated HHV-8 infected lymphoid cells and alveolar macrophages in both patients as well. CONCLUSIONS: HHV-8 was found in HIV-infected patients with otherwise unexplained interstitial pneumonitis, but the pathogenic role of HHV-8 in patients with interstitial pneumonia remains unclear.     

Detection of human herpesvirus 8 in cervicovaginal secretions and seroprevalence in human immunodeficiency virus type 1-seropositive and -seronegative women

Epidemiologic studies suggest that human herpesvirus 8 (HHV-8) may be sexually transmitted. To study the potential for HHV-8 transmission through cervicovaginal (CV) secretions, the presence of HHV-8 DNA was investigated by nested polymerase chain reaction in the cellular fraction of CV secretions from 36 human immunodeficiency virus type 1 (HIV-1)-seropositive and 29 HIV-1-seronegative women. The same patients were tested for antibodies to two defined HHV-8 antigens (latency-associated nuclear antigen and open-reading frame 65-encoded structural protein) and for HHV-8 DNA in their peripheral blood mononuclear cells (PBMC). The findings were compared with the rate of HHV-8 detection in semen samples of 20 HIV-1-infected men. HHV-8 DNA was detected in the CV samples from only 1 HHV-8-seropositive AIDS patient, in 3 PBMC samples (1/29 HIV-1-seronegative patients, 1/3 AIDS patients with Kaposi's sarcoma, and 1/19 AIDS patients), and in 1 of 20 semen samples. HHV-8 infection was more common in HIV-1-infected than uninfected women. Thus HHV-8 DNA is only rarely detectable in CV secretions and semen of HHV-8-infected individuals.     

Interaction of human immunodeficiency virus type 1 and human herpesvirus type 8 infections on the incidence of Kaposi's sarcoma

To determine Kaposi's sarcoma (KS) risk related to timing of human immunodeficiency virus type 1 (HIV-1) and human herpesvirus type 8 (HHV-8) infections, stored longitudinal sera from 400 homosexual men with known dates of HIV-1 seroconversion (+/-4.5 months) were tested for HHV-8 antibody. Times from HHV-8 seroconversion to KS were compared for the 69 men who became infected with HHV-8 after acquiring HIV-1 to the 182 men who were HHV-8 seropositive before their HIV-1 infection. None developed KS before coinfection. HHV-8 seroconversion after HIV-1 infection increased the risk of KS (risk ratio, 2.55; 95% confidence interval, 1.06-6.10) compared with those infected with HHV-8 before HIV-1. The KS hazards in HHV-8-infected men increased by 60% (P<.001) for each year of HIV-1 infection. Faster CD4 cell loss and higher HIV-1 RNA levels significantly predicted KS. The quicker development of KS in men acquiring HHV-8 after HIV-1 and its association with CD4 slope argues that KS is more likely if HHV-8 infection occurs in an immunocompromised person.     

Risk factors for Kaposi's sarcoma in men seropositive for both human herpesvirus 8 and human immunodeficiency virus

OBJECTIVE: To identify risk factors for Kaposi's sarcoma (KS) among men seropositive for both human herpesvirus 8 (HHV-8) and HIV. DESIGN: Cross-sectional study of 91 HHV-8 seropositive, HIV seropositive men who have sex with men (57 with KS), and 70 controls at lower risk for KS. METHODS: Patients received clinical evaluations. Blood, oral fluids, semen, rectal brush, rectal swab, and urine were collected, and tests for HHV-8 were performed. RESULTS: Men with KS were more likely to have HHV-8 DNA in peripheral blood mononuclear cells (PBMC) than men without KS [35.1 versus 5.9%, odds ratio (OR), 8.6, 95% confidence interval (CI), 1.9-39.9]. The prevalence of HHV-8 DNA in oral fluids was similar for the two groups (37.0 versus 32.4%; OR, 1.2; 95% CI, 0.5-3.0). HHV-8 DNA was rarely detected in specimens of other types from these men, or in any specimens from the 70 controls. Among men with KS, HHV-8 DNA in PBMC was associated with new KS lesions (OR, 4.5; 95% CI, 1.4-14.5), and HHV-8 DNA in oral fluids was associated with oropharyngeal KS lesions (OR, 3.1; 95% CI, 1.0-10.1). Men with high HHV-8 antibody titers were more likely to have KS (OR, 9.6; 95% CI, 1.2-78.2), but were less likely to have new KS lesions (OR, 0.2; 95% CI, 0.0-1.1) or HHV-8 DNA in PBMC (OR, 0.2; 95% CI, 0.0-1.6) or oral fluids (OR, undefined; = 0.001). CONCLUSIONS: In HHV-8- and HIV-seropositive men, HHV-8 DNA is associated with KS. Among men without KS, HHV-8 DNA is most commonly found in oral fluids. High HHV-8 antibody titers may protect against circulating HHV-8 and new KS lesions.     

Postnatal human herpesvirus 8 and human immunodeficiency virus type 1 infection in mothers and infants from Zambia

The specific route and timing of human herpesvirus (HHV) 8 infection in regions where Kaposi sarcoma is endemic are not known. HHV-8 infection and any risk factors that may be associated with HHV-8, including human immunodeficiency virus (HIV) type 1 infection, were monitored during the 12-month postdelivery period for 416 mothers and 485 infants from Lusaka, Zambia. HHV-8 incident infection rates during this period were 3.2 and 5.3 infections/100 person-years for infants and mothers, respectively. HHV-8 infection among infants was not associated with HHV-8 or HIV-1 infection in the mother. Among the HHV-8-positive infants, 2 of 12 tested were found to have HHV-8 DNA in their peripheral blood mononuclear cells at birth, which suggests that in utero infection is possible. However, most HHV-8-positive infants appeared to have acquired infection either intrapartum or postpartum. The present study indicates that transmission of HHV-8 to infants can occur early and is likely via multiple routes.     

Detection of human herpesvirus 8 by quantitative polymerase chain reaction: development and standardisation of methods

ABSTRACT: BACKGROUND: Human herpesvirus 8 (HHV-8), the aetiological agent of Kaposi's sarcoma (KS), multicentric Castleman's disease (MCD), and primary effusion lymphoma (PEL) is rare in Australia, but endemic in Sub-Saharan Africa, parts of South-east Asia and Oceania. While the treatment of external KS lesions can be monitored by clinical observation, the internal lesions of KS, MCD and PEL require extensive and expensive internal imaging, or autopsy. In patients with MCD and PEL, if HHV-8 viraemia is not reduced quickly, ~50% die within 24 months. HHV-8 qPCR is a valuable tool for monitoring HHV-8 viraemia, but is not available in many parts of the world, including those with high prevalence of KS and HHV-8. METHODS: A new molecular facility with stringent three-phase workflow was established, adhering to NPAAC and CLSI guidelines. Three fully validated quantitative assays were developed: two for detection and quantification of HHV-8; one for GAPDH, necessary for normalisation of viral loads in tissue and peripheral blood. RESULTS: The HHV-8 ORF73 and ORF26 qPCR assays were 100% specific. All qPCR assays, displayed a broad dynamic range (102 to 1010 copies/muL TE Buffer) with a limit of detection of 4.85x103, 5.61x102, and 2.59x102 copies/muL TE Buffer and a limit of quantification of 4.85x103, 3.01x102, and 1.38x102 copies/muL TE Buffer for HHV-8 ORF73, HHV-8 ORF26, and GAPDH respectively.The assays were tested on a panel of 35 KS biopsies from Queensland. All were HHV-8 qPCR positive with average viral load of 2.96x105 HHV-8 copies/muL DNA extract (range: 4.37x103 to 1.47x106 copies/muL DNA extract): When normalised these equate to an average viral load of 2.44x104 HHV-8 copies/103 cells (range: 2.20x102 to 7.38x105 HHV-8 copies/103 cells). CONCLUSIONS: These are the first fully optimised, validated and MIQE compliant HHV-8 qPCR assays established in Australia. They worked well for qualitative detection of HHV-8 in archival tissue, and are well-suited for quantitative detection in whole blood. They are now available for research, for clinical diagnosis of HHV-8 infection, and for monitoring treatment efficacy.