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

Molecular detection and genotyping of human herpes virus 8 in blood donors in Congo

OBJECTIVES

Human herpesvirus 8 (HHV8) is rarely studied in Congo, despite its prevalence in Africa. Among healthy individuals, HHV-8 does not always lead to a life-threatening infection; however, in immunocompromised individuals, it could lead to more severe disease. The distribution of HHV-8 genotypes varies depending on ethnicity and geographic region.

METHOD

A prospective cross-sectional study included 265 samples from healthy blood donors from the National Blood Transfusion Center in Brazzaville, with an average age of 35 years, with extremes ranging from 18 to 60 years. After DNA extraction, a nested PCR was carried out for molecular detection, followed by genotyping by amplification of specific primers.

RESULT

In this study, 4.9% were positive for molecular detection of HHV-8 DNA. All HHV-8 positive DNA samples that were subjected to genotyping by amplification with specific primers allowing discrimination of two major genotypes (A and B). Genotype A was identified in 5 (1.9%) samples and genotype B in 2 (0.7%) samples, indicating that both genotypes were predominant. The remaining viral DNA samples not identified as the major genotypes were classified as «indeterminate» and consisted of 6 (2.3%) samples.

CONCLUSION

The results of the study suggest that Congo is an area where HHV-8 infection is endemic.

HIV-associated cancers and lymphoproliferative disorders caused by Kaposi sarcoma herpesvirus and Epstein-Barr virus

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

HHV-8 Linked to Kaposi's Sarcoma and Castleman's Disease in HIV-1-infected patient: Case Report and Review of the Literature

Kaposi's sarcoma (KS) and multicentric Castleman's disease (MCD) are both linked to human herpesvirus-8 (HHV-8) infection which most commonly affects people living with human immunodeficiency virus (HIV).  Herein, we describe the case of a 57-year-old patient who has been admitted for fever, night sweats, weight loss, and diffuse lymphadenopathy with abdominal pain. HIV status was confirmed by a positive Western blot test. His initial CD4 cell count was equal to 270 cells/µL. A histological study of a peripheral lymph node concluded that KS is associated with MCD. These two conditions found in the same patient highlight the malignant potential of HHV-8, particularly in the case of HIV-induced immunodeficiency.

Seroprevalence and molecular diversity of Human Herpesvirus 8 among people living with HIV in Brazzaville, Congo

Human herpesvirus 8 (HHV8) is endemic in Africa, although studies of this infection are rare in Congo. We evaluated seroprevalence and HHV-8 diversity among people living with HIV. We included 353 patients receiving highly active antiretroviral therapy. Antibodies against HHV-8 latency-associated nuclear antigen were detected by indirect immunofluorescence. In HHV-8 positive patients, we performed HHV-8 quantification in blood and saliva by real-time PCR and typing by Sanger sequencing of K1 open reading frame. HHV-8 seroprevalence was 19%, being male (odd ratio [OR] = 1.741, [95% Confidence interval {CI}, 0.97-3.07]; p = 0.0581) and having multiple sex partners before HIV diagnosis (OR = 1.682, [CI 95%, 0.97-2.92]; p = 0.0629) tended to be associated with HHV-8 seropositivity. Of the 64 HHV-8 seropositive patients, HHV-8 DNA was detected in 10 (16%) in saliva, 6 (9%) in whole-blood and in 2 (3%) in both whole-blood and saliva. Three out of 6 HHV-8 strains were subtypes A5, 2 subtype B1 and 1 subtype C. HHV-8 seroprevalence was relatively low with more frequent carriage in men, associated with asymptomatic oral excretion and a predominance of subtype A5. These data tend to support the hypothesis of horizontal transmission in people living with HIV in Brazzaville.

Epidemiology and Genetic Variability of HHV-8/KSHV among Rural Populations and Kaposi's Sarcoma Patients in Gabon, Central Africa. Review of the Geographical Distribution of HHV-8 K1 Genotypes in Africa

Human herpesvirus 8 (HHV-8) is the etiological agent of all forms of Kaposi's sarcoma (KS). K1 gene studies have identified five major molecular genotypes with geographical clustering. This study described the epidemiology of HHV-8 and its molecular diversity in Gabon among Bantu and Pygmy adult rural populations and KS patients. Plasma antibodies against latency-associated nuclear antigens (LANA) were searched by indirect immunofluorescence. Buffy coat DNA samples were subjected to polymerase chain reaction (PCR) to obtain a K1 gene fragment. We studied 1020 persons; 91% were Bantus and 9% Pygmies. HHV-8 seroprevalence was 48.3% and 36.5% at the 1:40 and 1:160 dilution thresholds, respectively, although the seroprevalence of HHV-8 is probably higher in Gabon. These seroprevalences did not differ by sex, age, ethnicity or province. The detection rate of HHV-8 K1 sequence was 2.6% by PCR. Most of the 31 HHV-8 strains belonged to the B genotype (24), while the remaining clustered within the A5 subgroup (6) and one belonged to the F genotype. Additionally, we reviewed the K1 molecular diversity of published HHV-8 strains in Africa. This study demonstrated a high seroprevalence of HHV-8 in rural adult populations in Gabon and the presence of genetically diverse strains with B, A and also F genotypes.

Genetic diversity and phylogeographic analysis of human herpesvirus type 8 (HHV-8) in two distant regions of Argentina: Association with the genetic ancestry of the population

BACKGROUND

The genetic diversity of persistent infectious agents, such as HHV-8, correlates closely with the migration of modern humans out of East Africa which makes them useful to trace human migrations. However, there is scarce data about the evolutionary history of HHV-8 particularly in multiethnic Latin American populations.

OBJECTIVES

The aims of this study were to characterize the genetic diversity and the phylogeography of HHV-8 in two distant geographic regions of Argentina, and to establish potential associations with pathogenic conditions and the genetic ancestry of the population.

STUDY DESIGN

A total of 101 HIV-1 infected subjects, 93 Kaposi's Sarcoma (KS) patients and 411 blood donors were recruited in the metropolitan (MET) and north-western regions of Argentina (NWA). HHV-8 DNA was detected by ORF-26 PCR in whole blood, saliva and FFPE tissues. Then, ORF-26 and ORF-K1 were analyzed for subtype assignment. Mitochondrial DNA and Y chromosome haplogroups, as well as autosomal ancestry markers were evaluated in samples in which subtypes could be assigned. Phylogeographic analysis was performed in the ORF-K1 sequences from this study combined with 388 GenBank sequences.

RESULTS

HHV-8 was detected in 50.7%, 59.2% and 8% of samples from HIV-1 infected subjects, KS patients and blood donors, respectively. ORF-K1 phylogenetic analyses showed that subtypes A (A1-A5), B1, C (C1-C3) and F were present in 46.9%, 6.25%, 43.75% and 3.1% of cases, respectively. Analyses of ORF-26 fragment revealed that 81.95% of strains were subtypes A/C followed by J, B2, R, and K. The prevalence of subtype J was more commonly observed among KS patients when compared to the other groups. Among KS patients, subtype A/C was more commonly detected in MET whereas subtype J was the most frequent in NWA. Subtypes A/C was significantly associated with Native American maternal haplogroups (p = 0.004), whereas subtype J was related to non-Native American haplogroups (p < 0.0001). Sub-Saharan Africa, Europe and Latin America were the most probable locations from where HHV-8 was introduced to Argentina.

CONCLUSIONS

These results give evidence of the geographic circulation of HHV-8 in Argentina, suggest the association of ORF-26 subtype J with KS development and provide new insights about its relationship with ancient and modern human migrations and identify the possible origins of this virus in Argentina.

Lymphotropic Viruses EBV, KSHV and HTLV in Latin America: Epidemiology and Associated Malignancies. A Literature-Based Study by the RIAL-CYTED

The Epstein-Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

Low prevalence of human gammaherpesvirus 8 (HHV-8) infection among HIV-infected pregnant women in Rio De Janeiro, Brazil

Pregnant women coinfected with the human immunodeficiency virus (HIV) and human gammaherpesvirus 8 (HHV-8) are at higher risk of Kaposi's sarcoma development, increased viral load, and vertical transmission of these viruses. A total of 131 pregnant women infected with HIV were examined for antibodies against HHV-8 latency-associated nuclear antigen (LANA) and lytic antigens using immunofluorescence assays. The presence of HHV-8 DNA was confirmed using real-time polymerase chain reaction (qPCR) and nested PCR. Overall, 0.8% (1/131) of the patients contained antibodies to HHV-8 LANA and lytic antigens, and no HHV-8 DNA was detected. This study, including a small population of HIV-infected pregnant women in Brazil, indicates a low prevalence of HHV-8 seropositivity and absence of active infection in this group. However, a potential role of HHV-8 in the increased transmission and pathogenic activity of HIV in pregnant women is suggested. Attention should be given to the emergence of HHV-8 infection in this population group in order to avoid comorbidities and transmission of HIV.

Kaposi's sarcoma-associated herpesvirus seropositivity is associated with parasite infections in Ugandan fishing communities on Lake Victoria islands

We investigated the impact of helminths and malaria infection on Kaposi's sarcoma associated herpesvirus (KSHV) seropositivity, using samples and data collected from a cluster-randomised trial of intensive versus standard anthelminthic treatment. The trial was carried out in 2012 to 2016 among fishing communities on Lake Victoria islands in Uganda. Plasma samples from 2881 participants from two household surveys, the baseline (1310 participants) and the final (1571 participants) surveys were tested for KSHV IgG antibody responses to K8.1 and ORF73 recombinant proteins using ELISA. The baseline survey was carried out before the trial intervention while the final survey was carried out after three years of the trial intervention. Additionally, a subset sample of 372 participants from the final survey was tested for IgE, IgG and IgG4 antibody concentrations to S. mansoni adults worm antigen (SWA) and S. mansoni egg antigen (SEA) using ELISA. Infection by helminths (S. mansoni, N. americanus, T. trichiura and S. stercoralis) was diagnosed using real-time PCR, urine circulating cathodic antigen (CCA) and stool microscopy (Kato-Katz method) while malaria infection was diagnosed using microscopy. We analysed the relationship between helminth and malaria infections and KSHV seropositivity using regression modelling, allowing for survey design. At baseline, 56% of the participants were male while 48% of the participants were male in the final survey. The most prevalent helminth infection was S. mansoni (at baseline 52% and 34% in the final survey by microscopy, 86% by CCA and 50% by PCR in the final survey). KSHV seropositivity was 66% (baseline) and 56% (final survey) among those 1-12 years and >80% in those 13+ years in both surveys; malaria parasitaemia prevalence was 7% (baseline) and 4% (final survey). At baseline, individuals infected with S. mansoni (detected by microscopy) were more likely to be KSHV seropositive (aOR = 1.86 (1.16, 2.99) p = 0.012) and had higher anti-K8.1 antibody levels (acoefficient = 0.03 (0.01, 0.06) p = 0.02). In the final survey, S. mansoni (by microscopy, adjusted Odds Ratio (aOR = 1.43 (1.04-1.95), p = 0.028) and malaria parasitaemia (aOR = 3.49 (1.08-11.28), p = 0.038) were positively associated with KSHV seropositivity. Additionally, KSHV seropositive participants had higher S. mansoni-specific IgE and IgG antibody concentrations in plasma. Furthermore, HIV infected individuals on cART were less likely to be KSHV seropositive compared to HIV negative individuals (aOR = 0.46 (0.30, 0.71) p = 0.002). Schistosoma species skew the immune response towards Th2 and regulatory responses, which could impact on KSHV reactivation if co-infected with both organisms.

HIV, syphilis, and viral hepatitis among Latin American indigenous peoples and Afro-descendants: a systematic review

Objective

To identify and summarize existing literature on the burden of HIV, sexually transmitted infections (STIs), and viral hepatitis (VH) in indigenous peoples and Afro-descendants in Latin America to provide a broad panorama of the quantitative data available and highlight problematic data gaps.

Methods

Published and grey literature were systematically reviewed to identify documents published in English, Spanish, or Portuguese with data collected between January 2000 and April 2016 on HIV, STI, and VH disease burden among indigenous peoples and Afro-descendants in 17 Latin American countries.

Results

Sixty-two documents from 12 countries were found. HIV prevalence was generally low (< 1%) but pockets of high prevalence (> 5%) were noted in some indigenous communities in Venezuela (Warao) (9.6%), Peru (Chayahuita) (7.5%), and Colombia (Wayuu females) (7.0%). High active syphilis prevalence (> 5%) was seen in some indigenous communities in Paraguay (11.6% and 9.7%) and Peru (Chayahuita) (6.3%). High endemicity (> 8%) of hepatitis B was found in some indigenous peoples in Mexico (Huichol) (9.4%) and Venezuela (Yanomami: 14.3%; Japreira: 29.5%) and among Afro-descendant quilombola populations in Brazil (Frechal: 12.5%; Furnas do Dionísio: 8.4% in 2008, 9.2% in 2003).

Conclusions

The gaps in existing data on the burden of HIV, STIs, and VH in indigenous peoples and Afro-descendants in Latin America highlight the need to 1) improve national surveillance, by systematically collecting and analyzing ethnicity variables, and implementing integrated biobehavioral studies using robust methodologies and culturally sensitive strategies; 2) develop a region-wide response policy that considers the needs of indigenous peoples and Afro-descendants; and 3) implement an intercultural approach to health and service delivery to eliminate health access barriers and improve health outcomes for these populations.

Prospective study of human herpesvirus 8 oral shedding, viremia, and serological status among human immunodeficiency virus seropositive and seronegative individuals in Sao Paulo, Brazil

Human herpesvirus 8 (HHV-8) is a gamma-herpesvirus and etiological agent of all forms of Kaposi sarcoma (KS). Saliva may play an important role in HHV-8 transmission in specific populations. Little is known about HHV-8 oral shedding pattern and the possible correlation with the HHV-8 serological profile and viremia. A prospective study was conducted of HHV-8 salivary excretion among human immunodeficiency virus HIV-seronegative (n = 47) and -seropositive (n = 44) homosexual men and HIV-seropositive women (n = 32) over a 6-month period with monthly HHV-8 serologies (immunofluorescence assays to identify antibodies to latent and lytic HHV-8 viral proteins, and a whole-virus HHV-8 enzyme-linked immunosorbent assay [ELISA]), monthly HHV-8 DNA serum/plasma detection, and daily self-collected oral rinses for HHV-8-DNA detection using real-time polymerase chain reaction. HHV-8 seropositivity was 51.1%, 63.6%, and 37.5%, in the three studied groups. There was no case of HHV-8 DNA detection in serum/plasma. Intermittent detection of oral HHV-8 DNA was observed during 5.1% (110/2,160) of visits among 28% (18/64) of HHV-8-seropositive individuals, all of whom were males and HHV-8 ELISA seropositive. In immunologically controlled populations of Brazil, HHV-8 oral shedding was limited to HHV-8-seropositive men, occurred infrequently and intermittently, and was not linked to HHV-8 viremia, suggesting a limited potential for oral or blood transmission.

Angiosarcoma in HIV-negative patients is not associated with HHV-8

BACKGROUND:

Angiosarcoma is an aggressive, malignant neoplasm of vascular or lymphatic origin. Herpes virus 8 (HHV-8) is a member of the herpes family with a tropism for endothelial cells and it has been proven to induce vascular neoplasms, such as Kaposi's sarcoma. The role of HHV-8 in the pathogenesis of angiosarcoma has not been well defined.

OBJECTIVE:

To investigate the relationship between the presence of HHV-8 and angiosarcoma.

METHODS:

In this study, the team investigated the relationship between the presence of HHV-8, as determined by polymerase chain reaction, and angiosarcoma, using samples from patients with epidemic Kaposi's sarcoma as controls.

RESULTS:

While all control cases with epidemic Kaposi's sarcoma were positive for HHV-8, none of the angiosarcoma cases was.

CONCLUSION:

These findings support most previous studies that found no association between HHV-8 and angiosarcoma.

MDM2 gene polymorphisms and risk of classic Kaposi's sarcoma among Iranian patients

A single-nucleotide polymorphism (SNP) in the promoter region of MDM2 (SNP309T>G, rs2279744) has been shown to increase the expression of the MDM2 protein in various cancer types. However, only one study has analyzed the role of the MDM2 polymorphism in the development of Kaposi's sarcoma (KS). The association of MDM2 SNP309 with classic KS risk was evaluated in 79 Iranian patients with classic KS and 123 healthy controls. The MDM2 SNP309 was genotyped using PCR and restriction fragment length polymorphism methods. No significant correlation was found between the SNP309 polymorphism in MDM2 promoter and classic KS risk. There was no significant correlation between gender and disease stage. However, a significant association was found between SNP309 GG genotype and younger age (≤50 years) (odds ratio 9.5, 95% confidence intervals 1.5-60, p = 0.03). Our findings support no major role for the MDM2 SNP309 in KS development although it might influence the clinical outcome of KS in younger patients.

Genotypic distribution of HHV-8 in AIDS individuals without and with Kaposi sarcoma: Is genotype B associated with better prognosis of AIDS-KS?

AIDS-associated Kaposi's sarcoma (AIDS-KS) caused by human herpes virus 8 (HHV-8) is the most severe and resistant form of KS tumor. Our aim was to verify whether there is an association between HHV-8 variability and development of AIDS-KS in Brazil by comparing the HHV-8 variability between individuals without and with KS. Saliva samples and blood, when available, were analyzed by polymerase chain reaction (PCR) techniques for detection of the fragments of ORF K1 of HHV-8, which were then genotyped and analyzed regarding the genetic variability. Our study described 106 positive cases for HHV-8 in the saliva from 751 AIDS patients without previous KS. In addition, we performed a phylogenetic analysis of HHV-8 in 34 of the 106 AIDS patients without KS and in 33 of the 37 patients with active KS. The distribution of HHV-8 genotypes A, B, C, and F in AIDS individuals was indistinguishable by comparing non-KS and KS groups, as well as regarding ethnicity. Considering the KS group, genotype B was associated with better prognosis of KS tumor. Interestingly, we found a particular profile of diversity within clade C and 2 recombinant patterns of HHV-8 in the saliva of AIDS individuals without KS. We emphasize the need to achieve standard genotyping protocol for ORF K1 amplification, thus allowing for substantial detection of HHV-8 variants. Our findings can shed light on the role of HHV-8 variability in the pathogenesis of AIDS-KS.

Epidemiology and transmission of Kaposi's sarcoma-associated herpesvirus

This review summarizes the current knowledge pertaining to Kaposi sarcoma-associated herpesvirus (KSHV) epidemiology and transmission. Since the identification of KSHV twenty years ago, it is now known to be associated with Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease. Many studies have been conducted to understand its epidemiology and pathogenesis and their results clearly show that the worldwide distribution of KSHV is uneven. Some geographical areas, such as sub-Saharan Africa, the Mediterranean region and the Xinjiang region of China, are endemic areas, but Western Europe and United States have a low prevalence in the general population. This makes it imperative to understand the risk factors associated with acquisition of infection. KSHV can be transmitted via sexual contact and non-sexual routes, such as transfusion of contaminated blood and tissues transplants, or via saliva contact. There is now a general consensus that salivary transmission is the main route of transmission, especially in children residing in endemic areas. Therefore, there is a need to better understand the sources of transmission to young children. Additionally, lack of animal models to study transmission, gold standard serological assay and the lack of emphasis on endemic KS research has hampered the efforts to further delineate KSHV transmission in order to design effective prevention strategies.

Heterogeneity and breadth of host antibody response to KSHV infection demonstrated by systematic analysis of the KSHV proteome

The Kaposi sarcoma associated herpesvirus (KSHV) genome encodes more than 85 open reading frames (ORFs). Serological evaluation of KSHV infection now generally relies on reactivity to just one latent and/or one lytic protein (commonly ORF73 and K8.1). Most of the other polypeptides encoded by the virus have unknown antigenic profiles. We have systematically expressed and purified products from 72 KSHV ORFs in recombinant systems and analyzed seroreactivity in US patients with KSHV-associated malignancies, and US blood donors (low KSHV seroprevalence population). We identified several KSHV proteins (ORF38, ORF61, ORF59 and K5) that elicited significant responses in individuals with KSHV-associated diseases. In these patients, patterns of reactivity were heterogeneous; however, HIV infection appeared to be associated with breadth and intensity of serological responses. Improved antigenic characterization of additional ORFs may increase the sensitivity of serologic assays, lead to more rapid progresses in understanding immune responses to KSHV, and allow for better comprehension of the natural history of KSHV infection. To this end, we have developed a bead-based multiplex assay detecting antibodies to six KSHV antigens.

One hundred and five Kaposi sarcoma patients: a clinical study in Xinjiang, Northwest of China

BACKGROUND

Kaposi's sarcoma (KS) is an unusual illness that may be associated with human herpes virus 8 (HHV-8) infections, and appears mainly in Jews, Italians and Greeks. There is a lack of patient data in Xinjiang regarding the clinical characteristics of KS.

OBJECTIVES

To review the clinical characteristics of a series of patients with KS in Xinjiang, Northwest China, over 16-year period.

METHODS

A retrospective analysis of patients referred to a Xinjiang hospital in Northwest China with classic KS (CKS) and AIDS-associated KS (AIDS-KS) between January 1997 and April 2013 was performed. Reviewed information included demographics, clinical features, histopathological traits, treatment and presence of HHV-8 infection.

RESULTS

During the study period, 105 patients with a diagnosis of KS, including 77 CKS and 28 AIDS-KS, were referred to our hospital. Mean age at diagnosis was 55.8 ± 16.8 years (range: 25-85 years). There were 70 (90.9%) males and 7 (9.1%) females (male-to-female ratio: 10 : 1) having CKS and 21 (75.0%) males and 7 (25.0%) females (male-to-female ratio: 3 : 1) with AIDS-KS. Most of the patients were Uyghur, including 67 CKS and 24 AIDS-KS. The rate of multifocal lesions at diagnosis was 98.1% (103/105). The most common area of lesions was between 1% and 5% of CKS and AIDS-KS. The main types of lesions were nodules, patches and plaques. The lower extremity and foot were the most common locations for CKS and AIDS-KS. In addition to skin damage, the penis, mouth, lymph nodes and interstitial lung tissues were involved in some cases. No second primary malignancy was diagnosed. Systemic chemotherapy and radiotherapy were effective treatments for CKS. The HHV-8 positivity rate was 98.98% in 98 KS cases.

CONCLUSIONS

In Xinjiang, most CKS and AIDS-KS patients were older Uyghur men. AIDS-KS was found predominantly among 30-year-old Uyghur patients, compared with 60 years for those having CKS. The latter exhibited certain characteristics such as disseminated skin disease; in some patients, the condition was accompanied by lymphedema, visceral or lymph node involvement, but no secondary malignancies. In addition, the HHV-8 positivity rate associated with KS was very high.

Fifty percent tissue culture infective dose assay for determining the titer of infectious human herpesvirus 8

We have developed a human herpesvirus 8 (HHV-8) 50% tissue culture infective dose (TCID50) assay using the T1H6-DC-SIGN cell line. Infection of T1H6-DC-SIGN cells with HHV-8 induces expression of β-galactosidase, which was used to determine TCID50 levels. Validation of TCID50 values was performed by immunofluorescence assay of HHV-8 infection of immature dendritic cells at various TCID50 doses.

Early childhood infection of Kaposi's sarcoma-associated herpesvirus in Zambian households: a molecular analysis

Sub-Saharan Africa is endemic for Kaposi's sarcoma-associated herpesvirus (KSHV) and there is a high rate of early childhood infection; however, the transmission sources are not well characterized. We examined household members as potential KSHV transmission sources to young children in the KSHV-endemic country of Zambia. To this end, we enrolled and followed Zambian households with at least one KSHV-seropositive child and collected longitudinal buccal swab samples. KSHV burden was evaluated and K1 sequences from the children were determined and analyzed for differences to K1 sequences from household members. The K1 sequences were also analyzed for evolution over time. We generated K1 sequences from 31 individuals across 16 households. Nine households contained multiple KSHV-positive members, including at least one child. In six out of the nine households, the child had 100% sequence identity to all household members. However, in two households the child and mother had distinct K1 sequences. In the remaining household, the children were the only KSHV-infected individuals. Furthermore, we report that 1 out of 18 individuals had K1 sequence variation within the timespan analyzed. In our study, we provide evidence that (i) early childhood KSHV transmission occurs from both within and outside the household, (ii) intrahousehold transmission can occur via nonmaternal sources, (iii) viral shedding in the buccal cavity is highly variable and (iv) the dominant K1 sequence within an individual did not rapidly evolve over time. These results are important for developing KSHV intervention strategies.

Transmission of human herpesvirus type 8 infection within families in american indigenous populations from the Brazilian Amazon

BACKGROUND

The intrafamilial dynamics of endemic infection with human herpesvirus type 8 (HHV-8) in Amerindian populations is unknown.

METHODS

Serum samples were obtained from 517 Amerindians and tested for HHV-8 anti-latent nuclear antigen (anti-LANA) and antilytic antibodies by immunofluorescence assays. Logistic regression and mixed logistic models were used to estimate the odds of being HHV-8 seropositive among intrafamilial pairs.

RESULTS

HHV-8 seroprevalence by either assay was 75.4% (95% confidence interval [CI]: 71.5%-79.1%), and it was age-dependent (P(trend) < .001). Familial dependence in HHV-8 seroprevalence by either assay was found between mother-offspring (odds ratio [OR], 5.44; 95% CI: 1.62-18.28) and siblings aged ≥10 years (OR 4.42, 95% CI: 1.70-11.45) or siblings in close age range (<5 years difference) (OR 3.37, 95% CI: 1.21-9.40), or in families with large (>4) number of siblings (OR, 3.20, 95% CI: 1.33-7.67). In separate analyses by serological assay, there was strong dependence in mother-offspring (OR 8.94, 95% CI: 2.94-27.23) and sibling pairs aged ≥10 years (OR, 11.91, 95% CI: 2.23-63.64) measured by LANA but not lytic antibodies.

CONCLUSIONS

This pattern of familial dependence suggests that, in this endemic population, HHV-8 transmission mainly occurs from mother to offspring and between close siblings during early childhood, probably via saliva. The mother to offspring dependence was derived chiefly from anti-LANA antibodies.

Molecular epidemiology of human herpesvirus 8 variants in Kaposi's sarcoma from Iranian patients

Kaposi's sarcoma (KS) is a rare cancer in Iran and there is no epidemiological and molecular information about HHV-8 variants circulating among the Iranian population. In this study HHV-8 sequences have been analyzed in 43 cutaneous KS biopsies from Iranian patients mainly affected by classic KS. DNA samples were subjected to PCR amplification of HHV-8 ORF26, T0.7 and K1 followed by direct nucleotide sequencing and phylogenetic analysis. The analysis of ORF26 showed that 30 (69.8%) and 13 (30.2%) samples belonged to subtypes A/C and K, respectively. In general, the clustering of HHV-8 T0.7 variants paralleled that of ORF26. Genotyping of K1 sequences showed that the majority of samples (39 out of 41) fall into the large C clade with only 2 belonging to the A clade. In conclusion, HHV-8 variants identified among classic Iranian KS are largely related to Eurasian genotypes previously identified in KS from Mediterranean, Middle East, and East Asian regions.

The Zambia Children's KS-HHV8 Study: rationale, study design, and study methods

The epidemic of human immunodeficiency virus in Zambia has led to a dramatic rise in the incidence of human herpesvirus-8 (HHV-8)-associated Kaposi's sarcoma in both adults and children. However, there is a paucity of knowledge about the routes of HHV-8 transmission to young children. The Zambia Children's KS-HHV8 Study, a large, prospective cohort study in Lusaka, Zambia, was launched in 2004 to investigate the role of household members as a source of HHV-8 infection in young children and social behaviors that may modify the risk of HHV-8 acquisition. This cohort is distinct from other epidemiologic studies designed to investigate HHV-8 incidence and transmission because it recruited and followed complete households in the urban central African context. Between July 2004 and March 2007, 1,600 households were screened; 368 households comprising 464 children and 1,335 caregivers and household members were enrolled. Follow-up of this population continued for 48 months postrecruitment, affording a unique opportunity to study horizontal transmission of HHV-8 and understand the routes and sources of transmission to young children in Zambia. The authors describe the study rationale, design, execution, and characteristics of this cohort, which provides critical data on the epidemiology and transmission of HHV-8 to young children in Zambia.

Update on KSHV epidemiology, Kaposi Sarcoma pathogenesis, and treatment of Kaposi Sarcoma

Much has been learned since the discovery of KSHV in 1994 about its epidemiology and pathology but much of what has been learned has yet to be translated into clinical practice. In this review, we survey the current state of knowledge on KSHV epidemiology and KS pathogenesis and highlight therapeutic opportunities in both the developed and developing world.

Simultaneous quantification of human herpesvirus 8 DNA by real time PCR in different tissues of HIV infected cuban patients with Kaposi's sarcoma

In Cuba, previous reports have shown an increase of epidemic KS, reaching a total of 120 cases by the end of 2007, despite the use of HAART. To evaluate and compare the role of human herpes virus 8 (HHV-8) viral loads in different compartments of AIDS-related Kaposi's sarcoma (AIDS-KS) patients real-time polymerase chain reaction (RT-PCR) was used to determine the genome copy number of HHV-8 in plasma, saliva, tissue and peripheral blood mononuclear cells (PBMC) of 49 AIDS-KS patients. Overall, 98% of AIDS-KS patients harbored detectable HHV-8. HHV-8 could be detected in 91.6% of KS tissue lesions showing the highest viral load (median log = 3.14 copies/100 ng DNA) followed by saliva and PBMC which were positive in 78%, and 69.2%; respectively. In contrast, HHV-8 was detected in only 37% of plasma samples, which also showed lower viral loads. Men who had sex with men (MSM) were more likely to have three-times higher HHV-8 genome copies in KS lesions when compared with tissues from heterosexuals individuals (OR 3; 95% CI 1.1 to 12.5). These results emphasize the systemic nature of HHV-8-infection and demonstrate the possible role of saliva in HHV-8 transmission among MSM.

Human herpesvirus 8 genotype E in patients with Kaposi sarcoma, Peru

To determine human herpesvirus 8 (HHV-8) K1 genotypes in patients with Kaposi sarcoma (KS) from Peru, we characterized HHV-8 in 25 KS biopsy samples. Our findings of 8 A, 1 B, 14 C, and 2 E subtypes showed high HHV-8 diversity in these patients and association between E genotype and KS development.

The lytic activation of KSHV during keratinocyte differentiation is dependent upon a suprabasal position, the loss of integrin engagement, and calcium, but not the interaction of cadherins

We previously found that KSHV (HHV-8) lytic activation occurs during differentiation of oral keratinocytes in organotypic raft cultures. To further investigate the spatial and temporal aspects of KSHV lytic activation and the roles of integrins, cadherins, and calcium, we used rKSHV.219-infected primary oral keratinocytes in submerged, suspension, and direct suprabasal plating, models of differentiation. We found that early keratinocyte differentiation did not activate lytic KSHV in cells attached to a substratum, with activation only occurring in suprabasal cells. Temporally, KSHV lytic expression occurred between the expression of early and late differentiation markers. Keratinocytes differentiated in suspension culture, which mimics substratum loss that occurs with stratification, activated lytic KSHV. This lytic activation was inhibited by integrin engagement, showing that integrins are a control point for KSHV reactivation. A role for cadherins was not found. Elevated extracellular calcium was necessary, but not sufficient, for lytic activation.

Kaposi's Sarcoma Associated-Herpes Virus (KSHV) Seroprevalence in Pregnant Women in South Africa

Background

Factors previously associated with Kaposi's sarcoma-associated herpesvirus (KSHV) transmission in Africa include sexual, familial, and proximity to river water. We measured the seroprevalence of KSHV in relation to HIV, syphilis, and demographic factors among pregnant women attending public antenatal clinics in the Gauteng province of South Africa.

Methods

We tested for antibodies to KSHV lytic K8.1 and latent Orf73 antigens in 1740 pregnant women attending antenatal clinics who contributed blood to the "National HIV and Syphilis Sero-Prevalence Survey - South Africa, 2001". Information on HIV and syphilis serology, age, education, residential area, gravidity, and parity was anonymously linked to evaluate risk factors for KSHV seropositivity. Clinics were grouped by municipality regions and their proximity to the two main river catchments defined.

Results

KSHV seropositivity (reactive to either lytic K8.1 and latent Orf73) was nearly twice that of HIV (44.6% vs. 23.1%). HIV and syphilis seropositivity was 12.7% and 14.9% in women without KSHV, and 36.1% and 19.9% respectively in those with KSHV. Women who are KSHV seropositive were 4 times more likely to be HIV positive than those who were KSHV seronegative (AOR 4.1 95%CI: 3.4 - 5.7). Although, women with HIV infection were more likely to be syphilis seropositive (AOR 1.8 95%CI: 1.3 - 2.4), no association between KSHV and syphilis seropositivity was observed. Those with higher levels of education had lower levels of KSHV seropositivity compared to those with lower education levels. KSHV seropositivity showed a heterogeneous pattern of prevalence in some localities.

Conclusions

The association between KSHV and HIV seropositivity and a lack of common association with syphilis, suggests that KSHV transmission may involve geographical and cultural factors other than sexual transmission.

Variations in human herpesvirus type 8 seroprevalence in Native Americans, South America

To determine the epidemiology of human herpesvirus type 8 (HHV-8) among non-Amazonian native populations, we conducted a cross-sectional study in Brazil, Bolivia, and Paraquay. Our data show striking ethnic and geographic variations in the distribution of HHV-8 seroprevalences in Amazonian (77%) and non-Amazonian native populations (range 0%–83%).

Human herpesvirus-8 in northwestern China: epidemiology and characterization among blood donors

Background

Human herpes virus 8 (HHV-8) is the etiologic agent associated with development of classical, AIDS-related, iatrogenic, and endemic Kaposi's sarcoma (KS). Several studies provide strong evidence that HHV-8 can be transmitted by blood transfusion. We evaluated the seroprevalence and potential risk factors of HHV-8 infection in blood donors in one region. We surveyed HHV-8 infection among 4461 blood donors in Xinjiang, China, a unique endemic area for HHV-8 and KS.

Results

The HHV-8 seroprevalence was higher in local minority groups which comprise most KS cases in China, than in Han people. HHV-8 prevalence was 18.6% in the Han ethnic group, 25.9% in Uygur subjects, 29.2% in Kazak subjects, 36.8% in Mongolian subjects, and 21.9% in other ethnic groups. In several subgroups, the time of donation of whole blood seemed to be a risk factor. In HHV-8-seropositive subjects, a larger fraction of local minorities (23.9%) had high HHV-8 titers than that of Han subjects (9.2%). HHV-8 infection was associated with ethnicity and residence.

Conclusion

HHV-8 seroprevalence was significantly high among blood donors in Xinjiang, where the prevalence of KS correlates with HHV-8 prevalence and titers in Uygur and Kazak ethnic groups. Blood exposure represented by the frequency of blood donation indicated a possible blood-borne transmission route of HHV-8 in Xinjiang. Detecting anti-HHV-8 antibodies before donation in this region is therefore important.

Molecular epidemiology of Brazilian pseudorabies viral isolates

Pseudorabies is a disease caused by pseudorabies virus (PRV) and is responsible for considerable economic losses in the swine industry. The objective of this work was to use molecular epidemiology as a tool to facilitate the study of PRV outbreaks in Brazil. The standard PRV strain Shope, the vaccine strain Bartha and isolates from the south and the southeast regions of Brazil, were amplified for gE and gC partial genes by PCR. Results indicated that Brazilian PRV isolates are grouped in two clusters, A and B, except for one isolate that grouped with Bartha and Shope. Most Brazilian PRV isolates belonged to cluster B and diverged from virus isolated from other countries.

Seroprevalence of Kaposi sarcoma-associated herpesvirus and other serologic markers in the Brazilian Amazon

To determine the presence of Kaposi sarcoma–associated herpesvirus (KSHV) and other serologic markers, we tested serum specimens of 339 Amerindians, 181 rural non-Amerindians, and 1,133 urban blood donors (13 Amerindians) in the Brazilian Amazon. High KSHV seroprevalence in children and inverse association with herpes simplex virus type 2 indicates predominant nonsexual transmission among Amerindians.