Human herpesvirus 8 transmission from mother to child and between siblings in an endemic population

The Epidemiological Particularities of Malignant Hemopathies in French Guiana: 2005-2014

French Guiana is a French Overseas territory with singular features: it has a high prevalence of HIV and HTLV-1, its population is ethnically mixed, with widespread poverty, and up to 20% of the population lives in geographic isolation. In this context, we used registry data to estimate incidence and mortality due to hematological malignancies and to compare them with France and tropical Latin America. ICD codes C90 and C88 were compiled between 2005 and 2014. The direct standardization of age structure was performed using the world population. Survival analysis was performed, and Kaplan-Meier curves were drawn. The overall standardized incidence rate was 32.9 per 100,000 male years and 24.5 per 100,000 female years. Between 2005 and 2009, the standardized incidence rate was 29.6 per 100,000 among men and 23.6 per 100,000 among women, and between 2010 and 2014, it was 35.6 per 100,000 among men and 25.2 per 100,000 among women. Multiple myeloma/plasmocytoma and mature t/NK cell lymphomas, notably adult t-cell lymphoma/leukemia due to HTLV-1 infection, were the two most common hematologic malignancies and causes of death. Non-Hodgkin's lymphoma incidence estimates were greater than global estimates. After adjusting for age, sex, and type of malignancy, people born in a foreign country independently had a poorer case-fatality rate, presumably reflecting difficulties in accessing care. The epidemiology of hematological malignancies in French Guiana has features that distinguish it from mainland France or from Latin America. The incidence of multiple myeloma and adult t-cell lymphoma/leukemia was significantly greater in French Guiana than in France or other Latin American countries.

Is human herpesvirus 8 infection more common in men than in women? an updated meta-analysis

BACKGROUND

Clinically, most patients with Kaposi's sarcoma (KS) are male, and several direct and indirect mechanisms may underlie this increased susceptibility in men, Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is considered to be the primary etiological agent responsible for KS. Thus, we propose the hypothesis that men are more susceptible to HHV-8 infection, leading to a higher incidence of Kaposi's sarcoma among males. A meta-analysis was conducted to evaluate the association between gender and HHV-8 seropositivity in the general population.

METHODS

A comprehensive literature search was performed using 6 online databases: PubMed, EMBASE, Cochrane library, Web of Science, CNKI, and Wanfang. Studies published before March 15, 2023, were included.

RESULTS

In all, 33 articles including 41 studies were included in the meta-analysis. In the included adult population. men had a higher risk of HHV-8 infection than did women in adult populations from all over the world (odds ratio [OR]: 1.08, 95% confidence interval [CI]: 1.01-1.15), but no differences were found in child population from all over the world (OR: 0.90, 95% CI: 0.79-1.01). There was a significant difference in HHV-8 seroprevalence between men and women in sub-Saharan Africa (SSA) adult population (OR: 1.15, 95% CI: 1.05-1.26). However, no significant differences were observed in sub-Saharan Africa (SSA) child population (OR: 0.90, 95%CI 0.78-1.03). As for other continents, the results showed no significant difference, such as the Asian population (OR: 1.03, 95%CI: 0.92-1.16). or the European and American populations (OR 1.01, 95%CI 0.87-1.17).

CONCLUSION

There was a slight gender disparity for HHV-8 infection in the adult population. Among the adult populations from SSA and globally, men were more likely to be infected with HHV-8 than were women. However, no statistical significance was observed in the child populations from SSA and globally. In the future, the inclusion of more standardized studies may strengthen the results of this study.

Clinical and Demographic Factors Associated With Kaposi Sarcoma-Associated Herpesvirus Shedding in Saliva or Cervical Secretions in a Cohort of Tanzanian Women

Background

Reasons for the high prevalence of Kaposi sarcoma-associated herpesvirus (KSHV) in sub-Saharan Africa, and risk factors leading to viral reactivation and shedding, remain largely undefined. Preliminary studies have suggested that schistosome infection, which has been associated with impaired viral control, is associated with KSHV. In this study we sought to determine the relationship between active Schistosoma mansoni or Schistosoma haematobium infection and KSHV shedding.

Methods

We quantified KSHV DNA in saliva and cervical swabs from 2 cohorts of women living in northwestern Tanzanian communities endemic for S mansoni or S haematobium by real-time polymerase chain reaction. χ2 and Fisher exact tests were used to determine differences in clinical and demographic factors between those who were and were not shedding KSHV.

Results

Among 139 total women, 44.6% were KSHV seropositive. Six percent of those with S mansoni and 17.1% of those with S haematobium were actively shedding KSHV in saliva and none in cervical samples. Women from the S mansoni cohort who were shedding virus reported infertility more frequently (80% vs 19.5%, P = .009). There was no difference in frequency of KSHV salivary shedding between schistosome-infected and -uninfected women.

Conclusions

In an area with high KSHV seroprevalence and endemic schistosome infections, we provide the first report with data demonstrating no association between schistosome infection and salivary or cervical herpesvirus shedding. KSHV salivary shedding was associated with infertility, a known effect of another herpesvirus, human herpesvirus 6.

Immune checkpoints in T cells during oncogenic γ-herpesvirus infections

Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) are two persistent oncogenic γ-herpesviruses with an exclusive tropism for humans. They cause cancers of lymphocyte, epithelial and endothelial cell origin, such as Burkitt's and Hodgkin's lymphoma, primary effusion lymphoma, nasopharyngeal carcinoma, and Kaposi sarcoma. Mutations in immune-related genes but also adverse events during immune checkpoint inhibition in cancer patients have revealed molecular requirements for immune control of EBV and KSHV. These include costimulatory and coinhibitory receptors on T cells that are currently explored or already therapeutically targeted in tumor patients. This review discusses these co-receptors and their influence on EBV- and KSHV-associated diseases. The respective studies reveal surprising specificities of some of these receptors for immunity to these tumor viruses, benefits of their blockade for some but not other virus-associated diseases, and that EBV- and KSHV-specific immune control should be monitored during immune checkpoint inhibition to prevent adverse events that might be associated with their reactivation during treatment.

Kaposi Sarcoma with Mucocutaneous Involvement in French Guiana: An Epidemiological Study between 1969 and 2019

Data on Kaposi sarcoma in French Guiana are scarce and out of date. This territory presents unique epidemiological features. The objectives of this retrospective study were to analyse the clinical features, outcome and incidence of the different forms of Kaposi sarcoma in patients diagnosed between 1969 and 2019. The study population comprised a total of 52 patients. Clinical forms included epidemic Kaposi sarcoma (n=30), endemic (n=18), iatrogenic (n=2), classic (n=1) and unclassified Kaposi sarcoma (n=1). The mean annual incidence rate of epidemic Kaposi reached a peak in the 1990s (0.93/100,000) then decreased in the 2000s (0.33/100,000), while the incidence of endemic Kaposi sarcoma reached a peak in the 1980s (0.82/100,000) before decreasing in the 2000s (0.12/100,000). Factors associated with the epidemic form were: sexual intercourse between men (p=0.0054) and Haitian origin (p=0.035). The presence of nodules and/or tumour, lesions limited to the lower limbs, and age >65 years were associated with the endemic form. While Creole populations seem to be as affected by endemic Kaposi sarcoma as their African counterparts, the dynamics of Kaposi sarcoma in French Guiana are now dominated by the epidemic form.

Kaposi's Sarcoma-Associated Herpesvirus, the Etiological Agent of All Epidemiological Forms of Kaposi's Sarcoma

Simple Summary

Kaposi’s sarcoma-associated herpesvirus (KSHV) is one of the seven oncogenic viruses currently recognized by the International Agency for Research on Cancer. Its presence for Kaposi’s sarcoma development is essential and knowledge on the oncogenic process has increased since its discovery in 1994. However, some uncertainties remain to be clarified, in particular on the exact routes of transmission and disparities in KSHV seroprevalence and the prevalence of Kaposi’s sarcoma worldwide. Here, we summarized the current data on the KSHV viral particle’s structure, its genome, the replication, its seroprevalence, the viral diversity and the lytic and latent oncogenesis proteins involved in Kaposi’s sarcoma. Lastly, we reported the environmental, immunological and viral factors possibly associated with KSHV transmission that could also play a role in the development of Kaposi’s sarcoma.

Abstract

Kaposi’s sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is an oncogenic virus belonging to the Herpesviridae family. The viral particle is composed of a double-stranded DNA harboring 90 open reading frames, incorporated in an icosahedral capsid and enveloped. The viral cycle is divided in the following two states: a short lytic phase, and a latency phase that leads to a persistent infection in target cells and the expression of a small number of genes, including LANA-1, v-FLIP and v-cyclin. The seroprevalence and risk factors of infection differ around the world, and saliva seems to play a major role in viral transmission. KSHV is found in all epidemiological forms of Kaposi’s sarcoma including classic, endemic, iatrogenic, epidemic and non-epidemic forms. In a Kaposi’s sarcoma lesion, KSHV is mainly in a latent state; however, a small proportion of viral particles (<5%) are in a replicative state and are reported to be potentially involved in the proliferation of neighboring cells, suggesting they have crucial roles in the process of tumorigenesis. KSHV encodes oncogenic proteins (LANA-1, v-FLIP, v-cyclin, v-GPCR, v-IL6, v-CCL, v-MIP, v-IRF, etc.) that can modulate cellular pathways in order to induce the characteristics found in all cancer, including the inhibition of apoptosis, cells’ proliferation stimulation, angiogenesis, inflammation and immune escape, and, therefore, are involved in the development of Kaposi’s sarcoma.

Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases

Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.

Evidence for altered host genetic factors in KSHV infection and KSHV-related disease development

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), the most common AIDS-related malignancy. It also causes other rare, but certainly underreported, KSHV-associated pathologies, namely primary effusion lymphoma, multicentric Castleman disease and KSHV inflammatory cytokine syndrome. Epidemiology and pathogenicity studies point to the potential for host genetic predisposition to KSHV infection and/or the subsequent development of KSHV-associated pathologies partly explaining the peculiar geographic and population-specific incidence of KSHV and associated pathologies and discrepancies in KSHV exposure and infection and KSHV infection and disease development. This review consolidates the current knowledge of host genetic factors involved in the KSHV-driven pathogenesis. Studies reviewed here indicate a plausible connection between KSHV susceptibility and host genetic factors that affect either viral access to host cells via entry mechanisms or host innate immunity to viral infection. Subsequent to infection, KSHV-associated pathogenesis, reviewed here primarily in the context of KS, is likely influenced by an orchestrated concert of innate immune system interactions, downstream inflammatory pathways and oncogenic mechanisms. The association studies reviewed here point to interesting candidate genes that may prove important in achieving a more nuanced understanding of the pathogenesis and therapeutic targeting of KSHV and associated diseases. Recent studies on host genetic factors suggest numerous candidate genes strongly associated with KSHV infection or subsequent disease development, particularly innate immune system mediators. Taken together, these contribute toward our understanding of the geographic prevalence and population susceptibility to KSHV and KSHV-associated diseases.

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.

Distinct genetic architectures and environmental factors associate with host response to the γ2-herpesvirus infections

Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr Virus (EBV) establish life-long infections and are associated with malignancies. Striking geographic variation in incidence and the fact that virus alone is insufficient to cause disease, suggests other co-factors are involved. Here we present epidemiological analysis and genome-wide association study (GWAS) in 4365 individuals from an African population cohort, to assess the influence of host genetic and non-genetic factors on virus antibody responses. EBV/KSHV co-infection (OR = 5.71(1.58-7.12)), HIV positivity (OR = 2.22(1.32-3.73)) and living in a more rural area (OR = 1.38(1.01-1.89)) are strongly associated with immunogenicity. GWAS reveals associations with KSHV antibody response in the HLA-B/C region (p = 6.64 × 10-09). For EBV, associations are identified for VCA (rs71542439, p = 1.15 × 10-12). Human leucocyte antigen (HLA) and trans-ancestry fine-mapping substantiate that distinct variants in HLA-DQA1 (p = 5.24 × 10-44) are driving associations for EBNA-1 in Africa. This study highlights complex interactions between KSHV and EBV, in addition to distinct genetic architectures resulting in important differences in pathogenesis and transmission.

Herpes Virus Infections Other than Cytomegalovirus in the Recipients of Hematopoietic Stem Cell Transplantation

This review discusses the epidemiologic and clinical aspects of herpes viruses other than cytomegalovirus in patients who have undergone hematopoietic stem cell transplantation.

Kaposi Sarcoma-Associated Herpesvirus Glycoprotein H Is Indispensable for Infection of Epithelial, Endothelial, and Fibroblast Cell Types

Kaposi sarcoma-associated herpesvirus (KSHV) is an emerging pathogen and is the causative infectious agent of Kaposi sarcoma and two malignancies of B cell origin. To date, there is no licensed KSHV vaccine. Development of an effective vaccine against KSHV continues to be limited by a poor understanding of how the virus initiates acute primary infection in vivo in diverse human cell types. The role of glycoprotein H (gH) in herpesvirus entry mechanisms remains largely unresolved. To characterize the requirement for KSHV gH in the viral life cycle and in determination of cell tropism, we generated and characterized a mutant KSHV in which expression of gH was abrogated. Using a bacterial artificial chromosome containing a complete recombinant KSHV genome and recombinant DNA technology, we inserted stop codons into the gH coding region. We used electron microscopy to reveal that the gH-null mutant virus assembled and exited from cells normally, compared to wild-type virus. Using purified virions, we assessed infectivity of the gH-null mutant in diverse mammalian cell types in vitro Unlike wild-type virus or a gH-containing revertant, the gH-null mutant was unable to infect any of the epithelial, endothelial, or fibroblast cell types tested. However, its ability to infect B cells was equivocal and remains to be investigated in vivo due to generally poor infectivity in vitro Together, these results suggest that gH is critical for KSHV infection of highly permissive cell types, including epithelial, endothelial, and fibroblast cells.IMPORTANCE All homologues of herpesvirus gH studied to date have been implicated in playing an essential role in viral infection of diverse permissive cell types. However, the role of gH in the mechanism of KSHV infection remains largely unresolved. In this study, we generated a gH-null mutant KSHV and provided evidence that deficiency of gH expression did not affect viral particle assembly or egress. Using the gH-null mutant, we showed that gH was indispensable for KSHV infection of epithelial, endothelial, and fibroblast cells in vitro This suggests that gH is an important target for the development of a KSHV prophylactic vaccine to prevent initial viral infection.

EPHA2 sequence variants are associated with susceptibility to Kaposi's sarcoma-associated herpesvirus infection and Kaposi's sarcoma prevalence in HIV-infected patients

BACKGROUND

To determine if variations exist in the KSHV host receptor EPHA2's coding region that affect KSHV infectivity and/or KS prevalence among South African HIV-infected patients.

METHODS

A retrospective candidate gene association study was performed on 150 patients which were randomly selected from a total of 756 HIV-infected patients and grouped according to their KS status and KSHV serodiagnosis; namely group 1: KS+/KSHV+; group 2: KS-/KSHV+; group 3: KS-/KSHV-. Peripheral blood DNA was used to extract DNA and PCR amplify and sequence the entire EPHA2 coding region, which was compared to the NCBI reference through multiple alignment.

RESULTS

100% (95% CI 92.9-100%) of the KS positive patients, and 31.6% (95% CI 28.3-35.1%) of the KS negative patients were found to be KSHV seropositive. Aggregate variation across the entire EPHA2 coding region identified an association with KS (OR = 6.6 (95% CI 2.8, 15.9), p = 2.2 × 10-5). This was primarily driven by variation in the functionally important protein tyrosine kinase domain (Pkinase-Tyr; OR = 4.9 (95% CI 1.9, 12.4), p = 0.001) and the sterile-α-motif (SAM; OR = 13.8 (95% CI 1.7, 111.6), p = 0.014). Mutation analysis revealed two novel, non-synonymous heterozygous variants (c.2254 T > C: OR undefined, adj. p = 0.02; and c.2990 G > T: OR undefined, adj. p = 0.04) in Pkinase-Tyr and SAM, respectively, to be statistically associated with KS; and a novel heterozygous transition (c.2727C > T: OR = 6.4 (95% CI 1.4, 28.4), adj. p = 0.03) in Pkinase-Tyr to be statistically associated with KSHV.

CONCLUSIONS

Variations in the KSHV entry receptor gene EPHA2 affected susceptibility to KSHV infection and KS development in a South African HIV-infected patient cohort.

Human Papilloma Virus-Type 16 (HPV-16) & Human Herpes Virus-Type 8 (HHV-8) infections were found to be co-existing major cancer-contributing factors. Individualized, safe, effective treatment of hopelessly advanced cancer patients with metastasis by combining 4 methods of effective treatment: 1) Optimal dose of Vitamin D3 using its 10 unique beneficial effects, 2) Selective Drug Uptake Enhancement Method, 3) Stimulation of newly discovered Thymus gland representation areas on the back of each hand, & 4) Identification & removal of co-existing cancer-contributing factors

Previous study indicated Human Papilloma Virus-Type 16 (HPV-16) has important role in genesis of ovarian cancer, uterus cancer, & breast cancer. Omura, Y. noticed HPV-16 virus co-exists with single-cell parasite Toxoplasma Gondii (T.G.) infection in most of the cancer tissues he examined. Therefore, he thought some unknown virus must exist in the T.G. In early 2018, he found there is strong Human Herpes Virus-Type 8 (HHV-8) infection in every cell of Toxoplasma Gondii he examined. Thus, we found in every cancer cells there are co-existing cancer-promoting factors of HPV-16 & HHV-8 infection associated with Toxoplasma Gondii. As a common source of these infections in human cancer patients, we found most egg yolk has co-existing HPV-16, HHV-8 & Toxoplasma Gondii, but egg whites are free of these infections & can be eaten safely as protein supply. Many cats and dogs also have these infections. As most important, safe treatment of cancer, we found repeated optimal dose of Vitamin D3 with optimal interval of about 8 hours is ideal because of 10 unique, beneficial effects discovered by him. Individually determined one optimal dose of Vitamin D3 has most effective anti-cancer effects in hopeless, advanced, cancer patients by reducing extremely high Integrin α5β1 of over 1500ng to normal value of 0.002∼0.004ng and 8-OH-dG (proportional to DNA mutation which is required for cancer growth) of over 60∼80ng to normal value of 0.1∼0.25ng for average 8 hours and 6000∼9000ng of strong pathogenic infection of HPV-16 & HHV-8 in cancer tissue reduced to safe range of less than 500ng by markedly increased urinary excretion. Concerning beneficial effect of optimal dose of Vitamin D3, all the previous studies failed to use individualized optimal dose. As a result, they could not properly evaluate beneficial effects & side effects and many reports claimed there were no significant beneficial effects including anti-cancer effects. Although optimal dose of Vitamin D3 can eliminate these viral infections very significantly but not less than 500∼300ng. Cancer incidence is only significant when these viruses are above 6000ng inside the body. Thus, we can keep potentially serious patients with strong cancer-contributing virus infections at relatively safe low degree of infection of much less than 3000ng. Our ideal treatment for advanced cancer patients is a combination of 1) Individually determined Optimal dose of Vitamin D3 with optimal interval of about 8 hours, 2) Selective Drug Uptake Enhancement Method by manual stimulation organ representation area of pathological organs at hands, 3) Stimulation of Thymus gland representation area of the back of the hand which was discovered by Omura, Y. in 2017, & 4) Identification & removal of multiple co-existing cancer-promoting factors. This combination of 4 new methods of treatment was found to be most effective & safe treatment for not only hopelessly advanced cancer patients but also many other difficult medical problems.

Kaposi sarcoma herpesvirus pathogenesis

Kaposi sarcoma herpesvirus (KSHV), taxonomical name human gammaherpesvirus 8, is a phylogenetically old human virus that co-evolved with human populations, but is now only common (seroprevalence greater than 10%) in sub-Saharan Africa, around the Mediterranean Sea, parts of South America and in a few ethnic communities. KSHV causes three human malignancies, Kaposi sarcoma, primary effusion lymphoma, and many cases of the plasmablastic form of multicentric Castleman's disease (MCD) as well as occasional cases of plasmablastic lymphoma arising from MCD; it has also been linked to rare cases of bone marrow failure and hepatitis. As it has colonized humans physiologically for many thousand years, cofactors are needed to allow it to unfold its pathogenic potential. In most cases, these include immune defects of genetic, iatrogenic or infectious origin, and inflammation appears to play an important role in disease development. Our much improved understanding of its life cycle and its role in pathogenesis should now allow us to develop new therapeutic strategies directed against key viral proteins or intracellular pathways that are crucial for virus replication or persistence. Likewise, its limited (for a herpesvirus) distribution and transmission should offer an opportunity for the development and use of a vaccine to prevent transmission.

This article is part of the themed issue ‘Human oncogenic viruses’.

Seroepidemiology and phylogenetic analysis of human herpesvirus type 8 in injection drug users and men who have sex with men in northern Taiwan

Objectives

Human herpesvirus 8 (HHV-8) is transmissible and causes Kaposi’s sarcoma and other malignancies. This study analyzed the seroepidemiology and phylogeny of HHV-8 among 515 injection drug users (IDUs) and 229 men who have sex with men (MSM) in Taiwan.

Methods

Blood and peripheral mononuclear cells were analyzed for HHV-8 seroprevalence using enzyme-linked immunosorbent and immunofluorescence assays. Viral loads were measured using a real-time PCR assay. Phylogenetic analysis of the K1 gene was performed using nested PCR and DNA sequencing.

Results

HHV-8 infection rate was higher in MSM (24.9%) than in IDUs (3.8%). The rate of HHV-8 infection was higher in HIV-1-positive patients (32.8%, MSM; 5.5%, IDUs) than in HIV-1 negative patients. HHV-8 load was not significantly different between HHV-8 seropositive and seronegative patients. HHV-8 genotypes C and A variants were detected at frequencies of 80% and 20%, respectively, among IDUs; and genotypes C, D, E, and A were detected at frequencies of 55.6%, 11.1%, 11.1%, and 5.6%, respectively, among MSM. Variants of K1 amino acid residues 54–84 were detected in most IDUs and MSM.

Conclusions

HHV-8 prevalence was significantly higher among MSM than among IDUs. Evolution of the K1 gene occurred in HHV-8 variants of IDUs and MSM.

Association of Household Food- and Drink-Sharing Practices With Human Herpesvirus 8 Seroconversion in a Cohort of Zambian Children

Background

Human herpesvirus 8 (HHV-8) infection occurs in early childhood and is associated with human immunodeficiency virus type 1 (HIV-1) infection and risk for Kaposi sarcoma, but behaviors associated with HHV-8 transmission are not well described.

Methods

We enrolled and followed a prospective cohort of 270 children and their household members to investigate risk factors for HHV-8 transmission in Lusaka, Zambia.

Results

We report an incidence of 30.07 seroconversions per 100 child-years. Independent risk factors for HHV-8 incident infection included having a child who shared utensils with a primary caregiver (hazards ratio [HR], 2.33; 95% confidence interval [CI], 1.49-7.14), having an increasing number of HHV-8-infected household members (HR, 1.27; 95% CI, 1.09-2.79), and having ≥5 siblings/children in the household (HR, 2.24; 95% CI, 1.03-4.88). Playing with >5 children a day was protective against infection (HR, 0.54; 95% CI, .33-0.89), as was increasing child age (HR, 0.96; 95% CI, .93-.99).

Conclusions

This is the first study to find a temporal association between limited child feeding behaviors and risk for HHV-8 infection. Child food- and drink-sharing behaviors should be included in efforts to minimize HHV-8 transmission, and households with a large number of siblings should receive additional counseling as childhood infections occur in the home context.

Kaposi's disease in an HIV positive child, with probable contamination from his grandmother

Kaposi's disease in children with HIV is rarely reported in everyday practice. This is a case study of cutaneous Kaposi's disease revealing HIV in a 5-year-old child with polymorphic eruption of papules and nodules on the face, trunk, back, and limbs. Histopathological examination confirmed the diagnosis of Kaposi's disease. The child's HIV serology was positive with a CD4 count of 240/mm³, normochromic and normocytic anemia, and a hemoglobin level at 8.5 g/dl. It was found that the child, after early weaning from his HIV-negative mother, had repeatedly suckled his healthy grandmother, who had no skin lesions but was HIV1 positive. Both grandmother and child were referred for treatment in their locality. The case is noteworthy for the way in which the HIV1 virus infected the child during weaning and then being suckled by his grandmother. The child already had an initial dental flare that could have injured his grandmother. Thus, in our case, there is a contamination by HIV1 virus most likely from the grandmother and contamination by the HHV8 virus, source unidentified as a technical plateau was reached.

Oropharyngeal Kaposi Sarcoma in Related Persons Negative for Human Immunodeficiency Virus

Objectives: Kaposi sarcoma (KS) is a vascular tumor that can affect the mucosa of the upper aerodigestive tract. Although KS is the most common malignancy in patients with acquired immunodeficiency syndrome, it is rare in immunocompetent persons. We describe an unusual presentation of KS in 2 related individuals and describe our attempts to determine whether oropharyngeal KS is associated with human herpesvirus 8 (HHV-8).

Methods: All relevant clinical and surgical information, including information on tumor histopathologic and human immunodeficiency virus (HIV) serologic tests, was abstracted from the patient charts and electronic databases. HHV-8 immunohistochemistry was performed on paraffin-fixed specimens.

Results: Both patient 1 and patient 2 (the nephew of patient 1) were referred for workup of a tonsillar mass that was pathologically confirmed to be KS. In each case, HIV serologic testing was negative, and a screening immunologic workup, including a quantitative natural killer cell count, a B- and T-lymphocyte count, and immunoglobulin analysis, also yielded findings that were within normal limits. Immunohistochemistry performed on 1 pathological specimen showed positive staining for the presence of HHV-8, the etiologic agent of KS.

Conclusions: The presence of oropharyngeal KS in 2 related HIV-negative individuals supports a role for genetic factors in susceptibility to KS, a common exposure to an infectious agent such as HHV-8, or both. Whereas most KS cases in industrialized countries are associated with immunodeficiency, clinical and laboratory data do not suggest that either of the patients described in this report are immunodeficient. Their susceptibility to KS may be secondary to a subtle inherited defect in host resistance to HHV-8, or another unknown factor.

Kaposi's Sarcoma-Associated Herpesvirus: Epidemiology and Molecular Biology

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as Human herpesvirus 8 (HHV-8), is a member of the lymphotropic gammaherpesvirus subfamily and a human oncogenic virus. Since its discovery in AIDS-associated KS tissues by Drs. Yuan Chang and Patrick Moore, much progress has been made in the past two decades. There are four types of KS including classic KS, endemic KS, immunosuppressive therapy-related KS, and AIDS-associated KS. In addition to KS, KSHV is also involved in the development of primary effusion lymphoma (PEL) and certain types of multicentric Castleman's disease. KSHV manipulates numerous viral proteins to promote the progression of angiogenesis and tumorigenesis. In this chapter, we review the epidemiology and molecular biology of KSHV and the mechanisms underlying KSHV-induced diseases.

KSHV Entry and Trafficking in Target Cells-Hijacking of Cell Signal Pathways, Actin and Membrane Dynamics

Kaposi's sarcoma associated herpesvirus (KSHV) is etiologically associated with human endothelial cell hyperplastic Kaposi's sarcoma and B-cell primary effusion lymphoma. KSHV infection of adherent endothelial and fibroblast cells are used as in vitro models for infection and KSHV enters these cells by host membrane bleb and actin mediated macropinocytosis or clathrin endocytosis pathways, respectively. Infection in endothelial and fibroblast cells is initiated by the interactions between multiple viral envelope glycoproteins and cell surface associated heparan sulfate (HS), integrins (α3β1, αVβ3 and αVβ5), and EphA2 receptor tyrosine kinase (EphA2R). This review summarizes the accumulated studies demonstrating that KSHV manipulates the host signal pathways to enter and traffic in the cytoplasm of the target cells, to deliver the viral genome into the nucleus, and initiate viral gene expression. KSHV interactions with the cell surface receptors is the key platform for the manipulations of host signal pathways which results in the simultaneous induction of FAK, Src, PI3-K, Rho-GTPase, ROS, Dia-2, PKC ζ, c-Cbl, CIB1, Crk, p130Cas and GEF-C3G signal and adaptor molecules that play critical roles in the modulation of membrane and actin dynamics, and in the various steps of the early stages of infection such as entry and trafficking towards the nucleus. The Endosomal Sorting Complexes Required for Transport (ESCRT) proteins are also recruited to assist in viral entry and trafficking. In addition, KSHV interactions with the cell surface receptors also induces the host transcription factors NF-κB, ERK1/2, and Nrf2 early during infection to initiate and modulate viral and host gene expression. Nuclear delivery of the viral dsDNA genome is immediately followed by the host innate responses such as the DNA damage response (DDR), inflammasome and interferon responses. Overall, these studies form the initial framework for further studies of simultaneous targeting of KSHV glycoproteins, host receptor, signal molecules and trafficking machinery that would lead into novel therapeutic methods to prevent KSHV infection of target cells and consequently the associated malignancies.

Conceptual Emergence of Human Herpesvirus 8 (Kaposi’s Sarcoma-associated Herpesvirus) as an Oral Herpesvirus

Recognition of the various clinico-epidemiologic forms of Kaposi’s sarcoma, a disease putatively caused by an infectious agent, did not provide ready clues as to how that agent might be transmitted, although fecal and sexual routes were implicated. Application of serologic and genome-detection assays, and cell-culture studies following the identification of human herpesvirus 8 as the causative agent now implicate that virus as one that is orally shed. While oral transmission of the virus might account for the viral endemicity in Africa and Mediterranean countries, why it is particularly prevalent among male homosexuals in the West remains more difficult to explain. Such explanation may be sought from behavioral studies into the role saliva plays in sexual interactions.

Domestic cats seropositive for Felis catus gammaherpesvirus 1 are often qPCR negative

Felis catus gammaherpesvirus 1 (FcaGHV1) is a newly described virus that infects domestic cats. To identify FcaGHV1 antigens, we developed an immunofluorescent antibody assay by expressing FcaGHV1 open reading frames (ORFs) in feline cells and incubating fixed cells with sera from FcaGHV1-positive cats. Of the seven ORFs tested, ORF52 and ORF38 had the strongest, most consistent antibody responses. We used recombinant ORF52 and ORF38 proteins to develop two FcaGHV1 ELISAs. These assays were used to detect reactivity in cats previously tested by qPCR for FcaGHV1 in blood cell DNA. Results indicated 32%FcaGHV1seroprevalence, compared to 15%qPCR-evaluated prevalence (n=133);all but one qPCR positive animal was seropositive. ELISA results confirmed infection risk factors previously identified by qPCR: geographic location, male sex, and adult age. These data suggest that FcaGHV1is a common infection of domestic cats that has a seropositive but often qPCR negative state characteristic of herpesviral latency.

Molecular Epidemiology of Kaposi's Sarcoma-Associated Herpes Virus, and Risk Factors in HIV-infected Patients in Tehran, 2014

Background

Kaposi’s sarcoma (KS) remains the most common malignancy among HIV-infected patients. Human herpesvirus type-8 (HHV-8) is regarded as the infectious etiological agent of Kaposi’s sarcoma (KSHV). Diagnostic procedures associated with KSHV are not routinely performed in HIV-infected subjects.

Objectives

The main objective of this study is to obtain information on KSHV epidemiology in Iranian HIV-infected individuals.

Patients and Methods

In the present cross-sectional study, 109 patients with established HIV infection, who visited a governmental and referral center for HIV screening in Tehran (Tehran west health center (TWHC)) between May 2014 and July 2015 were enrolled according to the convenience sample strategy. After peripheral blood collection, isolation of plasma and peripheral blood mononuclear cell (PBMC) compartments, DNA extraction was performed. KSHV DNA was analyzed by nested polymerase chain reaction (nested PCR) using primers from ORF-26 (virus minor capsid).

Results

Among all 109 HIV-infected patients, 67 (61.5%) were male, with an age range of 2 - 64 years (mean ± standard deviation 35.8 ± 13.3). KSHV DNA was found in PBMC and plasma samples of six (5.5%) and four (3.6%) patients, respectively.

Conclusions

This study revealed a considerable prevalence of KSHV DNA, during latent and lytic phases, among HIV-infected patients. Risk factors for KSHV infection acquisition and concurrent. 0+infection with HIV were also evaluated. Diagnosis of KSHV in the group could be helpful for prognosis of Kaposi’s sarcoma and clinical management.

High seroprevalence of antibodies against Kaposi's sarcoma-associated herpesvirus (KSHV) among HIV-1-infected children and adolescents in a non-endemic population

Human herpesvirus-8 (HHV-8) is the etiological agent of Kaposi's sarcoma (KS), which primarily affects human immunodeficiency virus (HIV)-infected adults with advanced immunodeficiency. Currently, only limited prevalence data for HHV-8 infection in HIV-infected children living in non-endemic areas are available. This multicenter cross-sectional study was conducted in four university hospitals in Germany specializing in pediatric HIV care. Stored serum specimens obtained from 207 vertically HIV-1-infected children and adolescents were tested for antibodies against lytic and latent HHV-8 antigens. Logistic regression was used to assess independent risk factors associated with HHV-8 seropositivity. The overall HHV-8 seroprevalence was 24.6 % (n = 51/207) without significant differences related to sex, age, or ethnicity. In univariate analysis, HHV-8 seropositivity was significantly associated with a child having being born outside Germany, maternal origin from sub-Saharan Africa, a history of breastfeeding, CDC immunologic category 3, and deferred initiation of antiretroviral therapy (>24 months of age). In multivariate analysis, a child's birth outside Germany was the only significant risk factor for HHV-8 seropositivity (odds ratio 3.98; 95 % confidence interval 1.27-12.42). HHV-8-associated malignancies were uncommon; only one patient had a history of KS. Serum specimen of vertically HIV-infected children and adolescents living in Germany showed a high HHV-8 seroprevalence. These findings suggest that primary HHV-8 infection-a risk factor for KS and other HHV-8-associated malignancies-occurs early in life. Thus, management of perinatally HIV-infected children should include testing for HHV-8 coinfection and should consider future risks of HHV-8-associated malignancies.

Is human herpesvirus 8 infection more common in men than in women? Systematic review and meta-analysis

All forms of Kaposi sarcoma (KS) are more common in men than in women. It is unknown if this is due to a higher prevalence of human herpesvirus 8 (HHV-8), the underlying cause of KS, in men compared to women. We did a systematic review and meta-analysis to examine the association between HHV-8 seropositivity and gender in the general population. Studies in selected populations like for example, blood donors, hospital patients and men who have sex with men were excluded. We searched Medline and Embase from January 1994 to February 2015. We included observational studies that recruited participants from the general population and reported HHV-8 seroprevalence for men and women or boys and girls. We used random-effects meta-analysis to pool odds ratios (OR) of the association between HHV-8 and gender. We used meta-regression to identify effect modifiers, including age, geographical region and type of HHV-8 antibody test. We included 22 studies, with 36,175 participants. Men from sub-Saharan Africa (SSA) [OR 1.21, 95% confidence interval (CI) 1.09-1.34], but not men from elsewhere (OR 0.94, 95% CI 0.83-1.06), were more likely to be HHV-8 seropositive than women (p value for interaction = 0.010). There was no difference in HHV-8 seroprevalence between boys and girls from SSA (OR 0.90, 95% CI 0.72-1.13). The type of HHV-8 assay did not affect the overall results. A higher HHV-8 seroprevalence in men than women in SSA may partially explain why men have a higher KS risk in this region.

Clinical Factors Associated with Long-Term Complete Remission versus Poor Response to Chemotherapy in HIV-Infected Children and Adolescents with Kaposi Sarcoma Receiving Bleomycin and Vincristine: A Retrospective Observational Study

Kaposi sarcoma (KS) is the most common HIV-associated malignancy in children and adolescents in Africa. Pediatric KS is distinct from adult disease. We evaluated the clinical characteristics associated with long-term outcomes. We performed a retrospective observational analysis of 70 HIV-infected children and adolescents with KS less than 18 years of age diagnosed between 8/2010 and 6/2013 in Lilongwe, Malawi. Local first-line treatment included bleomycin and vincristine plus nevirapine-based highly active anti-retroviral therapy (HAART). Median age was 8.6 years (range 1.7–17.9); there were 35 females (50%). Most common sites of presentation were: lymph node (74%), skin (59%), subcutaneous nodules (33%), oral (27%), woody edema (24%), and visceral (16%). Eighteen (26%) presented with lymphadenopathy only. Severe CD4 suppression occurred in 28%. At time of KS diagnosis, 49% were already on HAART. Overall, 28% presented with a platelet count < 100 x 10⁹/L and 37% with hemoglobin < 8 g/dL. The 2-year event-free (EFS) and overall survival (OS) were 46% and 58% respectively (median follow-up 29 months, range 15–50). Multivariable analysis of risk of death and failure to achieve EFS demonstrated that visceral disease (odds ratios [OR] 19.08 and 11.61, 95% CI 2.22–163.90 and 1.60–83.95 respectively) and presenting with more than 20 skin/oral lesions (OR 9.57 and 22.90, 95% CI 1.01–90.99 and 1.00–524.13 respectively) were independent risk factors for both. Woody edema was associated with failure to achieve EFS (OR 7.80, 95% CI 1.84–33.08) but not death. Univariable analysis revealed that lymph node involvement was favorable for EFS (OR 0.28, 95% CI 0.08–0.99), while T₁ TIS staging criteria, presence of cytopenias, and severe immune suppression were not associated with increased mortality. Long-term complete remission is achievable in pediatric KS, however outcomes vary according to clinical presentation. Based on clinical heterogeneity, treatment according to risk-stratification is necessary to improve overall outcomes.

Kaposi Sarcoma of Childhood: Inborn or Acquired Immunodeficiency to Oncogenic HHV-8

Kaposi sarcoma (KS) is an endothelial malignancy caused by human herpes virus-8 (HHV-8) infection. The epidemic and iatrogenic forms of childhood KS result from a profound and acquired T cell deficiency. Recent studies have shown that classic KS of childhood can result from rare single-gene inborn errors of immunity, with mutations in WAS, IFNGR1, STIM1, and TNFRSF4. The pathogenesis of the endemic form of childhood KS has remained elusive. We review childhood KS pathogenesis and its relationship to inherited and acquired immunodeficiency to oncogenic HHV-8.

Infection and cancer: global distribution and burden of diseases

BACKGROUND

Infection is one of the main risk factors for cancer.

OBJECTIVES

Epidemiology, pathogenesis, and disease burden of infection-related cancers were reviewed by infectious agents.

FINDINGS

Chronic infection with Epstein-Barr virus, hepatitis B and C viruses, Kaposi sarcoma herpes virus, human immunodeficiency virus (HIV) type 1, human papillomavirus (HPV), human T-cell lymphotropic virus type 1, Helicobacter pylori, Clonorchis sinensis, Opisthorchis viverrini, and Schistosoma haematobium are associated with nasopharyngeal carcinoma; lymphoma and leukemia, including non-Hodgkin lymphoma, Hodgkin lymphoma, and Burkitt lymphoma; hepatocellular carcinoma; Kaposi sarcoma; oropharyngeal carcinoma; cervical carcinoma and carcinoma of other anogential sites; adult T-cell leukemia/lymphoma; gastric carcinoma; cholangiocarcinoma; and urinary bladder cancer. In 2008, approximately 2 million new cancer cases (16%) worldwide were attributable to infection. If these infections could be prevented and/or treated, it is estimated that there would be about 23% fewer cancers in less developed regions of the world, and about 7% fewer cancers in more developed regions.

CONCLUSION

Widespread application of existing public health methods for the prevention of infection, such as vaccination, safer injection practices, quality-assured screening of all donated blood and blood components, antimicrobial treatments, and safer sex practices, including minimizing one's lifetime number of sexual partners and condom use, could have a substantial effect on the future burden of cancer worldwide.

Quantification of viral genome in cord blood donors by real time PCR to investigate human herpesvirus type 8 active infection

Umbilical cord blood (UCB) is one of the most important sources of hematopoietic stem cells which can be used for transplantation. The transplanted CB stem cells might cause infections in recipients. The aim of this study is to evaluate Human Herpes Virus8 (HHV8) as a Rhadinovirus among CB samples in order to assess safety of cord blood stem cells transplantation. To assess this aim, we surveyed 800 cord blood specimens by Real Time PCR.The overall HHV8 incidence in cord blood mononuclear cells was 1.38% and none of them was in lytic phase of HHV8. The authors suggest further HHV8 study on CB samples for transplantation.

Incidence rate of Kaposi sarcoma in HIV-infected patients on antiretroviral therapy in Southern Africa: a prospective multicohort study

BACKGROUND

The risk of Kaposi sarcoma (KS) among HIV-infected persons on antiretroviral therapy (ART) is not well defined in resource-limited settings. We studied KS incidence rates and associated risk factors in children and adults on ART in Southern Africa.

METHODS

We included patient data of 6 ART programs in Botswana, South Africa, Zambia, and Zimbabwe. We estimated KS incidence rates in patients on ART measuring time from 30 days after ART initiation to KS diagnosis, last follow-up visit, or death. We assessed risk factors (age, sex, calendar year, WHO stage, tuberculosis, and CD4 counts) using Cox models.

FINDINGS

We analyzed data from 173,245 patients (61% female, 8% children aged <16 years) who started ART between 2004 and 2010. Five hundred and sixty-four incident cases were diagnosed during 343,927 person-years (pys). The overall KS incidence rate was 164/100,000 pys [95% confidence interval (CI): 151 to 178]. The incidence rate was highest 30-90 days after ART initiation (413/100,000 pys; 95% CI: 342 to 497) and declined thereafter [86/100,000 pys (95% CI: 71 to 105), >2 years after ART initiation]. Male sex [adjusted hazard ratio (HR): 1.34; 95% CI: 1.12 to 1.61], low current CD4 counts (≥500 versus <50 cells/μL, adjusted HR: 0.36; 95% CI: 0.23 to 0.55), and age (5-9 years versus 30-39 years, adjusted HR: 0.20; 95% CI: 0.05 to 0.79) were relevant risk factors for developing KS.

INTERPRETATION

Despite ART, KS risk in HIV-infected persons in Southern Africa remains high. Early HIV testing and maintaining high CD4 counts is needed to further reduce KS-related morbidity and mortality.

Seroepidemiology of hepatitis B and C viruses in the general population of burkina faso

Objectives. In Burkina Faso, few studies reported the prevalence of HBV and HCV in the general population. This study aimed to evaluate the prevalence of hepatitis B and C viruses in the general population and to determine the most affected groups in relation to the risk factors associated with the infection. Method. A voluntary testing opened to anyone interested was held at Saint Camille Medical Centre in Ouagadougou. Rapid tests were carried out on 995 persons who voluntarily answered a range of questions before the venous blood sampling. Results. The results revealed that the antigen HBs carriers in the general population represented 14.47% (144/995) and the prevalence of HCV was 1.00% (10/995). The difference between HBV's prevalence in men (18.58%) and that in women (11.60%) was statistically significant (P = 0.002). The most affected groups were undergraduated students (19.57%) and persons working in the informal sector (15.98%). The least affected group was high level students (8.82%). Conclusion. Burkina Faso is a country with a high prevalence of HBV, while the incidence of HCV is still low in the general population. Therefore, more campaigns on the transmission routes of HBV and HCV are needed to reduce the spread of these viruses in sub-Saharan Africa.

Epidemiology and genetic variability of HHV-8/KSHV in Pygmy and Bantu populations in Cameroon

Background

Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8) is the causal agent of all forms of Kaposi sarcoma. Molecular epidemiology of the variable K1 region identified five major subtypes exhibiting a clear geographical clustering. The present study is designed to gain new insights into the KSHV epidemiology and genetic diversity in Cameroon.

Methodology/Principal Findings

Bantu and Pygmy populations from remote rural villages were studied. Antibodies directed against latent nuclear antigens (LANA) were detected by indirect immunofluorescence using BC3 cells. Peripheral blood cell DNAs were subjected to a nested PCR amplifying a 737 bp K1 gene fragment. Consensus sequences were phylogenetically analyzed. We studied 2,063 persons (967 females, 1,096 males, mean age 39 years), either Bantus (1,276) or Pygmies (787). The Bantu group was older (42 versus 35 years: P<10⁻⁴). KSHV anti-LANA seroprevalence was of 37.2% (768/2063), with a significant increase with age (P<10⁻⁴) but no difference according to sex. Seroprevalence, as well as the anti-LANA antibodies titres, were higher in Bantus (43.2%) than in Pygmies (27.6%) (P<10⁻⁴), independently of age. We generated 29 K1 sequences, comprising 24 Bantus and five Pygmies. These sequences belonged to A5 (24 cases) or B (five cases) subtypes. They exhibited neither geographical nor ethnic aggregation. A5 strains showed a wide genetic diversity while the B strains were more homogenous and belonged to the B1 subgroup.

Conclusion

These data demonstrate high KSHV seroprevalence in the two major populations living in Southern and Eastern Cameroon with presence of mostly genetically diverse A5 but also B K1 subtypes.

Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8) is the causal agent of one of the most frequent skin tumors found endemically or epidemically associated to HIV in Central and Eastern Africa. This highly variable virus tends to cluster geographically according to specific major subtypes. Its prevalence is high in that area and increases with age. Despite its association to all forms of Kaposi sarcoma and high prevalence described in some low income populations in Cameroon, KSHV arouses limited interest, and only few focused previous studies have looked into prevalence and modes of transmission, especially in families. Extended molecular epidemiology is unknown both in healthy individuals and in Kaposi patients, which led to looking for new insights among Bantu and Pygmy populations from rural villages in three regions of Cameroon sharing a quite similar living environment but yet genetically, socially, and culturally different. The present study is designed to describe variations of molecular subtypes in each of these population groups regarding their geography in rural areas of southern, central, and eastern Cameroon.

A Review of Human Herpesvirus 8, the Kaposi's Sarcoma-Associated Herpesvirus, in the Pediatric Population

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma (KS)-associated herpesvirus, is the etiologic agent responsible for all types of KS. Although the majority of pediatric KS cases occur in sub-Saharan Africa, a rise in pediatric transplant KS has been reported in developed countries. In addition, HHV-8 is increasingly described as an infectious cause of hemophagocytic lymphohistiocytosis in children. Transmission of HHV-8 among children is poorly understood; however, the literature strongly suggests that horizontal transmission plays a critical role. Acute infection with HHV-8 and progression to KS in children may be different than in adults, and diagnosis may be overlooked. Currently, neither adult nor pediatric treatment guidelines exist. This review provides an overview of HHV-8 disease in children as it relates to epidemic KS, transplant KS, and other disease manifestations. The current state of the literature is reviewed and knowledge gaps are identified for future exploration.

HHV-8 seroprevalence: a global view

BACKGROUND

Human herpes virus 8 (HHV-8) is the underlying infectious cause of Kaposi sarcoma (KS) and other proliferative diseases; that is, primary effusion lymphoma and multicentric Castleman disease. In regions with high HHV-8 seroprevalence in the general population, KS accounts for a major burden of disease. Outside these endemic regions, HHV-8 prevalence is high in men who have sex with men (MSM) and in migrants from endemic regions. We aim to conduct a systematic literature review and meta-analysis in order 1) to define the global distribution of HHV-8 seroprevalence (primary objective) and 2) to identify risk factors for HHV-8 infection, with a focus on HIV status (secondary objective).

METHODS/DESIGN

We will include observational studies reporting data on seroprevalence of HHV-8 in children and/or adults from any region in the world. Case reports and case series as well as any studies with fewer than 50 participants will be excluded. We will search MEDLINE, EMBASE, and relevant conference proceedings without language restriction. Two reviewers will independently screen the identified studies and extract data on study characteristics and quality, study population, risk factors, and reported outcomes, using a standardized form. For the primary objective we will pool the data using a fully bayesian approach for meta-analysis, with random effects at the study level. For the secondary objective (association of HIV and HHV-8) we aim to pool odds ratios for the association of HIV and HHV-8 using a fully bayesian approach for meta-analysis, with random effects at the study level. Sub-group analyses and meta-regression analyses will be used to explore sources of heterogeneity, including factors such as geographical region, calendar years of recruitment, age, gender, ethnicity, socioeconomic status, different risk groups for sexually and parenterally transmitted infections (MSM, sex workers, hemophiliacs, intravenous drug users), comorbidities such as organ transplantation and malaria, test(s) used to measure HHV-8 infection, study design, and study quality.

DISCUSSION

Using the proposed systematic review and meta-analysis, we aim to better define the global seroprevalence of HHV-8 and its associated risk factors. This will improve the current understanding of HHV-8 epidemiology, and could suggest measures to prevent HHV-8 infection and to reduce its associated cancer burden.

Familial aggregation of metabolic syndrome indicators in Portuguese families

Background and Aims. Family studies are well suited to investigate the genetic architecture underlying the metabolic syndrome (MetS). The purposes of this paper were (i) to estimate heritabilities for each of the MetS indicators, and (ii) to test the significance of familial intratrait and cross-trait correlations in MetS markers. Methods and Results. This study included 1,363 individuals from 515 Portuguese families in which five MetS components, including waist circumference (WC), blood pressure (BP), HDL-cholesterol, triglycerides (TG), and glucose (GLU), were measured. Intratrait and cross-trait familial correlations of these five components were estimated using Generalized Estimating Equations. Each MetS component was significantly heritable (h² ranged from 0.12 to 0.60) and exhibited strong familial resemblance with correlations between biological relatives of similar magnitude to those observed between spouses. With respect to cross-trait correlations, familial resemblance was very weak except for the HDL-TG pair. Conclusions. The present findings confirm the idea of familial aggregation in MetS traits. Spousal correlations were, in general, of the same magnitude as the biological relatives' correlations suggesting that most of the phenotypic variance in MetS traits could be explained by shared environment.

Population-based assessment of kaposi sarcoma-associated herpesvirus DNA in plasma among Ugandans

Risk of Kaposi sarcoma (KS) is linked to detection of Kaposi sarcoma-associated herpesvirus (KSHV) DNA in plasma, but little is known about the prevalence and risk factors for plasma KSHV DNA detection among the general population where KS is endemic. Correlates of KSHV plasma detection were investigated in a population-based sample of adult Ugandans (15-59 years) who participated in an HIV/AIDS serobehavioral survey in 2004/2005. KSHV DNA was measured in plasma of 1,080 KSHV seropositive and 356 KSHV seronegative persons using polymerase chain reaction (PCR). KSHV DNA in plasma was detected in 157 (8.7%) persons; of these 149 (95%) were KSHV seropositive and 8 (5%) were seronegative. Detection of KSHV DNA in plasma was significantly associated with male sex (P < 0.001), older age (P = 0.003), residence in a rural versus urban area (P = 0.002), geographic region (P = 0.02), and being KSHV seropositive (13.8% seropositive vs. 2.3% seronegative, P < 0.001). In a multivariable model, KSHV DNA plasma quantity was significantly higher in men (P = 0.002), inversely associated with age (P = 0.05), and residing in an urban area (P = 0.01). In Uganda, KSHV is detected more frequently in the plasma of adult males and residents of rural regions, potentially explaining the increased risk of KS in these subsets of the Ugandan population.

Inherited human OX40 deficiency underlying classic Kaposi sarcoma of childhood

Human OX40 is necessary for robust CD4⁺ T cell memory and confers selective protective immunity against HHV-8 infection in endothelial cells.

Kaposi sarcoma (KS), a human herpes virus 8 (HHV-8; also called KSHV)–induced endothelial tumor, develops only in a small fraction of individuals infected with HHV-8. We hypothesized that inborn errors of immunity to HHV-8 might underlie the exceedingly rare development of classic KS in childhood. We report here autosomal recessive OX40 deficiency in an otherwise healthy adult with childhood-onset classic KS. OX40 is a co-stimulatory receptor expressed on activated T cells. Its ligand, OX40L, is expressed on various cell types, including endothelial cells. We found OX40L was abundantly expressed in KS lesions. The mutant OX40 protein was poorly expressed on the cell surface and failed to bind OX40L, resulting in complete functional OX40 deficiency. The patient had a low proportion of effector memory CD4⁺ T cells in the peripheral blood, consistent with impaired CD4⁺ T cell responses to recall antigens in vitro. The proportion of effector memory CD8⁺ T cells was less diminished. The proportion of circulating memory B cells was low, but the antibody response in vivo was intact, including the response to a vaccine boost. Together, these findings suggest that human OX40 is necessary for robust CD4⁺ T cell memory and confers apparently selective protective immunity against HHV-8 infection in endothelial cells.

Merkel cell polyomavirus infection occurs during early childhood and is transmitted between siblings

Merkel cell polyomavirus (MCPyV) is thought to be the etiological agent of Merkel cell carcinoma, but little is known about its distribution and modes of transmission. We conducted seroepidemiological surveys in more than 1000 individuals, from two populations from Cameroon. Overall MCPyV seroprevalence was high in both populations (>75% in adults). Data from the first population, comprising mainly children, indicated that MCPyV infections mostly occurred during early childhood, after the disappearance of specific maternal antibodies. Results from the second family-based population provided evidence for familial aggregation of MCPyV infection status. We observed significant sib-sib correlation (odds ratio=3.42 [95% CI 1.27-9.19], p=0.014), particularly for siblings close together in age, and a trend for mother-child correlation (OR=2.71 [0.86-8.44], p=0.08). Overall, our results suggest that MCPyV infection is acquired through close contact, possibly involving saliva and/or the skin, especially between young siblings and between mothers and their children.

The role of co-infections in mother-to-child transmission of HIV

In HIV-infected women, co-infections that target the placenta, fetal membranes, genital tract, and breast tissue, as well as systemic maternal and infant infections, have been shown to increase the risk for mother-to-child transmission of HIV (MTCT). Active co-infection stimulates the release of cytokines and inflammatory agents that enhance HIV replication locally or systemically and increase tissue permeability, which weakens natural defenses to MTCT. Many maternal or infant co-infections can affect MTCT of HIV, and particular ones, such as genital tract infection with herpes simplex virus, or systemic infections such as hepatitis B, can have substantial epidemiologic impact on MTCT. Screening and treatment for co-infections that can make infants susceptible to MTCT in utero, peripartum, or postpartum can help reduce the incidence of HIV infection among infants and improve the health of mothers and infants worldwide.

Human herpesviruses 6, 7, and 8 from a dermatologic perspective

Human herpesviruses (HHVs) have frequently been suspected as etiologic agents or cofactors in cutaneous disease. However, clearly established associations are rare. Investigations into an etiologic association between HHVs and cutaneous disease are complicated by the ubiquity and nearly universal prevalence of some herpesviruses. This article summarizes the associations between cutaneous disease and HHV-6, HHV-7, and HHV-8. In addition to a personal library of references, the PubMed database of biomedical literature was searched using the following Medical Subject Heading terms: HHV-6, HHV-7, and HHV-8, each in conjunction with cutaneous manifestations, virology, epidemiology, dermatopathology, and therapeutics, between 1998 and March 2011. Free-text searches with known or suspected disease associations were added for broader coverage. The results have been summarized to provide a practical review for the physician likely to encounter cutaneous diseases.

[Pulmonary involvement due to HHV-8 virus during the course of HIV infection]

HHV-8 is a herpes virus discovered in 1994 in Kaposi sarcoma cells. Its involvement was later demonstrated in multicentric Castleman disease and in primary lymphoma effusion lymphoma. These diseases arise almost exclusively in immunocompromised patients, mostly in association with HIV infection. Apart from Kaposi's sarcoma, combined antiretroviral therapy does not seem to have reduced the incidence of these diseases, which remain rare. In these three diseases, pulmonary involvement is common and may be the presenting feature. Kaposi's sarcoma of the lung is usually asymptomatic but may require specific therapy. Pulmonary involvement is mostly associated with cutaneous disease. Patients with Castleman disease typically present with fever and lymphadenopathy, associated with interstitial lung disease without opportunistic infection. Patients with primary lymphoma effusion presents with fever and an exudative lymphocytic pleural effusion, without a pleural mass on the CT-scan. Rapid diagnosis of these conditions avoids unnecessary invasive examinations and leads to prompt specific treatment.

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.

A major locus on chromosome 3p22 conferring predisposition to human herpesvirus 8 infection

Infection with human herpesvirus 8 (HHV-8), the etiological agent of Kaposi's sarcoma, has been shown to display strong familial aggregation, in countries in which HHV-8 infection is endemic. We investigated 40 large families (608 subjects aged one to 88 years) living in an isolated area of Cameroon in which HHV-8 is highly endemic. We performed a two-step genetic analysis for HHV-8 infection status (HHV-8+/HHV-8- determined by immunofluorescence) consisting of an initial segregation analysis followed by a model-based genome-wide linkage analysis. Overall HHV-8 seroprevalence was 60%, increasing with age. Segregation analysis provided strong evidence for a recessive major gene conferring predisposition to HHV-8 infection. This gene is predicted to have a major effect during childhood, with almost all homozygous predisposed subjects (∼7% of the population) becoming infected by the age of 10. Linkage analysis was carried out on the 15 most informative families, corresponding to 205 genotyped subjects. A single region on chromosome 3p22 was significantly linked to HHV-8 infection (LOD score=3.83, P=2.0 × 10(-5)). This study provides the first evidence that HHV-8 infection in children in endemic areas has a strong genetic basis involving at least one recessive major locus on chromosome 3p22.