Cytomegalovirus (CMV) shedding is highly correlated with markers of immunosuppression in CMV-seropositive women

Cytomegalovirus (CMV) enters latency following primary infection and can subsequently reactivate. Reinfection with a different viral strain can also occur. During these events, CMV is shed in bodily fluids. This study examined correlates of CMV shedding in specimens obtained from the HIV Epidemiology Research Study, a multicenter cohort study of US women with or at high risk for human immunodeficiency virus (HIV) infection. Among the women studied, 91.4 % (911/997) were CMV IgG seropositive. Of these women, 2.7 % (25/911) were CMV IgM seropositive. CMV DNA was detected via real-time PCR more frequently in cervicovaginal lavage (CVL) specimens (55/764, 7.2 %) than in peripheral blood mononuclear cells (PBMCs) (26/897, 2.9 %). CMV viral loads in 1 ml CVL (median 534; mean 2598; range = 40-74, 844) were higher than in 10⁶ PBMCs (median 264; mean 1287; range = 35-13 ,250). CMV DNA in PBMCs was associated with HIV seropositivity [odds ratio (OR) 13.5; 95 % confidence interval (CI) 1.8-100], increasing HIV viral load (P<0.001 for trend), decreasing CD4 cell counts (P<0.001 for trend) and CMV DNA in CVL (OR 26; 95 % CI 10.7-64). CMV DNA in CVL specimens was associated with CMV IgM seropositivity (OR 4.3; 95 % CI 1.5-12.3), HIV seropositivity (OR 7.3; 95 % CI 2.6-20), increasing HIV viral load (P<0.001 for trend) and decreasing CD4 cell counts (P<0.001 for trend). The positive predictive value of CMV IgM seropositivity for CMV DNA shedding in either PBMCs or CVL was 20 %. In summary, CMV shedding in CVL and PBMCs was highly correlated with each other and with markers of immune suppression.

Substantial regional differences in human herpesvirus 8 seroprevalence in sub-Saharan Africa: insights on the origin of the "Kaposi's sarcoma belt"

Equatorial Africa has among the highest incidences of Kaposi's sarcoma (KS) in the world, thus earning the name "KS Belt." This was the case even before the HIV epidemic. To date, there is no clear evidence that HHV-8 seroprevalence is higher in this region but interpretation of the available literature is tempered by differences in serologic assays used across studies. We examined representatively sampled ambulatory adults in Uganda, which is in the "KS Belt," and in Zimbabwe and South Africa which are outside the Belt, for HHV-8 antibodies. All serologic assays were uniformly performed in the same reference laboratory by the same personnel. In the base-case serologic algorithm, seropositivity was defined by reactivity in an immunofluorescence assay or in 2 enzyme immunoassays. A total of 2,375 participants were examined. In Uganda, HHV-8 seroprevalence was high early in adulthood (35.5% by age 21) without significant change thereafter. In contrast, HHV-8 seroprevalence early in adulthood was lower in Zimbabwe and South Africa (13.7 and 10.8%, respectively) but increased with age. After age adjustment, Ugandans had 3.24-fold greater odds of being HHV-8 infected than South Africans (p < 0.001) and 2.22-fold greater odds than Zimbabweans (p < 0.001). Inferences were unchanged using all other serologic algorithms evaluated. In conclusion, HHV-8 infection is substantially more common in Uganda than in Zimbabwe and South Africa. These findings help to explain the high KS incidence in the "KS Belt" and underscore the importance of a uniform approach to HHV-8 antibody testing.

Sex and geographic patterns of human herpesvirus 8 infection in a nationally representative population‐based sample in Uganda

BACKGROUND

Human herpesvirus 8 (HHV8), the infectious cause of Kaposi sarcoma, varies dramatically across Africa, suggesting that cofactors correlated with large-area geographic or environmental characteristics may influence risk of infection. Variation in HHV8 seropositivity across small-area regions within countries in Africa is unknown. We investigated this issue in Uganda, where Kaposi sarcoma distribution is uneven and well described.

METHODS

Archival samples from individuals aged 15-59 years randomly selected from a nationally representative 2004-2005 human immunodeficiency virus-AIDS serobehavioral survey were tested for HHV8 seropositivity with use of enzyme immunoassays based on synthetic peptides from the K8.1 and orf65 viral genes. Adjusted odds ratios and 95% confidence intervals (CIs) of association of HHV8 seropositivity with demographic risk factors were estimated.

RESULTS

Among 2681 individuals tested, HHV8 seropositivity was 55.4%. HHV8 seropositivity was lower in female than in male persons (adjusted odds ratio, 0.82 [95% CI, 0.69-0.97]) and increased 2.2% (95% CI, 1.0%-3.6%) in female persons and 1.2% (95% CI, 1.0%-2.3%) in male persons per year of age. HHV8 seropositivity was inversely associated with education ( P = .01, for trend) and was elevated in the West Nile region, compared with the Central region (adjusted odds ratio, 1.49 [95% CI, 1.02-2.18]) but not with other regions.

CONCLUSIONS

Our findings suggest that HHV8 seropositivity in Uganda may be influenced by cofactors correlated with small-area geography, age, sex, and education.

Public health and laboratory considerations regarding newborn screening for congenital cytomegalovirus

Congenital cytomegalovirus (CMV) infection is the most common infection in newborns worldwide and causes hearing loss and other neurological disability in 15-20% of infected infants. Only about half of the hearing loss resulting from congenital CMV infection is currently detected by universal newborn hearing screening because of late-onset hearing loss. Thus, much of the hearing loss and the majority of other CMV-associated disabilities remain undetected for years after birth and are never connected to CMV infection. Congenital CMV may be appropriate to include in national newborn screening (NBS) programs because it is more common than other disorders tested for by NBS programs and is a major cause of disability. Significant obstacles to the implementation of screening for congenital CMV include the lack of a standardized, high-throughput screening test and a protocol for follow-up of CMV-infected children. Nonetheless, screening newborns for congenital CMV infection merits further consideration.

Use of screening dried blood spots for estimation of prevalence, risk factors, and birth outcomes of congenital cytomegalovirus infection

OBJECTIVES

To determine the birth prevalence of cytomegalovirus (CMV) in a population-based sample of newborns by use of dried blood spots compared with previous studies that used established detection methods, and to evaluate risk factors and birth outcomes for congenital CMV infection.

STUDY DESIGN

A total of 3972 newborn dried blood spots collected for the California Newborn Screening Program were tested for presence of CMV DNA. Demographic and pregnancy data were obtained from linked newborn screening and live-birth records.

RESULTS

CMV prevalence among newborns by maternal race and ethnicity was 0.9% for blacks, 0.8% for Hispanics, 0.6% for whites, and 0.6% for Asians. Among Hispanics (n = 2053), infants who were infected had younger mothers (23 vs 26 years, P = .03), and prevalence was higher for children with no father information provided (2.6% vs 0.6%, P = .03). Overall CMV infection was associated with low birth weight (prevalence ratios [95% CI]: 3.4 [1.4-8.5]) and preterm birth (2.7 [1.4-5.1]). CMV viral loads were inversely related to birth weight and gestational age (both P = .03).

CONCLUSIONS

CMV prevalence measured with dried blood spots was similar to reports using standard viral culture methods. Dried blood spots may be suitable for detection of CMV infection in newborns and warrant further evaluation. Congenital CMV infection may contribute to low birth weight and preterm birth.

Cytomegalovirus seroprevalence in the United States: the national health and nutrition examination surveys, 1988-2004

BACKGROUND. Congenital cytomegalovirus (CMV) infection causes permanent disabilities in more than 5500 children each year in the United States. The likelihood of congenital infection and disability is highest for infants whose mothers were CMV seronegative before conception and who acquire infection during pregnancy. METHODS. To provide a current, nationally representative estimate of the seroprevalence of CMV in the United States and to investigate trends in CMV infection, serum samples from the National Health and Nutrition Examination Survey (NHANES) 1999-2004 were tested for CMV-specific immunoglobulin G antibody, and results were compared with those from NHANES III (1988-1994). Individuals aged 6-49 years (21,639 for NHANES III and 15,310 for NHANES 1999-2004) were included. RESULTS. For NHANES 1999-2004, the overall age-adjusted CMV seroprevalence was 50.4%. CMV seroprevalence was higher among non-Hispanic black and Mexican American children compared with non-Hispanic white children and increased more quickly in subsequent age groups. CMV seropositivity was independently associated with older age, female sex, foreign birthplace, low household income, high household crowding, and low household education. Compared with NHANES 1988-1994, the overall age-adjusted CMV seroprevalence for NHANES 1999-2004 was not significantly different. CONCLUSIONS. Many women of reproductive age in the United States are still at risk of primary CMV infection during pregnancy. There is an urgent need for vaccine development and other interventions to prevent and treat congenital CMV. The substantial disparities in CMV risk among seronegative women suggest that prevention strategies should include an emphasis on reaching racial or ethnic minorities and women of low socioeconomic status.

Kaposi sarcoma-associated herpesvirus (KSHV) seroprevalence in population-based samples of African children: evidence for at least 2 patterns of KSHV transmission

BACKGROUND

Kaposi sarcoma-associated herpesvirus (KSHV) infection is endemic among adult populations in Africa. A prevailing view is that childhood transmission is primarily responsible for the high seroprevalence of KSHV among adults that is observed throughout the continent. However, few studies have directly examined children, particularly in locations where KS is not commonly endemic.

METHODS

Participants were children aged 1.5-8.9 years, including 427 children from a population-based sample in South Africa, 422 from a population-based sample in Uganda, and 567 from a clinic-based sample in Uganda. All serum specimens were tested by the same laboratory for KSHV antibodies with use of 2 enzyme immunoassays (against K8.1 and ORF65) and 1 immunofluorescence assay.

RESULTS

KSHV seroprevalence was 7.5%-9.0% among South African children and was not associated with age. In contrast, in the Ugandan population-based sample, KSHV seroprevalence increased from 10% among 2-year-old children to 30.6% among 8-year-old children (P(trend) < .001). In the Ugandan clinic-based sample, seroprevalence increased from 9.3% among 2-year-old children to 36.4% among 8-year-old children (P(trend) < .001).

CONCLUSION

Two distinct relationships between age and KSHV infection among children imply that KSHV transmission among children is not uniform throughout Africa and is therefore not always responsible for the high seroprevalence observed in adults. There are at least 2 patterns of KSHV transmission in Africa.

Quantitation of human herpesvirus 8 (HHV-8) antibody in patients transfused with HHV-8-seropositive blood

BACKGROUND

Human herpesvirus 8 (HHV-8) is endemic in Uganda where seroprevalence is approximately 40%. In a previous study, Ugandan patients receiving blood transfusions had multiple serum specimens collected for 6 months after transfusion to monitor for HHV-8 infection. It was observed that several HHV-8-seronegative patients were unexpectedly HHV-8 seropositive after blood transfusion.

STUDY DESIGN AND METHODS

This study measured HHV-8 antibody in serially collected serum specimens from 542 patients who received transfusions and evaluated the risk of HHV-8 infection as a function of HHV-8 antibody levels in the donors.

RESULTS

HHV-8 antibody was observed in 52% of patients transfused with HHV-8-seropositive blood in amounts that corresponded with their donor's antibody titer and waned within 40 days. Higher levels of passive HHV-8 antibody in patients who received transfusions appeared to be associated with a lower risk of HHV-8 infection.

CONCLUSION

The source of transient antibody in patients who received transfusions was determined to be the transfused blood. Donors with higher HHV-8 antibody titers may have been less likely to have infectious virus in the blood.

Cytomegalovirus seroprevalence and childhood sources of infection: A population-based study among pre-adolescents in the United States

BACKGROUND

Among pre-adolescents, the importance of different sources of cytomegalovirus (CMV) infection is unclear.

OBJECTIVE

To assess the importance of several CMV sources among pre-adolescent children.

STUDY DESIGN

We used data from a United States population-based sample conducted from 1988 to 1994: 4-10-year-old participants (n=3386) of the Third National Health and Nutrition Examination Survey. We tested available sera for CMV-specific-IgG and assessed CMV prevalence differences by surrogates for exposure to childhood CMV sources (maternal CMV serostatus, breast-feeding, older sibling CMV serostatus, and child care center attendance).

RESULTS

CMV infection was more prevalent (70%) among Mexican American children with foreign-born householders than among children with native-born householders (31% non-Hispanic White, 39% non-Hispanic Black, and 37% Mexican American children). Child's serostatus was associated with their mother's (prevalence difference range (PDR)=33-40%) and older sibling's serostatus (PDR=39-50%). Breast-feeding was associated with CMV in some racial/ethnic and householder groups (PDR=-5.1% to 22.7%). There was little difference in CMV seroprevalence by child care center attendance (PDR=-6.5% to -0.4%).

CONCLUSIONS

This study expands understanding of CMV by identifying the importance of householder nativity and demonstrating the importance of family transmission among the general population of pre-adolescents.

New estimates of the prevalence of neurological and sensory sequelae and mortality associated with congenital cytomegalovirus infection

Congenital CMV is a major cause of neurological and sensory impairment in children. Reliable estimates of the prevalence of permanent sequelae and mortality associated with congenital CMV are needed to guide development of education and prevention programmes and to gauge the financial costs associated with this disease. To calculate such estimates, this review used data solely from studies in which children with congenital CMV were identified through universal screening. Based on 15 studies with a total of 117 986 infants screened, the overall CMV birth prevalence estimate was 0.7%. The percentage of infected children with CMV-specific symptoms at birth was 12.7%. The percentage of symptomatic children with permanent sequelae was 40-58%. The percentage of children without symptoms at birth who developed permanent sequelae was estimated to be 13.5%. The true burden of congenital CMV infection is unclear because data on important outcomes, such as visual impairment, are lacking and follow-up of infected children has been too short to fully identify late-onset sequelae. Therefore, the estimates of permanent sequelae associated with congenital CMV presented here are likely underestimates. Future studies should extend follow-up of CMV-infected children identified through universal screening and include the evaluation of visual impairment.

Human herpesvirus 8 presence and viral load are associated with the progression of AIDS-associated Kaposi's sarcoma

OBJECTIVE

We present the largest longitudinal study to date that examines the association between Kaposi's Sarcoma (KS) disease progression and the presence and viral load of human herpesvirus 8 (HHV-8).

METHODS

Ninety-six men were enrolled at HIV clinics in Atlanta, Georgia, who had KS (n = 47) or were without KS but seropositive for HHV-8. Visits occurred at 6-month intervals for 2 years at which the patient's KS status was evaluated and oral fluid and blood were collected for quantification of HHV-8 DNA and antibodies.

RESULTS

The presence of HHV-8 DNA in blood was more common (P < 0.001) and the viral load higher (P < 0.001) in men with KS in comparison with men without KS. Mean HHV-8 viral loads in blood and oral fluids were associated with disease status, being highest among patients with progressing KS, intermediate among patients with stable KS, and lowest among patients with regressing KS. Consistent with our previous report high antibody titers to HHV-8 orf 65 were inversely associated with HHV-8 shedding in oral fluid.

CONCLUSIONS

We observed a significant association between changes in KS disease severity and the presence and viral load of HHV-8. HHV-8 viral load in blood may provide useful information to clinicians for assessment of the risk of further disease progression in patients with KS.

Seroprevalence of cytomegalovirus infection in the United States, 1988-1994

BACKGROUND

Cytomegalovirus (CMV) is a leading cause of congenital illness and disability, including hearing loss and mental retardation. However, there are no nationwide estimates of CMV seroprevalence among pregnant women or the overall population of the United States.

METHODS

To determine CMV prevalence in a representative sample of the US population, we tested serum samples for CMV-specific immunoglobulin G from participants aged > or =6 years (n=21,639) in the third National Health and Nutrition Examination Survey (1988-1994).

RESULTS

The prevalence of CMV infection was 58.9% in individuals > or =6 years old. CMV seroprevalence increased gradually with age, from 36.3% in 6-11-year-olds to 90.8% in those aged > or =80 years. CMV seroprevalence differed by race and/or ethnicity as follows: 51.2% in non-Hispanic white persons, 75.8% in non-Hispanic black persons, and 81.7% in Mexican Americans. Racial and/or ethnic differences in CMV seroprevalence persisted when controlling for household income level, education, marital status, area of residence, census region, family size, country of birth, and type of medical insurance. Among women, racial and/or ethnic differences were especially significant; between ages 10-14 years and 20-24 years, seroprevalence increased 38% for non-Hispanic black persons, 7% for non-Hispanic white persons, and <1% for Mexican Americans.

CONCLUSIONS

On the basis of these results, we estimate that each year in the United States approximately 340,000 non-Hispanic white persons, 130,000 non-Hispanic black persons, and 50,000 Mexican American women of childbearing age experience a primary CMV infection. Given the number of women at risk and the significance of congenital disease, development of programs for the prevention of CMV infection, such as vaccination or education, is of considerable public health importance.

Transmission of human herpesvirus 8 by blood transfusion

BACKGROUND

Whether human herpesvirus 8 (HHV-8) is transmissible by blood transfusion remains undetermined. We evaluated the risk of HHV-8 transmission by blood transfusion in Uganda, where HHV-8 is endemic.

METHODS

We enrolled patients in Kampala, Uganda, who had received blood transfusions between December 2000 and October 2001. Pretransfusion and multiple post-transfusion blood specimens from up to nine visits over a 6-month period were tested for HHV-8 antibody. We calculated the excess risk of seroconversion over time among recipients of HHV-8-seropositive blood as compared with recipients of seronegative blood.

RESULTS

Of the 1811 transfusion recipients enrolled, 991 were HHV-8-seronegative before transfusion and completed the requisite follow-up, 43% of whom received HHV-8-seropositive blood and 57% of whom received seronegative blood. HHV-8 seroconversion occurred in 41 of the 991 recipients. The risk of seroconversion was significantly higher among recipients of HHV-8-seropositive blood than among recipients of seronegative blood (excess risk, 2.8%; P<0.05), and the increase in risk was seen mainly among patients in whom seroconversion occurred 3 to 10 weeks after transfusion (excess risk, 2.7%; P=0.005), a result consistent with the transmission of the virus by transfusion. Blood units stored for up to 4 days were more often associated with seroconversion than those stored for more than 4 days (excess risk, 4.2%; P<0.05).

CONCLUSIONS

This study provides strong evidence that HHV-8 is transmitted by blood transfusion. The risk may be diminished as the period of blood storage increases.

The Epidemiology and Prevention of Congenital Cytomegalovirus Infection and Disease: Activities of the Centers for Disease Control and Prevention Workgroup

Perhaps no single cause of birth defects and developmental disabilities in the United States currently provides greater opportunity for improved outcomes in more children than congenital cytomegalovirus (CMV). --Cannon and Davis. BMC Public Health 2005;5:70 Each year in the United States, thousands of children and their families are affected by congenital cytomegalovirus (CMV) infection. More children may be affected by congenital CMV than by other, better known childhood conditions, such as Down syndrome, fetal alcohol syndrome, and spina bifida. The Centers for Disease Control and Prevention (CDC) has formed a Workgroup on Congenital CMV, led by the National Center on Birth Defects and Developmental Disabilities and the National Center on Infectious Diseases. This report provides background on congenital CMV infection and describes the goals and activities of the workgroup for reducing the burden of sequelae of congenital CMV infection.

Possible transmission of human herpesvirus-8 by blood transfusion in a historical United States cohort

BACKGROUND

Transmission of human herpesvirus-8 (HHV-8) by blood transfusion in the United States appears plausible but has not been demonstrated. The objective of this study was to evaluate evidence of HHV-8 transmission via blood transfusion.

STUDY DESIGN AND METHODS

Serum specimens were collected before and 6 months after surgery from 406 patients who enrolled in the Frequency of Agents Communicable by Transfusion study (FACTS) in Baltimore, Maryland, from 1986 to 1990. The change in HHV-8 serostatus was measured by a lytic-antigen immunofluorescence assay.

RESULTS

Of the 284 patients who were initially HHV-8-seronegative and who received transfusions, 2 seroconverted, 1 with a postsurgery antibody titer of 1:160 and the other with a titer of 1:1280. These patients received 12 and 13 units of blood, respectively. None of the HHV-8-seronegative patients who did not receive transfusions seroconverted. If seroconversion was caused by transfused blood, the transmission risk per transfused component was 0.082 percent.

CONCLUSIONS

This is the first report suggesting transmission of HHV-8 via blood components in the United States. Because linked donor specimens were not available, other routes of transmission cannot be excluded; however, the evidence is consistent with infection being caused by transfusion. Future studies should include contemporary US populations with linked donor specimens and populations at higher risk for HHV-8 infection.

Evidence for both lytic replication and tightly regulated human herpesvirus 8 latency in circulating mononuclear cells, with virus loads frequently below common thresholds of detection

To address whether human herpesvirus 8 (HHV-8) DNA in peripheral blood mononuclear cells (PBMCs) might be the product of latent or lytic infection and to shed light on sporadic detection of HHV-8 DNA in individuals seropositive for the virus, we studied the frequency of infected cells, total virus load, and virus load per infected cell in PBMCs from men coinfected with HHV-8 and human immunodeficiency virus (HIV), some of whom had Kaposi's sarcoma. The low frequencies of infected cells detected (fewer than one per million cells in some individuals) suggest that the prevalence of the virus in circulating leukocytes was underestimated in previous studies that employed more conventional sampling methods (single, small-volume specimens). Mean virus loads ranged from 3 to 330 copies per infected PBMC; these numbers can represent much higher loads in individual lytically infected cells (>10(3) genomes/cell) in mixtures that consist predominantly of latently (relatively few genomes) infected cells. The presence in some subjects of high HHV-8 mean genome copy numbers per infected cell, together with viral DNA being found in plasma only from subjects with positive PBMCs, supports earlier suggestions that the virus can actively replicate in PBMCs. In some individuals, mean virus loads were less than 10 genomes per infected cell, suggesting a tightly controlled purely latent state. HHV-8 genome copy numbers are substantially higher in latently infected cells derived from primary effusion lymphomas; thus, it appears that HHV-8 is able to adopt more than one latency program, perhaps analogous to the several types of Epstein-Barr virus latency.

Repeated measures study of human herpesvirus 8 (HHV-8) DNA and antibodies in men seropositive for both HHV-8 and HIV

OBJECTIVE

To study the natural history and pathogenesis of human herpesvirus 8 (HHV-8) infection in HHV-8-seropositive, immunosuppressed men.

DESIGN

Longitudinal study of 87 HHV-8- and HIV-seropositive men [42 with Kaposi's sarcoma (KS)] during four visits over a 2 month period.

METHODS

: Patients provided oral fluid and blood. HHV-8 antibody titers were measured with peptide-based enzyme-linked immunosorbent assays (ELISA) for ORF65 and K8.1; HHV-8 DNA was detected with polymerase chain reaction ELISA.

RESULTS

HHV-8 DNA was present in oral fluid or peripheral blood mononuclear cells (PBMC) at one or more of the four visits in 71% of men with KS and 56% of men without KS. The strongest correlate of HHV-8 DNA in PBMC was the presence of KS [odds ratio (OR), 8.7; 95% confidence interval (CI), 3.4-22]. Detection of HHV-8 DNA in oral fluid or PBMC was often intermittent, but individuals who shed virus at one time point were more likely to shed at other times. Some men had incomplete epitope recognition in their anti-HHV-8 antibody response. High antibody titers were associated with the absence of circulating HHV-8, particularly for the ORF65 seroassay (OR, 0.16; 95% CI, 0.05-0.51).

CONCLUSIONS

Among HHV-8 seropositive men, circulating virus is common even in the absence of disease. The link between KS and HHV-8 DNA in PBMC suggests that anti-herpes drugs may impede KS development or progression. Seroassays should target multiple epitopes to achieve maximal sensitivity. HHV-8 replication may be limited by high antibody titers or other immune function for which antibodies are a marker.

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

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

Elevated Seroprevalence of Human Herpesvirus 8 among Men with Prostate Cancer

Background. To investigate any epidemiological association between human herpesvirus (HHV)-8 and prostate cancer, we determined the prevalence of HHV-8 seropositivity among prostate cancer case and control subjects in the United States and Trinidad and Tobago.Methods. Antibodies against HHV-8 were detected in 2 independent laboratories using either indirect immunofluorescence assay (IFA) or a combination of enzyme-linked immunosorbent assay and IFA.Results. Among 138 Tobago men with prostate cancer, HHV-8 seroprevalence was 39.9%-significantly higher than that among 140 age-matched control subjects (22.9%; P=.003; odds ratio [OR], 2.24; 95% confidence interval [CI], 1.29-3.90). Among 100 US men with prostate cancer, seroprevalence was 20%-significantly higher than that of 177 blood donors (5.1%; P=.001; OR, 4.67; 95% CI, 1.91-11.65) and higher than that of 99 men with cancer not related to HHV-8 (13%; P=.253; 95% CI, 0.77-3.54).Conclusions. HHV-8 seropositivity is elevated among men with prostate cancer compared with control subjects, which suggests that HHV-8 plays a role in the development of prostate cancer.

Multicenter comparison of serologic assays and estimation of human herpesvirus 8 seroprevalence among US blood donors

BACKGROUND

As part of assessing the possibility of transfusion transmission of human herpesvirus 8 (HHV-8 or Kaposi's sarcoma-associated herpesvirus), HHV-8 seroprevalence was estimated among US blood donors, the performance of HHV-8 serologic tests was compared, and the presence of HHV-8 DNA was tested for in donated blood.

STUDY DESIGN AND METHODS

Replicate panels of 1040 plasma specimens prepared from 1000 US blood donors (collected in 1994 and 1995) and 21 Kaposi's sarcoma patients were tested for antibodies to HHV-8 in six laboratories. HHV-8 PCR was performed on blood samples from 138 donors, including all 33 who tested seropositive in at least two laboratories and 22 who tested positive in at least one.

RESULTS

The estimated HHV-8 seroprevalence among US blood donors was 3.5 percent (95% CI, 1.2%-9.8%) by a conditional dependence latent-class model, 3.0 percent (95% CI, 2.0%-4.6%) by a conditional independence latent-class model, and 3.3 percent (95% CI, 2.3%-4.6%) by use of a consensus-derived gold standard (specimens positive in two or more laboratories); the conditional dependence model best fit the data. In this model, laboratory specificities ranged from 96.6 to 100 percent. Sensitivities ranged widely, but with overlapping 95 percent CIs. HHV-8 DNA was detected in blood from none of 138 donors evaluated.

CONCLUSIONS

Medical and behavioral screening does not eliminate HHV-8-seropositive persons from the US blood donor pool, but no viral DNA was found in donor blood. Further studies of much larger numbers of seropositive individuals will be required to more completely assess the rate of viremia and possibility of HHV-8 transfusion transmission. Current data do not indicate a need to screen US blood donors for HHV-8.

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

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

Absence of HBV and HCV, HTLV-I and -II, and human herpes virus-8 activation after allogeneic RBC transfusion in patients with advanced HIV-1 infection

BACKGROUND

The Viral Activation Transfusion Study was a prospective, randomized, double-blind comparison of transfusion with WBC-reduced versus non-WBC-reduced RBCs to HIV+ patients. The primary study characterized the effect of transfusion on HIV and CMV activation by monitoring viral load changes. The present study analyzed HBV, HCV, HTLV-I and -II, and human herpes virus-8 (HHV-8) viral load before and after transfusion to evaluate the further hypothesis that global immune stimulation following allogeneic RBC transfusion results in activation and increased viral proliferation of chronic viral infections other than HIV and CMV.

STUDY DESIGN AND METHODS

Baseline samples from 519 to 523 subjects were screened for HBV, HCV, HTLV-I and -II, and HHV-8 infection, and baseline, serial weekly, and quarterly blood samples from infected subjects in the non-WBC-reduced arm were evaluated for changes from baseline in viral nucleic acid and ALT levels.

RESULTS

Seroprevalence of HBV, HCV, HTLV-I and -II, and HHV-8 was 68, 25, 5, and 30 percent, respectively. No significant induction of HBV, HCV, HHV-8, or HTLV-I and -II viral replication following allogeneic transfusion of non-WBC-reduced blood was observed. A significant, albeit small, association was observed between transfusion and ALT.

CONCLUSIONS

Based on these results and our previous finding that no adverse effect on HIV and CMV viral load and disease progression results from allogeneic transfusion, no evidence is found to support the selective use of WBC-reduced blood components for HIV-infected patients.

Comparison of a microtiter plate system to Southern blot for detection of human herpesvirus 8 DNA amplified from blood and saliva

The recent discovery of human herpesvirus 8 (HHV-8) as the etiologic agent of Kaposi's sarcoma (KS) has led to the interest in the development of PCR for this virus that is accurate, rapid, and convenient. We developed a sensitive PCR assay for HHV-8 with microtiter plate detection of amplimers. DNA was purified from white blood cells and saliva from HIV-infected men with and without Kaposi's sarcoma and one-step PCR was undertaken with primer sets specific for the N-terminal region of the glycoprotein B gene and open reading frame (orf) 26 of HHV-8. PCR was performed on 40 clinical specimens, followed by Southern blot and microtiter plate detection of amplimers. Results from the two methods of detection were nearly identical. Sensitivity for both methods based on serial dilution of a known standard was five to ten copies of HHV-8 per 400 ng of cellular DNA. In conclusion, microtiter plate detection of HHV-8 PCR amplimers is as sensitive and specific as Southern blot with much faster turnaround time at comparable cost, and utilizes common laboratory equipment.