Biomedical subjects

Lawrence Corey

Publications and source records attributed to Lawrence Corey.

At least 37 records · Page 2Linked to original sources

PubMed2006

Sequence-based methods for identifying epidemiologically linked herpes simplex virus type 2 strains.

Traditional methods for confirming the identity of herpes simplex virus (HSV) isolates use restriction fragment length polymorphism (RFLP). However, RFLP is less amenable to high-throughput analyses of many samples, and the extent to which small differences in RFLP patterns distinguish between different viral strains remains unclear. Viral HSV type 2 (HSV-2) DNA isolates from 14 persons experiencing a primary HSV-2 infection and from their sexual partners were analyzed by RFLP and heteroduplex mobility assays. We also compared the HSV-2 sequences from seven regions, including noncoding regions between UL19 and UL20, UL24 and UL25, UL37 and UL38, and UL41 and UL42 and coding segments of the gC, gB, and gG genes. Although the resulting RFLP patterns of the couples were almost identical, minor banding differences existed between the source and susceptible partners in five couples. Heteroduplex mobility assays were unable to distinguish between unrelated strains. Overall, 22 sites of sequence variation were found in 1,482 bp of analyzed sequence. The DNA sequences differentiated between all unrelated infections, and epidemiologically related isolates had identical sequences in all but two pairs. Our results suggest that a multilocus assay based on several DNA sequences has the potential to be an informative tool for identifying epidemiologically related HSV-2 strains.

DNA, Viral↗

PubMed2006

Comparison of real-time PCR assays with fluorescent-antibody assays for diagnosis of respiratory virus infections in children.

Conventional fluorescent-antibody (FA) methods were compared to real-time PCR assays for detection of respiratory syncytial virus (RSV), influenza virus type A (FluA), parainfluenza virus types 1, 2, and 3 (PIV1, PIV2, and PIV3), human metapneumovirus (MPV), and adenovirus (AdV) in 1,138 specimens from children with respiratory illnesses collected over a 1-year period. At least one virus was detected in 436 (38.3%) specimens by FA and in 608 (53.4%) specimens by PCR (P<0.001). Specimen quality was inadequate for FA in 52 (4.6%) specimens; 13 of these (25%) were positive by PCR. In contrast, 18 (1.6%) specimens could not be analyzed by PCR; 1 of these was positive by FA. The number of specimens positive only by PCR among specimens positive by PCR and/or FA was 18 (7.0%) of 257 for RSV, 18 (13.4%) of 134 for FluA, 25 (64.1%) of 39 for PIV1, 8 (88.9%) of 9 for PIV2, 17 (30.1%) of 55 for PIV3, and 101 (76.5%) of 132 for AdV. MPV was detected in 6.6% of all specimens and in 9.5% of the 702 specimens negative by FA. The mean number of virus copies per milliliter in specimens positive by both PCR and FA was significantly higher, at 6.7x10(7), than that in specimens positive only by PCR, at 4.1x10(4) (P<0.001). The PCR assays were significantly more sensitive than FA assays for detecting respiratory viruses, especially parainfluenza virus and adenovirus. Use of real-time PCR to identify viral respiratory pathogens in children will lead to improved diagnosis of respiratory illness.

Adenoviridae↗

PubMed2006

Selection on the human immunodeficiency virus type 1 proteome following primary infection.

Typically during human immunodeficiency virus type 1 (HIV-1) infection, a nearly homogeneous viral population first emerges and then diversifies over time due to selective forces that are poorly understood. To identify these forces, we conducted an intensive longitudinal study of viral genetic changes and T-cell immunity in one subject at < or =17 time points during his first 3 years of infection, and in his infecting partner near the time of transmission. Autologous peptides covering amino acid sites inferred to be under positive selection were powerful for identifying HIV-1-specific cytotoxic-T-lymphocyte (CTL) epitopes. Positive selection and mutations resulting in escape from CTLs occurred across the viral proteome. We detected 25 CTL epitopes, including 14 previously unreported. Seven new epitopes mapped to the viral Env protein, emphasizing Env as a major target of CTLs. One-third of the selected sites were associated with epitopic mutational escapes from CTLs. Most of these resulted from replacement with amino acids found at low database frequency. Another one-third represented acquisition of amino acids found at high database frequency, suggesting potential reversions of CTL epitopic sites recognized by the immune system of the transmitting partner and mutation toward improved viral fitness in the absence of immune targeting within the recipient. A majority of the remaining selected sites occurred in the envelope protein and may have been subjected to humoral immune selection. Hence, a majority of the amino acids undergoing selection in this subject appeared to result from fitness-balanced CTL selection, confirming CTLs as a dominant selective force in HIV-1 infection.

Amino Acid Sequence↗

PubMed2006

Diversity of the CD8+ T-cell response to herpes simplex virus type 2 proteins among persons with genital herpes.

Cytolytic T cells play a major role in controlling herpes simplex virus type 2 (HSV-2) infections in humans. In an effort to more thoroughly evaluate the response to HSV-2 directly, ex vivo, we developed an enzyme-linked immunospot (ELISPOT) assay that utilized pools of overlapping synthetic peptides presented by autologous dendritic cells to purified CD8(+) T cells. Donor response rates to individual open reading frames (ORFs) ranged from fewer than 5% responding to as many as 70% responding, with the greatest frequency of responses (by ORF) being directed against UL39, UL25, UL27, ICP0, UL46, and UL47 in descending order of frequency. HSV-2-seropositive subjects responded to as few as 3 or as many as 46 of the 48 ORFs tested, with a median of 11 ORFs recognized. HLA-B*07 expression correlated with stronger responses overall that were directed primarily against UL49 and UL46. Cumulative precursor frequencies in the blood ranged from 500 to almost 6,000 HSV-2 spot-forming units/10(6) CD8(+) T cells. The magnitude and breadth of the response in the infected population were greater than previously appreciated. Whether this variability in the CD8(+) T-cell response within individuals is associated with the frequency of viral reactivation warrants further study.

CD8-Positive T-Lymphocytes↗

PubMed2006

Continued evolution of HIV-1 circulating in blood monocytes with antiretroviral therapy: genetic analysis of HIV-1 in monocytes and CD4+ T cells of patients with discontinued therapy.

The role of blood monocytes in HIV-1 infection is a relatively new field of interest. What happens to HIV-1 in monocytes and their relationship to CD4+ T cells before, during, and after suppressive antiretroviral therapy (ART) is largely unstudied. Here, considering that diversity is a good indicator of continued replication over time, we evaluated the effect of ART on HIV-1 in blood monocytes and CD4+ T cells by examining the diversity of HIV-1 from 4 infected patients who underwent and stopped therapy. We determined diversity and compartmentalization of HIV-1 between blood monocytes and CD4+ T cells in each patient in relationship to their ART regimens. Our data indicate that the rate of HIV-1 diversity increase in monocytes during therapy was significantly higher than in CD4+ T cells (P<0.05), suggesting that HIV-1 present in monocytes diversify more during therapy than in CD4+ T cells. Increased rates of HIV-1 compartmentalization between monocytes and CD4+ T cells while on therapy were also observed. These results suggest that ART inhibits HIV-1 replication in CD4+ T cells more than in blood monocytes and that better treatments to combat HIV-1 in monocytes/macrophages may be needed for a more complete suppression of HIV replication.

Anti-HIV Agents↗

PubMed2005

The relationship between condom use and herpes simplex virus acquisition.

BACKGROUND: Few studies have evaluated the relationship between condom use and herpes simplex virus type 2 (HSV-2) and HSV type 1 (HSV-1) acquisition. OBJECTIVE: To assess the relationship between condom use and acquisition of HSV-2 and HSV-1 among men and women. DESIGN: Analysis of data collected as part of a clinical trial of an ineffective candidate vaccine for HSV-2. SETTING: Sexually transmitted disease clinics. PARTICIPANTS: Men and women at risk for HSV-2 acquisition, defined as having 4 or more sexual partners or having a sexually transmitted disease in the past year. MEASUREMENT: Acquisition of HSV-2 and HSV-1 as measured by viral culture or change to positive HSV serostatus. RESULTS: Of 1843 participants, 118 (6.4%) became infected with HSV-2. In multivariate analyses, participants reporting more frequent use of condoms were at lower risk for acquiring HSV-2 than participants who used condoms less frequently (hazard ratio, 0.74 [95% CI, 0.59 to 0.95]); categories of increasing condom use were 0% to 25%, 25% to 75%, and greater than 75% of sexual acts. Nineteen (2.9%) of 659 participants at risk for infection with HSV-1 became infected. No statistically significant association between condom use and infection with HSV-1 was found (hazard ratio, 0.79 [CI, 0.48 to 1.31]). LIMITATIONS: Use of condoms was measured by self-report, and persons who used condoms may have differed from those who did not. CONCLUSIONS: Consistent use of condoms is associated with lower rates of infection with HSV-2 and should be routinely recommended.

Adult↗

PubMed2005

Use of "biokit HSV-2 Rapid Assay" to improve the positive predictive value of Focus HerpeSelect HSV-2 ELISA.

BACKGROUND: Commercially available assays to detect antibodies to the herpes simplex virus type 2 (HSV-2)-specific glycoprotein gG-2 have markedly improved serologic diagnosis of HSV-2 infection. However, even tests with high specificity can have low positive predictive values in low prevalence populations. HSV-2 is a chronic, life-long viral infection that requires both medical attention and potential alterations in health care strategy. As such, the concern for false positive diagnoses is high confirmatory testing is routine for other viral serologies such as HIV and hepatitis C. We evaluated such a strategy for HSV-2 serology by using an easily performed commercial test, biokitHSV-2 rapid test ("Biokit"; Biokit USA, Lexington MA) as a confirmatory test for the widely used gG-2 specific serology ("Focus;" HerpeSelect HSV-2 ELISA; Focus Diagnostics, Cypress CA). METHODS: We tested 782 sera by Focus HSV-2 ELISA, Biokit, and the current gold standard test, Western blot (WB). RESULTS: The positive predictive value of the Focus HSV-2 ELISA increased from 80.5% to 95.6% when Biokit testing was performed on sera that were initially positive by Focus HSV-2 ELISA. Confirmatory testing increased the specificity markedly among sera with Focus EIA values between 1.1 and 3.5: only 35% of low positive (index values 1.1-3.5) Focus HSV-2 ELISA results confirmed as positive by Biokit and WB compared with 92% of those with index values >3.5. Mathematical modeling of the data resulted in expected positive predictive values over 98% for populations with antibody prevalences typical of clinical practices in the US and Europe. CONCLUSION: Confirmatory Biokit testing of positive Focus HSV-2 ELISA results is fast, easy, and effective in reducing falsely positive HSV-2 antibody results. Patients, clinicians, and laboratories could benefit from the enhanced specificity of this simple HSV-2 serologic test combination.

Adult↗

PubMed2005

Antiretroviral therapy for HIV-1 vaccine efficacy trial participants who seroconvert.

Instead of preventing infection, most HIV-1 vaccines in clinical trials are directed at inducing cytotoxic HIV-1-specific T cell (CTL) responses which may control viral replication and subsequently modify the clinical course of HIV-1 infection. Thus, vaccine efficacy trial designs must follow participants who become HIV-infected and monitor the course of HIV-1 infection, in order to assess the effect of vaccination on HIV-1 disease progression. This post-infection evaluation will assess time to reach specific CD4 and viral load thresholds as well as time to initiation of antiretroviral therapy. This paper discusses current literature and guidelines on the initiation of highly active antiretroviral therapy (HAART) for persons who become HIV-infected during HIV-1 vaccine trials, focusing both on acute and early HIV-1 infection, since participants in HIV-1 vaccine and other prevention trials will typically be identified within 3-6 months after HIV-1 acquisition. A standardized HAART protocol for HIV-1 vaccine efficacy trial participants who become HIV-infected is essential to the evaluation of CTL-based HIV-1 vaccines on the natural history of HIV-1 infection.

AIDS Vaccines↗

PubMed2005

Inhibition of MHC class I is a virulence factor in herpes simplex virus infection of mice.

Herpes simplex virus (HSV) has a number of genes devoted to immune evasion. One such gene, ICP47, binds to the transporter associated with antigen presentation (TAP) 1/2 thereby preventing transport of viral peptides into the endoplasmic reticulum, loading of peptides onto nascent major histocompatibility complex (MHC) class I molecules, and presentation of peptides to CD8 T cells. However, ICP47 binds poorly to murine TAP1/2 and so inhibits antigen presentation by MHC class I in mice much less efficiently than in humans, limiting the utility of murine models to address the importance of MHC class I inhibition in HSV immunopathogenesis. To address this limitation, we generated recombinant HSVs that efficiently inhibit antigen presentation by murine MHC class I. These recombinant viruses prevented cytotoxic T lymphocyte killing of infected cells in vitro, replicated to higher titers in the central nervous system, and induced paralysis more frequently than control HSV. This increase in virulence was due to inhibition of antigen presentation to CD8 T cells, since these differences were not evident in MHC class I-deficient mice or in mice in which CD8 T cells were depleted. Inhibition of MHC class I by the recombinant viruses did not impair the induction of the HSV-specific CD8 T-cell response, indicating that cross-presentation is the principal mechanism by which HSV-specific CD8 T cells are induced. This inhibition in turn facilitates greater viral entry, replication, and/or survival in the central nervous system, leading to an increased incidence of paralysis.

Journal Article↗

PubMed2005

A randomized controlled trial of a replication defective (gH deletion) herpes simplex virus vaccine for the treatment of recurrent genital herpes among immunocompetent subjects.

BACKGROUND: A replication incompetent herpes virus lacking the glycoprotein H gene has been developed as a potential therapeutic vaccine for genital herpes. GOAL: To determine vaccine efficacy on reducing HSV reactivation and clinical disease among immunocompetent persons with recurrent genital HSV-2 infection. STUDY DESIGN: Randomized multicenter placebo-controlled trial. Healthy volunteers who had six or more recurrences of genital herpes per year were randomized to receive injections of vaccine at 0 and 8 or 0, 4, and 8 or 0, 2, 4, and 8 weeks or placebo and were followed for subsequent recurrences for 1 year. RESULTS: The median times to first recurrence of genital herpes (40 days versus 30 days versus 37 days versus 42 days, respectively), mean number of recurrences (3 versus 3 versus 2.4 versus 1.9, respectively), and time to lesion healing of the first recurrence (8 days versus 7.8 days versus 7.4 days versus 7.5 days, respectively), were similar for all treatment groups. Asymptomatic viral shedding was detected by PCR in 61/74 (82%) persons performing daily sample collection following completion of the vaccination series. No differences were noted in the proportion of days with shedding between treatment groups (11.9% versus 17.2% versus 13.1% versus 16.4%, respectively). CONCLUSION: This replication incompetent HSV-2 vaccine lacking the glycoprotein H gene was safe but had no clinical or virologic benefit in the amelioration of genital HSV-2 disease among immunocompetent men and women.

Adolescent↗

PubMed2005

High-dose recombinant Canarypox vaccine expressing HIV-1 protein, in seronegative human subjects.

BACKGROUND: In clinical trials, canarypox ALVAC-human immunodeficiency virus (HIV) vaccines have been shown to elicit human HIV-specific cytotoxic T lymphocyte (CTL) responses in some but not all healthy uninfected adults.Methods. A clinical trial was conducted to examine whether the vaccine vCP1452 would elicit a greater HIV-specific CTL response when given at a dose of 10(8.0) TCID50 (60 participants) than when given at the regular dose, 10(7.26) TCID50 (40 participants); as a control, a placebo vaccine preparation also was administered (10 participants). RESULTS: Two weeks after the last vaccination in a series, HIV-specific CTL responses were not significantly different when measured by either chromium-release assay (8% and 16% in the high- and regular-dose recipients, respectively) or interferon- gamma ELISpot assay (8% and 15% in the high- and regular-dose recipients, respectively); moreover, recipients of the higher dose had greater local and systemic reactions (P<.001). CONCLUSIONS: High reactogenicity associated with an increased dose of vCP1452 negates the need for further evaluation of this strategy to boost the frequency of HIV-specific CTL response in seronegative human subjects. Development of highly immunogenic canarypox vectors requires further work to optimize vector and insert design, as well as novel ways to increase dosage and to reduce reactogenicity.

AIDS Vaccines↗

PubMed2005

Acyclovir sensitivity of sequential herpes simplex virus type 2 isolates from the genital mucosa of immunocompetent women.

BACKGROUND: Despite widespread use of acyclovir, infection with acyclovir-resistant herpes simplex virus type 2 (HSV-2) remains uncommon. To understand the frequency and clinical significance of acyclovir-resistant isolates, we evaluated the in vitro acyclovir sensitivities of sequential isolates from 34 immunocompetent women. METHODS: HSV-2-seropositive women collected daily samples of genital secretions while receiving acyclovir or placebo, each for 10 weeks. In vitro acyclovir sensitivity testing was performed using the dye uptake assay; isolates for which the concentration of acyclovir that inhibited cytopathic effect by 50% (EC50) was > or = 3 microg/mL were defined as resistant. RESULTS: A total of 351 isolates from 26 women were tested (median, 10 isolates/woman [range, 3-45 isolates/woman]). The median EC50 was 0.91 microg/mL. Overall, 7 isolates (1.7%) from 6 women had EC50 values > or = 3 microg/mL. None of the women was receiving acyclovir when the acyclovir-resistant isolates were detected. Acyclovir-sensitive and acyclovir-resistant isolates were detected in samples collected on the same day from separate anatomic sites in 3 women. The acyclovir-resistant isolates were transient, because acyclovir-sensitive isolates were obtained before and after the acyclovir-resistant isolates from 5 women were detected. CONCLUSIONS: Among immunocompetent women, the finding of acyclovir-resistant HSV-2 isolates likely represents transient mucosal variants and does not predict treatment failure.

Acyclovir↗

PubMed2005

Improved outcome in central nervous system aspergillosis, using voriconazole treatment.

The mortality of central nervous system (CNS) aspergillosis approaches 100%, requiring improved therapies. Voriconazole gives superior efficacy and survival in invasive aspergillosis, compared with amphotericin B. Also, in contrast to other antifungal drugs, voriconazole penetrates well into the CNS. We evaluated, retrospectively, the outcome and survival of 81 patients who were treated with voriconazole for definite (n = 48) or probable (n = 33) CNS aspergillosis. Complete and partial responses were recorded in 35% of patients and varied by the underlying disease group: hematologic malignancies (54%), other underlying conditions (50%), chronic immunosuppression (45%), solid organ transplantation (36%), and hematopoietic stem cell transplantation (16%). Thirty-one percent of patients survived CNS aspergillosis for a median observation time of 390 days. There were 31 patients who underwent neurosurgical procedures, including craniotomy/abscess resection (n = 14), abscess drainage (n = 12), ventricular shunt (n = 4), and Ommaya-reservoir (n = 1). Multifactorial analysis revealed that neurosurgery was associated with improved survival (P = .02). Patients who underwent hematopoietic stem cell transplantation had a poorer survival (P = .02), but 7 (22%) of 32 survived for a median of 203 days. We conclude from this large cohort of patients that voriconazole treatment together with neurosurgical management, whenever feasible, is currently the best approach to treat patients with CNS aspergillosis.

Adult↗

PubMed2005

Longitudinal analysis of herpes simplex virus-specific CD4+ cell clonotypes in infected tissues and blood.

BACKGROUND: Genital infection by herpes simplex virus (HSV)-2 offers a unique model for study of the effects of a remitting and exacerbating infection on the survival and persistence of antigen-specific T cells. METHODS: We used complementarity-determining region 3 (CDR3) length analysis to examine the complete T cell receptor (TCR) beta -chain repertoire in skin-lesion biopsy samples from subjects with genital herpes. RESULTS: We found that herpetic skin lesions consistently demonstrated oligoclonal CDR3 DNA length distribution, indicating the presence of T cell expansions. Sequence analysis of representative HSV-specific lesional CD4(+) cell clones and TCR beta -variable (TCRBV) sequencing confirmed that the oligoclonal expansions were largely related to HSV-specific T cell proliferation. To assess the persistence of HSV-specific CD4(+) cells that localize to genital lesions, we developed a sensitive and highly specific clonal tracking technique using a combination of TCRBV-specific polymerase chain reaction, followed by liquid hybridization with clonotype-specific probes. CONCLUSION: Two different patterns of clonal persistence were observed. Some long-lasting clones appear to home to different epithelia, such as skin and genital mucosa, and to circulate in the peripheral blood, whereas others detected in lesions were absent or very rare in the peripheral blood.

Animals↗

PubMed2005

BK DNA viral load in plasma: evidence for an association with hemorrhagic cystitis in allogeneic hematopoietic cell transplant recipients.

We performed a case-control study to determine the association of BK plasma viremia with hemorrhagic cystitis (HC) in hematopoietic cell transplant (HCT) recipients. Thirty cases of HC (14 of which occurred after platelet engraftment with documented BK viruria [BK-HC]) were compared with matched controls. Weekly plasma samples were tested for BK virus DNA by polymerase chain reaction (PCR). BK viremia detected before or during the disease was independently associated with HC (adjusted odds ratio = 30, P < .001); BK viremia was even important before clinical symptoms of HC occurred (odds ratio = 11, P < .001). Cases of HC and BK-HC had a significantly higher peak of BK plasma viral load than controls. BK virus was detected by in situ hybridization in bladder biopsies of 2 cases with severe HC and long-lasting BK viremia. BK virus seems to play a role in the development of HC and quantitative detection of BK DNA in plasma appears to be a marker of BK virus disease in HCT recipients.

Adolescent↗

PubMed2005

Safety and antiviral activity of emtricitabine (FTC) for the treatment of chronic hepatitis B infection: a two-year study.

BACKGROUND/AIMS: The aim of this study was to evaluate long term safety and antiviral activity of different doses of emtricitabine given once daily to patients chronically infected with hepatitis B. METHODS: Eligible patients were randomized in a double-blind, parallel study to evaluate 25, 100 or 200 mg once daily doses of emtricitabine for 48 weeks. Patients were then followed for an additional 48 weeks on open-label 200 mg emtricitabine. Serum HBV DNA, ALT, and hepatitis B serology were measured at regular intervals over the 2 years. Resistance surveillance was performed after 1 and 2 years on viremic samples, i.e. > 4700 copies/mL. RESULTS: Emtricitabine was well tolerated and produced a dose proportional antiviral response. After 2 years, 53% of the patients had serum HBV DNA < or = 4700 copies/mL, 33% seroconverted to anti-HBe and 85% had normal ALT. Eighteen percent of the patients who had received 200 mg emtricitabine for 2 years developed resistance mutations. CONCLUSIONS: Emtricitabine was well tolerated and demonstrated a potent antiviral response for up to 2 years in patients with chronic hepatitis B infection. Based on these data, 200 mg emtricitabine once daily was chosen as the optimal dose for future hepatitis B studies.

Adult↗

PubMed2005

Clinical outcomes of human herpesvirus 6 reactivation after hematopoietic stem cell transplantation.

BACKGROUND: Although human herpesvirus 6 (HHV-6) is known to reactivate during hematopoietic stem cell transplantation (HSCT), the clinical significance of this finding is controversial. METHODS: We used a quantitative PCR test for HHV-6 to assay plasma samples prospectively collected from a cohort of 110 allogeneic HSCT recipients to evaluate the clinical effects of HHV-6 infection. A retrospective review of medical records was performed to determine clinical end points. RESULTS: HHV-6 reactivation occurred in 52 (47%) of the 110 subjects. Factors that increased the risk of subsequent HHV-6 reactivation were hematologic malignancy that occurred at a time other than the first remission (adjusted P = .002), a mismatch in the sexes of donor and recipient (adjusted P=.05), younger age (adjusted P = .01), and the receipt of glucocorticoids (adjusted P = .06). HHV-6 reactivation was associated with subsequent all-cause mortality (adjusted hazard ration [HR], 2.9; 95% confidence interval [CI], 1.1-7.5), grade 3-4 graft-versus-host disease (GVHD) (adjusted HR, 4.9; 95% CI, 1.5-16), a lower probability of monocyte engraftment (adjusted HR, 0.42; 95% CI; 0.22-0.80), a lower probability of platelet engraftment (adjusted HR, 0.47; 95% CI, 0.21-1.1; P = .05) and a higher platelet transfusion requirement (adjusted P = .02). A higher level of HHV-6 DNA was associated with subsequent central nervous system (CNS) dysfunction (HR, 21; 95% CI, 1.8-249). CONCLUSIONS: HHV-6 reactivation is common after allogeneic HSCT and is associated with subsequent delayed monocyte and platelet engraftment, increased platelet transfusion requirements, all-cause mortality, grade 3-4 GVHD, and CNS dysfunction.

Adolescent↗

PubMed2005

A population-based study of primary human herpesvirus 6 infection.

BACKGROUND: Serologic studies indicate that human herpesvirus 6 (HHV-6) infects 90 percent of children by two years of age. Little is known about the acquisition, virologic course, and clinical manifestations of HHV-6 infection. METHODS: We prospectively studied a cohort of 277 children from birth through the first two years of life to define the pattern of acquisition of HHV-6. The children's saliva was tested weekly for HHV-6 DNA with the use of the polymerase chain reaction. Parents maintained a daily log of signs and symptoms of illness in their children. RESULTS: Primary HHV-6 infection occurred in 130 children, with cumulative percentages of 40 percent by the age of 12 months and 77 percent by the age of 24 months. The peak age of acquisition was between 9 and 21 months. The acquisition of HHV-6 was associated with female sex (adjusted hazard ratio, 1.7; 95 percent confidence interval, 1.2 to 2.4) and having older siblings (adjusted hazard ratio, 2.1; 95 percent confidence interval, 1.4 to 2.9). Among 81 children with a well-defined time of acquisition of HHV-6, 93 percent had symptoms, and 38 percent were seen by a physician. None had seizures. As compared with children who had other illnesses, those with primary HHV-6 infection were more likely to have fever (P=0.003), fussiness (P=0.02), diarrhea (P=0.03), rash (P=0.003), and roseola (P=0.002) and were more likely to visit a physician (P=0.003). CONCLUSIONS: The acquisition of HHV-6 in infancy is usually symptomatic and often results in medical evaluation. Roseola occurs in a minority of patients, and febrile seizures are infrequently associated with primary HHV-6 infection. Older siblings appear to serve as a source of HHV-6 transmission.

Antibodies, Viral↗