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At least 775 records · Page 43Linked to original sources
PubMed2001

Herpes simplex virus type 2 seroepidemiology in Spain: prevalence and seroconversion rate among sexually transmitted disease clinic attendees.

BACKGROUND: Only limited data on the seroprevalence of herpes simplex virus type 2 (HSV-2) are available from European countries. Until recently, serologic tests for HSV-2 serotyping have been hampered by cross-reactivity to type-common antigens. The present study aims at providing data on the prevalence of HSV-2 infection in a group of STD clinic attendees using a reliable type-specific immunoassay. GOAL: To evaluate the seroprevalence of HSV-2 and the accumulated incidence of clinical genital herpes infection in a sample of Spanish sexually transmitted disease (STD) clinic attendees. STUDY DESIGN: The study consisted of two parts. First, a cross-sectional study of HSV-2 seroprevalence was conducted in patients with STDs. Second, a prospective cohort study was undertaken to evaluate the accumulated incidence of infection by HSV-2 and of clinical episodes of genital herpes in HSV-2-negative patients included in the first study during a follow-up period of 6 to 18 months. RESULTS: Of the 374 patients (129 men, 245 women) studied, 25% were seropositive for HSV-2 (12% of men, 30% of women). Antibodies to HSV-2 were related to female gender (odds ratio, 2.7; P < 0.001) and to the number of sexual partners (odds ratio, 4.1; P < 0.001). Fifty-two percent of patients (145 of 281 patients) who were initially seronegative returned to the clinic for a second serologic testing, of whom 1% (2 of 145 patients) had seroconverted. None of the patients developed genital herpes during the follow-up period. CONCLUSION: The relatively high seroprevalence (25%) and the low rate (4%) of HSV-2 previously reported in the general population in Spain suggest that the virus circulation may be restricted to certain risk groups. Therefore, future healthcare measures may target specific groups, such as patients with STDs.

Antibodies, Viral↗
PubMed1986

Risk of seroconversion for acquired immunodeficiency syndrome (AIDS) in San Francisco health workers.

The occupational risk of acquiring acquired immunodeficiency syndrome (AIDS) virus infection in health workers exposed to AIDS patients and specimens was assessed by a serologic study at San Francisco General Hospital and collaborating research laboratories. A total of 101 medical workers without risk factors for AIDS were examined for antibodies to two isolates of the AIDS retrovirus (AIDS-associated retrovirus 2[ARV-2] and human T cell lymphotropic virus III). Most had heavy, long-term exposure to AIDS patients and 29 had been exposed by needlestick or mucocutaneous accident. None of the 101 had antibodies to ARV-2 by immunofluorescence or to HTLV-III by enzyme-linked immunosorbent assay and Western Blot.

Acquired Immunodeficiency Syndrome↗
PubMed2001

HIV seroconversion during pregnancy and risk for mother-to-infant transmission.

Pregnant women infected with HIV-1 were enrolled in a prospective mother-to-infant transmission study from 1992 through 1994 in Bangkok. In participating hospitals, voluntary HIV testing was routinely offered at the beginning of antenatal care and again in the middle of the third trimester of pregnancy. Women who seroconverted to HIV during pregnancy were compared with women who had tested positive on their first antenatal test. Maternal HIV RNA levels were determined during pregnancy, at delivery, and postpartum using RNA polymerase chain reaction (PCR), and infection status in infants was determined by DNA PCR. No infants were breast-fed, but prophylactic antiretroviral therapy was not yet used in Thailand to prevent transmission from mother to infant. Among enrolled women, 16 who seroconverted during pregnancy and 279 who were HIV-1-seropositive at their first antenatal test gave birth. Median plasma RNA levels at delivery were similar for the two groups (17,505 and 20,845 copies/ml, respectively; p =.8). Two (13.3%) of 15 infants born to women who seroconverted and 66 (24.8%) of 266 infants born to previously HIV-seropositive women were infected with HIV (p =.5). There was no increased risk for mother-to-infant HIV transmission and no significant difference in viral load at delivery between HIV-infected women who seroconverted to HIV during pregnancy and those who were HIV-seropositive when first tested.

Adult↗
PubMed2002

HIV-1 infection in individuals with the CCR5-Delta32/Delta32 genotype: acquisition of syncytium-inducing virus at seroconversion.

Homozygosity for the 32 base-pair deletion (Delta32/Delta32) in the CCR5 coreceptor gene is associated with incomplete HIV-1 resistance. Six HIV-1-infected Delta32/Delta32 patients have been reported. We report 2 additional Delta32/Delta32-infected individuals, among 106 seroconverters in a vaccine preparedness study. Like the previous 6, these individuals experienced rapid CD4 decline. However, taken together, the 8 patients have neither uniformly high virus load nor rapid progression to AIDS. We obtained five virus isolates from 1 patient at 5, 6, 7, 10, and 12 months after the estimated time of infection. The earliest isolate exhibits the syncytium-inducing (SI) phenotype and exclusive use of the CXCR4 coreceptor, suggesting acquisition of HIV-1 through this coreceptor. Of the remaining 104 seroconverters, 8 were CCR5-Delta32/+ and 96 were CCR5-+/+. Three CCR5-+/+ seroconverters who showed the uncommon pattern of early SI virus and rapid CD4 decline had uniformly high viral load and more heterogeneous coreceptor usage. These results further support the conclusion that Delta32-mediated resistance is incomplete and is associated with acquisition of exclusively-X4 variants of HIV-1. The pathogenic potential of these viruses may be different from late-stage X4 virus or early X4 virus acquired by individuals with other CCR5 genotypes.

Base Pairing↗
PubMed1995

Cytotoxic T cell responses in patients with chronic hepatitis B virus infection undergoing HBe antigen/antibody seroconversion.

Cytotoxic T cells have been identified in the peripheral blood of patients with acute hepatitis B virus infections for a short period after clinical presentation. However, in patients in whom the virus persists these have been difficult to demonstrate. In the chronic infection during HBe antigen clearance, when there has been an exacerbation of the disease, we have been able to demonstrate an MHC class I-restricted cytolytic response directed against the nucleocapsid antigens. In an HLA-A2 patient this was induced in vitro with the peptide p18-27, previously described as an HLA-A2-restricted T cell epitope. In patients of other HLA types, recombinant core antigen was used to induce antigen-specific lysis: statistical analysis of the cytolytic responses of chronically infected patients demonstrated a nucleocapsid antigen-specific lysis in patients who were seroconverting. Removal of CD4+ cells reduced non-MHC-restricted cytolysis, allowing an MHC class I-restricted cytolytic component to be demonstrated.

Amino Acid Sequence↗
PubMed1984

A retrospective study on transmission of adult T cell leukemia virus by blood transfusion: seroconversion in recipients.

Possible transmission of adult T cell leukemia virus (ATLV) by blood transfusion was studied retrospectively. Of 41 recipients of whole blood or blood components containing cells from donors having antibodies to antigen that is associated with ATLV (anti-ATLA), 26 (63.4%) produced anti-ATLA. However, no anti-ATLA was detected in all 14 recipients of fresh-frozen plasma prepared from anti-ATLA-positive donors. None of 252 recipients of blood with cell components from anti-ATLA-negative donors produced anti-ATLA. The development of anti-ATLA in the recipients may correspond to antibody production after establishment of primary infection with ATLV that is associated with cells in blood from anti-ATLA-positive donors who are ATLV carriers.

Adolescent↗