Incomplete immune reconstitution after initiation of highly active antiretroviral therapy in human immunodeficiency virus-infected patients with severe CD4+ cell depletion. (41/285)

Immune function was observed for 144 weeks in 643 human immunodeficiency virus (HIV)-infected subjects who (1) had nadir CD4+ cell counts of <50 cells/mm3, followed by a sustained increase to > or =100 cells/mm3 after the initiation of HAART, and (2) were enrolled in a randomized trial of continued azithromycin prophylaxis versus withdrawal for prevention of Mycobacterium avium complex disease. The median CD4+ cell count was 226 cells/mm3 at entry and 358 cells/mm3 at week 144. Anergy (80.2% of patients) and lack of lymphoproliferative response to tetanus toxoid (TT; 73%) after immunization and impaired antibody responses after receipt of hepatitis A (54%) and TT (86%) vaccines were considered to be evidence of impaired immune reconstitution. Receipt of azithromycin did not have an effect on CD4+ cell count but was associated with higher rates of delayed-type hypersensitivity responses to TT (25% of subjects who received azithromycin vs. 15% of those who did not; P=.009) and mumps skin test antigen (29% vs. 17%; P=.001). Although the subjects had only partial responses to immune function testing, the rate of opportunistic infections was very low, and none of the tests was predictive of risk.  (+info)

Age-specific mumps seroprevalence of an unvaccinated population of adolescents in Ankara, Turkey. (42/285)

This study aimed to detect the age-specific mumps seroprevalence of an unvaccinated population of adolescents in Ankara, Turkey and to compare the prevaccination epidemiology of mumps with those of some other countries. Four hundred and forty adolescents (227 females, 213 males) aged 9 - 16 years who were admitted to the Adolescent Unit were included in this study. For each participant, a questionnaire was completed and mumps-specific IgG antibodies were screened quantitatively by enzyme-linked fluorescent assay. Of the 440 patients screened for mumps antibodies, 48 (10.9%) were seronegative. Mumps seronegativity according to sex and age groups were 13.6, 9.9, and 10.4% in females and 18, 10.2, and 6.2% in males in the age groups of 9 - 10, 11 - 13, and 14 - 16, respectively. Mumps immunization models similar to those of European countries might be acceptable for Turkey, but since a low vaccination coverage may shift mumps infection to older ages, mumps immunization of adolescents is important until a national mumps vaccination program with a high coverage could be sustained. The routine health supervision visit at ages 11 to 12 years is an ideal time to immunize unvaccinated adolescents.  (+info)

Seroprevalence of measles, mumps and rubella antibodies in Luxembourg: results from a national cross-sectional study. (43/285)

A serological prevalence survey was carried out in Luxembourg during 2000-2001 to determine the antibody status of the Luxembourg population against vaccine-preventable infections. Blood samples of children and adolescents were collected prospectively in randomly selected schools. Samples of adults were obtained through volunteer patients of the national health laboratory or of the mandatory pre-nuptial test. Measles, mumps and rubella (MMR) virus antibody concentrations were measured using commercial ELISA tests. Age-standardized prevalence of measles, mumps and rubella virus antibodies was found to be 96.58, 75.40 and 95.69% respectively. Significant age-dependence of serology was observed for all three infections, with study participants born after the introduction of the MMR vaccine experiencing a gradual decline of antibodies following vaccination in childhood. Older study participants who were more likely to have antibodies from natural infection had consistently higher titres than younger individuals. Present vaccination coverage with MMR appears to be sufficient to prevent large local outbreaks of measles and rubella, but probably not mumps.  (+info)

Genetic diversity of mumps virus in oral fluid specimens: application to mumps epidemiological study. (44/285)

Three hundred nine mumps virus (MuV) strains detected in the United Kingdom during 1995-2002 were characterized by partial sequencing of the small hydrophobic gene and were shown to belong to at least 6 different genotypes. A strain representing a new genotype was isolated from a seminal fluid specimen. Identical strains belonging to genotypes G and C were found to circulate for up to 3 years. One genotype H strain reappeared after an absence of 4 years. Distinct lineages (G1-G7) within genotype G were recognizable in the present study, and this level of characterization proved to be very useful for tracking MuV importations and subsequent transmission. We propose, here, a preliminary standardization of international nomenclature for genetic characterization of MuV strains, to facilitate future molecular epidemiological studies of mumps. Oral fluid (OF) specimens (n=1441) were used to detect both anti-MuV IgM and MuV genome, and the results indicate that OF specimens can be used successfully for diagnosis and have the potential to play a valuable role in diagnosis and surveillance of mumps.  (+info)

Comparison of a neutralization enzyme immunoassay and an enzyme-linked immunosorbent assay for evaluation of immune status of children vaccinated for mumps. (45/285)

A 50% neutralization enzyme immunoassay (N50-EIA) was compared with an indirect enzyme-linked immunosorbent assay (ELISA) for determining mumps virus antibodies in three consecutive serum samples from 138 children vaccinated with a live mumps vaccine at the age (in years) of 1.5. By the N50-EIA, most (132 of 138) preserum samples did not show neutralizing activity. Eight to 12 weeks after vaccination, 17 of the children were still negative, but only 7 remained so after 2.5 years, resulting in a seroconversion rate of 125 of 132 (95%). Over the same period, the neutralization geometric mean titer rose from 3.6 to 9.9. By an indirect ELISA, 128 of 138 preserum samples were found negative. The early and late postvaccination sera of 8 children were ELISA negative, resulting in a seroconversion rate of 120 of 128 (94%). Only two children remained seronegative by both methods. Seven of the late postvaccination serum samples yielded noncorresponding results, reflecting 95% correlation between both methods. Due to cross-reactivity with parainfluenza viruses, the ELISA proved to be less specific, but on the other hand, it showed a greater sensitivity than the N50-EIA.  (+info)

Comparison of vaccination with measles-mumps-rubella vaccine at 9, 12, and 15 months of age. (46/285)

To determine seroconversion rates with measles-mumps-rubella vaccine administered to children at 9, 12, or 15 months of age, we undertook a prospective randomized trial. Among children vaccinated at 15 months of age, 98% seroconverted to measles, compared with 95% of those vaccinated at 12 months of age and 87% of those vaccinated at 9 months of age. In each age group, children of mothers born in or before 1963 had lower rates of seroconversion against measles, with the lowest rate in children vaccinated at 9 months. The seroconversion rate of rubella paralleled that of measles, with the lowest seroconversion rates in children vaccinated at 9 months of age whose mothers were born in or before 1963. The response to mumps varied little by age of the child or birth year of the child's mother. These results support the recommended age for first vaccination with measles-mumps-rubella at 12-15 months.  (+info)

Central memory CD4+ T cell responses in chronic HIV infection are not restored by antiretroviral therapy. (47/285)

A strong CD4(+) T cell response has been correlated with better control of HIV infection. However, the effect of HIV on the maintenance of Ag-specific memory CD4(+) T cells is not fully understood. We characterized the function and phenotype of memory CD4(+) T cells generated by mumps and influenza A or B viruses in HIV-infected individuals receiving highly active antiretroviral therapy (n = 21), HIV-infected long-term nonprogressors (n = 10), and HIV-seronegative volunteers (n = 10). We observed significantly decreased proliferation of the Ag-specific central memory CD4(+) T cell population (CD28(+)/CCR7(+)/CD45RA(-)) in the antiretroviral treated HIV-infected individuals compared with the seronegative controls. Restored CD4(+) T cell count and decreased HIV viral load while on highly active antiretroviral therapy did not result in increased proliferation, whereas nadir CD4(+) T cell count predicted the presence of Ag-specific proliferation. Our results indicate that HIV infection leads to impaired maintenance of virus-induced or vaccine-generated central memory CD4(+) T cells that is not restored by HAART.  (+info)

Characterization of nucleocapsid binding by the measles virus and mumps virus phosphoproteins. (48/285)

We report an analysis of the interaction between the P protein and the RNA-associated N protein (N-RNA) for both measles and mumps viruses with proteins produced in a bacterial expression system. During this study, we verified that the C-terminal tail of the N protein is not required for nucleocapsid formation. For both measles and mumps virus N, truncated proteins encompassing amino acids 1 to 375 assemble into nucleocapsid-like particles within the bacterial cell. For measles virus N, the binding site for the P protein maps to residues 477 to 505 within the tail of the molecule, a sequence relatively conserved among the morbilliviruses. For mumps virus N, a binding site for the P protein maps to the assembly domain of N (residues 1 to 398), while no strong binding of the P protein to the tail of N was detected. These results suggest that the site of attachment for the polymerase varies among the paramyxoviruses. Pulldown experiments demonstrate that the last 50 amino acids of both measles virus and mumps virus P (measles virus P, 457 to 507; mumps virus P, 343 to 391) by themselves constitute the nucleocapsid-binding domain (NBD). Spectroscopic studies show that the NBD is predominantly alpha-helical in both viruses. However, only in measles virus P is the NBD stable and folded, having a lesser degree of tertiary organization in mumps virus P. With isothermal titration calorimetry, we demonstrate that the measles virus P NBD binds to residues 477 to 505 of measles virus N with 1:1 stoichiometry. The dissociation constant (K(d)) was determined to be 13 microM at 20 degrees C and 35 microM at 37 degrees C. Our data are consistent with a model in which an alpha-helical nucleocapsid binding domain, located at the C terminus of P, is responsible for tethering the viral polymerase to its template yet also suggest that, in detail, polymerase binding in morbilliviruses and rubulaviruses differs significantly.  (+info)