References of "Kreis, Stephanie 50002134"
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See detailPlacental transfer and decay of maternally acquired antimeasles antibodies in Nigerian children
Hartter, H. K.; Oyedele, O. I.; Dietz, K. et al

in Pediatric Infectious Disease Journal (2000), 19(7), 635-641

Background. In developing countries vaccination against measles virus (MV) is generally administered at 9 months of age, although it is well- documented that protection of most infants by passively ... [more ▼]

Background. In developing countries vaccination against measles virus (MV) is generally administered at 9 months of age, although it is well- documented that protection of most infants by passively acquired maternal MV antibodies is waning before immunization is given. The purpose of this study was to investigate the decay of maternally derived MV antibodies in Nigerian infants as well as to compare a German and Nigerian cohort of paired mothers and newborns regarding the placental transfer efficiency of MV-specific IgG and total IgG antibodies. Methods. MV-specific IgG antibodies were measured with a commercially available MV-enzyme-linked immunosorbent assay, a recombinant hemagglutinin enzyme-linked immunosorbent assay as well as a neutralization assay. Total IgG values were determined with a standard immunoturbidimetric test. Results. Anti-MV IgG titers were twice as high in German newborns as in Nigerian newborns. An increased concentration of immunoglobulins transferred via the placenta was found only in the German cohort. High concentrations of total maternal IgG reduced the concentration of MV-specific as well as total IgG that crossed the placenta. Furthermore only 17% of the 4-month-old Nigerian infants were still protected against measles. Antibodies had a biologic half-life of 33 days and a biochemical half-life of 48 days. Conclusions. Our findings demonstrate that the decay of passively acquired MV antibodies occurred even more rapidly than expected resulting in susceptibility to MV in most of the 4-month-old infants in Nigeria. Furthermore transfer of maternal anti-MV IgG and total IgG antibodies to the newborn was more efficient in the German cohort compared with the Nigerian group. These findings suggest the use of alternative vaccination strategies in developing countries to possibly reduce the window of susceptibility against measles. [less ▲]

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See detailIsolation of measles virus from a naturally-immune, asymptomatically re-infected individual
Vardas, E. A B; Kreis, Stephanie UL

in Journal of Clinical Virology (1999), 13(3), 173-179

Background: The changing epidemiology of measles with mild measles cases increasingly being recognised in previously-vaccinated individuals, suggests that more asymptomatic or subclinical cases might be ... [more ▼]

Background: The changing epidemiology of measles with mild measles cases increasingly being recognised in previously-vaccinated individuals, suggests that more asymptomatic or subclinical cases might be occurring. Although this has been clearly documented in previously-vaccinated individuals, the frequency of these asymptomatic infections in individuals previously naturally-infected with measles is not known. Also, it is not known whether these asymptomatic or mildly-infected individuals who do not display the full range of clinical signs of measles are capable of transmitting the virus to other susceptible persons. Objectives: To demonstrate the isolation of measles virus (MV) from previously, naturally-immune individuals asymptomatically infected with measles while in close contact with acutely infected family members and to document the secondary immune responses (SIR) associated with asymptomatic measles infection. Study Design: Throat swab and urine specimens from five acute measles cases and their family contacts, taken within 5 days of onset of rash in each acute case, were used to isolate MV by tissue culture. Positive tissue culture results were confirmed by indirect immunofluorescence (IF) staining. Measles specific antibodies (IgG and IgM), IgG urea avidity and measles-neutralising antibodies were measured in the one family (index family) where an asymptomatic measles infection of a contact was demonstrated. Results: The acutely infected patient in the index family (T1/96) had a measles-neutralising antibody titre of < 1:10, measles IgG urea avidity of 24% and MV was isolated and confirmed by IF from urine and throat swab specimens. T1/96 represents acute measles infection after primary vaccine failure because he had a clear history of being vaccinated against measles as a child. MV was also successfully isolated from throat swab and urine specimens from the other four acute cases and from the urine but not the throat swab of an asymptomatically infected family contact in the index family (mother, T2/96). T2/96 had a history of natural measles infection as a child approximately 50 years ago. In addition to detectable MV in urine this contact also had a SIR with a rise in measles specific neutralising antibody titre. No virus was isolated from the other contact in the index family (father, T3/96) or from the contacts of the other four acute cases examined. Conclusions: This is the first report of a confirmed asymptomatic MV infection, by MV isolation and IF testing and a concurrent SIR, in a previously naturally-immune contact of an acute case. The importance of these findings to the epidemiology and control of MV as well as the diagnostic value of MV urine isolation and IF confirmation for mild or asymptomatic cases must be examined further. [less ▲]

Detailed reference viewed: 104 (5 UL)
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See detailGenotypic and antigenic characterization of hemagglutinin proteins of African measles virus isolates
Truong, A. T.; Kreis, Stephanie UL; Ammerlaan, W. et al

in Virus Research (1999), 62(1), 89-95

A comprehensive phylogenetic study based on the hemagglutinin (H) protein of all known African measles virus (MV) isolates is presented. The study includes 64 new H gene sequences from Ghana, Nigeria and ... [more ▼]

A comprehensive phylogenetic study based on the hemagglutinin (H) protein of all known African measles virus (MV) isolates is presented. The study includes 64 new H gene sequences from Ghana, Nigeria and South Africa as well as viruses from Zambia and The Gambia for which only incomplete sequencing data were available and that have previously not been genotyped. The results provide further support to the tentative assignment of the Nigerian and Ghanaian viruses to a new genotype B3 within clade B. A distinct geographic distribution pattern emerged with clade B viruses circulating exclusively in African countries north of the equator. All MV strains from southern Africa grouped in clades A and D with the majority of viruses belonging to genotype D4. The viruses considerably differed by their sensitivity to neutralization by monoclonal antibodies (mAb), but three selected antibodies were sufficient to distinguish between African MVs representing four different genotypes. Copyright (C) 1999 Elsevier Science B.V. [less ▲]

Detailed reference viewed: 100 (6 UL)
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See detailCase report and molecular analysis of subacute sclerosing panencephalitis in a South African child
Vardas, E. A D; Leary, P. M. B; Yeats, J. C et al

in Journal of Clinical Microbiology (1999), 37(3), 775-777

This is the first case of subacute sclerosing panencephalitis from South Africa in which the molecular characteristics of the causative measles virus were examined. The virus found is classified as ... [more ▼]

This is the first case of subacute sclerosing panencephalitis from South Africa in which the molecular characteristics of the causative measles virus were examined. The virus found is classified as genotype D3, which has not previously been found in Africa and was last circulating in the United States before 1992. [less ▲]

Detailed reference viewed: 69 (6 UL)
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See detailPartial amplification of the measles virus nucleocapsid gene from stored sera and cerebrospinal fluids for molecular epidemiological studies
Kreis, Stephanie UL; Schoub, B. D.

in Journal of Medical Virology (1998), 56(2), 174-177

The analysis of stored sera for retrospective molecular epidemiological studies provides a powerful tool to investigate strain variation in measles viruses that had circulated up to 20 years ago. For this ... [more ▼]

The analysis of stored sera for retrospective molecular epidemiological studies provides a powerful tool to investigate strain variation in measles viruses that had circulated up to 20 years ago. For this purpose, a rapid and simple method for extraction of RNA from stored sera and cerebrospinal fluids (CSF) was developed. When used on sera and CSFs that have been frozen for as long as 20 years, this method proved to be more efficient than established techniques. The extracted RNA was reverse transcribed into cDNA by using random hexamer primers. The PCR amplification of the 3' terminus of the nucleocapsid gene (N) was divided into two overlapping fragments of 375 and 384 bp length, covering the entire region of interest. This region is thought to have the highest variability within the MV genome and has previously been shown to be suitable for strain characterization. The resulting PCR fragments were sequenced manually by using standard methods without the need of further clean-up steps. [less ▲]

Detailed reference viewed: 98 (5 UL)
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See detailSequence analysis of the nucleocapsid gene of measles virus isolates from South Africa identifies a new genotype
Kreis, Stephanie UL; Vardas, E.; Whistler, T.

in Journal of General Virology (The) (1997), 78(7), 1581-1587

Sequence analysis was performed on 20 measles virus (MV) isolates from South Africa, five of which were obtained between 1986 and 1989 and 15 isolates collected during the 1994/95 measles season. A 590 bp ... [more ▼]

Sequence analysis was performed on 20 measles virus (MV) isolates from South Africa, five of which were obtained between 1986 and 1989 and 15 isolates collected during the 1994/95 measles season. A 590 bp fragment of the carboxyl terminus of the nucleocapsid (N) was amplified by PCR and subjected to sequence and phylogenetic analysis. Comparison of the South African MV strains with those previously described revealed that at least two distinct groups of wild-type (wt) MV exist, one of which has been circulating since 1986. The major genotype (I) was represented by the more recent isolates which showed three characteristic amino acid substitutions. Furthermore, three vaccine-like viruses with sequences very similar to the Edmonston wt strain were identified. Phylogenetic analysis of 100 MV strains allowed the assignment of new definitions for MV genotypes and subgroups. Employing these definitions, the majority of South African isolates analysed here formed a new genotype. [less ▲]

Detailed reference viewed: 85 (14 UL)
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See detailMeasles virus transmission from infected to immune individuals - Implications for measles control and elimination
Vardas, E.; Andre, M.; Kreis, Stephanie UL et al

in South African Medical Journal (1997), 87(12), 1709

Detailed reference viewed: 67 (14 UL)
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See detailRapid identification of measles virus strains by the heteroduplex mobility assay
Kreis, Stephanie UL; Whistler, T.

in Virus Research (1997), 47(2), 472197-203

The continued endemic presence of measles virus (MV), and the large number of isolates which are made in South Africa each year, demanded the use of a rapid and reliable pre-screening technique to select ... [more ▼]

The continued endemic presence of measles virus (MV), and the large number of isolates which are made in South Africa each year, demanded the use of a rapid and reliable pre-screening technique to select isolates for molecular epidemiological studies by sequence analysis. The heteroduplex mobility assay (HMA) was used to genetically characterize 47 MV isolates collected from three different provinces in South Africa, made between 1986 and 1995. The carboxyl-terminal 590 nt of the nucleocapsid (N) gene - the most variable region of the genome - was amplified by polymerase chain reaction (PCR) and subsequently subjected to HMA analysis for initial genotyping. The results showed three different patterns of heteroduplex formation by gel electrophoresis, representing two distinct wild-type lineages and one group of vaccine-like viruses. Comparison of HMA results with phylogenetic analysis of sequence data for several of the South African MV strains showed a complete correlation of results. The HMA proved to be a useful tool for screening MV isolates for use in molecular epidemiological studies. [less ▲]

Detailed reference viewed: 72 (18 UL)