| 1. |
- Zhang, Shu-min, et al.
(författare)
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Dynamic changes in hepatitis C virus genotypes and sequence patterns in plasma donors exposed to reinfection
- 2001
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Ingår i: Journal of Medical Virology. - 1096-9071. ; 63:3, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- Sequential serum samples from four plasma donors (designated A, B, C, and D) at a Chinese blood bank with hepatitis C transmission problems were studied from 1994 to 1997. The samples were examined for antibodies to HCV, for HCV viremia by PCR and HCV genotyping. Co- and superinfections were studied by direct sequencing of the 5'-NCR, core, and HVR-1 regions, using low and high genotype-specific primers targeting the HVR-1, and by cloning of selected samples. Genotype changes occurred in all four donors: A (1b-2a-1b), B (1b-2a-2a/1b-1b), C (1b-2a), and D (1b/2a-1b). Donor D was married to donor B. The 1b isolates of donor A could not be sequenced in the HVR-1 due to low-level viremia. Two early 1b isolates from donors B and C showed high HVR-1 similarity. The later 1b isolates from B had changed significantly but were identical to the isolate from donor D. Spouses B and D also shared genotype 2a strains. The 2a isolates from donors A, B/D, and C differed by 8-10 nucleotides in the HVR-1. The frequent changes in genotype and the appearance of homologous isolates from different subjects indicate transmission at the blood bank. These four donors, all identified shortly after infection, developed very few mutations in the HVR-1 and few quasispecies during a period of 6-18 months. Highly specific primers proved to be superior to cloning for identification of minor virus populations. The results indicate nosocomial transmission of more than one strain at the blood bank studied.
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| 2. |
- Bläckberg, Jonas, et al.
(författare)
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Genotypic differences in the hepatitis B virus core promoter and precore sequences during seroconversion from HBeAg to anti-HBe
- 2000
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Ingår i: Journal of Medical Virology. - 1096-9071. ; 60:2, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis B virus (HBV) strains from anti-HBe positive patients often show specific mutations in the precore gene, the core promoter region, or both. The dynamics of seroconversion in relation to the appearance of these mutations has not been studied and compared between defined HBV genotypes. Samples from patients followed during seroconversion from HBeAg to anti-HBe were amplified by polymerase chain reaction (PCR), sequenced and genotyped. Among 16 sets of samples, 6 belonged to genotype A, 6 to genotype D, 2 to genotype B, 1 to genotype C, and 1 to genotype E. Whereas strains from genotypes B, C and E showed changes in the core promoter, precore codon 28 or both, genotype A and D strains displayed a different pattern. In 4 of 6 anti-HBe positive samples from genotype A, the precore had a wild-type sequence while the core promoter sequence showed a specific TGA mutation. In another genotype A strain a precore stop mutation was preceded by a mutation in codon 15, thus conserving base-pairing at the pregenomic RNA level in this region. In contrast, all genotype D strains showed wild-type sequences in both the core promoter and precore codon 28 in pre- and post-seroconversion samples. Thus, in 8 patients with a mean follow-up time of 17 months, wild-type sequences in both the core promoter and precore codon 28 were found after seroconversion to anti-HBe. This study also confirmed, for genotype D, that HBeAg seroconversion often occurs earlier than genomic conversion.
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| 3. |
- Shev, S, et al.
(författare)
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GBV-C/HGV infection in hepatitis C virus-infected deferred Swedish blood donors
- 1998
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Ingår i: Journal of Medical Virology. - 1096-9071 .- 0146-6615. ; 54:2, s. 75-79
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Tidskriftsartikel (refereegranskat)abstract
- Sera from 62 hepatitis C virus (HCV)-infected Swedish blood donors were tested by a nested polymerase chain reaction using primers targeting the 5'-noncoding region of the GB virus-C/hepatitis G (GBV-C/HGV) genome and an enzyme-linked immunosorbent assay that detects antibodies to the envelope protein E2 of GBV-C/HGV (anti-E2). Fourteen (22%) and 21 (34%) of the 62 blood donors were found to be GBV-C/HGV RNA and anti-E2 positive, respectively. None of the blood donors was positive for both GBV-C/HGV RNA and anti-E2. Thus, 35 of 62 (56%) HCV-infected donors had been exposed to GBV-C/HGV infection. At sequencing of the 14 GBV-C/HGV isolates, 12 were identified as subtype 2a and 2 as subtype 2b. One of 7 (14%) donors with mild liver disease such as steatosis and nonspecific reactive hepatitis had been exposed to GBV-C/HGV vs. 34 of 55 (62%) with chronic hepatitis with or without cirrhosis (P = 0.04). All other differences in histology were small between HCV and dual HCV GBV-C/HGV-infected donors. In conclusion, more than half of HCV-infected Swedish blood donors in this study were positive for either GBV-C/HGV RNA or anti-E2. GBV-C/HGV viremia and seropositivity were mutually exclusive.
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| 4. |
- Viazov, S, et al.
(författare)
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Hepatitis C virus genotypes in different regions of the former Soviet Union (Russia, Belarus, Moldova, and Uzbekistan)
- 1997
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Ingår i: Journal of Medical Virology. - 1096-9071. ; 53:1, s. 36-40
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of HCV genotypes in four republics of the former Soviet Union (Russia, Belarus, Moldova, and Uzbekistan) was investigated. Overall, 197 HCV isolates from 66 blood donors and 131 patients with chronic hepatitis were typed. Viral sequences from sera of infected subjects were amplified by nested RT-PCR using primers from the core region and typed by one or two techniques: (1) DNA enzyme immunoassay (DEIA) and (2) PCR with a set of type-specific primers. Only three major HCV genotypes were identified in this study population. HCV 1b was found to be the predominant virus type both among blood donors and chronic hepatitis patients, followed by 3a, 2a, and 1a (chronic hepatitis patients: 1b-82%; 3a-10%; 2a-4%, 1a-5% and 2c-1%; blood donors: 1b-77%; 3a-17%; and 2a-6%). No significant difference in genotype distribution was observed between different countries or between blood donors and chronic hepatitis patients within the same country. Results of the genotyping procedures were confirmed by direct sequencing of 216 nt PCR fragments corresponding to part of HCV core gene. Phylogenetic analysis of HCV 1b sequences from this study and from the Genbank demonstrated that the sequences from the former Soviet Union do not form evolutionary lineage(s) different from those of strains of the same subtype circulating in other geographical regions.
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| 5. |
- Enbom, Malin, et al.
(författare)
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Antibodies to human herpesvirus 8 latent and lytic antigens in blood donors and potential high-risk groups in Sweden : variable frequencies found in a multicenter serological study
- 2000
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Ingår i: Journal of Medical Virology. - 0146-6615 .- 1096-9071. ; 62:4, s. 498-504
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Tidskriftsartikel (refereegranskat)abstract
- Human herpesvirus 8 (HHV-8) is a herpesvirus associated with Kaposi's sarcoma (KS). An immunofluorescence assay was used for detection of IgG, IgM, and IgA antibodies against lytic and latent HHV-8 antigens to analyse samples from KS patients (n = 8), healthy blood donors (n = 162), individuals with a high risk sexual behaviour (n = 114), and bone marrow transplant patients (with high risk for bloodborne infections) (n = 34) in Sweden. Of the KS patients, 88% had IgG antibodies to both lytic and latent antigens by immunofluorescence. In all other groups, antilatent antibodies were rare (0-2.6%). IgG antibodies to the lytic antigens were found, by immunofluorescence, in 20% of the blood donors, 31% of the high risk patients, and in 24 and 29% of the bone marrow transplant patients (pre- and post-transplant samples, respectively). For verification of the specificity of the anti-lytic antibodies, 170 of the samples were also tested blindly at different laboratories world-wide with five other assays shown previously to detect HHV-8 antibodies in most KS patients. By using two recombinant HHV-8 proteins (ORF65/vp17 and K8.1/gp 35-37) in ELISA, a whole-virion ELISA and two immunofluorescence assays confirmation of the reactivity against lytic viral antigens was sought. The comparison of the different methods suggested the K8.1 ELISA to be highly specific and also showed a good agreement between two of the immunofluorescence assays. However, generally there was a poor correlation for positive results, indicating the need of further methodological development.
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| 6. |
- Wang, Z, et al.
(författare)
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Human papillomavirus antibody responses among patients with incident cervical carcinoma.
- 1997
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Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 52:4
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Tidskriftsartikel (refereegranskat)abstract
- The human papillomavirus (HPV) is recognized as a major cause of cervical cancer precursor lesions. HPV serology is a key method in the continuing elucidation of the importance of HPV exposure for cancer development and in predicting HPV-associated diseases. To extend previous HPV serological studies on cervical cancer, serum samples from a consecutive series of 216 women with incident untreated cervical carcinoma and 243 age- and sex-matched healthy blood donors were evaluated for the presence of antibodies against HPV capsids, a marker of past or present HPV exposure, as well as against several cervical cancer-associated defined HPV epitopes. Among the capsid antibody responses, HPV type 16 seropositivity had the strongest association with cervical cancer (OR 2.7, 95% CI 1.8-4.2), but HPV 18 and HPV 33 seropositivities were also significantly associated with cervical cancer (OR 1.6, 95% CI 1.1-2.5; and OR 1.5, 95% CI 1.0-2.2, respectively). The antibody responses against the defined HPV epitopes were confirmed to be associated with cervical cancer, at ORs ranging from 1.4 to 2.0. In conclusion, the study confirms that antibodies against defined HPV epitopes are associated with cervical cancer and provides evidence that seropositivities for HPV types 16, 18, and 33 are associated with cervical cancer risk.
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| 7. |
- Abou Ghayda, Ramy, et al.
(författare)
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The global case fatality rate of coronavirus disease 2019 by continents and national income: A meta-analysis
- 2022
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Ingår i: Journal of Medical Virology. - : WILEY. - 0146-6615 .- 1096-9071. ; 94:6, s. 2402-2413
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study is to provide a more accurate representation of COVID-19s case fatality rate (CFR) by performing meta-analyses by continents and income, and by comparing the result with pooled estimates. We used multiple worldwide data sources on COVID-19 for every country reporting COVID-19 cases. On the basis of data, we performed random and fixed meta-analyses for CFR of COVID-19 by continents and income according to each individual calendar date. CFR was estimated based on the different geographical regions and levels of income using three models: pooled estimates, fixed- and random-model. In Asia, all three types of CFR initially remained approximately between 2.0% and 3.0%. In the case of pooled estimates and the fixed model results, CFR increased to 4.0%, by then gradually decreasing, while in the case of random-model, CFR remained under 2.0%. Similarly, in Europe, initially, the two types of CFR peaked at 9.0% and 10.0%, respectively. The random-model results showed an increase near 5.0%. In high-income countries, pooled estimates and fixed-model showed gradually increasing trends with a final pooled estimates and random-model reached about 8.0% and 4.0%, respectively. In middle-income, the pooled estimates and fixed-model have gradually increased reaching up to 4.5%. in low-income countries, CFRs remained similar between 1.5% and 3.0%. Our study emphasizes that COVID-19 CFR is not a fixed or static value. Rather, it is a dynamic estimate that changes with time, population, socioeconomic factors, and the mitigatory efforts of individual countries.
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