Biomedical subjects

V Nemecek

Publications and source records attributed to V Nemecek.

5 recordsLinked to original sources

PubMed2006

Long-term protective effect of post-exposure Havrix administration during viral hepatitis Type A outbreaks.

Administration of human normal immunoglobulin (HNIG) post-exposure has been routinely used in Slovakia for outbreak control of hepatitis A, but requires deep intramuscular injection, provides only short-lived protection and is a human blood product. The protective effect of post-exposure administration of an inactivated hepatitis A vaccine was evaluated during 10 outbreaks in Slovakia. Direct contacts of confirmed hepatitis A cases received either: a single dose of hepatitis A vaccine (n = 2171) or immunoglobulin (HNIG, n = 3837). In the HNIG group the number of hepatitis A confirmed cases dropped within the first 7 weeks, however the decrease was not as rapid or as marked as that observed in the vaccinated group where the number of hepatitis A cases dropped within the first 4 weeks after vaccination. Among contacts, 67 cases of hepatitis A were detected during the maximum incubation period of 45 days: 16 cases (0.7%) in the vaccine group and 51 cases (1.3%) in the HNIG group (p < 0.05). After two and three years respectively, 50 and 39 volunteers who had previously received one dose of hepatitis A vaccine received a booster dose and anti-HAV antibodies were measured. Differences in anti-HAV antibody GMCs before and after the booster were statistically significant. The longer time interval (3 years instead of 2) between primary vaccination and booster administration did not seem to impact the magnitude of the booster response. The results of this study show that active post-exposure immunisation with only one dose of inactivated vaccine confers high and long-term protection and effectively controls viral hepatitis A outbreaks.

Adolescent↗

PubMed2005

[HCV genotyping by combination of the Cobas Amplicor HCV 2.0 test and the reverse hybridization Versant HCV Genotype Assay].

Genotyping of hepatitis C virus (HCV) is of relevance to scheduling the treatment of patients with chronic hepatitis C (VHC), making their prognosis and monitoring the treatment efficacy. A set of 62 sera testing HCV RNA positive in Cobas Amplicor HCV 2.0 test (CA) were genotyped using Versant HCV Genotype Assay (LiPA) Bayer, i.e. the reverse hybridization method, with the CA amplified product being directly used in the assay. Fifty-six out of 57 samples reactive in reverse hybridization (92%) were genotyped. One sample showed a profile differing from any genotype, five samples were not reactive and one sample was not tested within this study design. Two out of five non-reactive sera and one non-tested serum could be genotyped by nested PCR based reverse hybridization. It can be concluded that the CA product resulting from one-step HCV RNA amplification is suitable for use in genotyping by reverse hybridization. The CA product based genotyping procedure is easier to perform, less time-consuming and less costly. The nested PCR based procedure could be used for typing of sera with lower HCV concentrations nontypeable with the combination of CA and Versant HCV Genotype Assay. Forty-eight selected samples were typed not only by reverse hybridization but also by a serological kit Murex HCV Serotyping 1-6 Assay (Abbot Murex). Thirty-seven (77%) of these sera, including all of three sera negative in reverse hybridization, appeared typeable by this kit. Although less sensitive, serotyping may be of relevance to typing of sera with low HCV levels or not containing detectable viral NA which are nontypeable by reverse hybridization. Thirty-three sera appeared genotypeable by both of the methods tested with the results being in good agreement. In two cases only the serotyping method revealed one more type of virus (mixed genotype) compared to the reverse hybridization.

Genotype↗

PubMed2005

Hepatitis D.

Hepatitis D virus (HDV) is a small, RNA-containing virus that requires the concomitant presence of Hepatitis B virus (HBV) in an obligate manner for its survival and pathogenicity. HDV infection is very uncommon in Czech Republic. The results of antiviral therapy of hepatitis D patients are not satisfactory. Alpha-interferon (alpha-IFN) in high doses (9-10 MU three times a week for 12 months) is usually recommended.

Antiviral Agents↗

PubMed2003

The 2001 serological survey in the Czech Republic--viral hepatitis.

Within serological surveys 2001, prevalence of markers of hepatitis viruses A (anti-HAV), B (anti-HBc, HBsAg, anti-HBs) and for the first time also C (anti-HCV) was investigated. Sera were collected in 2001 and tested by respective kits AxSYM, Abbott. HAV: 2,623 sera were tested for the presence of anti-HAV antibodies. Comparison with serological surveys of 1984 and 1996 revealed again shifts of the age prevalence curve for anti-HAV antibodies towards higher age groups corresponding to time intervals between epidemiological surveys. High prevalence rates of anti-HAV antibodies (more than 20%) were only found for the population age groups who lived in the period of high incidence of VHA, i.e. up to 1965. The prevalence of anti-HAV antibodies increased by about 5-10% in the population under 20 years of age, the increase being significant and assumingly attributable to vaccination against VHA, and remained the same as in 1996 in the age group 20-29 years. HBV: 2,568 sera were tested for the presence of anti-HBc antibodies and 76 reactive specimens were further tested for the presence of HBsAg and anti-HBs antibodies. The prevalence of anti-HBc antibodies continuously increases with age. The total prevalence of anti-HBc antibodies calculated for the Czech population is 5.59% compared to 6.95% recorded in 1996. The calculated prevalence rate of HBsAg is 0.56% and that of anti-HBs antibodies is 3.99% for the non-vaccinee population. HCV: The prevalence rate of anti-HCV antibodies was 0.2% with 6 out of 2,950 sera testing positive. Age dependence could not be assessed because of the small number of positive persons. HCV infection is known to afflict high-risk groups, likely to escape a general serological survey, rather than the normal population.

Adolescent↗

PubMed1995

The serology of hepatitis C virus (HCV) infection: antibody crossreaction in the hypervariable region 1.

We determined the NS1/E2 N-terminal sequence including the hypervariable region 1 (HVR1) from five individuals chronically infected with HCV: two from the Czech Republic and three from Germany. From each sequence, six 12-mer overlapping peptides were synthesized and used in a peptide scan to evaluate seroreactivity of each of those patients, as well as three anti-HCV positive blood donors to the different isolates. We could show the general presence of antibodies to multiple HVR1 specific sequences reflecting the existence of multiple variants in infected persons. Finally, we observed the persistance of HCV infections in all individuals despite an active humoral response directed against the virus.

Base Sequence↗