Hepatitis B virus genotypes and resistance mutations in patients under long term lamivudine therapy: characterization of genotype G in Brazil

Submitted by Sandra Infurna ([email protected]) on 2018-08-02T14:46:32Z No. of bitstreams: 1 kiciamro_etal_IOC_2008.pdf: 506267 bytes, checksum: f7829a89c2411e97f96c3d5a4123f436 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-08-02T14:57:58Z (GMT) No. of bitstreams: 1 kiciamro_etal_IOC_2008.pdf: 506267 bytes, checksum: f7829a89c2411e97f96c3d5a4123f436 (MD5)Made available in DSpace on 2018-08-02T14:57:58Z (GMT). No. of bitstreams: 1 kiciamro_etal_IOC_2008.pdf: 506267 bytes, checksum: f7829a89c2411e97f96c3d5a4123f436 (MD5) Previous issue date: 2008Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Molecular. Rio de Janeiro, RJ. Brasil.Universidade Federal de Mato Grosso. Faculdade de Ciências Médicas. Núcleo de Estudos de Doenças Infecciosas e Tropicais. Cuiabá, MT, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Molecular. Rio de Janeiro, RJ. Brasil / Fundação Municipal de Saúde de Petrópolis. Hospital Alcides Carneiro. Petrópolis, RJ. Brasil.Universidade Federal do Estado do Rio de Janeiro. Hospital Universitário Gaffrée e Guinle. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Hospital Universitário Gaffrée e Guinle. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Molecular. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Virologia Molecular. Rio de Janeiro, RJ. Brasil.Lamivudine is an oral nucleoside analogue widely used for the treatment of chronic hepatitis B. The main limitation of lamivudine use is the selection of resistant mutations that increases with time of utilization. Hepatitis B virus (HBV) isolates have been classified into eight genotypes (A to H) with distinct geographical distributions. HBV genotypes may also influence pathogenic properties and therapeutic features. Here, we analyzed the HBV genotype distribution and the nature and frequency of lamivudine resistant mutations among 36 patients submitted to lamivudine treatment for 12 to 84 months

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates

<p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) isolates have been classified in eight genotypes, A to H, which exhibit distinct geographical distributions. Genotypes A, D and F are predominant in Brazil, a country formed by a miscegenated population, where the proportion of individuals from Caucasian, Amerindian and African origins varies by region. Genotype F, which is the most divergent, is considered indigenous to the Americas. A systematic molecular characterization of HBV isolates from different parts of the world would be invaluable in establishing HBV evolutionary origins and dispersion patterns. A large-scale study is needed to map the region-by-region distribution of the HBV genotypes in Brazil.</p> <p>Results</p> <p>Genotyping by PCR-RFLP of 303 HBV isolates from HBsAg-positive blood donors showed that at least two of the three genotypes, A, D, and F, co-circulate in each of the five geographic regions of Brazil. No other genotypes were identified. Overall, genotype A was most prevalent (48.5%), and most of these isolates were classified as subgenotype A1 (138/153; 90.2%). Genotype D was the most common genotype in the South (84.2%) and Central (47.6%) regions. The prevalence of genotype F was low (13%) countrywide. Nucleotide sequencing of the S gene and a phylogenetic analysis of 32 HBV genotype F isolates showed that a great majority (28/32; 87.5%) belonged to subgenotype F2, cluster II. The deduced serotype of 31 of 32 F isolates was <it>adw4</it>. The remaining isolate showed a leucine-to-isoleucine substitution at position 127.</p> <p>Conclusion</p> <p>The presence of genotypes A, D and F, and the absence of other genotypes in a large cohort of HBV infected individuals may reflect the ethnic origins of the Brazilian population. The high prevalence of isolates from subgenotype A1 (of African origin) indicates that the African influx during the colonial slavery period had a major impact on the circulation of HBV genotype A currently found in Brazil. Although most genotype F isolates belonged to cluster II, the presence of some isolates belonging to clusters I (subgroup Ib) and IV suggests the existence of two or more founder viral populations of genotype F in Brazil.</p

Infection by the hepatitis C virus in chronic renal failure patients undergoing hemodialysis in Mato Grosso state, central Brazil: a cohort study

BACKGROUND: Hepatitis C virus (HCV) is a significant problem for patients undergoing hemodialysis therapy. This situation has never been studied in Mato Grosso state, central Brazil. This study was conducted aiming to estimate the prevalence of the anti-HCV and the incidence of seroconversion in the main metropolitan region of the state. METHODS: 433 patients from the six hemodialysis units were interviewed and anti-HCV was tested by a third-generation enzyme immunoassay. An open cohort of patients who tested negative for anti-HCV at the entry of the study was created and seroconversions was assessed monthly. The staff responsible for the units were interviewed to assess whether the infection control measures were being followed. Logistic and Cox regression analysis were performed in order to assess risk factor to HCV. RESULTS: The entry on the study took place between January 2002 and June 2005. 73 out of 433 (16.9%, CI95%: 13.3–20.8) was found to be anti-HCV reactive. The multivariate analysis indicated as risk factors associated to anti-HCV the duration of the hemodialysis treatment, the number of transfusions received, and the unit of treatment. An open cohort of 360 patients who tested negative for anti-HCV was created, with a following average of 24 (± 15) months. Forty seroconversions were recorded corresponding to an incidence density of 4.6/1000 patient-months, ranges 0 to 30 among the units. Cox regression indicated the time of hemodialysis (RR = 2.2; CI95%: 1.1–4.6; p < 0.05) and the unit where treatment was performed (RR = 42.4; CI95%: 9.9–180.5; p < 0.05) as risk factors for seroconversion. The three units with highest anti-HCV prevalence and incidence were identified as those that more frequently failed to apply control measures. CONCLUSION: The study demonstrated high prevalence and incidence of anti-HCV in some of the hemodialysis units. Time on hemodialysis therapy was an independent factor associated to HCV. Blood transfusion was associated with anti-HCV in initial survey but was not important in incident cases. Failure of applying control meaures was more evident in units with the highest HCV prevalence and incidence. The results suggest that nosocomial transmission was the main spread factor of HCV in the studied population

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates-2

<p><b>Copyright information:</b></p><p>Taken from "Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates"</p><p>http://www.biomedcentral.com/1471-2180/7/103</p><p>BMC Microbiology 2007;7():103-103.</p><p>Published online 23 Nov 2007</p><p>PMCID:PMC2231365.</p><p></p>Northeast region; 3 – Central-West region; 4 – Southeast region; 5 – South region)

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates-0

<p><b>Copyright information:</b></p><p>Taken from "Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates"</p><p>http://www.biomedcentral.com/1471-2180/7/103</p><p>BMC Microbiology 2007;7():103-103.</p><p>Published online 23 Nov 2007</p><p>PMCID:PMC2231365.</p><p></p>Northeast region; 3 – Central-West region; 4 – Southeast region; 5 – South region)

Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates-1

<p><b>Copyright information:</b></p><p>Taken from "Hepatitis B virus genotypes circulating in Brazil: molecular characterization of genotype F isolates"</p><p>http://www.biomedcentral.com/1471-2180/7/103</p><p>BMC Microbiology 2007;7():103-103.</p><p>Published online 23 Nov 2007</p><p>PMCID:PMC2231365.</p><p></p>onding region of the sample (N: North region; NE: Northeast region; CW: Central-West region; SE: Southeast region) with RFLP pattern in brackets. International sequences are designated with their accession number followed by their countries of origin