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Hepatitis B virus (HBV) infection is more common in African Americans than in white Americans. We compared the epidemiologic, clinical, and virological characteristics of US-born African Americans (USAAs) to those of foreign-born African Americans (FBAAs) with chronic hepatitis B. The adult cohort study of the Hepatitis B Research Network enrolls patients with HBV infection from 21 clinical sites in the United States and Canada. A total of 237 (15%) of the adult participants with chronic HBV infection that were enrolled from January 20, 2011, to October 2, 2013, were of African descent, including 57 USAAs and 180 FBAAs (76%). Compared with FBAAs, USAAs were older and more likely to have acquired HBV through sexual exposure, to be HBeAg-positive, to have higher HBV DNA levels, and to be infected with HBV genotype A2. FBAAs from West Africa were more likely to have elevated serum alanine aminotransferase (72% vs. 50%; P < 0.01) and higher HBV DNA levels (median, 3.2 log10 IU/mL vs. 2.8 log10 IU/mL; P = 0.03) compared with East African FBAAs. The predominant HBV genotype among West African FBAAs was E (67%), whereas genotypes A (78%) and D (16%) were common in East African FBAAs. Significant differences were found between USAAs and FBAAs, highlighting the need for tailored strategies for prevention and management of chronic HBV infection for African Americans. [ABSTRACT FROM AUTHOR]

A 76-year-old Cambodian man co-infected with hepatitis B virus (HBV) and hepatitis C virus (HCV) 6c-1 presented for care. HBV DNA was intermittently detectable despite anti-HBs levels being above the protective threshold. During treatment for HCV, HBV DNA levels increased. Sequencing revealed multiple mutations including vaccine escape mutation and mutations predicted to enhance fitness. This case represents exacerbation of an HBV vaccine escape mutant during a direct-acting antiviral therapy.

Background: Herein, the predicted atomic structures of five representative sequence variants of the reverse transcriptase protein (RT) of hepatitis B virus (HBV), sampled from patients with rapid or slow response to tenofovir disoproxil fumarate (TDF) treatment, have been examined to identify structural variations between them in order to assess structural and functional properties of HBV-RT variants associated with the differential responses to TDF treatment. Results: We utilized a hybrid computational approach to model the atomistic structures of HBV-RT/DNA-RNA/dATP and HBV-RT/DNA-RNA/TFV-DP (tenofovir diphosphate) complexes with the native hybrid DNA-RNA substrate in place. Multi-nanosecond molecular dynamics (MD) simulations of HBV-RT/DNA-RNA/dATP complexes revealed strong coupling of the natural nucleotide substrate, dATP, to the active site of the RT, and the differential involvement of the two putative magnesium cations (Mg2+) at the active site, whereby one Mg2+ directly bridges the interaction between dATP and HBV-RT and the other serves as a coordinator to maintain an optimal configuration of the active site. Solvated interaction energy (SIE) calculated in MD simulations of HBV-RT/DNA-RNA/TFV-DP complexes indicate no differential binding affinity between TFV-DP and HBV-RT variants identified in patients with slow or rapid response to TDF treatment. Conclusion: The predicted atomic structures accurately represent functional states of HBV-RT. The equivalent interaction between TFV-DP and each examined HBV-RT variants suggests that binding affinity of TFV-DP to HBV-RT is not associated with delayed viral clearance. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of reconstructing viral quasispecies from next-generation sequencing reads obtained from amplicons (i.e., reads generated from predefined amplified overlapping regions). We compare the parsimonious and likelihood models for this problem and propose several novel assembling algorithms. The proposed methods have been validated on simulated error-free HCV and real HBV amplicon reads. The new algorithms have been shown to outperform the method of Prosperi et. al [24]. Our experiments also show that viral quasispecies can be reconstructed in most cases more accurately from amplicon reads rather than shotgun reads. All algorithms have been implemented and made available at https://bitbucket.org/nmancuso/bioa/. [ABSTRACT FROM AUTHOR]

Presents information on the tests carried out on Ralstonia solanacearum for acryl-HSL production, with focus on bacteriology. How is the virulence determinants of Ralstonai solanacearum controlled; What Ralstonia causes; Detailed information on the results from the tests.

Background: Guyana expanded its HIV response in 2005 but the epidemiology of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections has not been characterized., Methods: The 2011 Seroprevalence and Behavioral Epidemiology Risk Survey for HIV and STIs collected biologic specimens with demographic and behavioral data from a representative sample of Guyana military personnel. Diagnostics included commercial serum: HIV antibody; total antibody to hepatitis B core (anti-HBc); IgM anti-HBc; hepatitis B surface antigen (HBsAg); anti-HBs; antibody to HCV with confirmatory testing; and HBV DNA sequencing with S gene fragment phylogenetic analysis. Chi-square, p-values and prevalence ratios determined statistical significance., Results: Among 480 participants providing serologic specimens, 176 (36.7%) tested anti-HBc-positive. Overall, 19 (4.0%) participants tested HBsAg-positive; 17 (89.5%) of the HBsAg-positive participants also had detectable anti-HBc, including 1 (5.3%) IgM anti-HBc-positive male. Four (6.8%) females with available HBV testing were HBsAg-positive, all aged 23-29 years. Sixteen (16, 84.2%) HBsAg-positive participants had sufficient specimen for DNA testing. All 16 had detectable HBV DNA, 4 with viral load >2x104IU/ml. Sequencing found: 12 genotype (gt) A1 with 99.9% genetic identity between 1 IgM anti-HBc-positive and 1 anti-HBc-negative; 2 gtD1; and 2 with insufficient specimen. No statistically significant associations between risk factors and HBV infection were identified., Conclusions: Integrated HIV surveillance identified likely recent adult HBV transmission, current HBV infection among females of reproductive age, moderate HBV infection prevalence (all gtA1 and D1), no HCV infections and low HIV frequency among Guyana military personnel. Integrated HIV surveillance helped characterize HBV and HCV epidemiology, including probable recent transmission, prompting targeted responses to control ongoing HBV transmission and examination of hepatitis B vaccine policies., Competing Interests: The authors have declared that no competing interests exist.

Despite the significant public health problems associated with hepatitis B virus (HBV) in sub-Saharan Africa, many countries in this region do not have systematic HBV surveillance or genetic information on HBV circulating locally. Here, we report on the genetic characterization of 772 HBV strains from Tanzania. Phylogenetic analysis of the S-gene sequences showed prevalence of HBV genotype A (HBV/A, n =671, 86.9 %), followed by genotypes D (HBV/D, n =95, 12.3 %) and E (HBV/E, n =6, 0.8 %). All HBV/A sequences were further classified into subtype A1, while the HBV/D sequences were assigned to a new cluster. Among the Tanzanian sequences, 84 % of HBV/A1 and 94 % of HBV/D were unique. The Tanzanian and global HBV/A1 sequences were compared and were completely intermixed in the phylogenetic tree, with the Tanzanian sequences frequently generating long terminal branches, indicating a long history of HBV/A1 infections in the country. The time to the most recent common ancestor was estimated to be 188 years ago [95 % highest posterior density (HPD): 132 to 265 years] for HBV/A1 and 127 years ago (95 % HPD: 79 to 192 years) for HBV/D. The Bayesian skyline plot showed that the number of transmissions 'exploded' exponentially between 1960-1970 for HBV/A1 and 1970-1990 for HBV/D, with the effective population of HBV/A1 having expanded twice as much as that of HBV/D. The data suggest that Tanzania is at least a part of the geographic origin of the HBV/A1 subtype. A recent increase in the transmission rate and significant HBV genetic diversity should be taken into consideration when devising public health interventions to control HBV infections in Tanzania.

Background: Hepatitis B virus (HBV) transmission has been reported after patient-to-patient blood exposure during assisted monitoring of blood glucose (AMBG). Three assisted-living facility (ALF) residents who underwent AMBG developed acute HBV infection (HBVI) within 10 days. We investigated HBV transmission and implemented preventive measures., Methods: A retrospective cohort study was conducted. Infection control practices were assessed. HBVI screening was conducted for all staff and epidemiologically linked residents. Viral DNA sequences were compared for a subset of isolates., Results: Lancing devices and glucometers were shared among residents without proper sanitization. Serologic testing of all 34 residents with diabetes and 12 epidemiologically linked residents present during the exposure period detected 6 residents with diabetes with current HBVI and 4 residents with diabetes and 1 epidemiologically linked resident with previous HBVI. A cohort study of 32 individuals with diabetes identified AMBG as a significant risk factor for HBVI (relative risk, 6.7; 95% confidence interval, 1.7-26.3). Viral DNA sequences for 5 AMBG-exposed residents' isolates were identical, suggesting a common source., Conclusions: AMBG was significantly associated with HBVI in ALF residents with diabetes. Despite clear preventive recommendations, bloodborne pathogen transmission continues to occur in the setting of AMBG. Strengthening direct care provider, infection preventionist, and health department partnerships with ALFs is crucial to ensure safe AMBG practices and prevent HBV transmission., (Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.)

Background: Transmission of bloodborne pathogens due to breaches in infection control is becoming increasingly recognized as greater emphasis is placed on reducing health care-associated infections. Two women, aged 60 and 77 years, were diagnosed with acute hepatitis B virus (HBV) infection; both received chemotherapy at the same physician's office. Due to suspicion of health care-associated HBV transmission, a multidisciplinary team initiated an investigation of the hematology-oncology office practice., Methods: We performed an onsite inspection and environmental assessment, staff interviews, records review, and observation of staff practices. Patients who visited the office practice between January 1, 2006 and March 3, 2009 were advised to seek testing for bloodborne pathogens. Patients and medical providers were interviewed. Specimens from HBV-infected patients were sent to the Centers for Disease Control and Prevention for HBV DNA testing and phylogenic analysis., Results: Multiple breaches in infection control were identified, including deficient policies and procedures, improper hand hygiene, medication preparation in a blood processing area, common-use saline bags, and reuse of single-dose vials. The office practice was closed, and the physician's license was suspended. Out of 2,700 patients notified, test results were available for 1,394 (51.6%). Twenty-nine outbreak-associated HBV cases were identified. Specimens from 11 case-patients demonstrated 99.9%-100% nucleotide identity on phylogenetic analysis., Conclusion: Systematic breaches in infection control led to ongoing transmission of HBV infection among patients undergoing invasive procedures at the office practice. This investigation underscores the need for improved regulatory oversight of outpatient health care settings, improved infection control and injection safety education for health care providers, and the development of mechanisms for ongoing communication and cooperation among public health agencies., (Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.)

This paper addresses the problem of reconstructing viral quasispecies from next-generation sequencing reads obtained from amplicons (i.e., reads generated from predefined amplified overlapping regions). We compare the parsimonious and likelihood models for this problem and propose several novel assembling algorithms. The proposed methods have been validated on simulated error-free HCV and real HBV amplicon reads. The new algorithms have been shown to outperform the method of Prosperi et. al. Our experiments also show that viral quasispecies can be reconstructed in most cases more accurately from amplicon reads rather than shotgun reads. All algorithms have been implemented and made available at https://bitbucket.org/nmancuso/bioa/.