Anthony E. T. Yeo

A comparison of the molecular clock of hepatitis C virus in the United States and Japan predicts that hepatocellular carcinoma incidence in the United States will increase over the next two decades

The prevalence of hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) is considerably lower in the U.S. than in Japan. To elucidate this difference, we determined the time origin of the HCV epidemic in each country by using molecularly clocked long-term serial samples obtained from HCV carriers of genotypes 1a and 1b. The molecular clock estimated that HCV genotype 1 first appeared in Japan in around 1882, whereas emergence in the U.S. was delayed until around 1910. In addition, by statistical analysis using coalescent theory, the major spread time for HCV infection in Japan occurred in the 1930s, whereas widespread dissemination of HCV in the U.S. occurred in the 1960s. These estimates of viral spread time are consistent with epidemiologic observations and predict that the burden of HCC in the U.S. will increase in the next two to three decades, possibly to equal that currently experienced in Japan.

Genomic and Molecular Evolutionary Analysis of a Newly Identified Infectious Agent (SEN Virus) and Its Relationship to the TT Virus Family

A new group of transmissible single-stranded (ss) DNA viruses (SENV) distantly related to the large TT virus (TTV) family was recently identified. Eight different SENV isolates have been found, some with an association with posttransfusion hepatitis. A phylogenetic analysis of near-complete open-reading frame 1, including conserved motifs and excluding recombinant regions, was performed. The analysis used TTV-like minivirus as an outgroup, to determine a root of the phylogenetic tree, and compared 8 SENV isolates, 6 prototype TTV isolates, and 7 TTV variants (including SANBAN, TUS01, PMV, and YONBAN). Four distinct clusters separated by a bootstrap value of 100% were observed. YONBAN isolates formed a distinct outer group, representing the earliest recognized phylogenetic divergence (group 1). Prototype TTV formed group 2, PMV formed group 3, and SENV, SANBAN, and TUS01 isolates formed group 4, the most recently evolved group. This taxonomic classification suggests that these circular ssDNA viruses probably evolved from a common ancestor virus.

Investigation of SEN Virus Infection in Patients with Cryptogenic Acute Liver Failure, Hepatitis-Associated Aplastic Anemia, or Acute and Chronic Non–A–E Hepatitis

SEN virus (SENV) has been tentatively linked to transfusion-associated non-A-E hepatitis. We investigated SENVs role in unexplained hepatitis in other settings. Polymerase chain reaction amplification was used to detect 2 SENV variants (SENV-D and SENV-H) in 1706 patients and control subjects. SENV was detected in 54 (22%) of 248 patients with acute or chronic non-A-E hepatitis, 9 (35%) of 26 patients with hepatitis-associated aplastic anemia, and 0 of 17 patients with cryptogenic acute liver failure, compared with 150 (24%) of 621 control subjects with liver disease and 76 (10%) of 794 healthy control subjects. When controlling for geographic region, the prevalence of SENV among case and control subjects was not significantly different. The severity of acute or chronic hepatitis A, B, or C was not influenced by coexisting SENV infection. No etiological role for SENV in the cause of cryptogenic hepatitis could be demonstrated.

Molecular Characteristics of Occult Hepatitis B Virus from Blood Donors in Southeast China

ABSTRACT The characteristics of 30 carriers with occult hepatitis B virus (HBV) infection (OBI) were compared with those of 30 individuals diagnosed as being HBV carriers at the time of blood donation, 60 asymptomatic carriers, and 60 chronic hepatitis patients. The prevalence of genotype C was significantly higher in carriers with OBIs than in any other HBsAg-positive (HBsAg+) group (P < 0.001). Specific amino acid substitutions in the regions from amino acids 117 to 121 and amino acids 144 to 147 located in the major hydrophilic region of the S gene were associated with carriers with OBIs (P < 0.01 for carriers with OBIs versus HBsAg+ donors, carriers with OBIs versus HBsAg+ asymptomatic carriers, and carriers with OBIs versus HBsAg+ chronic hepatitis patients). G145R was the major variation in the HBV isolates responsible for local occult HBV infections.

Novel Double-Antigen Sandwich Immunoassay for Human Hepatitis B Core Antibody

ABSTRACT A novel diagnostic immunoassay testing procedure for hepatitis B virus core antibody (anti-HBc) using homogeneous purified full-length hepatitis B virus core antigen (HBcAg) capsids obtained from Escherichia coli was compared with Abbott Architect anti-HBc chemiluminescent microparticle immunoassay (CMIA; indirect method) against a library of specimens. A monoclonal anti-HBc neutralization confirmatory assay was then used to determine the degree of discordance between specimens. The new assay was found to be superior in both sensitivity and specificity.

Association between SEN Virus Infection and Hepatitis C in Japan

There is a strong association between 2 SEN virus (SENV) variants (SENV-D and SENV-H) and transfusion-associated non-A-E hepatitis. In total, 200 subjects from a Japanese region where hepatitis C virus (HCV) is highly endemic and 194 persons from a contiguous area where HCV is not endemic were tested for SENV-D and SENV-H DNA by polymerase chain reaction. SENV DNA was detected equally in subjects from each area (56% prevalence in the area of high endemicity vs. 61% in the nonendemic area). Age-specific prevalence of SENV was similar to that of TT virus, with equal distribution at all ages in both areas; HCV was predominant in the elderly population. Alanine aminotransferase levels were significantly associated with HCV viremia but not with SENV viremia. SENV is a common infection that appears to have transmission routes and age-related prevalence that are distinct from those of HCV. No evidence was found that SENV caused hepatitis or worsened the course of hepatitis C.

The oral health status, practices and knowledge of pregnant women in South-western Sydney

BACKGROUND Current evidence highlights the importance of oral health during pregnancy. However, little is known about the oral health of pregnant women in Australia. The aim of this study was to report the oral health status, knowledge and practices of pregnant women in south-western Sydney. METHODS A cross-sectional survey of 241 pregnant women attending a large hospital in south-western Sydney. RESULTS More than half (59.3%) reported dental problems during pregnancy, less than a third (30.5%) saw a dentist in the last six months, only 10% had received any information about perinatal oral health and many (>50%) were unaware of the potential impact of poor maternal oral health on pregnancy and infant outcomes. Analysis revealed a significant difference (<0.05) in the uptake of dental services among pregnant women who had higher household incomes, private health insurance, received information about perinatal oral health and knowledge about maternal oral health. CONCLUSIONS The participants reported significant barriers to obtaining dental care including limited access to affordable dental services and lack of awareness about the importance of maternal oral health. The findings suggest the need for preventive strategies involving dentists and antenatal providers to improve maternal oral health in Australia.

Prevalence of hepatitis G virus in patients with hemophilia and their steady female sexual partners.

Background: Hepatitis G virus (HGV), also known as GB virus C, is a newly discovered Flavivirus that is transmissible by blood transfusion and other possible routes. Objective: To study the risk of sexual transmission of HGV in female sexual partners of men with hemophilia (n = 161 couples). Methods: Blood samples obtained from 11 medical centers were analyzed for (1) HGV RNA by polymerase chain reaction; (2) antibodies to HGV by enzyme immunoassay; and (3) other viruses and T‐cell counts by routine laboratory tests. Subjects completed a questionnaire that assessed sexual intercourse frequency, number of sexual partners, condom usage, sexually transmitted diseases, illicit drug usage, and needlestick or broken‐glass injuries. Results: The HGV infection (RNA ± antibody positive) prevalence was 48% among men and 21% among women. Prevalence of hepatitis C virus, hepatitis B virus, and HIV among men was 99%, 94%, and 86%, compared with 3%, 11%, and 12% among women, respectively. The odds ratio for HGV infection for women with an HGV‐positive male sexual partner was 2.14 (P = 0.06) without adjustment, and 2.77 (P = 0.03) with adjustment for other variables, none of which were independently significant. Conclusion: These results suggest a low level of HGV sexual transmission.

Prevalence of SEN Viruses among Injection Drug Users in the San Francisco Bay Area

SEN viruses (SENVs) are newly discovered bloodborne viruses that may play a role in liver disease. SENV strain prevalence was examined in a race/ethnicity-stratified sample of 531 injection drug users (IDUs) from the San Francisco Bay area. Weighted prevalences were as follows: SENV-A, 45.7%; SENV-C/H, 35.6%; and SENV-D, 10.3%. Infection was associated with a longer duration of injection drug use. SENV-A was more common in black subjects (adjusted odds ratio [OR(a)], 4.37; 95% confidence interval [CI], 2.65-7.21) and Hispanic subjects (OR(a), 2.30; 95% CI, 1.38-3.85) than in white and non-Hispanic subjects, and the pattern was similar for SENV-C/H. For SENV-D, prevalence was similar in black and white subjects, but lower in Hispanic subjects; infection was less common among women than men (OR(a), 0.32; 95% CI, 0.15-0.71) and more common among men with at least 1 recent male sex partner than among heterosexual men (OR(a), 7.05; 95% CI, 2.62-18.95). SENV strains are common among San Francisco Bay area IDUs, and prevalence varies demographically within this group.