This research investigated a number of issues regarding hepatitis B virus (HBV) in the silvery gibbon (Hylobates moloch). Due to the relatively recent discovery of the virus in nonhuman primate populations, specific knowledge of the biological behaviour of the virus is presently lacking, with current information largely extrapolated from the behaviour of HBV in human infections. In order to manage the captive and wild populations of this critically endangered species, information regarding the behaviour of the virus in gibbons and the likely impact of the viral infection is essential. The research was performed at Perth Zoo, with the study population consisting of the current and historical members of the zoo’s silvery gibbon colony. Because this gibbon species is critically endangered, the study was conducted with minimal intervention to the population with samples collected largely on an opportunistic basis from a small study population. Review of the history of the virus within the Perth Zoo colony provided epidemiological evidence to indicate vertical transmission in three gibbons (Hecla, Uban and Jury). It would appear that vertical transmission is the primary mode of transmission leading to dispersal of the virus through the captive population of silvery gibbons. Elevated concentrations of the liver enzymes alanine aminotransferase and aspartate aminotransferase were found in three gibbons (Perth 2, Uban and Jury), and may suggest a pathogenic role of the virus in this species. Histological examination of the livers of Uban and Perth 2 failed to demonstrate definitive evidence of cirrhosis, however mild fibrosis was seen in both cases and may represent an early stage of liver pathology associated with chronic hepatitis B infection. The vaccination protocol developed at Perth Zoo was successful in preventing neonatal transmission of the virus from a high infectivity carrier mother in at least two individuals, and was also successful in producing a protective level of immunity against the virus in all three of the individuals tested. Sequencing of the complete hepatitis B genome from one gibbon (Hecla) revealed that she was infected with GiHV (Gibbon hepatitis B virus), an indigenous strain of HBV previously identified in a number of gibbon species, but not previously confirmed in the silvery gibbon. Hecla's strain of HBV was shown to be more closely related to other nonhuman primate strains of HBV than to any of the human strains of HBV. 100% nucleotide similarity to two of Hecla’s siblings indicates that infection in all three animals was the result of vertical transmission from their mother. Partial sequencing of the virus from a second gibbon (Uban) identified another strain of GiHBV which supports the results of the epidemiological study. Neither gibbon showed a high sequence similarity to the virus sequenced from Ivan, the father of the third carrier gibbon (Jury), although only limited sequence data was available from Ivan. Consequently it is likely that at least three different strains of GiHBV are present within the silvery gibbon population. The information contained in this thesis will assist in the understanding and management of hepatitis B infection in silvery gibbons, as well as the numerous other species of nonhuman primates now shown to be susceptible to this virus.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 4 uppsatser.

Thesis (Ph.D.)--University of Melbourne, Dept. of Microbiology and Immunology, The Macfarlane Burnet Institute for Medical Research and Public Health, 2006. / Typescript. Includes bibliographical references (leaves 155-177).

Thesis (M.Sc. (Microbiology))--Mahidol University, 1979. / Financial support from University Development Committee and National Cancer Institute.

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 157-186). Also available in print.

Thesis (Ph. D.)--University of Hong Kong, 1995. / Includes bibliographical references.

Stuttgart, Univ., Diss., 2004.

Thesis (doctoral)--Utrecht, 1979.

München, Techn. Univ., Diss., 2002.

Orientador: Paulo Inácio da Costa / Banca: Iguatemy Lourenço Brunetti / Banca: Fernanda de Freitas Aníbal / Resumo: Os perfis metabólicos correlacionam-se com a infecção pelo VHC e são prognósticos da resposta viral em pacientes crônicos. Porém, pouco se sabe a respeito da associação entre perfis lipídicos e carga viral do VHC entre infecções dos genótipos 1, 2 ou 3. Portanto, o objetivo deste trabalho foi estudar a influência da viremia e dos genótipos do VHC sobre o metabolismo lipídico através das variações de lipoproteínas séricas (colesterol total, LDL, HDL, VLDL, triglicérides) e apolipoproteína B (Apo B) em hepatopatas crônicos, avaliando se o VHC predispõe os indivíduos ao aparecimento de complicações vasculares. O grupo amostral constituiu-se de um total de 150 pacientes crônicos do VHC com genótipos 1, 2 ou 3, e de um grupo controle de 20 indivíduos saudáveis (10 homens e 10 mulheres) em idade adulta (20 à 50 anos). Os níveis séricos de HDL (28%), VLDL (26%) e triglicérides (26%) nos portadores crônicos do VHC se mostraram diminuídos em relação ao grupo controle, enquanto os níveis de LDL (25%) e Apo B (29%) se mostraram elevados, resultados que foram mais importantes nos portadores do genótipo 3a. Observou-se correlação positiva entre a viremia e alterações nos níveis de apo B (r = 0,5763) nos portadores do genótipo 1b. Assim, foi pressuposto que o risco de pacientes portadores do VHC desenvolverem complicações vasculares é elevado, pois 1% de redução nos níveis de LDL está associado com uma redução de 2-3% no risco de desenvolvimento de doenças cardíacas, e como cerca de 90% da proteína na LDL se constitui de apo B, sua concentração plasmática indica o número total de partículas potencialmente aterogênicas. Desta forma, o perfil lipídico auxilia no diagnóstico da severidade da infecção hepática causada pelo VHC e ainda atua como um bom sinal prognóstico. / Abstract: The metabolic profiles correlate with the hepatitis C virus infection and are prognostics for the viral reply in chronic patients. However, little is known regarding the distinguishing association between lipid profiles and hepatitis C viral load in patients carrying genotypes 1, 2 or 3. Therefore, the objective of this work was to study viremia and genotypes on the lipid metabolism through the serum lipoprotein variations (total cholesterol, LDL, HDL, VLDL, triglycerides) and apolipoprotein B (Apo B) in chronic carriers of this infection, evaluating if the HCV premakes the individual to the lipidic disequilibrium and favors the appearance of vascular complications. The amostral group consisted of 150 HCV chronic patients with genotypes 1, 2 or 3, and a control group consisted of 20 healthful individuals (10 men and 10 women) in adult age (20 to 50 years). The levels of HDL (28%), VLDL (26%) and triglycerides (26%) of the HCV chronic patients were lower than the control group, while the LDL levels (25%) and the Apo B levels (29%) were higher. These findings were more significant in the genotype 3a carrying patients. Positive correlation occurred between the viremia and the alterations in the Apo B levels (r = 0.5763) in the genotype 1b carrying patients. Consequently it was inferred that the risk of HCV patients to develop vascular complication is elevated. In general, 1% of reduction in the LDL levels is associated with a reduction of 2-3% in the risk of development of cardiac illnesses, and, as about 90% of the protein in the LDL is constituted of apo B, its plasmatic concentration indicates the total potentially atherogenics particles number. The lipid profile aids in the diagnosis of the severity of the hepatic infection and equally acts as a good signal prognostic, therefore its analysis must be carried through in all the cases of advanced hepatic infection. / Mestre