Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A high prevalence (42.6%) of hepatitis B virus (HBV) infection was suspected in 195 formerly captive orangutans due to a large number of serum samples which cross-reacted with human HBV antigens. It was assumed that such viral infections were contracted from humans during captivity. However, two wild orangutans were identified which were HBV surface antigen positive, indicating that HBV or related viruses may be occurring naturally in the orangutan populations. Sequence analyses of seven isolates revealed that orangutans were infected with hepadnaviruses but that these were clearly divergent from the six known human HBV genotypes and those of other nonhuman hepadnaviruses reported. Phylogenetic analyses revealed geographic clustering with Southeast Asian genotype C viruses and gibbon ape HBV. This implies a common origin of infection within this geographic region, with cross-species transmission of hepadnaviruses among hominoids.
 ...
PMID:A new group of hepadnaviruses naturally infecting orangutans (Pongo pygmaeus). 1043 80

Oligonucleotides containing immunostimulatory CpG motifs (CpG ODN) have been shown to be potent Th1-type adjuvants for augmenting antigen-specific responses in mice against hepatitis B surface antigen (HBsAg). The hepatitis B virus (HBV) infects only humans and great apes and appears to exist among wild chimpanzees and orangutans. An outbreak of HBV among orangutans being rehabilitated for re-introduction to the jungle caused the death of several animals. A prophylactic vaccination program revealed that orangutans are quite hypo-responsive to a current commercial vaccine compared to results obtained previously in humans and chimpanzees. Addition of CpG ODN to hepatitis B vaccine greatly increased the seroconversion rate and the titers of antibody against HBsAg (anti-HBs). This is the first demonstration of CpG DNA in a great ape and the results have important implications for the vaccination of humans against HBV and other diseases.
 ...
PMID:CpG DNA overcomes hyporesponsiveness to hepatitis B vaccine in orangutans. 1069 41

We characterized hepatitis B virus (HBV) isolates from sera of 21 hepatitis B virus surface antigen-positive apes, members of the families Pongidae and Hylobatidae (19 gibbon spp., 1 chimpanzee, and 1 gorilla). Sera originate from German, French, Thai, and Vietnamese primate-keeping institutions. To estimate the phylogenetic relationships, we sequenced two genomic regions, one located within the pre-S1/pre-S2 region and one including parts of the polymerase and the X protein open reading frames. By comparison with published human and ape HBV isolates, the sequences could be classified into six genomic groups. Four of these represented new genomic groups of gibbon HBV variants. The gorilla HBV isolate was distantly related to the chimpanzee isolate described previously. To confirm these findings, the complete HBV genome from representatives of each genomic group was sequenced. The HBV isolates from gibbons living in different regions of Thailand and Vietnam could be classified into four different phylogenetically distinct genomic groups. The same genomic groups were found in animals from European zoos. Therefore, the HBV infections of these apes might have been introduced into European primate-keeping facilities by direct import of already infected animals from different regions in Thailand. Taken together, our data suggest that HBV infections are indigenous in the different apes. One event involving transmission between human and nonhuman primates in the Old World of a common ancestor of human HBV genotypes A to E and the ape HBV variants might have occurred.
 ...
PMID:Molecular epidemiology of hepatitis B virus variants in nonhuman primates. 1079 18

The aim of this study was to determine the prevalence of hepatitis B virus (HBV) infection in nonhuman primates. Serum samples from Europe, Thailand and Vietnam were analyzed. Sera obtained from 262 apes and 454 monkeys were tested for HBV infection serologically and for HBV DNA using nested PCR (nPCR). A total number of 198 ape sera and all but one (Cercopithecus aethiops) of the 4543 monkey sera had no serological signs of HBV infection. Among the 64 of 262 (24.4%) seropositive ape sera, we found, as in humans, different stages of HBV infection: very early HBV infection, active infection with high level of infectivity, virus carriers with low infectivity, and passed HBV infection. In the cases with passed infection, 47.8% harbored HBV DNA in the presence of protective antibodies to the HBV surface antigen (HBsAb). This indicates HBV persistence in apes despite immune control. In contrast to apes, in monkeys HBV infection is a very rare event.
 ...
PMID:Prevalence of hepatitis B virus infections in nonhuman primates. 1139 59

There are six well characterised genotypes (A-F) of human hepatitis B virus that have distinct geographic ranges which generally relate to chronic HBV infection. A seventh human genotype (G) has recently been described, but there is limited information on ethnic and geographic distribution. Despite the fact that early studies indicated that HBV antigens were present in other primates, the prevailing dogma that HBV was a human disease precluded alternative explanations. Within the past 5 years, hepatitis B viruses have been characterised from all the Old World great apes (orangutan, gibbons, gorillas and chimpanzees) and from a New World woolly monkey. Each group of non-human primates appears to have a distinct strain of hepatitis B virus that can be distinguished from human sequences based upon the nucleotide sequence and selected amino acid changes in the viral proteins. The woolly monkey HBV is most divergent from other primate and human sequences, while the great ape HBV sequences cluster together with separate branches for each group.
 ...
PMID:Primate hepatitis B viruses - genetic diversity, geography and evolution. 1198 38

Infection with hepatitis B virus (HBV) has been detected in human populations throughout the world, as well as in a number of ape species (Pan troglodytes, Gorilla gorilla, gibbons [Nomascus and Hylobates species] and Pongo pygmaeus). To investigate the distribution of naturally occurring HBV infection in these species and other African Old World monkey species (Cercopithecidae), we screened 137 plasma samples from mainly wild caught animals by polymerase chain reaction (PCR) using several of highly conserved primers from the HB surface (HBs) gene, and for HBs antigen (HBsAg) by ELISA. None of the 93 Cercopithecidae screened (6 species) showed PCR or serology evidence for HBV infection; in contrast 2 from 8 chimpanzees and 5 from 22 gibbons were PCR-positive with each set of primers. Complete genome sequences from each of the positive apes were obtained and compared with all previously published complete and surface gene sequences. This extended phylogenetic analysis indicated that HBV variants from orangutans were interspersed by with HBV variants from southerly distributed gibbon species (H. agilis and H. moloch) occupying overlapping or adjacent habitat ranges with orangutans; in contrast, HBV variants from gibbon species in mainland Asia were phylogenetically distinct. A geographical rather than (sub)species association of HBV would account for the distribution of HBV variants in different subspecies of chimpanzees in Africa, and explain the inlier position of the previously described lowland gorilla sequence in the chimpanzee clade. These new findings have a number of implication for understanding the origins and epidemiology of HBV infection in non-human primates.
 ...
PMID:Geographic and species association of hepatitis B virus genotypes in non-human primates. 1451 90

As well as being distributed widely in human populations, hepatitis B virus (HBV) infections occur frequently in chimpanzee, gibbon and other ape populations in sub-Saharan Africa and South-East Asia. To investigate the frequency and genetic relationships of HBV infecting gibbons in Cambodia, pileated gibbons (Hylobates pileatus) that were originally wild-caught were screened for surface antigen. Twelve of 26 (46 %) were positive, of which 11 were positive for HBV DNA. Phylogenetic analysis of complete genome sequences revealed two distinct genetic groups in the gibbon/orangutan clade. Three were similar to previously described variants infecting H. pileatus in Thailand and eight formed a distinct clade, potentially representing distinct strains of HBV circulating in geographically separated populations in South-East Asia. Because of the ability of HBV to cross species barriers, large reservoirs of infection in gibbons may hamper ongoing attempts at permanent eradication of HBV infection from human populations in South-East Asia through immunization.
 ...
PMID:Frequent infection of Hylobates pileatus (pileated gibbon) with species-associated variants of hepatitis B virus in Cambodia. 1565 52

Hepatitis B virus (HBV) infection is widely distributed in both human and ape populations throughout the world and is a major cause of human morbidity and mortality. HBV variants are currently classified into the human genotypes A to H and species-associated chimpanzee and gibbon/orangutan groups. To examine the role of recombination in the evolution of HBV, large-scale data retrieval and automated phylogenetic analysis (TreeOrder scanning) were carried out on all available published complete genome sequences of HBV. We detected a total of 24 phylogenetically independent potential recombinants (different genotype combinations or distinct breakpoints), eight of which were previously undescribed. Instances of intergenotype recombination were observed in all human and ape HBV variants, including evidence for a novel gibbon/genotype C recombinant among HBV variants from Vietnam. By recording sequence positions in trees generated from sequential fragments across the genome, violations of phylogeny between trees also provided evidence for frequent intragenotype recombination between members of genotypes A, D, F/H, and gibbon variants but not in B, C, or the Asian B/C recombinant group. In many cases, favored positions for both inter- and intragenotype recombination matched positions of phylogenetic reorganization between the human and ape genotypes, such as the end of the surface gene and the core gene, where sequence relationships between genotypes changed in the TreeOrder scan. These findings provide evidence for the occurrence of past, extensive recombination events in the evolutionary history of the currently classified genotypes of HBV and potentially in changes in its global epidemiology and associations with human disease.
 ...
PMID:Recombination in the genesis and evolution of hepatitis B virus genotypes. 1630 18

Anthropozoonotic (human to nonhuman animal) transmission of infectious disease poses a significant threat to wildlife. A large proportion of travelers to tropical regions are not protected against vaccine-preventable illnesses, and a majority of these travelers demonstrate poor recall of actual vaccination status. Here we characterize self-perceived vaccination status among a large sample of ecotourists at the Sepilok Orangutan Rehabilitation Centre, Sabah, Malaysia. Despite their recognized travel itinerary to view endangered animals, tourists at wildlife sanctuaries are not adequately protected against vaccine-preventable illnesses. Of 633 surveys, over half reported being currently vaccinated against tuberculosis, hepatitis A, hepatitis B, polio, and measles. Fewer participants reported current vaccination status for influenza, rabies, and chickenpox. Despite the fact that the majority of visitors to Sepilok are from temperate regions where influenza is relatively more prevalent, 67.1% of those surveyed with medical-related occupations reported not being currently vaccinated for influenza. Ecotourists concerned about environmental protection are themselves largely unaware of their potential contribution to the spread of diseases to animals. The risks of negatively affecting animal populations must be communicated to all concerned parties, and this may begin by urging travelers to examine their actual vaccination status, particularly as the ecotourism industry continues its rapid expansion, and is seen increasingly as a possible tool to save great ape populations from extinction.
 ...
PMID:Perceived vaccination status in ecotourists and risks of anthropozoonoses. 1881 May 50

Hepatitis B virus (HBV) of a novel genotype (J) was recovered from an 88-year-old Japanese patient with hepatocellular carcinoma who had a history of residing in Borneo during the World War II. It was divergent from eight human (A to H) and four ape (chimpanzee, gorilla, gibbon, and orangutan) HBV genotypes, as well as from a recently proposed ninth human genotype I, by 9.9 to 16.5% of the entire genomic sequence and did not have evidence of recombination with any of the nine human genotypes and four nonhuman genotypes. Based on a comparison of the entire nucleotide sequence against 1,440 HBV isolates reported, HBV/J was nearest to the gibbon and orangutan genotypes (mean divergences of 10.9 and 10.7%, respectively). Based on a comparison of four open reading frames, HBV/J was closer to gibbon/orangutan genotypes than to human genotypes in the P and large S genes and closest to Australian aboriginal strains (HBV/C4) and orangutan-derived strains in the S gene, whereas it was closer to human than ape genotypes in the C gene. HBV/J shared a deletion of 33 nucleotides at the start of preS1 region with C4 and gibbon genotypes, had an S-gene sequence similar to that of C4, and expressed the ayw subtype. Efficient infection, replication, and antigen expression by HBV/J were experimentally established in two chimeric mice with the liver repopulated for human hepatocytes. The HBV DNA sequence recovered from infected mice was identical to that in the inoculum. Since HBV/J is positioned phylogenetically in between human and ape genotypes, it may help to trace the origin of HBV and merits further epidemiological surveys.
 ...
PMID:A genetic variant of hepatitis B virus divergent from known human and ape genotypes isolated from a Japanese patient and provisionally assigned to new genotype J. 1964 Sep 77


1 2 Next >>