A new genotype of hepatitis A virus causing transient liver enzyme elevations in Mauritius-origin laboratory-housed Macaca fascicularis

Hepatitis A virus (HAV) infects humans and nonhuman primates, typically causing an acute self-limited illness. Three HAV genotypes have been described so far for humans, and three genotypes have been described for nonhuman primates. We observed transiently elevated liver enzymes in Mauritius-origin laboratory-housed macaques in Germany and were not able to demonstrate an etiology including HAV by serology and polymerase chain reaction (PCR). HAV is a rare pathogen in cynomolgus macaques, and since all employees were routinely vaccinated against HAV, it was not a part of the routine vaccination and screening program. A deep sequencing approach identified a new HAV genotype (referred to as Simian_HAV_Macaca/Germany/Mue-1/2022) in blood samples from affected animals. This HAV was demonstrated by reverse transcription PCR in blood and liver and by in situ hybridization in liver, gall bladder, and septal ducts. A commercial vaccine was used to protect animals from liver enzyme elevation. The newly identified simian HAV genotype demonstrates 80% nucleotide sequence identity to other simian and human HAV genotypes. There was deeper divergence between Simian_HAV_Macaca/Germany/Mue-1/2022 and other previously described HAVs, including both human and simian viruses. In situ hybridization indicated persistence in the biliary epithelium up to 3 months after liver enzymes were elevated. Vaccination using a commercial vaccine against human HAV prevented reoccurrence of liver enzyme elevations. Because available assays for HAV did not detect this new HAV genotype, knowledge of its existence may ameliorate potential significant epidemiological and research implications in laboratories globally.

Detection of chicken chapparvovirus 2 in chickens with hemorrhagic hepatitis in Japan

Chicken chaphamaparvovirus causes diarrheal symptoms and can be detected in fecal samples. This study reports the detection of chicken chapparvovirus 2 in debilitated chickens with hemorrhagic hepatitis at a broiler farm in Japan. After euthanasia and necropsy, liver hemorrhage was observed. Nuclear inclusion bodies in the hepatocytes were identified using histological analysis. High-throughput sequencing analysis using RNA from livers of three affected chickens revealed infection by chicken chapparvovirus 2 and chicken anemia virus. Polymerase chain reaction analysis showed that all three chickens were positive for chicken chapparvovirus 2, and only one was positive for both chicken chapparvovirus 2 and chicken anemia virus. In conclusion, chicken chapparvovirus 2 causes infection in chickens in Japan and might be involved in hemorrhagic hepatitis.

Evidence of vertical transmission of fowl adenovirus 8b in ducks

Fowl adenovirus mainly causes hydropericardium hepatitis syndrome (HHS), inclusion body hepatitis (IBH) and gizzard erosion (GE), etc. In 2015, the first outbreak of HHS was reported in broiler chickens in central China, followed by an outbreak in waterfowl. The first outbreak of HHS in broiler flocks in central China in 2015, followed by outbreaks in waterfowl, has severely restricted the healthy development of the poultry industry. During the investigation, fowl adenovirus was detected in ducklings from a total of seven hatcheries in Shandong, Inner Mongolia and Jiangsu provinces. In addition, the DNA of fowl adenovirus was detected in breeding ducks and their progeny. To test the hypothesis that FAdV can be transmitted vertically, sixty 250-day-old Cherry Valley breeder ducks were divided equally into three groups for experimental infection. FAdV-8b SDLY isolate (duck/Shandong/SDLY/2021, SDLY) preserved in our laboratory was injected intramuscularly into group A and inoculated orally into group B. FAdV-8b DNA was detected in the yolk membranes, embryos and allantoic fluid of duck embryos in the FAdV-infected group after inoculation. In addition, the FAdV-8b hexon gene isolated from yolk membranes, embryos, allantoic fluid and duck eggs was close to 100% nucleotide homology to the FAdV-8b hexon gene isolated from laying duck ovaries, indicating that fowl adenovirus can be transmitted vertically in ducks. These findings provide evidence for the possible vertical transmission of fowl adenovirus from breeder ducks to ducklings.

Necrotizing hepatitis caused by Clostridium novyi type B in a dog with no predisposing liver lesions: a case report

BACKGROUND

Infectious necrotic hepatitis (INH) is typically a disease of ruminants caused by Clostridium novyi type B. Growth of the causative agent is supported by development of an anaerobic environment within the liver. In dogs, C. novyi is rare and has only been previously reported as a post-mortem diagnosis. In one case, infection was secondary to metastatic pancreatic adenocarcinoma and the other was presumptively diagnosed on histopathology of a hepatic lesion in a dog initially presented for acute collapse.

CASE PRESENTATION

An 8-year-old spayed, female mixed breed dog was presented for acute onset of hyporexia and vomiting. Serum biochemistry revealed elevated hepatocellular injury and cholestatic liver enzymes. Ultrasound revealed peritoneal fluid accumulation and multiple hepatic masses. Cytologic examination of liver aspirates and peritoneal fluid revealed frequent 4 × 1 μm bacilli with a terminal endospore. Anaerobic bacterial growth isolated from the fluid sample could not be identified using typical laboratory identification techniques. Long-read, whole genome sequencing was performed, and the organism was identified as Clostridium novyi type B. Antimicrobial and hepatic support treatment were initiated. The patient re-presented 27 days later, and the follow up liver aspirate with cytology revealed no appreciable bacteria and anaerobic culture was negative. The patient was presented four months later and a large hepatic mass and peritoneal fluid were again identified on abdominal ultrasound. Cytologic examination of the peritoneal fluid revealed bacilli similar to those identified on initial presentation. The patient was euthanized. The most significant finding on necropsy was necrotizing hepatitis with intralesional endospore-forming bacilli compatible with recurrence of Clostridium novyi type B. There was no identifiable cause of an anaerobic insult to the liver.

CONCLUSIONS

This case demonstrates the diagnostic utility of using cytology as part of the initial diagnostic work up for infectious hepatitis. The cytologic findings coupled with whole genome sequencing and anaerobic culture were crucial for the identification and classification of the organism identified on fine needle aspirate. Clostridium novyi type B should be considered when bacilli organisms containing a terminal endospore are identified on liver aspirates collected from canine patients.

The investigation of hepatitis A virus and hepatitis E virus co-infection in humans and animals in China

The aim of this study was to investigate the prevalence of co-infection of hepatitis A and hepatitis E virus (HAV/HEV) in patients with acute hepatitis as well as in different animal species. A total of 46 serum samples from patients diagnosed as hepatitis A or hepatitis E and 675 fecal samples of 11 animal species were collected. The IgM class antibodies to HEV and HAV, respectively, were detected by enzyme-linked immunosorbent assay. HEV and HAV RNAs were extracted from serum and fecal samples for the nested reverse transcription polymerase chain reaction. At least 10.9% (5/46) of the patients were co-infected with both HAV and HEV. Fifteen percent (18/120) of rabbit fecal samples and 17.5% (7/40) of swine fecal samples were positive for HEV RNA, but only 1% (2/200) of ferret fecal samples were positive for HAV RNA. Our study showed that co-infection with both HAV and HEV in patients and animals is infrequent. At least in our study, we showed that ferrets may represent the potential HAV hosts. Keywords: hepatitis A virus; hepatitis E virus; co-infection; zoonosis; prevalence.

[Markers of hepatitis A in the monkeys of the Adlers primate center.]

Hepatitis A is a widespread viral infection. The HAV strains of "human" and "monkey" origin are similar in their morphological and antigenic properties, but differ genotypically.

OBJECTIVES

The aim of this research was a comparative study of serological and molecular-genetic markers of HAV infection in monkeys born at the Adler Primate Center and in those imported from different countries.

MATERIAL AND METHODS

Fecal samples (n = 313) and serum (n = 266) from various species of monkey using ELISA and RT-PCR were studied.

RESULTS AND DISCUSSION

The frequency of anti-HAV-IgG was high (78.9%) in imported animals (vervet monkeys from Tanzania and cynomolgus monkeys from Vietnam) and as well as in various species of monkeys (rhesus monkeys, cynomolgus monkeys, green monkeys and papio hamadryas) of the Center (88.6%). At the same time, in the imported monkeys, the markers of "fresh" HAV infection (IgM-27.2%, Ag-HAV-16.7%, RNA-22.0%) were detected significantly more often (p> 0.05) than in monkeys kept at the Colony (IgM-7.5%, HAV-Ag - 5.2%, RNA - 3.6%). In general, anti-IgG reactivity ranged from 1.064 to 2.073 OD₄₅₀, anti-IgM ranged from 0.546 to 1.059 OD₄₅₀. The number of HAV-Ag was 0.496 - 1.995 OD₄₅₀. RNA HAV only in rhesus monkeys and cynomolgys monkeys born at the Colony, as well as in imported vervet monkeys was detected.

CONCLUSIONS

The data obtained indicate a wide circulation of HAV among monkeys born in the Adler Primate Center and among the imported animals. Markers of "fresh" HAV infection varied depending on the species of monkeys and their origin.

Genetic variation of the VP1 gene of the virulent duck hepatitis A virus type 1 (DHAV-1) isolates in Shandong province of China

To investigate the relationship of the variation of virulence and the external capsid proteins of the pandemic duck hepatitis A virus type 1 (DHAV-1) isolates, the virulence, cross neutralization assays and the complete sequence of the virion protein 1 (VP1) gene of nine virulent DHAV-1 strains, which were isolated from infected ducklings with clinical symptoms in Shandong province of China in 2007-2008, were tested. The fifth generation duck embryo allantoic liquids of the 9 isolates were tested on 12-day-old duck embryos and on 7-day-old ducklings for the median embryonal lethal doses (ELD(50)s) and the median lethal doses (LD(50)s), respectively. The results showed that the ELD(50)s of embryonic duck eggs of the 9 DHAV-1 isolates were between 1.9 × 10(6)/mL to 1.44 × 10(7)/mL, while the LD(50)s were 2.39 × 10(5)/mL to 6.15 × 10(6)/mL. Cross-neutralization tests revealed that the 9 DHAV-1 isolates were completely neutralized by the standard serum and the hyperimmune sera against the 9 DHAV-1 isolates, respectively. Compared with other virulent, moderate virulent, attenuated vaccine and mild strains, the VP1 genes of the 9 strains shared 89.8%-99.7% similarity at the nucleotide level and 92.4%-99.6% at amino acid level with other DHAV-1 strains. There were three hypervariable regions at the C-terminus (aa 158-160, 180-193 and 205-219) and other variable points in VP1 protein, but which didn't cause virulence of DHAV-1 change.

Deep fungal dermatitis in three inland bearded dragons (Pogona vitticeps) caused by the Chrysosporium anamorph of Nannizziopsis vriesii

The Chrysosporium anamorph of Nannizziopsis vriesii (CANV), a keratinophilic fungus that naturally and experimentally causes severe and often fatal dermatitis in multiple reptile species, was isolated in pure culture from skin samples of three inland bearded dragons (Pogona vitticeps) with deep granulomatous dermatomycosis. The first animal presented with a focal maxillary swelling involving the skin and gingiva. This lizard died while undergoing itraconazole and topical miconazole therapy. The second presented with focally extensive discoloration and thickening of the skin of the ventrum and was euthanized after 10 weeks of itraconazole therapy. A third lizard presented with hyperkeratotic exudative dermatitis on a markedly swollen forelimb. Amputation and itraconazole therapy resulted in a clinical cure. Histopathology of tissue biopsies in all cases demonstrated granulomatous dermatitis with intralesional hyphae morphologically consistent with those produced by the CANV. The second lizard also had granulomatous hepatitis with intralesional hyphae. Evidence in this report suggests that the CANV is the etiologic agent of an emerging condition in captive bearded dragons that has been called 'yellow fungus disease'.

Detection of hepatitis A virus in mussels from different sources marketed in Puglia region (South Italy)

Hepatitis A virus (HAV) infection is endemic in Puglia (South Italy). Epidemiological studies indicate that shellfish consumption, particularly mussels, is a major risk factor for HAV infection, since these products are eaten raw or slightly cooked. Nested reverse transcriptase-polymerase chain reaction (RT-PCR) has been shown to be a sensitive technique for the detection of HAV in mussels. The aim of the present study was to detect the presence of HAV in a large sample of mussels by nested RT-PCR and to confirm the presence of infectious viral particles in positive samples by cell culture infection and RT-PCR confirmation. Two hundred and ninety samples of mussels from different sources were collected between December 1999 and January 2000. One hundred samples were collected before being subjected to depuration, 90 after depuration, and 100 were sampled in different seafood markets. HAV-RNA was detected in 20 (20.0%) of non-depurated mussels, in 10 (11.1%) of depurated samples, and in 23 (23.0%) of samples collected in the shellfish markets, without any significant difference in the prevalence of positive samples by collection sources (chi2 = 4.79, p = 0.09). Of the 53 samples found positive by nested RT-PCR, 18 (34.0%) resulted positive by cell culture assay. No relationship between viral contamination and bacterial contamination was found (p = 0.41). This study confirms the usefulness of molecular techniques in detecting HAV in shellfish and, thus, for the screening of a large sample of naturally contaminated mussels. Improved shellfish depuration methods are needed to obtain virus-safe shellfish and reduce the risk for public human health.

[An experimental study of immunity to hepatitis A in monkeys]

In this work the experimental model of hepatitis A on monkeys, adequate to human hepatitis A, was used. Ten monkeys (6 Macaca mulatta and 4 Cercopithecus aethiops) were reinfected with different doses of hepatitis A virus (HAV) a year after recovery from spontaneous and experimental hepatitis A. The monkeys were completely resistant to the inoculation of the virus in moderate doses (10(3) ID50). The inoculation of HAV in large doses (10(4)-10(5) ID50) induced a mild form of this infection in the animals with a transient rise in the level of serum alanin aminotransferase and HAV shedding in feces, but in the absence of morphological changes in the liver. It should be specially pointed out that after the reinfection of monkeys virus shedding in feces was observed, which may be of great epidemiological importance. After reinfection the absence of IgM and a pronounced rise in the titers of IgC antibodies were observed.

Attenuation phenotype of a cell culture-adapted variant of hepatitis A virus (HM175/p16) in susceptible New World owl monkeys

The virulence of a clonally isolated, cell culture-adapted hepatitis A virus (HM175/p16) was assessed in 4 seronegative owl monkeys inoculated intravenously with 2.8 x 10(4) radioimmunofocus-forming units of virus. The virus was highly attenuated, even though its complete nucleotide sequence contains only 19 mutations from the wild-type genome. Only 3 monkeys developed antibodies to hepatitis A virus (only 2 within 96 days of virus inoculation). One monkey had viremia and significantly elevated serum aminotransferase levels. In this animal, maximum viremia and fecal shedding of virus occurred 30-33 days after inoculation. In contrast, in earlier studies of a related cell culture-adapted but still hepatovirulent virus (HM175/S18), viremia was documented in 6 of 6 animals and peak viremia and fecal shedding of virus occurred 18 or 19 days after intravenous inoculation of about one-tenth as much virus.

Histopathological and immunohistochemical studies of hepatitis A virus infection in marmoset Callithrix jacchus

Samples of serum, feces and liver tissue and organs of six cotton-eared marmosets Callithrix jacchus infected intravenously with two different strains of hepatitis A virus (HAV), were studied by conventional histologic techniques, by serological techniques and by immunocytochemical methods, such as immunofluorescence (IF) and peroxidase-antibody techniques. Hepatitis A antigen (HAAg) was detectable in daily collected stools, in liver biopsy obtained sequentially, and in organs collected at necropsy. Two marmosets also developed antibodies to HAV. By contrast, serum transaminases were not altered and there were histological hepatic lesions consistent with acute viral hepatitis in all inoculated animals. The data obtained, demonstrate that these primates are susceptible to human HAV and may be a useful animal model for the study of infection by this virus.

[Spontaneous and experimental hepatitis A in Papio hamadryas]

Data on high susceptibility of Papio hamadryas to HAV are presented. For the first time, P. hamadryas were shown to be able to respond to both natural and experimental infection developing the features typical of hepatitis A: increased aminotransferase activity, virus shedding in feces, production of anti-HAV IgG and IgM, histological liver lesions. An infection lingering for 3-4 months was observed, as well as a case of chronic experimental hepatitis A with relapse in 7 months of the disease. Virological evidence of HAV infection was obtained in both lingering and chronic disease. HAV-PH strain was isolated for the first time and is described at length. It was isolated from a baboon with spontaneous infection which did not differ from that in man by antigenic and morphological features. The virus replicated in continuous African green monkey kidney cell line (AGMK) and was pathogenic for P. hamadryas. The HAV-PH isolate can be used for modelling hepatitis A in P. hamadryas.

[Virus persistence in hepatitis A in monkeys]

A long-term complex observation of 16 cynomolgus monkeys (Macaca fascicularis) and 8 African green monkeys (Cercopithecus aethiops) with spontaneous and experimental hepatitis A revealed two forms of the illness: acute and chronic. Some monkeys developed undulating chronic course of the disease consisting of 2-6 waves. Others developed relapses (1 to 3) which occurred within 2-4 or 6-11.5 months of the infection. The morphological changes in the liver persisted for 7-28 months. Alaninaminotransferase elevations in the blood and HAV shedding in feces were observed periodically for 7-20 months. HAV persistence was documented by radioimmunoassay, enzyme immunoassay, immune electron microscopy and molecular hybridization. Persisting HAV was shown to remain pathogenic for monkeys. Virological evidence of the etiological association of HAV with chronic infection and late relapses has been obtained for the first time.

Natural hosts of hepatitis A virus

The host range for hepatitis A virus (HAV) is limited to man and several species of non-human primates, and involvement of vertebrates other than primates in HAV circulation is unlikely. Spontaneous hepatitis A infection has been reported to occur in captive non-human primates including the great apes (chimpanzee) as well as Old World (cynomolgus, African vervet, stump-tailed) and New World (aotus) monkeys. The presence of anti-HAV antibody in the sera of newly captured monkeys of these species shows that infection may also spread in their natural habitat. HAVs isolated from spontaneously infected monkeys, although antigenically closely related to human HAV, exhibit a significant degree of genomic heterogeneity. There are at least four distinct simian HAVs differing from each other and from all human HAV strains. It is suggested that each virus is native to a given species reflecting evolutionary relationships among HAVs and their hosts in the order of Primates.

Simian hepatitis A virus (HAV) strain AGM-27: comparison of genome structure and growth in cell culture with other HAV strains

Fragments of cDNA representing greater than 99% of the entire genome of wild-type hepatitis A virus (HAV) strain AGM-27, isolated from an African green monkey, were obtained by the polymerase chain reaction and sequenced. Comparison with other HAV isolates revealed differences in the predicted amino acid sequence in functionally critical parts of the genome. Comparison of the biological properties of AGM-27 with those of human wild-type and cell culture-adapted HM-175 strains revealed that AGM-27 grew in cell culture significantly better than did wild-type HM-175, but not as well as cell culture-adapted HM-175. AGM-27 and cell culture-adapted HM-175 were distinguishable by their differential growth in CV-1, FRhK-4 and primary AGMK cells.

Sequence analysis of a new hepatitis A virus naturally infecting cynomolgus macaques (Macaca fascicularis)

A new isolate of hepatitis A virus (HAV), CY-145, was isolated from stool specimens obtained from cynomolgus macaques naturally infected with this agent. Sequence analysis of the capsid region of the genome indicated that this virus differed from other sequenced HAV strains by about 20% at the nucleotide level and 7% at the amino acid level. Two amino acid residues (residues 70 of VP3 and 102 of VP1), previously identified as constituting an immunodominant site and conserved in all sequenced HAVs, were changed in the CY-145 virus. Sequence analysis of a second cynomolgus HAV isolate (CY-55), which came from a different geographical location, showed the same amino acid replacement at these two sites. In addition both isolates had an amino acid substitution at the VP3-VP1 cleavage site. These data suggest that the cynomolgus HAV differs genetically and antigenically from all other sequenced HAVs.

[Susceptibility of Macaca rhesus to infection with hepatitis A virus strains isolated from man and monkeys]

The results of infection of Macaca rhesus monkeys with hepatitis A virus (HAV) strains isolated from monkeys and man are presented. After inoculation of monkeys with human NAV strains the infection could not be reproduced whereas simian HAV strains were found to be pathogenic for M. rhesus monkeys both on experimental inoculation and during natural contacts with infected monkeys in the animal house.

Hepatitis A virus infection in a chimpanzee: duration of viremia and detection of virus in saliva and throat swabs

The pathogenesis of hepatitis A virus was studied by orally inoculating a chimpanzee with wild-type virus. The virus was initially detected in the animal's serum (day 14 after inoculation); then viral antigen was detected in the tonsils (day 16), virus in the saliva and throat swabs (day 18), and viral antigen in the liver (day 21). The animal was viremic for 2 w. While this study involved a single animal, the presence of hepatitis A virus in saliva and throat swabs suggests a possible oropharyngeal site for viral replication.

Variations in genome fragments coding for RNA polymerase in human and simian hepatitis A viruses

The genome of hepatitis A virus (HAV) isolated from spontaneously infected African vervet monkey (Cercopithecus aethiops) has been cloned and partially sequenced. Comparison of genome fragments (1248 and 162 bp) from the 3D (RNA polymerase) region with the corresponding parts of human HAV genomes revealed a high degree of heterogeneity: there were altogether 257 nucleotide changes leading to 44 substitutions in predicted amino acid sequence, i.e. 89% amino acid identity. This divergence is considered to be significantly greater than genomic variations usually found among human HAV strains, where amino acid identity in the 3D region is over 98%.

[The immune structure and specific laboratory indices of acute hepatitis A in lower monkeys of the Sukhumi Nursery]

The study of the rate of occurrence of hepatitis A (HA) markers among monkeys, both newly arriving and those born and living for long periods (aboriginals) in the Sukhumi farm, was carried out. The rate of detection of antibody to HAV (anti-HAV) was shown to vary from 47% (Papio hamadryas) to 100% (Macaca arctoides and Macaca fascicularis). The level of infection with HAV varied among different groups of the same species: Macaca rhesus from 30% to 96%, Papio hamadryas from 0 to 82%. During a long-term observation period seroconversion to HAV was observed in monkeys arriving to the farm from natural habitats. In M. rhesus upon arrival the anti-HAV were detected in 7% and by the end of the observation period reached 100%, in green monkeys 28% and 92%, respectively. Anti-HAV of the IgM class were detected in animals with seroconversion. In fecal extracts from M. rhesus and in the liver, feces, and intestinal contents of green monkeys HAV was found cross-reacting with simian and human sera containing anti-HAV. The virions isolated from a green monkey liver had a buoyant density in CsCl 1.36 g/cm3, and HAV from feces of a M. rhesus sedimented in the density zone of 1.34 g/cm3.

[Spontaneous hepatitis similar to hepatitis A in African green monkeys]

Circulation of a virus similar to human hepatitis A virus by antigenic and some other properties was observed among African green monkeys imported from their natural habitats. In some of the monkeys this virus caused a disease similar to hepatitis A in many features.

[Spontaneous hepatitis A with a fatal outcome in rhesus monkeys]

This is the first report of virologically verified spontaneous hepatitis A in M. rhesus monkeys with severe involvement of the liver leading to the death of the animals. In 21 out of 23 dead monkeys morphological lesions in the liver have been characterized as acute hepatitis. In 6 (26%) animals no other pathological processes were found. In 15 animals hepatitis was combined with other diseases (dysentery, parasitic infestations, coronavirus infection). Antigen of hepatitis A virus was detected by an enzyme immunoassay in the intestinal contents of 8 monkeys and in the livers of 3 of them. Immune electron microscopic studies detected in the intestines some virus particles morphologically and antigenically similar to human hepatitis A virus.

Evidence of hepatitis A infection in immature rhesus monkeys

Forty immature (less than 2 years old) rhesus monkeys (Macaca mulatta) with marked increases in aspartate and alanine aminotransferase activities were examined. Serological and histopathological evaluations were done to determine if affected animals were infected with hepatitis A virus. Although no clinical signs of illness were noted in any of the monkeys, an excellent correlation was found between the increased serum aminotransferase values and seropositivity with the acute phase (IgM) HAVAB-M antibody. Histopathological evaluations of livers of selected animals revealed hepatic lesions consistent with those in chimpanzees and marmosets infected with hepatitis A virus: generalized activation of sinusoidal lining cells, focal hepatocellular necrosis with occasional acidophilic bodies, and cuffs of mononuclear cells in the portal areas. Although no animals were seropositive for HAVAB upon receipt from the breeding colony, a total of ten of 18 animals for which serological data were available had seroconverted to HAVAB positivity during the 4-month observation period. These results are consistent with hepatitis A infection in immature rhesus monkeys and indicate the potential significance of serological testing in animals in which hepatic function is being evaluated.

[Hepatitis A in Macaca fascicularis and M. arctoides infected by the Java monkey-55 strain of hepatitis A virus]

The results are presented dealing with experimental inoculation of M. fascicularis and M. arctoides with a strain of hepatitis A virus (HAV), YaM-55, isolated from a M. fascicularis with spontaneous hepatitis A, and parallel experiments on inoculation of these monkey species with HAV preparations (strain HAS-15) obtained as a result of the strain propagation in FRhK-4 cell culture and with specimens from human hepatitis A patients containing HAV particles. The YaM-55 strain of HAV was found to be capable of producing an infectious process quite similar to HA in the inoculated seronegative M. fascicularis and M. arctoides. Two different isolates of HAV derived from humans and the HAS-15 strain of HAV propagated for a long time in FRhK-4 cell culture failed to induce a disease in these monkey species. The classification of the YaM-55 strain with HAV was verified by specific serological studies and by molecular hybridization with cloned cDNA of HAV.

[Viral hepatitis A and B in anthropoid apes of the Moscow Zoo]

The rate of occurrence of hepatitis A and B virus specific markers in anthropoid apes of the Moscow Zoo (3 chimpanzees, 3 gorillas, 8 orang-outangs) was studied. Long-term persistence of HBs-antigen in orang-outang accompanied by the presence of HBe-antigen and anti-HBs was demonstrated. The presence of anti-HBs in gorillas and orang-outangs was recorded. Antibodies to hepatitis A virus were found in all the animal species examined. Cases of acute virus hepatitis A in orang-outangs are described contracted from the personnel handling the animals and suffering from this type of hepatitis. Morphological features of the course of hepatitis A in the presence of HBs-antigen carrier state are described. The possibility of active immunization of susceptible animals and the personnel of the zoo against viral hepatitides is discussed.

Acute hepatitis A infection in hepatitis B chimpanzee carriers

Two hepatitis B virus carrier chimpanzees which were superinfected with hepatitis A virus developed acute hepatitis followed by the production of antibodies to hepatitis A virus. The Southern blot technique employed to monitor liver hepatitis B virus DNA revealed that the amount of viral DNA in both animals was significantly reduced during the acute phase of hepatitis A infection. The levels of plasma hepatitis B DNA polymerase activity were also reduced in one chimpanzee. The high titers of HBsAg in the circulation remained unchanged throughout the study, and antibodies to the surface antigen and to e antigen were not detected. The morphological lesions in the liver were severe in one chimpanzee from whom one specimen showed both periportal focal necrosis and zonal parenchymal necrosis.

Malaria, arbovirus and hepatitis infections in Macaca fascicularis from Malaysia

Naturally occurring malaria, arbovirus infection and hepatitis in monkeys can be a hazard for the investigator and might interfere with the outcome of experiments. 63 young adult Macaca fascicularis from Malaysia were screened for these infections. About 1 year after their arrival in France, parasitaemia due to Plasmodium spp., was present in 6.4% of the animals and specific antibodies in 55.5%. 19 of 35 initially positive monkeys were tested again 2 years later. Parasitaemia was found in 1 of 4 monkeys and antibodies in 11 of 19 monkeys which were initially positive. 9 of the monkeys initially tested had low titres of antibodies to the Flavivirus genus. All animals were negative for the hepatitis B surface antigen and anti-HBc. The prevalence of IgG antibodies against hepatitis A was 46.0%. The implications in terms of control are discussed.

Transmission of hepatitis A virus among recently captured Panamanian owl monkeys

The presence of antibody to hepatitis A virus (anti-HAV) in 60% of procured owl monkeys (Aotus trivirgatus) held within the United States prompted a study of recently captured A trivirgatus in Panama. Only 2 of 145 newly captured monkeys, but all of 35 A trivirgatus held within a colony for over 100 days, were found to have anti-HAV. Of 41 sero-negative, newly captured monkeys followed prospectively, 25 became infected with hepatitis A virus (HAV) as evidenced by seroconversion or demonstration of virus in the liver at death. Only one monkey that survived over 60 days within the colony was not infected. HAV was identified in the feces of most infected monkeys prior to the development of antibody and was antigenically indistinguishable from human HAV in cross-blocking radioimmunoassays. This colony-centered epizootic provides strong evidence that A trivirgatus is susceptible to HAV and should be investigated further as a potential model of human hepatitis A.

Fulminant type A viral hepatitis in a chimpanzee

A case of a chimpanzee with fulminant hepatitis caused by spontaneous hepatitis A virus (HAV) infection was reported. The liver at autopsy revealed massive liver cell necrosis with mononuclear and polymorphonuclear cell infiltration. Aggregation of HAV-like particles (22-25 nm in diameter) were found within the vesicles of hepatocytes under the electron microscope. Immunofluorescent examination of the liver showed positive staining for HAV antigen, C1q, C3, C4, immunoglobulin M (IgM), and immunoglobulin G (IgG) in the hepatocytes and/or Kupffer cells in a granular fashion. The anti-HAV antibody (IgM type) and circulating immune complexes were detected in the postmortem serum. The present study suggests the possibility that the deposition of immune complexes of HAV and anti-HAV antibody in the liver cell plays an important role in the pathogenesis of massive liver cell necrosis in fulminant type A viral hepatitis.

Biophysical and biochemical characterization of hepatitis A virus

Biophysical and biochemical analysis of hepatitis A virus has shown it to be a 27- to 32-nm icosahedral particle with 32 capsomers. The mature virion has a buoyant density of 1.33-1.34 g/cm3, a sedimentation coefficient of 156-160S, and is composed of four polypeptides with molecular weights of 30,000-33,000 (VP1), 24,000-27,000 (VP2), 21,000-23,000 (VP3), and 7,000-14,000 (VP4). The genome of hepatitis A virus consists of a single piece of single-stranded RNA which sediments at 32-35S and has a buoyant density of 1.64 g/cm3. The molecular weight of RNA is 2.25 x 10(6) when measured under nondenaturing conditions and 2.8 x 10(6) when measured under fully denaturing conditions. The genome contains a 40-80 nucleotide sequence of polyadenylic and is capable of infecting cell cultures. These findings, together with the observation that the virion is stable at pH 3.0 and resistant to ether and a temperature of 60 degrees for 1 h, indicate that hepatitis A virus should now be classified as an Enterovirus within the family Picornaviridae.

Susceptibility of monkeys to human hepatitis A virus

A stump-tailed monkey, newly caught and without antibody to hepatitis B virus (HAV), was successfully infected with human HAV. The following alterations were observed in the monkey's functions: (1) elevation in activities of serum glutamic pyruvic transaminase, lactate dehydrogenase, and its type 5 isoenzyme (electrophoretically the fastest moving); (2) development of antibody to HAV; and (3) shedding of HAV antigen in feces. The virus isolated from the monkey, designated the Hangzhou A-1A strain of HAV, was serially transmitted to two other stump-tailed monkeys. Thus, the stump-tailed monkey (Macaca speciosa) is susceptible to infection with human HAV.

Nonhuman primate-associated viral hepatitis type A. Serologic evidence of hepatitis A virus infection

Since 1961, viral hepatitis has been recognized as an occupational hazard among handlers of newly imported chimpanzees and other nonhuman primates. To determine whether previously reported cases were caused by human viral hepatitis type A, we tested paired serum samples from two outbreaks for antibody to hepatitis A antigen (anti-HA) by immune adherence hemagglutination (IAHA), recently available test. In both outbreaks, one of hepatitis transmitted from chimpanzee to man (Michigan, 1964), the second from chimpanzee to chimpanzee, man, and woolly monkey (Connecticut, 1971), serologic data documented recent hepatitis A virus infection among contacts-human and nonhuman primate-of implicated chimpanzees. This confirms serologically a previously noted epidemiologic association between nonhuman primate-associated hepatitis and human viral hepatitis, type A.

Agarose gel filtration of concentrated fecal extracts containing virus-like particles associated with hepatitis A

Virus-like particles shown to be associated with hepatitis A infection were recently visualized by immune electron microscopy in human and chimpanzee acute-phase fecal extracts. Agarose gel filtration of concentrated chimpanzee fecal extracts containing those 27-nm diameter particles separated more than 99% of the high molecular weight fecal impurities into two major peaks as determined by absorbance at 280 and 260 nm. The hepatitis A-associated particles were found between these two peaks by both immune electron microscopy and a new immunoradiometric assay.