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Aim: Steam autoclaving is the gold standard for decontaminating dental instruments, but worldwide disinfection is still widely employed. We have evaluated a range of procedures for their ability to inactivate duck hepatitis B virus contaminating dental syringes.Methods: Residual infectivity of virus suspensions following 2% glutaraldehyde treatment, ultrasonication or steam sterilisation at 121 degrees or 134 degrees was assayed by injecting day-old ducklings and examining their livers for viral DNA 2.5 weeks later. Dental syringes were contaminated with DHBV positive blood, then treated by the same methods. An anaesthetic cartridge containing water was loaded into the syringe and 400microl aliquots used to inject day-old ducklings. Used dental syringes were examined by Scanning Electron Microscopy.Results: Suspension test:- ultrasonic treatment failed to inactivate DHBV in suspension, but complete inactivation was achieved by 2% glutaraldehyde and autoclaving. Syringe test:- neither ultrasonic treatment nor glutaraldehyde inactivated DHBV. Autoclaving at 134 degrees (3 minutes) permitted transmission to 1/16 ducklings but steam sterilisation at 121 degrees (15 minutes) was effective. Electronmicroscopy demonstrated organic debris (biofilm) in the lumen of used syringes.Conclusion: Short autoclaving cycles, albeit at raised temperatures, may fail to inactivate the virus because of poor steam penetration, inadequate heat transfer and the accumulation of protective biofilm. [ABSTRACT FROM AUTHOR]

Natural Duck Hepatitis B Virus (DHBV) infection has been studied in Australian ducks. Sera from 430 Pekin Aylesbury cross-bred ducks taken from three separate flocks were examined for duck hepatitis B virus (DHBV) DNA using a DNA dot hybridisation assay. In one flock there was significant infection with DHBV (98/140), but none was detectable in the other two flocks. Episomal DHBV DNA in liver tissue was demonstrated by gel blot hybridisation only in birds with DHBV DNA in serum. Polymerase-labelled DHBV DNA migrated as expected for linear double-stranded DNA 3-1 kilobase (kb) in length. Virus particles with characteristic DHBV morphology were observed in DHBV DNA-positive serum on electron microscopy. No overt morbidity has been noted in naturally infected ducks, but moderately severe hepatitis was found in 3/40 ducks examined histologically. These 3 ducks had DHBV DNA in serum and liver tissue. Mild hepatitis was observed in 27 ducks, but, in these, there was no correlation between the hepatitis and the presence of DHBV in serum or in liver tissue. This is the first report of DHBV in Australia. An animal model may now be established to study aspects of Hepadna virus infection which are pertinent to Hepatitis B virus (HBV) disease in man. [ABSTRACT FROM AUTHOR]

The persistence of Langerhans cells, melanocytes and ABH red cell antigens in human epidermal cell cultures derived from neonatal foreskin explants has been investigated. Langerhans cells were recognised via the detection of ATPase activity and by immunohistochemical staining for T6 and HLA-DR antigens. Melanocytes were detected by the dihydroxyphenylalanine (DOPA) technique; whilst the presence of red cell antigens was confirmed by immunohistochemical tests using monoclonal anti-A, anti-B, and anti-H antibodies. Langerhans cells were not detected in the cultured epidermis, and few melanocytes were found more than 0-2 mm from the periphery of the explants. However, both Langerhans cells and melanocytes were found to persist for up to 4 weeks in the explants themselves. Red cell antigens, consistent with the blood group of the donor infant, were consistently detected on the surface of the differentiating keratinocytes throughout their in vitro lifespan. The significance of these findings is discussed. [ABSTRACT FROM AUTHOR]

The literature concerning hepatitis B in pregnancy is reviewed and problems of management of both the acute and chronic infections are discussed. [ABSTRACT FROM PUBLISHER]

This paper describes six mother and infant pairs where the mother developed serum hepatitis during pregnancy. These findings are compared with those in three Australian antigen carrier mothers and their babies. The literature is also reviewed and it is concluded that neonatal hepatitis seldom occurs in infants whose mothers have hepatitis early in pregnancy or are chronic carriers of Australia antigen. In contrast the risk of infection of infants born to mothers who develop serum hepatitis later in pregnancy or in the puerperium approaches 50%. [ABSTRACT FROM PUBLISHER]

Hepatitis B core antigen (HBcAg) was prepared from human liver tissue and used in an immunoelectro-osmophoresis screening test to detect antibody to HBcAg (anti-HBc) in patients with evidence of liver disease and in blood donors. With the exception of two immunosuppressed HBsAg carriers, anti-HBc was found in all cases of hepatitis B infection even when HBsAg was detectable only by radioimmunoassay. Non-specific reactions were observed in 'non-B' hepatitis but, in spite of this problem, antib-HBc screening was considered a useful addition to routine tests in the clinical hepatitis laboratory. [ABSTRACT FROM PUBLISHER]

Background: Reports from around the world indicate that multiply transfused patients are at increased risk of hepatitis C virus (HCV) infection, with reported rates of between 4% and 44%. Such reports are mostly of haematological and renal patients. As recipients of blood products in the newborn period, premature infants share this risk, but there is little information regarding their risk. Aim: To assess the risk of HCV infection in children who, as premature neonates, received multiple blood products prior to the introduction of screening of donated blood for HCV. Methods: Premature infants born between January 1985 and January 1990 who had attended our high-risk follow-up clinic were selected on the basis of the number of transfusions of blood, platelets or fresh frozen plasma they received in the newborn period. Ethical approval to offer HCV testing to parents was obtained from the Central Sydney Area Health Service Ethics Review Committee. Parents of infants who received three or more transfusions were then contacted by mail with the approved letter explaining the study, and offered HCV testing. Detection of anti-HCV antibodies was undertaken using second, and later third generation enzyme immunoassay kits. Samples which were found to be ‘indeterminate’ were tested using a Wellcozyme HCV western blot assay (Murex Diagnostics Ltd, Datford, UK). Hepatitis C virus–ribonucleic acid (RNA) was detected using an ‘in-house’ polymerase chain reaction (PCR) assay. Alanine transaminase (ALT) was also measured, with values above 55 U/L considered abnormal. Results: Consent was obtained for 45 children (25 males, 20 females). The mean (± SEM) gestational age and weight of the children at birth was 26.7 ± 0.2 weeks and 938 ± 27 g, respectively. The children received 198 transfusions of blood products, an average of 4.4 U per child. All of the infants except for one were negative for anti-HCV antibodies. One infant was ‘indeterminate’ (low positive on third generation test but negative on second generation test), but proved negative subsequently on both western blot and PCR testing. HCV–RNA was not detected in any of the infants on PCR testing. All of the samples had normal ALT values, the mean being 16 U/L (range 8–52). Conclusion: None of the children consenting to this study had evidence of current HCV infection. Because of the sample size, we were not able to estimate the true risk of infection from this study, except that the upper limit for the risk is about 1/200 per transfused blood sample. [ABSTRACT FROM AUTHOR]

A new commercial test for hepatis B surface antigen based on an enzyme-linked immunosorbent-assay system was evaluated and compared with other tests already available. It was of comparable sensitivity to the radioimmunoassay test but required less expensive equipment (in terms of both outlay and upkeep) and did not use radioisotopes; the reagents were more stable. [ABSTRACT FROM PUBLISHER]

Ten cases of serum hepatitis occurring after open-heart surgery at the National Heart Hospital, London are reported. The incidence seemed to be rising and was at least 2% before antigen-screened blood became available. Investigation of 135 patients for the presence of Australia antigen and antibody showed that five (3·7%) had responses to exposure to the infective agent. All were and remained clinically well, but such patients may constitute a source of infection. Since tested blood has been used no hepatitis cases have been recognized. [ABSTRACT FROM PUBLISHER]

Abstract Background During acute Human parvovirus B19 (B19) infection a transient reduction in blood haemoglobin concentration is induced, due to a 5-7 day cessation of red cell production. This can precipitate severe anaemia in subjects with a range of pre-existing conditions. Of the disease markers that occur during B19 infection, high IgM levels occur closest in time to the maximum reduction in haemoglobin concentration. Previous studies of the contribution of B19 to severe anaemia among young children in Africa have yielded varied results. This retrospective case/control study seeks to ascertain the proportion of severe anaemia cases precipitated by B19 among young children admitted to a Kenyan district hospital. Methods Archival blood samples from 264 children under 6 years with severe anaemia admitted to a Kenyan District Hospital, between 1999 and 2004, and 264 matched controls, were tested for B19 IgM by Enzyme Immunosorbent Assay and 198 of these pairs were tested for B19 DNA by PCR. 536 samples were also tested for the presence of B19 IgG. Results 7 (2.7%) cases and 0 (0%) controls had high B19 IgM levels (Optical Density > 5 × cut-off value) (McNemar's exact test p = 0.01563), indicating a significant association with severe anaemia. The majority of strongly IgM positive cases occurred in 2003. 10/264 (3.7%) cases compared to 5/264 (1.9%) controls tested positive for B19 IgM. This difference was not statistically significant, odds ratio (OR) = 2.00 (CI95 [0.62, 6.06], McNemar's exact test p = 0.3018. There was no significant difference between cases and controls in the B19 IgG (35 (14.8%) vs 32 (13.6%)), OR = 1.103 (CI95 [0.66, 1.89], McNemar's exact test, p = 0.7982), or the detection of the B19 DNA (6 (3.0%) vs 5 (2.5%)), OR = 1.2 (CI95 [0.33, 4.01], McNemar's exact test p = 1). Conclusions High B19 IgM levels were significantly associated with severe anaemia, being found only among the cases. This suggests that 7/264 (2.7%) of cases of severe anaemia in the population of children admitted to KDH were precipitated by B19. While this is a relatively small proportion, this has to be evaluated in the light of the IgG data that shows that less than 15% of children in the study were exposed to B19, a figure much lower than reported in other tropical areas.

Commentary. Discusses a paper by Peter Simmonds, et al, which was published in the July 18, 1998 issue of `The Lancet.' Aspects of the transfusion-transmittable virus known as TTV; The pathogenic role of TTV; Suggestion that TTV may be a parvovirus; The strong circumstantial evidence of transmission of TTV by transfusion; Effects of the discovery of TTV.

Presents an abstract of the article "A Study of Human Papillomavirus Type 16 Involvement in Cervical Carcinomas 1920-1990," by B. Rose, C. Thompson, M. Flampoulidou, J. Grace and Y. Cossart, published in the December 2, 1990 issue of the journal "Immunology & Cell Biology."

Background: During acute Human parvovirus B19 (B19) infection a transient reduction in blood haemoglobin concentration is induced, due to a 5-7 day cessation of red cell production. This can precipitate severe anaemia in subjects with a range of pre-existing conditions. Of the disease markers that occur during B19 infection, high IgM levels occur closest in time to the maximum reduction in haemoglobin concentration. Previous studies of the contribution of B19 to severe anaemia among young children in Africa have yielded varied results. This retrospective case/control study seeks to ascertain the proportion of severe anaemia cases precipitated by B19 among young children admitted to a Kenyan district hospital., Methods: Archival blood samples from 264 children under 6 years with severe anaemia admitted to a Kenyan District Hospital, between 1999 and 2004, and 264 matched controls, were tested for B19 IgM by Enzyme Immunosorbent Assay and 198 of these pairs were tested for B19 DNA by PCR. 536 samples were also tested for the presence of B19 IgG., Results: 7 (2.7%) cases and 0 (0%) controls had high B19 IgM levels (Optical Density > 5 x cut-off value) (McNemar's exact test p = 0.01563), indicating a significant association with severe anaemia. The majority of strongly IgM positive cases occurred in 2003.10/264 (3.7%) cases compared to 5/264 (1.9%) controls tested positive for B19 IgM. This difference was not statistically significant, odds ratio (OR) = 2.00 (CI95 [0.62, 6.06], McNemar's exact test p = 0.3018. There was no significant difference between cases and controls in the B19 IgG (35 (14.8%) vs 32 (13.6%)), OR = 1.103 (CI95 [0.66, 1.89], McNemar's exact test, p = 0.7982), or the detection of the B19 DNA (6 (3.0%) vs 5 (2.5%)), OR = 1.2 (CI95 [0.33, 4.01], McNemar's exact test p = 1)., Conclusions: High B19 IgM levels were significantly associated with severe anaemia, being found only among the cases. This suggests that 7/264 (2.7%) of cases of severe anaemia in the population of children admitted to KDH were precipitated by B19. While this is a relatively small proportion, this has to be evaluated in the light of the IgG data that shows that less than 15% of children in the study were exposed to B19, a figure much lower than reported in other tropical areas.

The early phase after hepatitis B virus infection could play a crucial role in clearance and/or persistence of the virus, particularly in neonates. This work compared the early phase of duck hepatitis B virus infection in 1-day-old (D1) and 28-day-old (D28) ducks to determine whether differences in viral or host innate immune response can be related to the difference in outcome. In the first phase, almost immediately after inoculation, virus was taken up by components of the reticulo-endothelial systems, particularly liver-specific macrophages, Kupffer cells. Very early after infection, the induction of alpha interferon by infected hepatocytes occurred and was rapidly reinforced by recruitment of effector lymphocytes, which directly or indirectly caused apoptosis, eliminating infected hepatocytes, as was seen in mature birds. In addition, a lack of lymphocytic infiltration of the liver was found in D1 ducks, which supports the suggestion that the innate immune network is less effective in D1 ducks. Taken together, these results suggest that failure of the co-ordinated innate immune response rather than a defect in induced antiviral cell-mediated immunity may be the key factor which makes baby ducks vulnerable to persistence of hepadnavirus infection.

Parvovirus B19 (B19) is a common childhood infection that has recently been found to be associated with severe anemia in Papua New Guinean children. Population surveys were performed in 15 villages in Maprik district, East Sepik Province, Papua New Guinea in 2005. Plasma samples collected from children less than 10 years of age were tested for IgM and IgG antibodies to B19 by enzyme immunoassay. The prevalence of IgG antibody to B19 was 53.8% and ranged from 20% in those less than one year of age to 85.5% in those nine years of age. Considerable variation in IgG prevalence was observed between study areas, indicating complex patterns of transmission. Prevalence of IgM antibody to B19 was 1.5%. This study confirms that B19 infection is common among children in this tropical area. With 19.5% of children one year of age showing evidence of previous infection, any preventive measures should be targeted at the very young.

This study investigates human papillomavirus (HPV) infection in the oral cavities of 88 Australian renal transplant recipients and 88 immunocompetent controls. Oral cavities were examined for lesions and brushings collected for HPV analysis by consensus PCR. No warts were identified; HPV DNA was detected in 18% of transplant versus 1% control samples (P<0.001). Cutaneous HPVs predominated. One patient had HPV16 in samples taken four years apart without evidence of associated lesions or malignancy. Transplant recipients were more likely than controls to have current cutaneous warts (P<0.001), fewer sexual partners (P=0.001), and to have never consumed alcohol (P=0.01). Among the transplant group, the risk of an HPV-positive sample was higher among older patients (P=0.05), and those with past cutaneous warts (P=0.04). This study extends previous surveys by encompassing overt and asymptomatic infection, a broad spectrum of cutaneous and genital HPVs, and by providing new data on risk factors for oral HPV infection.

Background: Severe anemia (hemoglobin level, <50 g/L) is a major cause of death among young children, and it arises from multiple factors, including malaria and iron deficiency. We sought to determine whether infection with parvovirus B19 (B19), which causes the cessation of erythropoiesis for 3-7 days, might precipitate some cases of severe anemia., Methods: Archival blood samples collected in the Wosera District of Papua New Guinea, from 169 children 6 months-5 years old with severe anemia and from 169 control subjects matched for age, sex, and time were tested for B19 immunoglobulin M (IgM) by enzyme immunoassay and for B19 DNA by nested polymerase chain reaction (PCR). A total of 168 separate samples from children in the Wosera District were tested for B19 IgG., Results: A strong association between acute B19 infection (positive by both IgM and PCR) and severe anemia was found (adjusted odds ratio, 5.61 [95% confidence interval, 1.93-16.3]). The prevalence of parvovirus B19 IgG reached >90% in 6-year-olds., Conclusions: B19 infections play a significant role in the etiology of severe anemia in this area of malarial endemicity. Given the high levels of morbidity and mortality associated with severe anemia in such regions, the prevention of B19 infection with a vaccine might be a highly effective public health intervention.

Background: Biofilm consisting of bacteria enclosed in a matrix of exopolysaccharide (EPS) forms on many medical devices such as catheters and implants. Nosocomial infection is, thus, a newly recognized scenario of biofilm development. Biofilm removal by physical methods such as ultrasound and mechanical cleaning is reasonably effective but difficult to supervise in practice. Chemical methods are often ineffective because of biofilm resistance to biocides. In this study, we compared the efficiency of different detergents used in endoscope reprocessing., Methods: Escherichia coli biofilm was generated on Teflon and medical grade PVC tubing under low flow conditions. Sections of biofilm covered tubing were washed using test detergents and biofilm removal was assessed by counting remaining adherent bacteria after washing and by scanning electron microscopy to qualitatively assess the amount and nature of the remaining biofilm., Results: Control tubing developed a multilayered biofilm consisting of >10(5) bacterial cells/cm(2). Only Matrix (Whiteley Medical, Sydney, Australia) produced >4 log reduction in viable bacterial numbers. Matrix and Epizyme Rapid (3M Australia, Pymble, Australia) were able to remove up to 75% and 60% of the biofilm, respectively., Conclusions: Many commonly used enzymatic cleaners fail to reduce the viable bacterial load or remove the bacterial EPS. Cleaners with high enzyme activity, Epizyme Rapid, removed more biofilm but failed to reduce bacterial numbers more than 2 logs. The only cleaner containing no enzymes, Matrix, significantly reduced bacterial viability and residual bacterial EPS.

The functional significance of sequence variation within the upstream regulatory region (URR) of six human papillomavirus type 16 (HPV16) cervical cancer isolates from Australia was investigated. Specific changes in transcription factor binding sites leading to increased promoter activity may explain the transforming ability of some episomal HPV16 isolates.