Autochthonous and Travel Acquired Hepatitis E Virus in Australia

BACKGROUND

Hepatitis E virus (HEV) is a common cause of acute viral hepatitis with significant morbidity and mortality, particularly in pregnant women. There are four major genotypes which can cause disease in humans. Genotypes 1 and 2 are usually associated with outbreaks and spread via facal/oral route or contaminated water. Genotypes 3 and 4 are zoonotic and usually associated with handling of pigs or consumption of contaminated pork. The strains circulating in Australia have never been characterized.

RATIONALE/AIMS

The aims for this project are to identify the HEV genotypes found in Australia and link them to possible sources of transmission by phylogenetic analysis.

MATERIALS AND METHODS

Between 2015 and 2020, 91 HEV isolates were sequenced and genotyped using an in-house PCR. Sixty-six of these were also sequenced by using the international HEVnet primers. Genotypes were determined using the BLASTn program. Relatedness to other strains in Australia was determined by phylogenetic analyses of the HEVnet sequences. Isolates were also stratified by state of origin, gender, age, predisposing factors and travel history (if known).

RESULTS

Of the 91 HEV isolates sequenced, 55 (60.4%) were genotype 1. There were 34 (37.4%) genotype 3 strains and two genotype 4 (2.2%). At least 20 of the genotype 1 strains have been linked to travel in India, and another three with Pakistan. Five of the "Indian" strains were closely related and are suspected to have originated in Gujarat. Phylogenetic analysis also showed that 12 genotype 3 strains were genetically related and potentially acquired in/from New South Wales, Australia. The two genotype 4 strains may have originated in China.

DISCUSSION

This is the first study to describe the HEV isolates identified in Australia. The results infer that HEV may be acquired during overseas travel as well as locally, presumably from consumption of pork or pork-related products. The phylogenetic analyses also reveal clusters of infection originating from India and Pakistan. This study provides some insight into the source and epidemiology of HEV infection in Australia which may be used to guide public health procedure and enable the implementation of measures to deal with potential outbreaks of infection.

Racial disparity in all-cause mortality among hepatitis C virus-infected individuals in a general US population, NHANES III

There are few long-term nationally representative studies of all-cause mortality among those infected with hepatitis C virus (HCV). When an additional 5 years of data were made publicly available in 2015, the Third National Health and Nutrition Examination Survey Linked Mortality File became the longest nationally representative study in the United States. Our objective was to update the estimated HCV-associated all-cause mortality in the general US population and determine any differences by sex, age and race/ethnicity. HCV status was assessed in 9117 nationally representative adults aged 18-59 years from 1988 to 1994, and mortality follow-up of the same individuals was completed through 2011 and made publicly available in 2015. There were 930 deaths over a median follow-up of 19.8 years. After adjusting for all covariate risk factors, chronic HCV had 2.63 times (95% CI: 1.59-4.37; P=.0002) higher all-cause mortality rate ratio (MRR) compared with being HCV negative. All-cause MRR was stratified by sex, age and race/ethnicity. Only race/ethnicity was a significant effect modifier of MRR (P<.0001) as the highest MRR of chronic HCV compared to HCV negative was 7.48 (95% CI: 2.15-26.10, P=.001) among Mexican Americans, 2.67 (95% CI: 2.67-5.56, P=.009) among non-Hispanic Whites and 2.02 (95% CI: 1.20-3.40, P=.007) among non-Hispanic Blacks. Racial disparity was seen in the all-cause mortality as Mexican Americans with chronic HCV had approximately seven times higher mortality rate than HCV-negative individuals. This suggests that these at-risk individuals should be targeted for HCV screening and treatment, given the availability of new highly effective HCV therapies.

In situ biaxial rotation at low-temperatures in high magnetic fields

We report the design, construction, and characterization of a biaxial sample rotation stage for use in a cryogenic system for orientation-dependent studies of anisotropic electronic transport phenomena at low temperatures and high magnetic fields. Our apparatus allows for continuous rotation of a sample about two axes, both independently and simultaneously.

Detection of HCV-Specific IFN-γ Responses in HCV Antibody and HCV RNA Negative Injecting Drug Users

BACKGROUND

Detectable HCV-specific cellular immune responses in HCV antibody and RNA negative people who inject drugs (PWID) raise the question of whether some are resistant to HCV infection. Immune responses from people who have been exposed to hepatitis C virus (HCV) and remain anti-HCV negative are of interest for HCV vaccine development; however, limited research addresses this area.

OBJECTIVES

In a cohort of HCV antibody and RNA negative PWID, we assessed whether the presence of HCV-specific IFN-γ responses or genetic associations provide any evidence of protection from HCV infection.

PATIENTS AND METHODS

One hundred and ninety-eight participants were examined longitudinally for clinical, behavioral, social, environmental and genetic characteristics (IFNL3 genotype [formally IL-28B] and HLA type). Sixty-one of the 198 participants were HCV antibody and RNA negative, with 53 able to be examined longitudinally for HCV-specific IFN-γ ELISpot T cell responses.

RESULTS

Ten of the 53 HCV antibody and RNA negative participants had detectable HCV-specific IFN-γ responses at baseline (18%). The magnitude of IFN-γ responses averaged 131 +/- 96 SFC/106 PBMC and the breadth was mean 1 +/- 1 pool positive. The specificity of responses were mainly directed to E2, NS4b and NS5b. Participants with (10) and without (43) HCV-specific IFN-γ responses did not differ in behavioral, clinical or genetic characteristics (P > 0.05). There was a larger proportion sharing needles (with 70%, without 49%, P = 0.320) and a higher incidence of HCV (with 35.1 per 100 py, 95% CI 14.6, 84.4, without 16.0 per 100 py, 95% CI 7.2, 35.6, P = 0.212) in those with IFN-γ responses, although not statistically significant. Half the participants with baseline IFN-γ responses became HCV RNA positive (5/10), with one of these participants spontaneously clearing HCV. The spontaneous clearer had high magnitude and broad Th1 responses, favorable IFNL3 genotype and favorable HLA types.

CONCLUSIONS

This study demonstrated the detection of HCV-specific IFN-γ responses in HCV antibody and RNA negative individuals, with a tendency for HCV-specific IFN-γ responses to be associated with HCV exposure. The potential role of HCV-specific IFN-γ responses in those who remained HCV RNA negative is of value for the development of novel HCV therapeutics.

Hepatitis C virus phylogenetic clustering is associated with the social-injecting network in a cohort of people who inject drugs

It is hypothesized that social networks facilitate transmission of the hepatitis C virus (HCV). We tested for association between HCV phylogeny and reported injecting relationships using longitudinal data from a social network design study. People who inject drugs were recruited from street drug markets in Melbourne, Australia. Interviews and blood tests took place three monthly (during 2005-2008), with participants asked to nominate up to five injecting partners at each interview. The HCV core region of individual isolates was then sequenced and phylogenetic trees were constructed. Genetic clusters were identified using bootstrapping (cut-off: 70%). An adjusted Jaccard similarity coefficient was used to measure the association between the reported injecting relationships and relationships defined by clustering in the phylogenetic analysis (statistical significance assessed using the quadratic assignment procedure). 402 participants consented to participate; 244 HCV infections were observed in 238 individuals. 26 genetic clusters were identified, with 2-7 infections per cluster. Newly acquired infection (AOR = 2.03, 95% CI: 1.04-3.96, p = 0.037, and HCV genotype 3 (vs. genotype 1, AOR = 2.72, 95% CI: 1.48-4.99) were independent predictors of being in a cluster. 54% of participants whose infections were part of a cluster in the phylogenetic analysis reported injecting with at least one other participant in that cluster during the study. Overall, 16% of participants who were infected at study entry and 40% of participants with newly acquired infections had molecular evidence of related infections with at least one injecting partner. Likely transmission clusters identified in phylogenetic analysis correlated with reported injecting relationships (adjusted Jaccard coefficient: 0.300; p<0.001). This is the first study to show that HCV phylogeny is associated with the injecting network, highlighting the importance of the injecting network in HCV transmission.

Summary of FDA antibody-mediated rejection workshop

The Food and Drug Administration (FDA) held an open public workshop in June 2010 to discuss the current state of science related to antibody-mediated rejection (AMR) in kidney transplantation. Desensitization, acute AMR and chronic AMR (CAMR) were considered in the context of clinical trial design. Participants discussed experiences with HLA antibody detection and quantitation and the utility of monitoring donor-specific antibodies (DSAs) to inform the management of patients with AMR. The role for animal models was discussed. Diagnostic and prognostic features of histology were presented, followed by discussion of sensitivity and specificity of various criteria. The published literature on treatment of acute AMR was summarized, which consisted of case series and limited data from controlled clinical trials. Considerations for future clinical trials were presented, including endpoints and statistical evaluations of outcome. Although many issues need further consideration, the meeting enabled an important exchange of ideas between experts in the field.

51 SCRIPTAID AND MG132 IMPROVE DEVELOPMENT OF PORCINE EMBRYOS RECONSTRUCTED BY SOMATIC CELL NUCLEAR TRANSFER

Nuclear transfer efficiency in pigs and other large animal species is low. Previous studies have shown that histone deacetylase inhibitor (Scriptaid) and proteasomal inhibitor (MG132) treatment of somatic cell nuclear transfer (SCNT) pig embryos enhances blastocyst formation and pregnancy. The current experiment was carried out to determine the effects of combined MG132 and Scriptaid treatment on early development of cloned pig embryos reconstituted by SCNT. A total of 328 sow oocytes procured from ART (Madison, WI, USA) were reconstructed using α-1,3-Galactosyltransferase knockout hDAF transgenic pig fetal-derived fibroblast cells. Immediately after electrofusion and activation, SCNT oocytes were treated with 0, 1, or 10 μM MG132 for 2 h and then treated with 500 nM Scriptaid for another 16 h. The SCNT embryos were washed and cultured in Porcine Zygote Medium 3 for 7 days. Percent cleavage was determined on Day 2, and blastocyst formation and cell number were determined on Day 7. The experiment was repreated 8 times. There was no difference (P > 0.05) in percent cleavage (57.9 to 66.7%), or cell number (25.5 to 30.6) among the 3 groups. Interestingly, while there was no difference in the percent blastocyst between the 1 μM and 0 μM MG132 treatment groups, more oocytes from the 1 μM MG132 group developed into blastocysts than in the 10 μM MG132 group (25.1 ± 4.6% v. 12.9 ± 3.3%; P = 0.045). Further research will be conducted to transfer these embryos to surrogate gilts to determine the true developmental competence of these embryos. Supported by the National Institutes of Health National Center for Research Resources (RR018877 and RR013438), and Food for the 21st Century.

The occurrence of ventilator-associated pneumonia in a community hospital: risk factors and clinical outcomes

STUDY OBJECTIVES

To prospectively identify the occurrence of ventilator-associated pneumonia (VAP) in a community hospital, and to determine the risk factors for VAP and the influence of VAP on patient outcomes in a nonteaching institution.

DESIGN

Prospective cohort study.

SETTING

A medical ICU and a surgical ICU in a 500-bed private community nonteaching hospital: Missouri Baptist Hospital.

PATIENTS

Between March 1998 and December 1999, all patients receiving mechanical ventilation who were admitted to the ICU setting were prospectively evaluated.

INTERVENTION

Prospective patient surveillance and data collection.

RESULTS

During a 22-month period, 3,171 patients were admitted to the medical and surgical ICUs. Eight hundred eighty patients (27.8%) received mechanical ventilation. VAP developed in 132 patients (15.0%) receiving mechanical ventilation. Three hundred one patients (34.2%) who received mechanical ventilation died during hospitalization. Logistic regression analysis demonstrated that tracheostomy (adjusted odds ratio [AOR], 6.71; 95% confidence interval [CI], 3.91 to 11.50; p < 0.001), multiple central venous line insertions (AOR, 4.20; 95% CI, 2.72 to 6.48; p < 0.001), reintubation (AOR, 2.88; 95% CI, 1.78 to 4.66; p < 0.001), and the use of antacids (AOR, 2.81; 95% CI, 1.19 to 6.64; p = 0.019) were independently associated with the development of VAP. The hospital mortality of patients with VAP was significantly greater than the mortality of patients without VAP (45.5% vs 32.2%, respectively; p = 0.004). The occurrence of bacteremia, compromised immune system, higher APACHE (acute physiology and chronic health evaluation) II scores, and older age were identified as independent predictors of hospital mortality.

CONCLUSIONS

These data suggest that VAP is a common nosocomial infection in the community hospital setting. The risk factors for the development of VAP and risk factors for hospital mortality in a community hospital are similar to those identified from university-affiliated hospitals. These risk factors can potentially be employed to develop local strategies for the prevention of VAP.

CLINICAL IMPLICATIONS

ICU clinicians should be aware of the risk factors associated with the development of VAP and the impact of VAP on clinical outcomes. More importantly, they should cooperate in the development of local multidisciplinary strategies aimed at the prevention of VAP and other nosocomial infections.

[Study on hepatitis C virus genotyping in some parts of China]

OBJECTIVE

To study the genotypes of hepatitis C virus in some parts of China.

METHODS

Twenty-seven sera of plasma donors from Guan county of Hebei province, Zhoukou district of Henan province, and 36 patients with chronic hepatitis C from Beijing and Qingdao cities were tested for HCV RNA by Amplicor PCR kit. Thirty-six of 38 HCV RNA positive sera were further genotyped, using INNO-LiP A HCV II kit.

RESULTS

The HCV RNA positive rates of plasma donors and patients with chronic hepatitis C were 48.15% (13/27) and 69.44% (25/36) respectively. Genotyping data from 13 plasma donors and 23 patients with chronic hepatitis C showed that 29 (80.55%) were 1b, 5 (13.89%) were genotype 2, and 2 (5.56%) remained untyped.

CONCLUSION

1b seemed to be the prevalent HCV genotype in some parts of China.

Early effects of lead on bone marrow cell responsiveness in mice challenged with Listeria monocytogenes

Listeria monocytogenes challenge of lead-treated mice results in increased mortality. Since macrophage development constitutes the initial phase of the immune response to L. monocytogenes, bone marrow and spleens from Pb-treated mice that were infected with L. monocytogenes were analyzed for their ability to form colonies when exposed to the macrophage growth factor CSF-1. Serum colony-stimulating activity also was evaluated. Data obtained indicate the Pb exposure results in decreased responsiveness of bone marrow and spleen cells to CSF-1 while colony-stimulating activity in serum rises. This lack of bone marrow-derived macrophage development may contribute to the increased mortality observed with L. monocytogenes challenged. Pb-treated mice.

Lead-induced alterations of in vitro bone marrow cell responses to colony stimulating factor-1

Bone marrow cell responsiveness to hematopoietic growth factors is an integral part of immune responsiveness. Since host resistance is often dependent on bone marrow cell responsiveness and Pb alters host resistance, the influence of Pb on bone marrow cell responsiveness to the hematopoietic growth factor CSF-1 was evaluated. Cell number, soft agar colony formation, cell cycle analysis, as well as 3H-thymidine incorporation were utilized to determine if CSF-1 driven bone marrow-derived macrophage (BMDM) proliferation in vitro is altered in the presence of PbCl2. Data obtained indicate that Pb potentiates the ability of CSF-1 to stimulate thymidine incorporation by BMDM; however, colony formation is inhibited reversibly, and the absolute number of cells in culture is adversely affected by Pb. Propagation of BMDM appears to be more sensitive to Pb (100 nM) than other immune parameters. The decrease in bone marrow cell responsiveness to CSF-1 in the presence of Pb observed in this system may contribute to the decrease in host resistance observed in Pb-exposed animals.

Effect of lead on macrophage function

Lead (Pb) has been shown to alter various parameters of immune function such as host resistance and antibody formation. In addition, various heavy metals have been implicated as inducers of autoimmunity. In these experiments, macrophages, isolated from the peritoneal cavity of mice exposed to various doses of lead in vivo as well as cells exposed in vitro were tested for the following immunologic parameters: phagocytosis, antigen presentation, interleukin 1 production, and their ability to stimulate the autologous mixed lymphocyte reaction (AMLR). The results obtained indicate that Pb appears to alter the ability of macrophages to present antigen by enhancing the AMLR while having no effect on phagocytosis or IL-1 production. These data suggest that Pb may interfere with antigen-specific interactions between macrophages and T cells.