Occupational exposure of health care personnel to hepatitis B and hepatitis C: prevention and surveillance strategies

Healthcare Waste Management: A Case Study from Sudan

Healthcare waste (HCW) represents a major public health issue, especially in developing countries. Among HCW categories, sharps waste is one of the most hazardous. Exposure to needle-stick injuries can lead to blood-borne pathogens, therefore HCW should be managed in an effective manner. The main aims of this study were to assess the current management of used needles and to suggest suitable recommendations for an improved and safer system for needle management in Khartoum, Sudan. The study showed that the management of both healthcare and home-generated HCW in Sudan is inefficient, as all wastes are mixed together and disposed of improperly, especially used needles. The study attributes this to many reasons, including lack of waste segregation at the source, lack of policies, failure of planning, inadequate training, lack of awareness of the hazardous nature of such kinds of waste, weak infrastructure, and a lack of suitable treatment technologies. The estimated average generated rate of HCW ranged from 0.38 to 0.87 kg/bed/day in 2009 and 2012, respectively. Such ineffective healthcare waste management HCWM, especially used needles, can put public health as well as the environment at risk, particularly waste workers, thus urgent action needs to be taken by all involved parties and at all levels.

Postobstructive Cyst Formation in Pancreatic Duct affecting Surgical Approach

How to cite this article: Ezer A, Parlakgumus A. Postobstructive Cyst Formation in Pancreatic Duct affecting Surgical Approach. Euroasian J Hepato-Gastroenterol 2018;8(1):99-100.

Seroepidemiology of HBV infection among health-care workers in South Sulawesi, Indonesia

BACKGROUND

Hepatitis B virus (HBV) infection is a world health problem with an estimated 257 million chronically infected people. Indonesia, with 7.1% prevalence of hepatitis B surface antigen (HBsAg), is classified as a moderately endemic country. Healthcare workers (HCWs) are at high occupational risk for HBV infection and potentially becoming transmitters for further infections. In Indonesia, the extent of hepatitis B among HCWs and specific control strategy are not available. This study evaluated the seroprevalence of HBV infection and associated risk factors in HCWs from four areas in South Sulawesi, Indonesia.

METHODS

A total of 467 HCWs (median age 28 years, male/female 89/378) were recruited. All HCWs were classified into three age groups (< 20-29, 30-39, and ≥ 40 years old), three work types (administration, non-intervention, and intervention), and three service periods (< 5, 5-9, and ≥ 10 years). Data on socio-demographic characteristics and risk factors were obtained by questionnaire and serum samples were tested for HBV markers (HBsAg, its antibody [anti-HBs], and antibody to core antigen [anti-HBc]. Chi-square or Fisher's exact test was used to determine differences in categorical variables, while risk factors were reported as odds ratios (OR).

RESULTS

The prevalence of current HBV infection (HBsAg+), exposure to HBV (anti-HBc+), and immunity to HBV (anti-HBs+) was 6.2, 19.2, and 26.1%, respectively. Two thirds (66.17%) of all HCWs did not express any of HBV markers. In relation to the age groups, intervention work-type, and service period of HCWs, increasing trends were observed in the exposure to HBV (p < 0.001, p < 0.001, and p < 0.010, respectively) and the immunity to HBV by natural infection (HBsAg-, anti-HBc+, anti-HBs+) (p = 0.004, p < 0.001, and p < 0.010, respectively). Needlestick injury contributed the highest risk factor (OR = 1.71; 95% CI: 1.05-2.77; p = 0.029) for infection acquisition, which mostly occurred in the intervention group (p = 0.046).

CONCLUSION

Exposure to HBV showed significant association with HCWs' age, work type, and service period. Needlestick injury was the highest risk factor for the acquisition of HBV, with highest events in the intervention work-type. Two thirds of HCWs were still susceptible to HBV infection. Intervention strategies at the national level are required to mount prevention, control, and management of HBV infection in HCWs.

Hepatitis B Virus Infection among Health Care Workers in Indonesia

Hepatitis B virus (HBV) infection is a global health problem with an estimated 257 million chronically infected people. Indonesia is a moderately hepatitis B-endemic country with 7.1% prevalence of hepatitis surface antigen (HBsAg). This infection is considered as an important occupational hazard among health care workers (HCWs), who may become further transmitters of this infection. The extent of hepatitis B among HCWs and specific control strategy are not available in Indonesia. A study was done on 644 HCWs, who were categorized into administration, nonintervention, and intervention groups. The prevalence of HBsAg, antibody to HBV core antigen (anti-HBc), and antibody to HBsAg (anti-HBs) was 4.7, 18.5, and 36.7% respectively, while 57.3% were negative for all seromarkers, indicating susceptibility to this infection. Increasing trend with age was observed in the exposure to infection (anti-HBc) (p <0.001) and the marker of resolved infection (HBsAg-, anti-HBc+, anti-HBs+) (p = 0.004), suggesting accumulated exposure to HBV infection by increasing age. Rising trend of exposure rate was also observed across the administration, nonintervention, and intervention groups (p < 0.001). By length of service period, significant escalation of exposure (p = 0.010) and resolved infection (p < 0.001) were also observed, suggesting increasing occupational risk to HBV infection. There is an urgent need to safeguard the HCWs with hepatitis B vaccination and provide continuing education at various health care setups. The establishment of a national policy and a roadmap for effective and efficient intervention is required for the prevention, diagnosis, postexposure management, and treatment of HBV infection in this special population.

How to cite this article: Muljono DH, Wijayadi T, Sjahril R. Hepatitis B Virus Infection among Health Care Workers in Indonesia. Euroasian J Hepato-Gastroenterol 2018;8(1):88-92.

F-18 Fluorodeoxyglucose Positron Emission Tomography/ Computed Tomography Findings of Isolated Gastric Tuberculosis mimicking Gastric Cancer and Lymphoma

Introduction

Tuberculosis (TB) infection is still a challenging health issue, especially in developing countries. Diagnosing extrapulmonary infections, especially isolated organ involvement, is difficult in most cases even with the radiological, endoscopic, and histopathological examinations done for accurate diagnosis. Here we describe a case of isolated gastric TB with specific F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) findings mimicking gastric cancer/ lymphoma.

Case report

A 20-year-old male patient was admitted to our hospital with abdominal pain in the epigastric region, weight loss, and fever especially at nights for 2 months. Physical examination was normal. Hemoglobin was 9.6 gm/dL; the patient had iron deficiency anemia. Upper gastrointestinal (GI) endoscopy was suggestive of gastric ulcer mimicking malignancy. F-18 FDG PET/CT revealed multiple hypermetabolic malignant lymphadenopathies in the abdomen and diffuse gastric wall thickening as linitis plastica and multiple hypermetabolic peritoneal implants in the omentum. Exploratory laparotomy was done for tissue diagnosis and exploration of the peritoneum for TB infection, lymphoma, and Crohn’s disease to make differential diagnosis. Histopathology revealed granulomatous lymphadenitis with granulomas including giant cells, suspecting TB. Patient was put on antituberculosis treatment (ATT). After treatment, the complaints resolved, and he gained weight. Fusion PET/CT exhibited a complete response to ATT with no residual disease.

Conclusion

According to our knowledge, this is the first report about F-18 FDG PET/CT findings in the diagnosis of isolated gastric TB. F-18 FDG PET/CT may provide help in the diagnosis and follow-up of isolated gastric TB in challenging cases.

How to cite this article: Akdogan RA, Rakici H, Güngör S, Bedir R, Akdogan E. F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Isolated Gastric Tuberculosis mimicking Gastric Cancer and Lymphoma. Euroasian J Hepato-Gastroenterol 2018;8(1):93-96.

Trichobezoar: Ravenous for Hair

Trichophagia is the habit of chewing hair. On an average, only 1% patients with trichophagia develop trichobezoar. They are usually symptomless until they reach a large size. It is common in young females usually with an underlying psychiatric disorder. The gold standard for diagnosis is upper gastrointestinal endoscopy (UGIE). Here we present a case of trichobezoar in an 11-year-old girl who presented in the emergency with complaint of pain abdomen and symptoms of obstruction.

Devices for preventing percutaneous exposure injuries caused by needles in healthcare personnel

BACKGROUND

Percutaneous exposure injuries from devices used for blood collection or for injections expose healthcare workers to the risk of blood borne infections such as hepatitis B and C, and human immunodeficiency virus (HIV). Safety features such as shields or retractable needles can possibly contribute to the prevention of these injuries and it is important to evaluate their effectiveness.

OBJECTIVES

To determine the benefits and harms of safety medical devices aiming to prevent percutaneous exposure injuries caused by needles in healthcare personnel versus no intervention or alternative interventions.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, NHSEED, Science Citation Index Expanded, CINAHL, Nioshtic, CISdoc and PsycINFO (until 11 November 2016).

SELECTION CRITERIA

We included randomised controlled trials (RCT), controlled before and after studies (CBA) and interrupted time-series (ITS) designs of the effect of safety engineered medical devices on percutaneous exposure injuries in healthcare staff.

DATA COLLECTION AND ANALYSIS

Two of the authors independently assessed study eligibility and risk of bias and extracted data. We synthesized study results with a fixed-effect or random-effects model meta-analysis where appropriate.

MAIN RESULTS

We included six RCTs with 1838 participants, two cluster-RCTs with 795 participants and 73,454 patient days, five CBAs with approximately 22,000 participants and eleven ITS with an average of 13.8 data points. These studies evaluated safe modifications of blood collection systems, intravenous (IV) systems, injection systems, multiple devices, sharps containers and legislation on the implementation of safe devices. We estimated the needlestick injury (NSI) rate in the control groups to be about one to five NSIs per 1000 person-years. There were only two studies from low- or middle-income countries. The risk of bias was high in 20 of 24 studies. Safe blood collection systems:We found one RCT that found a safety engineered blood gas syringe having no considerable effect on NSIs (Relative Risk (RR) 0.2, 95% Confidence Interval (95% CI) 0.01 to 4.14, 550 patients, very low quality evidence). In one ITS study, safe blood collection systems decreased NSIs immediately after the introduction (effect size (ES) -6.9, 95% CI -9.5 to -4.2) but there was no further decrease over time (ES -1.2, 95% CI -2.5 to 0.1, very low quality evidence). Another ITS study evaluated an outdated recapping shield, which we did not consider further. Safe Intravenous systemsThere was very low quality evidence in two ITS studies that NSIs were reduced with the introduction of safe IV devices, whereas one RCT and one CBA study provided very low quality evidence of no effect. However, there was moderate quality evidence produced by four other RCT studies that these devices increased the number of blood splashes when the safety system had to be engaged actively (relative risk (RR) 1.6, 95% CI 1.08 to 2.36). In contrast there was low quality evidence produced by two RCTs of passive systems that showed no effect on blood splashes. Yet another RCT produced low quality evidence that a different safe active IV system also decreased the incidence of blood leakages. Safe injection devicesThere was very low quality evidence provided by one RCT and one CBA study showing that introduction of safe injection devices did not considerably change the NSI rate. One ITS study produced low quality evidence showing that the introduction of safe passive injection systems had no effect on NSI rate when compared to safe active injection systems. Multiple safe devicesThere was very low quality evidence from one CBA study and two ITS studies. According to the CBA study, the introduction of multiple safe devices resulted in a decrease in NSI,whereas the two ITS studies found no change. Safety containersOne CBA study produced very low quality evidence showing that the introduction of safety containers decreased NSI. However, two ITS studies evaluating the same intervention found inconsistent results. LegislationThere was low to moderate quality evidence in two ITS studies that introduction of legislation on the use of safety-engineered devices reduced the rate of NSIs among healthcare workers. There was also low quality evidence which showed a decrease in the trend over time for NSI rates.Twenty out of 24 studies had a high risk of bias and the lack of evidence of a beneficial effect could be due to both confounding and bias. This does not mean that these devices are not effective.

AUTHORS' CONCLUSIONS

For safe blood collection systems, we found very low quality evidence of inconsistent effects on NSIs. For safe passive intravenous systems, we found very low quality evidence of a decrease in NSI and a reduction in the incidence of blood leakage events but moderate quality evidence that active systems may increase exposure to blood. For safe injection needles, the introduction of multiple safety devices or the introduction of sharps containers the evidence was inconsistent or there was no clear evidence of a benefit. There was low to moderate quality evidence that introduction of legislation probably reduces NSI rates.More high-quality cluster-randomised controlled studies that include cost-effectiveness measures are needed, especially in countries where both NSIs and blood-borne infections are highly prevalent.

[Incidence of accidental exposure to blood and body fluids among healthcare professionals in a community hospital]

OBJECTIVE

To determine the annual incidence of healthcare professionals' accidental exposure to blood and body fluids in a community hospital and describe their characteristics, associated situations and follow-up.

METHOD

A longitudinal, retrospective study of biological accidents voluntarily reported on a yearly basis by exposed healthcare professionals at Fundació Hospital de l'Esperit Sant (in Santa Coloma de Gramenet, Barcelona, Spain), between 2005 and 2014. A descriptive analysis of the variables related to the exposed professional, the exposure itself, its production mechanism and the source patient was conducted. The rate of exposure was calculated per 100 occupied beds and by job category.

RESULTS

318 exposures were reported; 89.62% were percutaneous and the remainder were non-intact skin or mucous contamination. The mean percutaneous exposure incidence rate from 2005 to 2014 was 17.6 per 100 occupied beds/year (limits 10.3 in 2013 and 24.5 in 2005). Doctors were exposed to the greatest risk (5.29 exposures per 100 doctors). Over 50% occurred in a surgical setting. 44.2% of exposed healthcare professionals had been working at the centre for 1 year or less on average. Puncture was the most common percutaneous lesion. No cases of occupational viral transmission were reported.

CONCLUSIONS

The rate of percutaneous exposure reported in this hospital fluctuated significantly throughout the analysis period. Risk of exposure is related to job category, work experience, the setting and the activity performed.

Hepatocellular carcinoma and the risk of occupational exposure

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. The main risk factors for HCC are alcoholism, hepatitis B virus, hepatitis C virus, nonalcoholic steatohepatitis, obesity, type 2 diabetes, cirrhosis, aflatoxin, hemochromatosis, Wilson's disease and hemophilia. Occupational exposure to chemicals is another risk factor for HCC. Often the relationship between occupational risk and HCC is unclear and the reports are fragmented and inconsistent. This review aims to summarize the current knowledge regarding the association of infective and non-infective occupational risk exposure and HCC in order to encourage further research and draw attention to this global occupational public health problem.

Percutaneous and Mucocutaneous Exposure Among Orthopaedic Surgeons: Immediate Management and Compliance With CDC Protocol

BACKGROUND

Orthopaedic surgeons are at a high risk of sustaining a percutaneous or mucocutaneous exposure to blood and body fluids. The Center for Disease Control and Prevention recommends a wash with soap and water and notification of the concerned hospital authorities after any percutaneous/mucocutaneous exposure, but a systematic amenability with these guidelines is not always seen. This cross-sectional study was undertaken to determine current knowledge and practices of orthopaedic surgeons in case of a percutaneous sharp injury exposure, emphasizes the immediate first aid steps taken after an exposure, the degree of reporting, and to explore the reasons for noncompliance. Finally, we sought to create awareness about the prevailing Center for Disease Control and Prevention guidelines after any exposure to blood or body fluids.

MATERIALS AND METHODS

We conducted a cross-sectional survey using an anonymous prepared questionnaire. The study population included exclusively orthopaedic surgeons, including residents, fellows, and attending physicians at 4 US institutions. The questionnaire was also available online on the OTA Web site as a part of survey monkey. The questionnaire comprised 9 multiple choice questions, and more than 1 response could be given for some questions. The questions addressed previous needle stick/sharp injury exposure, number of times that had happened, whether reported to the hospital administration, reason for nonreporting, and risk perception for transmission of blood-borne pathogens (human immunodeficiency virus, HBsAg, and hepatitis C virus). The questions were also asked based on what should be done in four different clinical settings based on respondents risk perception.

RESULTS

Of fifty eight attendings, 7 fellows, 45 residents, and 7 respondents who did not indicate their position participated in the survey for a total of 117 respondents. Out of 99, 24 had sustained it once, 18 twice, 11 three times, and 35 at least 4 times. When questioned about informing the incident to the hospital administration, 38% had always reported the incident, 33% had never reported the incident, and the remaining 29% had not reported it every time. Of note, 87% gave the correct response about the risk of transmission of human immunodeficiency virus after an exposure. On questioning about the risk of hepatitis B transmission, from an HBsAg- and HBeAg-positive source, 13% gave the correct response, whereas from HBsAg-positive and HBeAg-negative source, 30% gave the correct response. Regarding transmission of hepatitis C virus from a positive source, 36% responded correctly. The surgeons seemingly attempted to risk stratify their exposure, and they were more likely to report their exposure in the higher risk scenarios.

CONCLUSIONS

This study demonstrates that orthopaedic surgeons of all levels of training are at high risk of occupational exposure to blood-borne pathogens. Moreover, despite the level of training, the majority of surgeons do not follow the recommended steps, although we do not know the reasons for such behavior. Also, there is a low awareness of the significant risk of hepatitis transmission among orthopaedic surgeons treating a population with a high prevalence of undiagnosed hepatitis.

Predictors of Hepatitis B Preventive Behavioral Intentions in Healthcare Workers

Background

Healthcare workers' practices regarding hepatitis B have an important effect on the control of this problem in workplaces.

Methods

A questionnaire-based cross-sectional study was used to investigate the role of knowledge, cues to action, and risk perceptions as predictors of preventive behavioral intentions for hepatitis B among healthcare works in Broujen, Iran (n = 150). History of hepatitis B vaccination, hepatitis B surface antigen test, and demographic characteristics were investigated. The psychometric properties of the questionnaire were established.

Results

Those who had a history of hepatitis B surface antigen test had a statistically significant higher level of risk perceptions (30.89 ± 4.08 vs. 28.41 ± 3.93, p < 0.01) and preventive behavioral intentions (5.05 ± 1.43 vs. 4.45 ± 1.29, p < 0.01). The mean score of cues to action was significantly correlated with age and work history (r = 0.20, p = 0.02 and r = 0.19, p = 0.02). Preventive behavioral intentions were significantly correlated with cues to action and risk perceptions but not with knowledge level. Cognitional factors were responsible for a 17% change in observed variance of preventive behavioral intentions, which was statistically significant.

Conclusion

Risk perceptions were the most important determinant of preventive behavioral intentions for hepatitis B among health personnel; thus, emphasizing risk perceptions is recommended in educational programs aimed at increasing health personnel's practices regarding hepatitis B.

Health care-associated hepatitis C virus infection

Hepatitis C virus (HCV) is a blood-borne pathogen that has a worldwide distribution and infects millions of people. Care-associated HCV infections represented a huge part of hepatitis C burden in the past via contaminated blood and unsafe injections and continue to be a serious problem of public health. The present review proposes a panorama of health care-associated HCV infections via the three mode of contamination that have been identified: (1) infected patient to non-infected patient; (2) infected patient to non-infected health care worker (HCW); and (3) infected HCW to non infected patient. For each condition, the circumstances of contamination are described together with the means to prevent them. As a whole, the more important risk is represented by unsafe practices regarding injections, notably with the improper use of multidose vials used for multiple patients. The questions of occupational exposures and infected HCWs are also discussed. In terms of prevention and surveillance, the main arm for combating care-associated HCV infections is the implementation of standard precautions in all the fields of cares, with training programs and audits to verify their good application. HCWs must be sensitized to the risk of blood-borne pathogens, notably by the use of safety devices for injections and good hygiene practices in the operating theatre and in all the invasive procedures. The providers performing exposed-prone procedures must monitor their HCV serology regularly in order to detect early any primary infection and to treat it without delay. With the need to stay vigilant because HCV infection is often a hidden risk, it can be hoped that the number of people infected by HCV via health care will decrease very significantly in the next years.

Devices for preventing percutaneous exposure injuries caused by needles in healthcare personnel

BACKGROUND

Needlestick injuries from devices used for blood collection or for injections expose healthcare workers to the risk of blood borne infections such as hepatitis B and C, and human immunodeficiency virus (HIV). Safety features such as shields or retractable needles can possibly contribute to the prevention of these injuries and it is important to evaluate their effectiveness.

OBJECTIVES

To determine the benefits and harms of safety medical devices aiming to prevent percutaneous exposure injuries caused by needles in healthcare personnel versus no intervention or alternative interventions.

SEARCH METHODS

We searched CENTRAL, MEDLINE, EMBASE, NHSEED, Science Citation Index Expanded, CINAHL, Nioshtic, CISdoc and PsycINFO (until January 2014) and LILACS (until January 2012).

SELECTION CRITERIA

We included randomised controlled trials (RCT), controlled before and after studies (CBA) and interrupted time-series (ITS) designs on the effect of safety engineered medical devices on needlestick injuries in healthcare staff.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and risk of bias and extracted data. We synthesized study results with a fixed-effect or random-effects model meta-analysis where appropriate.

MAIN RESULTS

We included four RCTs with 1136 participants, two cluster-RCTs with 795 participants and 73,454 patient days, four CBAs with approximately 22,000 participants and seven ITS with an average of seven data points. These studies evaluated safe modifications of blood collection systems, intravenous (IV) systems, injection systems, multiple devices and sharps containers. The needlestick injury (NSI) rate in the control groups was estimated at about one to five NSIs per 1000 person-years. There was only one study from a low- or middle-income country. The risk of bias was high in most studies.In one ITS study that evaluated safe blood collection systems, NSIs decreased immediately after the introduction (effect size (ES) -6.9, 95% confidence interval (CI) -9.5 to -4.2) and there was no clear evidence of an additional benefit over time (ES -1.2, 95% CI -2.5 to 0.1). Another ITS study used an outdated recapping shield.There was very low quality evidence that NSIs were reduced with the introduction of safe IV devices in two out of four studies but the other two studies showed no clear evidence of a trend towards a reduction. However, there was moderate quality evidence in four other studies that these devices increased the number of blood splashes where the safety system had to be engaged actively (relative risk (RR) 1.6, 95% CI 1.08 to 2.36).There was no clear evidence that the introduction of safe injection devices changed the NSI rate in two studies.The introduction of multiple safety devices showed a decrease in NSI in one study but not in another. The introduction of safety containers showed a decrease in NSI in one study but inconsistent results in two other studies.There was no evidence in the included studies about which type of device was better, for example shielding or retraction of the needle.

AUTHORS' CONCLUSIONS

For safe blood collection systems, we found very low quality evidence in one study that these decrease needlestick injuries (NSIs). For intravenous systems, we found very low quality evidence that they result in a decrease of NSI compared with usual devices but moderate quality evidence that they increase contamination with blood. For other safe injection needles, the introduction of multiple safety devices or the introduction of sharps containers the evidence was inconsistent or there was no clear evidence of a benefit. All studies had a considerable risk of bias and the lack of evidence of a beneficial effect could be due both to confounding and bias. This does not mean that these devices are not effective.Cluster-randomised controlled studies are needed to compare the various types of safety engineered devices for their effectiveness and cost-effectiveness, especially in low- and middle-income countries.

Sharps injuries: the risks and relevance to plastic surgeons

Surgeons are at risk for injury in the operating room daily. Because of the ubiquity of occupational hazards, injuries remain prevalent and expensive. Although occupational hazards can include musculoskeletal conditions, psychosocial stress, radiation exposure, and the risk of communicable diseases, sharps injuries remain the most common among surgeons in practice and the most frequent route of transmission of blood-borne pathogens. Therefore, increased attention to the health, economic, personal, and social implications of these injuries is essential for appropriate management and future prevention.

An update on the management of hepatitis C: guidelines for protease inhibitor-based triple therapy from the Latin American Association for the Study of the Liver

Hepatitis C is a common cause of end-stage liver disease, and the main indication for liver transplantation in Latin America. Treatment of hepatitis C infected patients improves important long-term outcomes as mortality. Sustained viral response is reached in near 50% of patients with the previous management based in pegylated interferon and ribavirin. Recently new drugs were available increasing sustained viral response significantly, changing the standard of care to triple therapy. This guidelines provides a framework for practitioner in Latin America, to the management of patients with hepatitis C chronic infection. 

Repeated exposure to trace amounts of woodchuck hepadnavirus induces molecularly evident infection and virus-specific T cell response in the absence of serological infection markers and hepatitis

Exposure to multiple small doses of hepatitis B virus (HBV) is a frequent occurrence in high-risk groups, including close relatives of infected individuals, primary care givers, and intravenous drug users. It remains uncertain whether such repeated contact may culminate in a symptomatic infection coinciding with hepatitis in individuals not immunoprotected. In this study, we evaluated consequences of multiple exposures to small, liver-nonpathogenic amounts of infectious hepadnavirus in the woodchuck model of hepatitis B. Virus-naïve animals were intravenously injected with 6 weekly doses of 110 DNase digestion-protected virions of woodchuck hepatitis virus (WHV), injected again with 6 weekly 110-virion doses after 7.5 months, and then challenged or not with a liver-pathogenic dose of 1.1 × 10(6) virions of the same inoculum. The data revealed that two rounds of such repeated exposure did not result in serologically evident infection or hepatitis. However, a low-level WHV DNA-positive infection accompanied by a WHV-specific T cell response in the absence of antiviral antibody reactivity was established. The kinetics of the virus-specific and mitogen-induced (generalized) T cell responses and the inability to induce immunoprotection against challenge with a large, liver-pathogenic virus dose were closely comparable to those previously reported for occult infection initiated by a single liver-nonpathogenic dose of WHV. Thus, repeated exposures to small quantities of hepadnavirus induce molecularly evident but serologically silent infection that does not culminate in hepatitis or generate immune protection. The findings imply that the HBV-specific T cell response encountered in the absence of serological markers of infection likely reflects ongoing occult infection.

Hepatitis B immunoglobulin for prevention of hepatitis B virus infection and recurrence after liver transplantation

Intravenous hepatitis B immunoglobulin (HBIG) is a human plasma-derived purified gammaglobulin (IgG) that has proven efficacy and dose-dependent response in the prevention of hepatitis B virus (HBV) recurrence after liver transplantation. It is also indicated for postexposure prophylaxis after contact with blood or body fluids of serum hepatitis B surface antigen (HBsAg)-positive carriers and in prevention of mother-to-child (vertical) transmission. The exact mechanism of passive immunization is unknown; HBIG may block HBV entry and binding to hepatocytes, neutralize circulating HBV and target HBV-infected cells through an antibody-mediated immune response. The drug is well tolerated and common side effects include fever, chills and arthralgias that are usually mild and transient. This article summarizes the main indications and the recommendations for use of intravenous HBIG, as well as the usage of intramuscular HBIG in the liver transplant setting.