Risk of Hepatitis B transmission by healthcare workers – a systematic review

Risk of Hepatitis B Transmission by health care workers – a systematic review Background: The risk of transmission of Hepatitis B virus (HBV) to healthcare workers is well known. However, evidence for supporting guidelines with respect to exclusion of infected HCW from exposure prone procedures remains poorly characterized. Method: A systematic review of studies providing serological data for HBV transmissions from infected healthcare workers to patients was performed. Databases MEDLINE, Scopus and Cochrane were searched to identify publications prior to September 2024. Results: 39 studies from nine countries met the inclusion criteria. 66 transmissions from healthcare workers to patients were confirmed through DNA analysis; in 100 patients HBV transmissions were considered probable and in 480 patients at least possible. Of the 36 studies in which HBeAg in health care workers was determined, the antigen was positive in 29 studies, and negative only in seven studies, comprising a total of only 31 and 17 HCW, respectively. The HBV viral load of the transmitting health care worker was measured only in 8 studies including 18 workers, of those four were HBeAg-positive and 14 HBeAg-negative. In this latter group, there was also considerable variation of viral load with values up to 1,5 x 109 copies/ml serum. Due to the low evidence on the association of viral load and transmission, the safety thresholds for excluding infected health care workers from performing exposure prone procedures in most recent national guidelines still differ by factors of as much as 5 (200 IU/mL to 1000 IU/mL). Conclusions: The published literature on HBV transmission from HCW to patients is sparse and offers only limited guidance on national prevention guidelines. Keywords: health care workers – hepatitis B – transmission – infectivity – professional-to-patient – guidelines – exposure prone procedures

The incidence of hepatitis B virus (HBV) infection in dialysis populations has declined over recent decades, largely because of improvements in infection control and widespread implementation of HBV vaccination. Regardless, outbreaks of infection continue to occur in dialysis units, and prevalence rates remain unacceptably high. For a variety of reasons, dialysis patients are at increased risk of acquiring HBV. They also demonstrate different disease manifestations compared with healthy individuals and are more likely to progress to chronic carriage. This paper will review the epidemiology, modes of transmission and diagnosis of HBV in this population. Prevention and treatment will be discussed, with a specific focus on strategies to improve vaccination response, new therapeutic options and selection of patients for therapy.

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1Departments of Pathology and Laboratory Medicine, Medicine, and Microbiology and Infectious Diseases, University of Calgary, Calgary, Alberta; 2Queen Elizabeth II Health Sciences Centre and Dalhousie University, Halifax, Nova Scotia Correspondence: Dr John Conly, Departments of Pathology and Laboratory Medicine, Medicine, and Microbiology and Infectious Diseases, Room 930, 9th Floor, North Tower, 1403 29th Street Northwest, Calgary, Alberta T2N 2T9. Telephone 403-944-8222, fax 403-944-1095, e-mail jconly@ucalgary.ca and Dr Lynn Johnston, Department of Medicine, Room 5014 ACC, Queen Elizabeth II Health Sciences Centre, 1278 Tower Road, Halifax, Nova Scotia B3H 2Y9. Telephone 902-473-5553, fax 902-473-7394, e-mail ljohnsto@dal.ca T risks to health care workers (HCWs) of occupationallyacquired infection with hepatitis B virus (HBV), human immunodeficiency virus (HIV) and, to a lesser extent, hepatitis C virus (HCV) have been reasonably well quantified (1). Evidence from the HIV and HBV experience suggests that the risk of infection is increased where the level of viremia is high, as manifested by high HIV viral load or the presence of hepatitis B e antigen (HbeAg) (1). It has also been recognized that patients may acquire one of these viruses following significant exposure to the blood of an infected HCW (2-4). While the magnitude of this risk to patients is considerably less than that to HCWs, the 1990 report by the Centers for Disease Control and Prevention (CDC) that a Florida dentist had transmitted HIV to patients in the course of dental care triggered widespread public concern about the risk of infection from HCWs. In 1991 CDC published recommendations for preventing HIV and HBV transmission to patients, which included the recommendation that HCWs who are infected with HIV or HBV (and HbeAg positive, a marker of higher infectivity) should not perform exposure-prone procedures unless they have sought counsel from an expert review panel (5). In 1998, Health Canada published guidelines for the management of HCWs infected with HBV, HCV, and/or HIV (6). Both these documents generated controversy at the time of their publication. Since that time, however, several provincial regulatory bodies have formed committees to advise physicians infected with these bloodborne pathogens (BBPs) regarding their practice. This article reviews what we know about the transmission of HBV, HCV and HIV from infected HCWs to patients in medical and dental settings.

To determine the longitudinal changes in viral load of hepatitis B virus (HBV)-infected healthcare workers (HCWs) and its consequences for exclusion of infected HCWs performing exposure-prone procedures, various HBV DNA safety thresholds, and the frequency of monitoring. Retrospective cohort study June 1, 1996-January 31, 2013. Participants In the Netherlands, chronically HBV-infected HCWs performing exposure-prone procedures are notified to the Committee for Prevention of Iatrogenic Hepatitis B. Of the 126 notified HCWs, 45 had 2 or more HBV DNA levels determined without antiviral therapy. A time-to-event analysis for HBV-infected HCWs categorized in various viremia levels surpassing a HBV DNA threshold level of 1×105 copies/mL, above which exposure-prone procedures are not allowed in the Netherlands. Fluctuations of HBV DNA in follow-up samples ranged from -5.4 to +2.2 log10 copies/mL. A high correlation was seen for each HBV DNA level with the 3 previous levels. In a time-to-event analysis, after 6 months 7.2%, 6.5%, and 14.3% of individuals had surpassed the threshold of 1×105 copies/mL for viral load categories 4.8×103 to 1.5×104; 1.5×104 to 4.0×104; and 4.0×104 to 1.0×105, respectively. We propose standard retesting every 6 months, with more frequent retesting just below the high threshold value (1×105 copies/mL), and prolonging this standard interval to 1 year after 3 consecutive levels below the threshold in policies with lower safety thresholds (1×103 or 1×104 copies/mL). Infect Control Hosp Epidemiol 2016;37:655-660.

BACKGROUNDThe hepatitis B virus (HBV) infection is a global public health concern that affects about 2 billion people and causes 1 million people deaths yearly. HBV is a blood-borne disease and healthcare workers (HCWs) are a high-risk group because of occupational hazard to patients’ blood. Different regions of the world show a highly variable proportion of HCWs infected and/or immunized against HBV. Global data on serologic markers of HBV infection and immunization in HCWs are very important to improve strategies for HBV control.AIMTo determine the worldwide prevalence of HBV serological markers among HCWs.METHODSIn this systematic review and meta–analyses, we searched PubMed and Excerpta Medica Database (Embase) to identify studies published between 1970 and 2019 on the prevalence of HBV serological markers in HCWs worldwide. We also manually searched for references of relevant articles. Four independent investigators selected studies and included those on the prevalence of each of the HBV serological markers including hepatitis B surface antigen (HBsAg), hepatitis e antigen (HBeAg), immunoglobulin M anti-HBc, and anti-HBs. Methodological quality of eligible studies was assessed and random-effect model meta-analysis resulted in the pooled prevalence of HBV serological markers HBV infection in HCWs. Heterogeneity (I²) was assessed using the χ² test on Cochran’s Q statistic and H parameters. Heterogeneity’ sources were explored through subgroup and metaregression analyses. This study is registered with PROSPERO, number CRD42019137144.RESULTSWe reviewed 14059 references, out of which 227 studies corresponding to 448 prevalence data among HCWs (224936 HCWs recruited from 1964 to 2019 in 71 countries) were included in this meta-analysis. The pooled seroprevalences of current HBsAg, current HBeAg, and acute HBV infection among HCWs were 2.3% [95% confidence interval (CI): 1.9-2.7], 0.2% (95%CI: 0.0-1.7), and 5.3% (95%CI: 1.4-11.2), respectively. The pooled seroprevalences of total immunity against HBV and immunity acquired by natural HBV infection in HCWs were 56.6% (95%CI: 48.7-63.4) and 9.2% (95%CI: 6.8-11.8), respectively. HBV infection was more prevalent in HCWs in low-income countries, particularly in Africa. The highest immunization rates against HBV in HCWs were recorded in urban areas and in high-income countries including Europe, the Eastern Mediterranean and the Western Pacific.CONCLUSIONNew strategies are needed to improve awareness, training, screening, vaccination, post-exposure management and treatment of HBV infection in HCWs, and particularly in low-income regions.

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Different guidelines exist for the management of hepatitis B virus (HBV)-infected health care workers (HCWs). Various HBV DNA levels are used as a cutoff level to determine whether an HBV-infected HCW is allowed to perform exposure-prone procedures (EPPs) or not. In this paper we discuss the factors that determine HBV DNA levels and the implications of different HBV DNA cutoff levels for EPP performing HCWs. If the level of HBV DNA in the serum of HCWs is used to determine acceptability for the conduct of EPPs, it is necessary to take into account the variability in time of HBV DNA levels in HBV carriers and the reliability and reproducibility of the molecular diagnostic test involved. The issue of standardization has to be addressed, before a universal, maximum level of viraemia for EPP performing HCWs can be introduced.