Cluster of hepatitis B transmitted by a physician

Hepatitis B in healthcare workers: Transmission events and guidance for management

Hepatitis B virus (HBV) is the most efficiently transmissible of the bloodborne viruses that are important in healthcare settings. Healthcare workers (HCWs) are at risk for exposure to HBV from infected patients and, if infected, are similarly at risk of transmitting HBV to patients. Published cases of HBV transmission from HCW to patient are relatively rare, having decreased in frequency following the introduction of standard (universal) precautions, adoption of enhanced percutaneous injury precautions such as double-gloving in surgery, and routine HBV vaccination of HCWs. Here we review published cases of HCW-to-patient transmission of HBV, details of which have helped to guide the creation of formal guidelines for the management of HBV-infected HCWs. We also compare the published guidelines for the management of HBV-infected HCWs from various governing bodies, focusing on their differences with regard to vaccination requirements, viral load limits, frequency of monitoring, and restrictions on practice. Importantly, while there are differences among the recommendations from governing bodies, no guidelines uniformly restrict HBV-infected HCWs from performing invasive or exposure-prone procedures.

Healthcare providers as sources of vaccine-preventable diseases

Vaccine-preventable infectious diseases may be introduced into the healthcare setting and pose a serious risk to vulnerable populations including immunocompromised patients. Healthcare providers (HCPs) are exposed to these pathogens through their daily tasks and may serve as a reservoir for ongoing disease transmission in the healthcare setting. The primary method of protection from work-related infection risk is vaccination that protects not only an individual HCP from disease, but also subsequent patients in contact with that HCP. Individual HCPs and healthcare institutions must balance the ethical and professional responsibility to protect their patients from nosocomial transmission of preventable infections with HCP autonomy. This article reviews known cases of HCP-to-patient transmission of the most common vaccine-preventable infections encountered in the healthcare setting including hepatitis B virus, influenza virus, Bordetella pertussis, varicella-zoster virus, measles, mumps and rubella virus. The impact of HCP vaccination on patient care and current recommendations for HCP vaccination against vaccine-preventable infectious diseases are also reviewed.

Health care workers as source of hepatitis B and C virus transmission

Transmission of hepatitis B and C from health care workers to patients remains rare in developed medical care systems but may be more common in systems that are still developing. Since the 1970s, at least 69 health care workers infected with hepatitis B or C have been implicated in transmission of their infection. This likely underestimates the magnitude of the problem. In this article, risk factors associated with transmission are reviewed and infection prevention and control practices outlined. Management of infected providers is also discussed. National guidelines are compared, highlighting different countries' approaches to this complex challenge.

Hospital transmission of hepatitis B virus in the absence of exposure prone procedures

In February and in June 1998, two people developed acute hepatitis B following in-patient care in a district general hospital. Initial enquiries indicated their infections were not attributable to staff undertaking exposure-prone procedures (EPPs). We report the findings and implications of the subsequent investigation: a multi-disciplinary, multi-agency investigation, including molecular epidemiological analysis. Occupational Health records showed that staff involved in EPPs with the patients were HBsAg negative. No contact between the patients was identified nor were there failures in sterilization. The patients' HBV strains were identical, indicating a common source. A total of 231 out of 232 staff who might have treated either patient were tested for HBsAg; the remaining doctor, working abroad, was HBsAg- and HBeAg-positive and had the same HBV strain as the patients. On two occasions the doctor's hand had been cut while breaking glass vials, but there was no documentation linking these events to the two patients. The doctor had been vaccinated in 1993 and tested for anti-HBs prior to commencing work in 1997. The doctor was recalled to Occupational Health but did not attend and was not followed up. In total, 4948 patients potentially treated by the doctor received an explanatory letter and 3150 were tested for HBsAg. Only one was positive, and HBV sequencing showed no link to the doctor. Occasionally transmission of HBV from heath-care workers can occur in a non-EPP setting and the implications of this require examination by those setting national policy. Occupational Health Services should investigate clinical heath-care workers who do not respond to vaccination. They should ensure HBV carriers are identified and offer them appropriate advice to prevent transmission to patients.

Assessment of new chemical disinfectants for HBV virucidal activity in a cell culture model

Several new chemical disinfectants were processed for Hepatitis B virus (HBV) virucidal activity in a cell culture model. A pooled HBV infected human plasma with 10(10.4) HBV DNA copies/mL was treated with the tested disinfectant. It was then subjected, for three days at several dilutions, to cell culture using the human hepatoma cell line, HepG2, with 4% polyethyleneglycol and 3 mM sodium butyrate. Thirty-seven assays were performed on 12 products, with up to 3 concentrations and 3 time exposures for each product tested. The mean viral titre without disinfectant was 10(5.18) infectious units per mL. Our results showed that products all four hand rubs examined, two of the three surface disinfectants and two of the three instrument disinfectants were highly active whatever concentrations and time exposures, reducing viral times by factors of 10(3)-10(4). However, other products such as one of the surface disinfectants was only active at concentrations above 0.5% for 15 min. Similarly the skin disinfectant, one of the instrument disinfectants and the hand wash agent (diluted to 50%) were less or not active (of <10(3) fold reduction). This is the first study using a cell culture model to assess virucidal activity against HBV of new disinfectants. It showed that most 9/12 products were active by either HBs antigen alteration (8/9) or probable envelope disruption (1/9). Further studies are in progress using this model to assess the activity of other chemical disinfectants such as peracetic acid against HBV.

Injection practices in Romania: progress and challenges

OBJECTIVE

To identify breaks in infection control practices that might put Romanians at risk for transmission of hepatitis B virus (HBV) from injections.

METHODS

A standardized questionnaire was administered to a systematic sample of the 1,906 nurses in Vâlcea District, Romania, to collect information on their knowledge, attitudes, and practices regarding injection administration and universal precautions.

RESULTS

Of the 180 nurses interviewed, 91% (95% confidence interval [CI95], 86% to 95%) reported having attended training for universal precautions; 58% (CI95, 49% to 67%) accurately reported that HBV remains infectious for at least 1 week in the environment; and 4% (CI95, 2% to 8%) knew that HBV is transmitted more efficiently than HIV through percutaneous exposures. No nurses reported reusing syringes or needles on different patients, but 4 (2%; CI, 1% to 6%) would reuse a syringe and 3 (2%; CI95, 0% to 5%) would reuse a needle on the same patient in an emergency. Fifty-three percent (CI95, 44% to 61%) of nurses reported having a dedicated area for the preparation of injectable medications separate from where blood-contaminated items were handled. Shortages of infection control supplies were common.

CONCLUSIONS

Although nurses in Vâlcea do not report reusing injection equipment without sterilization, other unsafe practices occur that may facilitate HBV transmission through injections, including preparing injectable medications in areas potentially contaminated with blood. Inadequate knowledge of blood-borne pathogen transmission and shortages of infection control supplies may contribute to these unsafe practices. Addressing these deficits could improve injection safety in Romania.

Inactivation of hepatitis B virus in plasma by hospital in-use chemical disinfectants assessed by a modified HepG2 cell culture

Because of the difficulties of the chimpanzee model and the genetic differences using the duck model, we developed a cell culture method to measure human hepatitis B virus (HBV) inactivation in vitro. Pooled HBV-infected human plasma that had been exposed to a disinfectant was left in contact for three days with a cell culture of the human hepatoma cell line, HepG2, with 4% polyethyleneglycol and 3 mM sodium butyrate. The mean log10 of the viral titre of unexposed plasma was 4.87 infectious units per mL. Our results showed that 1% glutaraldehyde, sodium hypochlorite at 4700 ppm free chlorine and an iodophor-detergent disinfectant containing 3.6% povidone-iodine reduced viral titres by factors exceeding 10(3)-10(4). However, sodium hypochlorite at 1000 ppm free chlorine had minimal activity and povidone-iodine at 9, 5 and 3.6% had no measurable activity (less than 10-fold reduction). This is the first study using a cell culture model to assess disinfectant activity against HBV. It demonstrates more rapidly than the chimpanzee model that glutaraldehyde and sodium hypochlorite, using standard concentrations and exposure times compatible with clinical practice, were highly active against HBV. However, unexpectedly for an enveloped virus, we found no antiviral activity for iodine in the absence of detergent.

Improving infection control in general practice

Infection control measures in the health care setting should protect patients and staff from cross-infection. The prevention of harm is an essential part of good medical practice and failure might result in professional misconduct proceedings by the General Medical Council (GMC) and prosecution under the Health and Safety at Work legislation, as well as civil liability. For a health authority, overall responsibility for public health includes arrangements for the control of communicable diseases and infection in hospital and the community (NHS Management Executive, 1993), a function usually led by the Consultant in Communicable Disease Control (CCDC). This paper describes one district's collaborative approach between public health and GPs to assess and improve local infection control standards.

Preventing bloodborne pathogen transmission from health-care workers to patients. The CDC perspective

The development of recommendations to manage the risk of bloodborne pathogen transmission from health-care workers to patients during invasive procedures has been difficult, primarily because of the limitations of available scientific data. Ultimately, both health-care workers and patients will be protected best by compliance with infection control precautions and by development of new instruments, protective equipment, and techniques that reduce the likelihood of intraoperative blood exposure without adversely affecting patient care.

Hepatitis B virus infection and health care workers

Hepatitis B virus (HBV) infection is the major occupational risk of health care workers, among whom HBV infection risk is 2 to 10-fold elevated above that of the general population. Risk is most clearly related to the degree of direct contact with human blood and body fluids, and to frequency of traumatic exposures in the workplace. Most exposures result from unsuspected asymptomatic HBV carriers, who represent 1 to 2% of hospitalized patients. Risk of HBV infection also varies with the frequency of HBV carriers in the patient population. In the USA, the annual number of new cases has been constant over the last decade, despite a 50% overall increase in acute HBV disease. Control of HBV in the work setting is based on universal precautions for exposure to human blood or body fluids, and hepatitis B vaccination. Increased attention to these recommendations appears to be reducing this problem in the USA.

Hepatitis B infections after gynaecological surgery

When acute hepatitis B developed in 3 patients who had had gynaecological surgery, the surgeon was found to be a carrier of hepatitis B e antigen. Of 268 patients operated on by this surgeon in one hospital, 247 were screened for markers of recent or current hepatitis B. 22 (9%) had such markers, associated with symptoms in 5. The operations carrying greatest risk of infection were hysterectomy (10/42) and caesarean section (10/51). These findings strengthen the case for vaccination of all surgeons and medical students against hepatitis B.

The risk of hepatitis B transmission from health care workers to patients in a hospital setting--a prospective study

A prospective study was designed to determine the risk of hepatitis B transmission from health care deliverers to patients in the hospital setting. Six chronic carriers of hepatitis B were identified: 2 surgeons, 1 dialysis nurse, 1 pediatric ICU nurse, 1 pharmacist and 1 orderly. Three of the six were HBeAg-positive. Two of the HBeAG-positive chronic carriers also had circulating hepatitis B virus DNA and accounted for approximately two-thirds of the total patient contacts. Two hundred thirteen patients were exposed 450 times to these six hepatitis B carrier staff without evidence of hepatitis B acquisition over a 6-month follow up. One-hundred nineteen control patients, exposed 789 times to noncarrier health care deliverers, were also negative. Another 33 patients were exposed to three additional individuals who were in the prodrome of acute hepatitis B: an intensive care nurse, a dental hygienist and a medical student. These patients showed no evidence of hepatitis B during 6 months of follow-up, nor did 25 separate control patients. Thus, 246 patients were exposed a total of 483 times to nine health care personnel who had either acute or chronic hepatitis B. No evidence of hepatitis B transmission was found. One-hundred forty-four controls revealed similar results after 814 exposures. Based on the number of exposures to chronic carriers alone, the risk of hepatitis B transmission is estimated to be less than 1%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Viral hepatitis B. Risk for the anesthetist]

The risk of hepatitis B, previously reported in other countries, has never been investigated in French anaesthetic medical staff. The prevalence of hepatitis B viral markers has been calculated among the medical staff of the Department of Anaesthesiology, the hospital health care personnel, patients before surgical procedure and renal transplantation patients. The frequency in anaesthesiologists (18.75%; 12 out of 64) was significantly greater (p less than 0.05) than in health care personnel (10.5%; 91 out of 863). Prevalence increased with the length of practice in anaesthesiology. Prevalence of markers is 8.7% (27 out of 196) in patients undergoing surgery and 82% (27 out of 33) in patients operated on for renal transplantation in 1981. Frequency of carriers of the hepatitis B surface antigen is 0% in medical staff, 0.2% in health care personnel and 0.5% in patients before surgery. Among the health care staff, anaesthesiologists belong to a high risk population for hepatitis B. Prevention by administration of hepatitis B vaccine is recommended to protect the anaesthesiologist, his relatives and his patients.