An outbreak of hepatitis A among health care workers: risk factors for transmission

Ethanol is indispensable for virucidal hand antisepsis: memorandum from the alcohol-based hand rub (ABHR) Task Force, WHO Collaborating Centre on Patient Safety, and the Commission for Hospital Hygiene and Infection Prevention (KRINKO), Robert Koch Institute, Berlin, Germany

BACKGROUND

The approval of ethanol by the Biocidal Products Regulation has been under evaluation since 2007. This follows concern over alcohol uptake from ethanol-based hand rubs (EBHR). If ethanol is classified as carcinogenic, mutagenic, or reprotoxic by the European Chemicals Agency (ECHA), then this would affect infection prevention and control practices.

AIM

A review was performed to prove that ethanol is toxicological uncritical and indispensable for hand antisepsis because of its unique activity against non-enveloped viruses and thus the resulting lack of alternatives. Therefore, the following main points are analyzed: The effectiveness of ethanol in hand hygiene, the evidence of ethanol at blood/tissue levels through hand hygiene in healthcare, and the evidence of toxicity of different blood/tissue ethanol levels and the non-comparability with alcoholic consumption and industrial exposure.

RESULTS

EBHR are essential for preventing infections caused by non-enveloped viruses, especially in healthcare, nursing homes, food industry and other areas. Propanols are effective against enveloped viruses as opposed to non-enveloped viruses but there are no other alternatives for virucidal hand antisepsis. Long-term ingestion of ethanol in the form of alcoholic beverages can cause tumours. However, lifetime exposure to ethanol from occupational exposure < 500 ppm does not significantly contribute to the cancer risk. Mutagenic effects were observed only at doses within the toxic range in animal studies. While reprotoxicity is linked with abuse of alcoholic beverages, there is no epidemiological evidence for this from EBHR use in healthcare facilities or from products containing ethanol in non-healthcare settings.

CONCLUSION

The body of evidence shows EBHRs have strong efficacy in killing non-enveloped viruses, whereas 1-propanol and 2-propanol do not kill non-enveloped viruses, that pose significant risk of infection. Ethanol absorbed through the skin during hand hygiene is similar to consumption of beverages with hidden ethanol content (< 0.5% v/v), such as apple juice or kefir. There is no risk of carcinogenicity, mutagenicity or reprotoxicity from repeated use of EBHR. Hence, the WHO Task Force strongly recommend retaining ethanol as an essential constituent in hand rubs for healthcare.

Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020

HEPATITIS A IS A VACCINE-PREVENTABLE, COMMUNICABLE DISEASE OF THE LIVER CAUSED BY THE HEPATITIS A VIRUS (HAV). THE INFECTION IS TRANSMITTED VIA THE FECAL-ORAL ROUTE, USUALLY FROM DIRECT PERSON-TO-PERSON CONTACT OR CONSUMPTION OF CONTAMINATED FOOD OR WATER. HEPATITIS A IS AN ACUTE, SELF-LIMITED DISEASE THAT DOES NOT RESULT IN CHRONIC INFECTION. HAV ANTIBODIES (IMMUNOGLOBULIN G [IGG] ANTI-HAV) PRODUCED IN RESPONSE TO HAV INFECTION PERSIST FOR LIFE AND PROTECT AGAINST REINFECTION; IGG ANTI-HAV PRODUCED AFTER VACCINATION CONFER LONG-TERM IMMUNITY. THIS REPORT SUPPLANTS AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) REGARDING THE PREVENTION OF HAV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS ROUTINE VACCINATION OF CHILDREN AGED 12-23 MONTHS AND CATCH-UP VACCINATION FOR CHILDREN AND ADOLESCENTS AGED 2-18 YEARS WHO HAVE NOT PREVIOUSLY RECEIVED HEPATITIS A (HEPA) VACCINE AT ANY AGE. ACIP RECOMMENDS HEPA VACCINATION FOR ADULTS AT RISK FOR HAV INFECTION OR SEVERE DISEASE FROM HAV INFECTION AND FOR ADULTS REQUESTING PROTECTION AGAINST HAV WITHOUT ACKNOWLEDGMENT OF A RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE GUIDANCE FOR VACCINATION BEFORE TRAVEL, FOR POSTEXPOSURE PROPHYLAXIS, IN SETTINGS PROVIDING SERVICES TO ADULTS, AND DURING OUTBREAKS.

Immunization of Health-Care Providers: Necessity and Public Health Policies

Health-care providers (HCPs) are at increased risk for exposure to vaccine-preventable diseases (VPDs) in the workplace. The rationale for immunization of HCPs relies on the need to protect them and, indirectly, their patients from health-care-associated VPDs. Published evidence indicates significant immunity gaps for VPDs of HCPs globally. Deficits in knowledge and false perceptions about VPDs and vaccines are the most common barriers for vaccine uptake and may also influence communication about vaccines between HCPs and their patients. Most countries have immunization recommendations for HCPs; however, there are no universal policies and significant heterogeneity exists between countries in terms of vaccines, schedules, frame of implementation (recommendation or mandatory), and target categories of HCPs. Mandatory influenza immunization policies for HCPs have been implemented with high vaccine uptake rates. Stronger recommendations for HCP immunization and commitment at the level of the health-care facility are critical in order to achieve high vaccine coverage rates. Given the importance to health, mandatory immunization policies for VPDs that can cause serious morbidity and mortality to vulnerable patients should be considered.

Vaccination of healthcare personnel: spotlight on groups with underlying conditions

Healthcare personnel (HCP) are at increased risk of acquiring vaccine-preventable diseases (VPDs). Vaccination protects HCP and their patients from nosocomial transmission of VPDs. HCP who have underlying diseases (e.g., immunocompromised, HIV-infected, or those with chronic diseases) and HCP in particular phases of life (e.g., pregnant, elderly) require special consideration in regards the provision of vaccines. On the one hand, live virus vaccines may be contraindicated (e.g., pregnant HCP, immunocompromised HCP), while on the other hand, vaccines not routinely recommended (e.g., pneumococcal) may be indicated (e.g., elderly or immunocompromised HCP). It is not known how many HCP with underlying conditions require special consideration in the healthcare setting. This is an important issue, because the risk for serious morbidity, complications and mortality for HCP with underlying conditions will only increase. The prevention of nosocomial infections requires comprehensive occupational safety programs. The healthcare system must engage HCP and occupational physicians to ensure sufficient vaccination rates as part of an effective nosocomial infection prevention and HCP safety strategy.

The issue of mandatory vaccination for healthcare workers in Europe

Mandatory policies have occasionally been implemented, targeting optimal vaccination uptake among healthcare workers (HCWs). Herein, we analyze the existing recommendations in European countries and discuss the feasibility of implementing mandatory vaccination for HCWs. As reflected by a survey among vaccine experts from 29 European countries, guidelines on HCW vaccination were issued in all countries, though with substantial differences in targeted diseases, HCW groups and type of recommendation. Mandatory policies were only exceptionally implemented. Results from a second survey suggested that such policies would not become easily adopted, and recommendations might work better if focusing on specific HCW groups and appropriate diseases such as hepatitis B, influenza and measles. In conclusion, guidelines for HCW vaccination, but not mandatory policies, are widely adopted in Europe. Recommendations targeting specific HCW groups and diseases might be better accepted and facilitate higher vaccine uptake than policies vaguely targeting all HCW groups.

Attitudes toward mandatory occupational vaccinations and vaccination coverage against vaccine-preventable diseases of health care workers in primary health care centers

BACKGROUND

The aim of this study was to assess the attitudes regarding mandatory occupational vaccinations and the vaccination coverage against vaccine-preventable diseases among health care workers (HCWs) working in primary health care centers in Greece.

METHODS

A standardized questionnaire was distributed to HCWs working in all primary health care centers in Greece (n = 185).

RESULTS

A total of 2,055 of 5,639 HCWs (36.4% response rate) from 152 primary health care centers participated. The self-reported completed vaccination rates were 23.3% against measles, 23.3% against mumps, 29.8% against rubella, 3% against varicella, 5.8% against hepatitis A, 55.7% against hepatitis B, and 47.3% against tetanus-diphtheria; corresponding susceptibility rates were 17%, 25%, 18.6%, 16.7%, 87.5%, 35%, and 52.6%. Mandatory vaccinations were supported by 65.1% of 1,807 respondents, with wide differences by disease. Multiple logistic regression analysis revealed higher rates of acceptance of mandatory vaccination in physicians compared with other HCW categories.

CONCLUSIONS

Despite the fact that two-thirds of HCWs working in primary health care centers in Greece support mandatory vaccination for HCWs, completed vaccination rates against vaccine-preventable diseases are suboptimal.

National athletic trainers' association position statement: skin diseases

OBJECTIVE

To present recommendations for the prevention, education, and management of skin infections in athletes.

BACKGROUND

Trauma, environmental factors, and infectious agents act together to continually attack the integrity of the skin. Close quarters combined with general poor hygiene practices make athletes particularly vulnerable to contracting skin diseases. An understanding of basic prophylactic measures, clinical features, and swift management of common skin diseases is essential for certified athletic trainers to aid in preventing the spread of infectious agents.

RECOMMENDATIONS

These guidelines are intended to provide relevant information on skin infections and to give specific recommendations for certified athletic trainers and others participating in athletic health care.

The World Health Organization Guidelines on Hand Hygiene in Health Care and their consensus recommendations

The World Health Organization's Guidelines on Hand Hygiene in Health Care have been issued by WHO Patient Safety on 5 May 2009 on the occasion of the launch of the Save Lives: Clean Your Hands initiative. The Guidelines represent the contribution of more than 100 international experts and provide a comprehensive overview of essential aspects of hand hygiene in health care, evidence- and consensus-based recommendations, and lessons learned from testing their Advanced Draft and related implementation tools.

[Diagnostic flexible bronchoscopy. Recommendations of the Endoscopy Working Group of the French Society of Pulmonary Medicine]

These guidelines on flexible bronchoscopy depict important clues to be known and taken into account while practicing flexible bronchoscopy, in adult, except in emergency situations. This is a practical clarification. Safety conditions, complications, anesthesia, infectious risks, cleaning and disinfection are detailed from a review of the literature. Intensive care practice of bronchoscopy requires more attention due to higher risks patients and is discussed extensively. Standards and performances of the various sampling techniques complete this work. Indications for bronchoscopy, therapeutic and paediatric bronchoscopy are not covered in these guidelines.

The risk of hepatitis A infection among healthcare workers: a review of reported outbreaks and sero-epidemiologic studies

All reports of hepatitis A (HA) outbreaks in healthcare settings published between 1975 and 2003 were studied to determine the background immunity or susceptibility of healthcare workers (HCWs) to HA. Twenty-six reports were found. The number of infected personnel ranged from one to 66 and, in most outbreaks, nurses accounted for the majority of personnel infected, reflecting high attack rates reaching 15-41%. In addition, we found 23 sero-epidemiological studies for HA among HCWs that had been performed in 13 different countries. Seroprevalence rates of HCWs with anti-HA antibody ranged between 4% among paramedical workers in Germany to 88% among hospital maintenance workers in Portugal. Effective infection control of HA outbreaks in hospitals demands early recognition, including awareness of atypical presentations of the infection, and strict adherence to universal infection control measures. Education programmes are of special importance for HCWs in neonatal, paediatric and intensive care units. The findings of the current study suggest that a pre-employment screening policy and administration of active vaccination to susceptible HCWs, particularly nurses, should be seriously considered in high-risk settings.

Cost-effectiveness of hepatitis A-B vaccine versus hepatitis B vaccine for healthcare and public safety workers in the western United States

OBJECTIVE

To determine the cost-effectiveness of substituting hepatitis A-B vaccine for hepatitis B vaccine when healthcare and public safety workers in the western United States are immunized to protect against occupational exposures to hepatitis B.

PARTICIPANTS

A cohort of 100,000 hypothetical healthcare and public safety workers from 11 western states with hepatitis A rates twice the national average.

DESIGN

A Markov model of hepatitis A was developed using estimates from U.S. government databases, published literature, and an expert panel. Added costs of hepatitis A-B vaccine were compared with savings from reduced hepatitis A treatment and work loss. Cost-effectiveness was expressed as the ratio of net costs to quality-adjusted life-years (QALYs) gained.

RESULTS

Substituting hepatitis A-B vaccine would prevent 29,796 work-loss-days, 222 hospitalizations, 6 premature deaths, and the loss of 214 QALYs. Added vaccination costs of $5.4 million would be more than offset by $1.9 million and $6.1 million reductions in hepatitis A treatment and work loss costs, respectively. Cost-effectiveness improves as the time horizon is extended, from $232,600 per QALY after 1 year to less than $0 per QALY within 11 years. Estimates are most sensitive to community-wide hepatitis A rates and the degree to which childhood vaccination may reduce future rates.

CONCLUSION

For healthcare and public safety workers in western states, substituting hepatitis A-B vaccine for hepatitis B vaccine would reduce morbidity, mortality, and costs.

Risk groups for hepatitis A virus infection

We report the conduct and results of a systematic search for evidence of risk of infection with hepatitis A virus (HAV) among blood transfusion recipients, travellers, the military, healthcare workers, sewage workers, foodhandlers, day care assistants, institutionalised subjects, blood transfusion recipients, drug addicts, homosexuals, prisoners and other risk groups such a liver transplantees. We report our recommendations for the use of the HAV vaccine in these groups.

The role of vaccine in controlling hepatitis A epidemics

We report the conduct and results of a review of recent literature to describe various types of epidemics and outbreaks in Italy or countries with similar epidemiological profiles and to assess vaccine use in outbreak situations. We identified three scenarios most likely to occur in Italy: outbreaks occurring in small closed communities (nursery or a primary school), outbreaks in communities of limited dimensions (small towns or villages) and open community settings in which epidemics occur at regular intervals (person-to-person transmission). In closed communities we recommend vaccination of family members and school personnel living or working in close proximity to the index case as well as classmates. We also recommend vaccination when there is a proof of secondary transmission within the community. In small open communities we recommend vaccination of more susceptible age groups such as children and adolescents. For large open communities the only practicable alternative strategy is vaccination of close family contacts of acute cases couple with non-immunity boosting control measures.

Guideline for Hand Hygiene in Health-Care Settings. Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HIPAC/SHEA/APIC/IDSA Hand Hygiene Task Force

The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings. This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence. New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized. Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

Guideline for Hand Hygiene in Health-Care Settings: recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force

The Guideline for Hand Hygiene in Health-Care Settings provides health-care workers (HCWs) with a review of data regarding handwashing and hand antisepsis in health-care settings. In addition, it provides specific recommendations to promote improved hand-hygiene practices and reduce transmission of pathogenic microorganisms to patients and personnel in health-care settings. This report reviews studies published since the 1985 CDC guideline (Garner JS, Favero MS. CDC guideline for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43) and the 1995 APIC guideline (Larson EL, APIC Guidelines Committee. APIC guideline for handwashing and hand antisepsis in health care settings. Am J Infect Control 1995;23:251-69) were issued and provides an in-depth review of hand-hygiene practices of HCWs, levels of adherence of personnel to recommended handwashing practices, and factors adversely affecting adherence. New studies of the in vivo efficacy of alcohol-based hand rubs and the low incidence of dermatitis associated with their use are reviewed. Recent studies demonstrating the value of multidisciplinary hand-hygiene promotion programs and the potential role of alcohol-based hand rubs in improving hand-hygiene practices are summarized. Recommendations concerning related issues (e.g., the use of surgical hand antiseptics, hand lotions or creams, and wearing of artificial fingernails) are also included.

Cost analysis of two strategies for hepatitis A vaccination of hospital health-care personnel in an intermediate endemicity area

The aim of the study was to carry out a cost analysis to allow the comparison of the cost of two vaccination strategies against Hepatitis A in health-care personnel. A total of 423 health-care workers were recruited at one General Hospital of Madrid, Spain. Blood specimens were obtained for anti-HAV antibody determination. The prevalence of anti-HAV antibody was 40% (95% CI: 35-45) and it was directly correlated with age. Cost analysis determined that the critical value of prevalence for vaccination with HAV vaccine was 23%. In hospital health-care workers < or =30 years in age, vaccination with HAV vaccine (without screening) would be the less costly strategy. In those >30 years in age, it would be less costly to screen for anti-HAV antibody first and vaccinate those who are antibody-negative.

Nosocomial spread of viral disease

Viruses are important causes of nosocomial infection, but the fact that hospital outbreaks often result from introduction(s) from community-based epidemics, together with the need to initiate specific laboratory testing, means that there are usually insufficient data to allow the monitoring of trends in incidences. The most important defenses against nosocomial transmission of viruses are detailed and continuing education of staff and strict adherence to infection control policies. Protocols must be available to assist in the management of patients with suspected or confirmed viral infection in the health care setting. In this review, we present details on general measures to prevent the spread of viral infection in hospitals and other health care environments. These include principles of accommodation of infected patients and approaches to good hygiene and patient management. They provide detail on individual viral diseases accompanied in each case with specific information on control of the infection and, where appropriate, details of preventive and therapeutic measures. The important areas of nosocomial infection due to blood-borne viruses have been extensively reviewed previously and are summarized here briefly, with citation of selected review articles. Human prion diseases, which present management problems very different from those of viral infection, are not included.

Hepatitis A: old and new

The hepatitis A virus (HAV), a picornavirus, is a common cause of hepatitis worldwide. Spread of infection is generally person to person or by oral intake after fecal contamination of skin or mucous membranes; less commonly, there is fecal contamination of food or water. Hepatitis A is endemic in developing countries, and most residents are exposed in childhood. In contrast, the adult population in developed countries demonstrates falling rates of exposure with improvements in hygiene and sanitation. The export of food that cannot be sterilized, from countries of high endemicity to areas with low rates of infection, is a potentially important source of infection. After ingestion and uptake from the gastrointestinal tract, the virus replicates in the liver and is excreted into the bile. Cellular immune responses to the virus lead to destruction of infected hepatocytes with consequent development of symptoms and signs of disease. Humoral immune responses are the basis for diagnostic serologic assays. Acute HAV infection is clinically indistinguishable from other causes of acute viral hepatitis. In young children the disease is often asymptomatic, whereas in older children and adults there may be a range of clinical manifestations from mild, anicteric infection to fulminant hepatic failure. Clinical variants include prolonged, relapsing, and cholestatic forms. Management of the acute illness is supportive, and complete recovery without sequelae is the usual outcome. Research efforts during World War II led to the development of passive immunoprophylaxis. Pooled immune serum globulin is efficacious in the prevention and attenuation of disease in exposed individuals. More recently, active immunoprophylaxis by vaccination has been accomplished. Future eradication of this disease can now be contemplated.

Current paradoxes and changing paradigms in vaccinology

Other than the provision of clean water, food and sanitation, no other deliberate human intervention has prolonged the human life span as much as the provision of vaccines and the control of infectious disease. Since 1950, 25 vaccines have been licensed in the US, 15 of these for routine universal use in the population. On the horizon are vaccines not only to prevent infectious diseases, but also vaccines against cancer and a host of other human ills. Despite these public health and scientific accomplishments however, the manner in which we think about, develop and apply vaccines to the public health has common heuristic flaws which prevent realizing the full benefits of vaccines to society. This paper will discuss a number of current paradoxes and changing paradigms related to the field of vaccinology.

Immune globulin and vaccine therapy to prevent hepatitis A infection

The hepatitis A virus is usually transmitted person-to-person due to fecal-oral exchange of virus. Approximately 30,000 infections are reported each year in the United States, with the actual incidence being much greater. Prophylaxis with immune globulin has had a minimal impact on the overall incidence of hepatitis A. The recent availability and proven efficacy of a hepatitis A vaccine offers the hope that the incidence of infection may be substantially reduced. Pre- and postexposure prophylaxis should be targeted to individuals at increased risk of either acquiring infection, transmitting infection, or developing fulminant hepatitis, or to help control epidemics. This article reviews the current literature and discusses recommendations for pre- and postexposure prophylaxis against hepatitis A virus.

Exposure Workups

Exposure workups are an important responsibility for infection control personnel. A well-designed plan for investigating exposures, which includes appropriate algorithms, will enable infection control personnel to evaluate exposures rapidly and consistently so that nosocomial transmission is minimized. Infection control personnel should use their own data to develop policies and procedures that suit the needs of their facility. After they have imple-merited the plan, infection control personnel should continue to collect data on exposures so they can continuously improve their performance.

Frontiers of occupational health. New vaccines, new prophylactic regimens, and management of the HIV-infected worker

New prophylactic or treatment options are available for a number of infectious diseases that may be transmitted in the health care setting. Infectious diseases that can now be prevented by vaccination of the employee include hepatitis A, pertussis, hepatitis B, and primary varicella. New prophylactic or treatment regimens are available for Neisseria meningitidis, Streptococcus pyogenes, and Bordetella pertussis; treatment of multidrug-resistant tuberculosis is also discussed. Finally, management of the HIV-infected health care worker is reviewed.

Hepatitis in children

Epidemic jaundice was first described by Hippocrates. Within approximately the past 10 years vaccines for HAV and HBV have been developed as have new diagnostic tests for HCV and HDV. Treatment of pediatric patients with interferon alpha-a and alpha-2b for chronic hepatitis C is promising (Ramos-Soriano and Schwarz, 1994). The focus of the 1990s has shifted toward antiviral therapy of chronic viral hepatitis. Katkov and Dienstag (1995) warn that the importance of vaccination should not be minimized. Vigilance on the part of health caregivers and involvement in environmental "clean-up" issues and health care policies to protect people from the possible serious consequences of liver infection are essential.

An outbreak of hepatitis A in an intensive care unit

We describe an outbreak of hepatitis A that occurred in an Intensive Care Unit (ICU) in a regional hospital in North Queensland. Seven people were infected including two patients, two close contacts of the index patient and three ICU nursing staff. The index case was admitted with an overdose and multiple trauma; he was not suspected to be incubating hepatitis A. The outbreak was initiated as a result of inadequate precautions taken whilst handling the index patient's bile. Problems identified upon reviewing the outbreak were inadequate terminal cleaning of equipment, food consumption in the ICU and inadequate handwashing practices. Implementation and maintenance of standard infection control practices is vital if further outbreaks of hospital-acquired hepatitis A and other enteric infections are to be avoided. We also suggest that the inactivated hepatitis A vaccine be considered for ICU staff.

Safety and Immunogenicity of a High-Potency Inactivated Hepatitis A Vaccine

Background: In recent years, several hepatitis A vaccines have been developed. We wished to evaluate the safety, reactogenicity, and immunogenicity of an inactivated hepatitis A vaccine, containing 1440 EI.U., and to monitor the kinetics of the antibodies monthly for the first year after administration of a single dose of vaccine. Methods: We conducted an open clinical trial, started in March 1992 and completed in July 1993, at two general hospitals and one pediatric hospital in Antwerp, Belgium, with 194 healthy adult healthcare volunteers. Each volunteer received a single dose hepatitis A vaccine, given intramuscularly at month 0 and a booster at month 12. We undertook serologic follow-up of antihepatitis A virus (antiHAV) antibodies and liver enzymes at day 15 and at months 1, 6, 9, 12, and 13. For a random subgroup of participants, blood samples were taken monthly. In addition, all participants noted local and general symptoms following administration of the vaccine. Results: This single dose vaccine was well-tolerated; 2 weeks after the vaccination, 80% of the participants had seroconverted (antiHAV antibodies >=20 mIU/mL); after 1 month, seroconversion reached 99% (geometric mean titer (GMT): 383 mIU/mL). One year after the single dose of vaccine, 94% still had antiHAV antibodies above 20 mIU/mL (GMT: 176 mIU/mL). One month after the booster dose, seroconversion was 100%, and GMT increased from 176 mIU/mL at month 12 to 4775 mIU/mL at month 13. Conclusions: The single dose hepatitis A vaccine is safe and highly immunogenic; it gives a rapid antibody production and a rapid increase of GMT. The persistence of protective antibodies until month 12 allows a booster at month 12. This schedule will easily fit into existing travel or occupational health vaccination schedules and will improve vaccination compliance.

New developments in hepatitis A control

An inactivated vaccine for hepatitis A was recently licensed in Canada. This is the first important development in control of the disease in 50 years. This article presents new information about the vaccine and about the groups who might benefit from it. It also provides a review of the clinical and epidemiological aspects of hepatitis A.

Viral hazards to and from health care workers

Much attention has been directed towards nosocomial transmission of viruses as a result of clear evidence of patient-to-staff and staff-to-patient transmission of the blood-borne viruses HIV and hepatitis B virus. Although the relatively long incubation periods of these viruses, together with the frequency of asymptomatic infections, renders problems for surveillance it has been possible to study modes of transmission and levels of risk over a number of years. Information on trends of incidence of other nosocomial virus infections has been difficult to obtain for a number of reasons. Often, an outbreak in the health care setting parallels an epidemic in the community. Although it may be possible to define nosocomial transmission from recording dates of onset of illness relative to admission date and, at times, demonstrate circulation of a common strain by molecular techniques, the relative contributions of patient-to-staff and staff-to-patient transmission may be difficult to clarify. In this review, details are presented of the major viruses associated with nosocomial transmission with examples of infections to and from staff where these have occurred. The major defences against patient-to-staff and staff-to-patient transmission are awareness of potential risks, education and adherence to infection control policies, immunization of staff, effective decontamination and sterilization and the adoption of 'Universal Precautions' in patient care. In addition, there may be occasions when additional measures should be considered including isolation, cohorting and the use of specific chemo- and immunoprophylaxis.