Epidemiology and prophylaxis of the hospital contamination of medical personnel with viruses of hepatitis B and C

Medical personnel is one of the main risk groups with respect to hospital infections for which hepatitis B and C are professional pathology. The degree of the risk of contamination of the personnel greatly depends on the character, urgency and duration of professional activity, accuracy in following the rules of personal safety while working with infected material, the proportion of patients contaminated with viruses of hepatitis B and C in specialized departments, the epidemiological danger of therapeutic and diagnostic methods, the possibility of reliable disinfection and sterilization of the equipment. In the system of measures aimed at preventing the infection of the medical personnel a special role belongs to the specific immunoprophylaxis of hepatitis B. Prolonged experience in the immunization of the medical personnel of a big hospital demonstrates a high immunological and epidemiological efficiency of the use of vaccine against hepatitis B, produced by the Research and Manufacturing Complex "Combiotech", Russia.     

Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang vaccine in adolescents from low income families in Central Brazil

In order to evaluate the seroepidemiology and response to Butang vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. further, three 20 microg Butang vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182), the seroresponse was evaluated in 170 individuals by quantitative anti-HBs. an overall hbv prevalence of 5.9% was found: four adolescents were HBsAg positive, 24 were anti-HBc, anti-HBs-reactive, and 11 were anti-HBc only. The analyse of risk factors showed that age 16-19 years, place of birth outside Goiás, school B and body piercing were statistically associated with HBV infection markers (p < 0.05). All 170 adolescents responded to Butang, and a geometric mean titer (gmt) of 4344 mUI/ml was obtained. these results reinforce the importance of hepatitis b vaccine in adolescents despite of the hbv regional endemicity, and suggest that three doses of 20 microg of the Butang should guarantee protective anti-hbs levels to individuals at a critical time for hepatitis b acquiring such as latter adolescence and adulthood.     

Recurrent pneumococcal meningitis in a splenectomised HIV-infected patient

Background

Hepatitis B virus infection although preventable by vaccination remains an important health issue throughout the world due to its morbidity, mortality and economical losses. Early seroprotection is desirable for people at high risk of exposure. The aim of this study was to determine whether three-week hepatitis B vaccination (on days 0, 10 and 21) provide seroprotection or not.

Methods

The 120 subjects enrolled into the study were divided into two groups and vaccinated by the classic (months 0, 1, and 2) or the accelerated (days 0, 10, and 21) schedules and antibody response determined on days 30, 60, and 90 and, if below 10 mIU/ml^-1, again on day 180. For each individual in the classic group (B) three subjects were enrolled in the accelerated group (A). Recombinant hepatitis B vaccine (Gen-Hevac B, Pasteur) was given as 20 micrograms intramuscular injections via the deltoid muscle. A booster dose on day 365 was administered for each group. Family members of hepatitis B carriers and volunteer health personnel were enrolled into group A. To the B group only volunteers who wanted vaccination against hepatitis B were included.

Results

After three doses of vaccine, Anti-HBs titers reached protective levels in both groups. The number of vaccinees with seroprotective levels of Anti-HBs (≥10 mIU/ml^-1) on day 30 was 53 (58.9%) in group A and 9 (30.0%) in group B (p < 0.05). On day 60, there was no difference between group A and B, with response rates of 84.4% (n = 76) and 80.0% (n = 24) respectively (p > 0.05). On day 90 there was no difference between group B and group A; with 26 (86.7%) and 79 (87.7%) responders respectively. In both groups those with Anti-HBs levels <10 mIU/ml^-1 attained protective levels by day 180.

Conclusion

In this study, the three-week vaccination provided protective antibody titers within a shorter time compared to the classic schedule. Therefore, in order to provide rapid antibody production against hepatitis B virus, the accelerated vaccination schedule seems to be a good preference.     

Primary prevention of hepatocellular carcinoma in developing countries

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world with 80% of cases occurring in developing countries. The cancer is rapidly fatal in almost all cases with survival generally less than 1 year from diagnosis. The major risk factors for this cancer have been identified as chronic infection with hepatitis B (HBV) and hepatitis C (HCV) viruses and dietary exposure to aflatoxins. There is a safe and effective vaccine to prevent chronic HBV infection. Given estimates that approximately 70% of HCC in developing countries is attributable to HBV then vaccination could prevent more than 250,000 cases per year in these areas of the world. A major challenge now is to ensure the availability of vaccine in countries with endemic infection. Development of a vaccine against HCV is more problematic due to the genetic heterogeniety of the virus. However, with 24% of HCC in developing countries attributable to HCV (approximately 93,000 cases per year) a vaccine would make a major contribution to cancer prevention. Aflatoxins contaminate dietary staple foods (groundnuts, maize), are potent animal hepatocarcinogens and are carcinogenic in humans with particularly high risks in individuals with a concomitant infection with HBV. Reduction of exposure can be addressed at the community level either pre- or post-harvest by limiting fungal contamination of crops; approaches may involve low technology post-harvest measures to limit fungal growth or genetic engineering of crops to be resistant to fungal infection or toxin biosynthesis. An alternative measure is to modulate the metabolism of aflatoxins once ingested using chemopreventive agents e.g., oltipraz. The resources available in countries with endemic hepatitis infection and fungal contamination of foods are often severely limited. Clearly HBV vaccination has to be the priority in the reducing the incidence of HCC. However, there are currently 360 million chronic HBV carriers worldwide and HBV vaccine is still not incorporated into many national immunisation programs. Thus measures to reduce food spoilage by fungi and the associated dietary exposure to aflatoxins is also a desirable public health goal.     

Infection in Health Personnel with High and Low Levels of Exposure in a Hospital Setting during the H1N1 2009 Influenza A Pandemic

A novel H1N1 influenza A virus caused the first pandemic of the 21^st century in 2009. Hospitals had an increased demand of health consultations, that made it difficult to estimate the incidence of infection in hospital personnel due to asymptomatic presentations and the under notification of cases. To estimate and compare the rate of exposure of high versus low risk health personnel to 2009 pandemic H1N1 (H1N1pdm2009) influenza A virus in a University Hospital in Chile, we performed a comparative and prospective study. Serum samples were obtained from 117 individuals that worked in the emergency room (ER) and the operating room (OR) during the peak of the pandemic. Antibody titers were determined by the hemagglutination inhibition (HI) assay. Of the samples analyzed, 65% were workers at the ER and 35% at the OR. Of the total number of the subjects tested, 29.1% were seropositive. One out of 3 (36.8%) workers at the ER had positive HI titers, meanwhile only 1 out of 7 (14.6%) workers from the OR was seropositive to the virus. The possibility of being infected in the ER as compared to the OR was 3.4 times greater (OR 3.4; CI 95%, 1.27–9.1), and the individuals of the ER had almost twice as much antibody titers against H1N1pdm2009 than the personnel in the OR, suggesting the potential of more than one exposure to the virus. Of the 34 seropositive subjects, 12 (35.3%) did not develop influenza like illness, including 2 non-clinical personnel involved in direct contact with patients at the ER. Considering the estimated population attack rate in Chile of 13%, both groups presented a higher exposure and seropositive rate than the general population, with ER personnel showing greater risk of infection and a significantly higher level of antibodies. This data provide a strong rationale to design improved control measures aimed at all the hospital personnel, including those coming into contact with the patients prior to triage, to prevent the propagation and transmission of respiratory viruses, particularly during a pandemic outbreak.     

Canadians for Health Research conference

Dentists were surveyed regarding a history of hepatitis and the presence in the blood of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) to determine whether they were at high risk of exposure to hepatitis B virus. Of 288 Canadian dentists 5.2% gave a history of hepatitis after graduation. This proportion is similar to that for 1462 Ontario dentists (6.3%) and that for 3162 accountants (5.1%) who had previously completed a mailed questionnaire. One dentist (0.3%) was HBsAg-positive and 42 (14.6%) were anti-HBs-positive. Of 210 healthy volunteer blood donors matched for age, sex and ethnic origin with the group of dentists none was HBsAg-positive and 2.9% significantly fewer (P less than 0.005), were anti-HBs-positive. Among Ontario blood donors 0.3% were HBsAg-positive and 3% were anti-HBs-positive. Thus, in Canada, dentists are not at increased risk of acquiring clinical hepatitis or becoming carriers, but they are more likely than other groups to have anti-HBs in the blood. Among dentists from outside Canada a higher proportion had a history of hepatitis (10.3%) and were HBsAg-positive (1.6%), but approximately the same proportion were anti-HBs-positive (15.9%).     

The structure of hepatitis B surface antigen and its antigenic sites

Hepatitis B virus infects about 200 million people worldwide yearly. The consequences of the infection range from mild, self-limiting hepatitis with full recovery and immunity to chronic infection with liver disease of varying severity, including fulminant hepatitis and death. Alternatively, individuals may become healthy carriers of the virus and thus serve as a reservoir of infection. In addition, all chronic carriers of the virus are also at risk for development of primary hepatocellular carcinoma later in life. Efforts to combat this disease on a global scale require an inexpensive vaccine. Studies of the hepatitis B viral coat protein (HBsAg) have permitted the development of two generations of vaccine to date, and detailed structural studies of its antigenic sites may eventually allow the development of a completely synthetic (and therefore inexpensive) vaccine in the future.     

Immunisation of neonates at high risk of hepatitis B in England and Wales: national surveillance.

The results of a voluntary programme of immunisation against hepatitis B in neonates at high risk (mother being positive for hepatitis B surface antigen and without hepatitis B e antibody or having had acute hepatitis B late in pregnancy) are reported. The programme was offered in England and Wales from November 1982. Passive immunisation alone was available in the first six months of life until 1985, after which infants received passive and active immunisation from birth; in addition, some infants received passive immunisation for six months followed by a course of hepatitis B vaccine. All but a few infants received the first immunising dose within 48 hours after birth. Blood samples for analysing markers of hepatitis B virus were available at 1 year from 147 of the 223 infants given passive immunisation, 54 of the 72 given passive followed by active immunisation, and 102 of the 155 given passive and active immunisation at birth. At 1 year 11 of the 127 (9%) infants given four or more doses of specific hepatitis B immunoglobulin were positive for hepatitis B surface antigen compared with four of the 20 given three or fewer doses; 11 had levels of hepatitis B surface antibody greater than 50 IU/l. Only one of the 54 infants given passive then active immunisation was positive for hepatitis B surface antigen at 1 year and four infants had low (less than or equal to 50 IU/l) levels of hepatitis B surface antibody. Four of the 102 infants who received passive and active immunisation at birth were positive for hepatitis B surface antigen. Two had received the fill course of vaccine, whereas in the other two vaccination was incomplete or unstated. In 79 of the 89 infants who received a complete course of vaccination the level of hepatitis B surface antibody was known, and 70 had levels at 1 year greater than 100 IU/1. Reactions to immunisation were not severe at any age. The incidence of side effects was 8% for the immunoglobulin, 11% for the vaccine, and 9% when immunoglobulin and vaccine were given together. Wider collaboration in the programme is requested.     

Prevalence of hepatitis B antibodies in hospital personnel.

Of 426 hospital staff tested for hepatitis B surface antibody (anti-HBS) by the radioimmunoassay method 57 (13.4%) had positive results. Laboratory staff had the highest prevalence, followed by nurses, and both values were significantly higher than that of administrative staff. Clerical staff working in laboratories were at the same risk for hepatitis B as general-duty nurses. Significantly more staff with anti-HBS had a history of hepatitis (19.3%) compared with staff without anti-HBS (79%), and significantly more staff with a history of hepatitis had anti-HBS (25.6%) compared with staff without such a history (12.0%). History of blood transfusions was not related to prevalence of anti-HBS. The risk for hepatitis B is greater in hospital staff who are in direct contact with patients or handle patients'' blood and other specimens. However, contact with patients is less important than contact with patients'' blood and other specimens.     

Serosurveillance of Vaccine Preventable Diseases and Hepatitis C in Healthcare Workers from Lao PDR

Background and Aims

Healthcare workers (HCW) have an increased risk of exposure to infectious diseases and are a potential source of infections for their patients. The Lao People’s Democratic Republic (Lao PDR) has no national policy regarding HCW vaccinations and routine vaccination coverage is low within the general population. This cross-sectional serostudy determines the level of exposure and risk of infection in Lao HCW against 6 vaccine preventable diseases and hepatitis C.

Methods

1128 HCW were recruited from 3 central, 2 provincial and 8 district hospitals. Sera were tested by ELISA for the presence of antibodies and antigens to hepatitis B, hepatitis C, measles, rubella, varicella zoster, tetanus and diphtheria.

Results

Only 53.1% of the HCW had protective anti-hepatitis B surface antigen antibodies (anti-HBs) with 48.8% having anti-hepatitis B core antibodies (anti-HBc), indicating previous exposure and 8.0% were hepatitis B surface antigen carriers. 3.9% were hepatitis C seropositive. Measles and rubella antibodies were detected in 95.4% and 86.2% of the HCW, with 11.9% of females being unprotected against rubella. Antibodies against varicella zoster, tetanus and diphtheria were detected in 95%, 78.8% and 55.3%, respectively. Seroprevalence varied according to age, gender and number of children.

Conclusion

An unacceptably high proportion of Lao HCW remain susceptible to infection with hepatitis B, diphtheria, tetanus and rubella. Furthermore, a high number of healthcare workers are chronically infected with hepatitis B and C viruses. These data emphasize the need for a robust HCW vaccination policy in addition to increased awareness within this subpopulation.     

Prevalence of viral hepatitis among the hospital staff in CSR between 1980 and 1982

The hepatitis morbidity data were used to study prevalence rate of manifest viral hepatitis among the hospital staff members in CSR over a 3-year period between 1980 and 1982. This study showed that the overall hepatitis morbidity rate was 2.68 per 1,000 health personnel and was 3.6 times as high as that recorded in a normal population matched by age. The mean HBsAg positivity rate was 1.67 per 1,000 and was 5.8 times the rate in the control population group. The rate of HBsAg-negative cases of hepatitis was 1.01 per 1,000 health personnel and was higher than double the rate of morbidity encountered in an age-matched normal population. The highest morbidity rates were recorded in the lower-grade and auxiliary health personnel. When compared with an age-matched normal population the hospital staff members at all departments had distinctly higher morbidity rates than the general population, but the highest risk of acquiring viral hepatitis was evidently run by the personnel at departments of renal dialysis, biochemistry, hematology, infectious diseases, internal medicine, surgery, urology and TRD (tuberculosis and respiratory diseases). Of a total number of recorded cases of viral hepatitis those with HBsAg positivity predominated, especially at departments of urology, TRD, internal medicine, renal dialysis, psychiatry and hematology. Analyzed by specialty and professional status of personnel these viral hepatitis morbidity rates encountered among the hospital staff members seem to point to at least two conclusions: this infection in the health personnel is work-related and its transmission and spread is dependent on the frequency and intensity of contact with the blood and other secretions of infectious patients.     

Immune response to a new hepatitis B vaccine in healthcare workers who had not responded to standard vaccine: randomised double blind dose-response study.

OBJECTIVE: To evaluate the immunogenicity and reactogenicity of a new triple S recombinant hepatitis B vaccine in a cohort of healthy people in whom currently licensed hepatitis B vaccines had persistently not induced an immune response. DESIGN: Single centre, randomised, double blind, dose-response study. SETTING: Research vaccine evaluation centre at a teaching hospital. SUBJECTS: 100 healthcare workers aged 18-70 years with a history of failure to seroconvert after at least four doses of a licensed hepatitis B vaccine containing the S component. INTERVENTION: Each subject was randomly allocated two doses of 5, 10, 20, or 40 micrograms of a new hepatitis B vaccine two months apart. MAIN OUTCOME MEASURES: Immunogenicity of the four doses. Seroconversion and seroprotection were defined as an antibody tire > 10 IU/l and > 100 IU/l respectively against an international antibody standard. RESULTS: 69 subjects seroconverted after a single dose of the vaccine. After the booster vaccination one other subject seroconverted, bringing the overall seroconversion rate to 70%. Fifteen subjects given 5 micrograms of vaccine, 19 given 10 micrograms, 16 given 20 micrograms, and 20 given 40 micrograms seroconverted. Seroconversion rates in the four antigen dose groups were 60% (15/25), 76% (19/25), 64% (16/25), and 80% (20/25). After the booster dose there was no significant dose-response effect on the overall seroconversion rate, although the small sample size meant that a clinically important dose-response could not be ruled out. CONCLUSION: A single dose of 20 micrograms of the vaccine was as effective as two doses of either 40 micrograms or 20 micrograms of this vaccine formulation in terms of seroconversion, seroprotection, and geometric mean titres.     

Observational Study of Vaccine Efficacy 24 Years after the Start of Hepatitis B Vaccination in Two Gambian Villages: No Need for a Booster Dose

Objectives

To determine the duration of protection from hepatitis B vaccine given in infancy and early childhood and asses risk factors for HBV infection and chronic infection.

Methods

In 1984 infant HBV vaccination was started in two Gambian villages. Cross sectional serological surveys have been undertaken every 4 years to determine vaccine efficacy. In the current survey 84.6% of 1508 eligible participants aged 1–28 years were tested. A spouse study was conducted in females (aged 14 years and above) and their male partners.

Results

Vaccine efficacy against chronic infection with hepatitis B virus was 95.1% (95% confidence interval 91.5% to 97.1%), which did not vary significantly between age groups or village. Efficacy against infection was 85.4% (82.7% to 87.7%), falling significantly with age. Concentrations of hepatitis B antibody fell exponentially with age varying according to peak response: 20 years after vaccination only 17.8% (95% CI 10.1–25.6) of persons with a low peak response (10–99 mIU/ml) had detectable HBs antibody compared to 27% (21.9% to 32.2%) of those with a high peak response (>999 mIU/ml). Time since vaccination and a low peak response were the strongest risk factors for HBV infections; males were more susceptible, marriage was not a significant risk for females. Hepatitis B DNA was not detected after infection, which tested soley core antibody positive. An undetectable peak antibody response of <10 mIU/ml and a mother who was hepatitis B e antigen positive were powerful risk factors for chronic infection.

Conclusions

Adolescents and young adults vaccinated in infancy are at increased risk of hepatitis B infection, but not chronic infection. Married women were not at increased risk. There is no compelling evidence for the use of a booster dose of HBV vaccine in The Gambia.     

HBsAg阴性母亲及其婴儿乙肝疫苗接种情况和免疫效果研究

目的：了解乙肝表面抗原阴性（HBsAg阴性）母亲及其婴儿乙肝疫苗接种情况及抗-HBs滴度水平,从而为今后针对该特殊人群进行更好的乙肝疫苗免疫策略提供依据。方法：2010年5月～2010年10月,对陕西省227对HBsAg阴性母亲及其婴幼儿（月龄为8～24月）进行流行病学调查并采集血液标本,对母婴血清抗-HBs进行定性及定量检测。结果：母亲乙肝表面抗体（抗-HBs）阳性率为45.4%,抗-HBs平均滴度为12.88 mIU/mL（95%CI：8.91-18.19）。婴儿乙肝疫苗首针、第二针和第三针的及时接种率分别为95.2%,93.8%和85.9%。婴儿抗-HBs阳性率为77.1%,抗-HBs平均滴度为37.15 mIU/mL（95%CI：28.18-48.98）。结论：婴儿乙肝疫苗首针及时接种率较高,但三针全程及时接种率仍需提高。母亲抗-HBs阳性率较低,应当重视HBsAg阴性孕龄妇女的乙肝疫苗接种及乙肝标志物的检测,从而提高该人群的乙肝免疫水平。     

A Population-Based Study Examining Hepatitis B Virus Infection and Immunization Rates in Northwest China

Background and Aim

Current baseline data regarding the prevalence of hepatitis B virus (HBV) infections and the immune status in hyperendemic areas is necessary in evaluating the effectiveness of ongoing HBV prevention and control programs in northwest China. This study aims to determine the prevalence of chronic HBV infections, past exposure rates, and immune response profiles in Wuwei City, northwest China in 2010.

Methods

Cross-sectional household survey representative of the Wuwei City population. 28,579 participants were interviewed in the seroepidemiological survey ≥1 year of age. House to house screening was conducted using a standard questionnaire. All serum samples were screened by enzyme-linked immunoassays for the presence of hepatitis B surface antigen, antibodies against HBV surface antigen, and antibodies to the hepatitis B core antigen.

Results

Among individuals ≥1 year of age, 7.2% (95%CI: 6.3–8.1%) had chronic HBV infections, 43.9% (CI: 40.4–47.4%) had been exposed to HBV, and 23.49% (CI: 21.6–25.3%) had vaccine-induced immunity. Multi-factor weighted logistic regression analysis showed that having household contact with HBV carriers (OR = 2.6, 95%CI: 2.3–3.0) and beauty treatments in public places (OR = 1.2, 95%CI: 1.1–1.3) were the risk factors of HBV infection in whole population. Having household contact with HBV carriers (OR = 3.8, 95% CI: 2.2–6.5) and lack of hepatitis vaccination (OR = 2.0, 95% CI: 1.4–3.3) were the risk factors for HBV infection in children aged 1–14 years.

Conclusions

Hepatitis B infection remains a serious public health problem in northwest China. Having household contact with HBV carriers and beauty treatments in public places represented HBV infection risk factors. Hepatitis B vaccine immunization strategies need further improvement, particularly by targeting the immunization of rural migrant workers.     

Knowledge on HBV vaccine and vaccination status among health care workers of Hawassa University Comprehensive Specialized Hospital,Hawassa, southern Ethiopia: a cross sectional study

Objectives

The study was conducted to assess the knowledge on HBV vaccine and vaccination status among health care workers of Hawassa University Comprehensive Specialized Hospital.

Result

From the total 258 questionnaire prepared for the study participant, data was collected from 241 participants making the response rate of 93.4%. Regarding socio-demographic characteristics of respondents 98 (40.7%), and 159 (66%) were females and Bachelor of Science graduates respectively. Only 73 (30.3%) respondents reported that they are vaccinated for hepatitis B vaccine. But only 16 (21.9%) received three doses of Hepatitis B vaccine, which was 6.6% of the total health care workers. More than half 146 (60.6%) of the respondents had good knowledge about hepatitis B virus infection and 120 (49.8%) had good knowledge about hepatitis B vaccine. Regarding knowledge about hepatitis B virus infection prevention and control methods, 131 (28.5%) of the respondents have good knowledge.

     

Anti-pre-S2 antibody response in subjects vaccinated against hepatitis B and in naturally immunized subjects

Serum samples from individuals immunized with a pepsinized or non-pepsinized vaccine and from patients who had recovered from acute hepatitis B or who developed a chronic form of the disease, were analysed for the presence of antibody against the pre-S2 epitope of the hepatitis B virus.Anti-pre-S2 antibody was absent in all but one individual immunized with the pepsinized vaccine. Thirty-eight percent of the subjects who responded by anti-HBs production to the non-pepsinized preparation showed anti-pre-S2 antibody one year after complete vaccination. Among subjects who did not produce anti-HBs after immunization with this vaccine, 1 single individual produced anti-pre-S2 antibody. Anti-preS2 antibody was detectable after one year in 38% of the patients who recovered from acute hepatitis B, but in none of those with chronic hepatitis B. The kinetics of anti-pre-S2 antibody response to a booster injection was also analysed 1 month and 1 year after the 3rd injection and 1 month after the 4th injection of the non-pepsinized vaccine.     

Review of management of incidents involving exposure to blood in a London teaching hospital, 1989-91.

OBJECTIVE--To review management of incidents involving exposure to blood reported to an occupational health unit. DESIGN--Analysis of all reported incidents from January 1989 to June 1991. SETTING--London teaching hospital. SUBJECTS--447 health care workers and students. MAIN OUTCOME MEASURES--Immunisation against hepatitis B virus before exposure, proportion of known source patients tested for hepatitis B surface antigen and HIV antibodies, and reasons for not testing known source patients. RESULTS--447 incidents were reported: 337 sharps injuries and 110 other exposures. 310 staff reporting incidents (205 (82%) nurses) were already immune to hepatitis B virus, nearly always because of immunisation. 345 source patients were identified, 77 of whom had already been tested for hepatitis B surface antigen (28 positive results) and 58 for HIV antibodies (18 positive results). Of those not previously tested, 145 of 266 were subsequently tested for hepatitis B surface antigen (two positive) and 149 of 287 for HIV antibodies (none positive). The main reasons for not testing source patients were that the incident was not considered a risk, that the patient had gone home, and that the clinical team were unwilling to ask the patient. Specific hepatitis B immunoglobulin was given to 18 staff who were not immune and was avoided in 11 cases by a negative result for the patient. Prophylactic zidovudine was discussed but not given to any staff member. CONCLUSIONS--Management of exposure to blood is improved by widespread immunisation against hepatitis B virus and by knowledge of source patients'' hepatitis B virus and HIV status.