A curriculum for training healthcare workers in the management of highly infectious diseases.

The SARS epidemic, the threat of bioterrorism, and recent examples of imported highly infectious diseases (HID) in Europe have all highlighted the importance of competent clinical and public health management of infectious disease emergencies. Although the European Union of Medical Specialists in Europe and the Infectious Diseases Society of America have developed curricula for training in infectious disease medicine, neither of those mentions training in the management of HIDs. The European Network for Infectious Diseases (EUNID, http://www.eunid.com) is a European Commission co-funded network of experts in HID management, created to help improve the preparedness for HID emergencies within Europe. One of EUNID's agreed tasks is the development of a curriculum for such a training. Between April 2005 and September 2006, EUNID developed a curriculum and accompanying training course on the basis of a questionnaire that was sent to all country representatives and discussion, followed by amendment of drafts shared through the project website, and a final consensus meeting. The resulting curriculum consists of a two-module course covering the core knowledge and skills that healthcare workers need to safely treat a patient who has, or who may have, an HID. The first module introduces theoretical aspects of HID management, including disease-specific knowledge, infection control, and the public health response, through didactic teaching and class-based discussion. The second module involves a "skill station" and a clinical scenario, and equips trainees with relevant practical skills, including the use of specialised equipment and teamwork practice in patient management. Together, the curriculum and course contribute to the creation of a common framework for training healthcare professionals in Europe, and although they are designed primarily for clinicians that are directly involved in patient care, they are relevant also to public health professionals and others who may be involved in HID management and emergency response.

Hospital preparedness to bioterrorism and other infectious disease emergencies.

In the last 2 decades, successive outbreaks caused by new, newly recognised and resurgent pathogens, and the risk that high-consequence pathogens might be used as bioterrorism agents amply demonstrated the need to enhance capacity in clinical and public health management of highly infectious diseases. In this article we review these recent and current threats to public health, whether naturally occurring or caused by accidental or intentional release. Moreover, we discuss some components of hospital preparedness for, and response to, infectious disease of the emergencies in developed countries. The issues of clinical awareness and education, initial investigation and management, surge capacity, communication, and caring for staff and others affected by the emergency are discussed. We also emphasise the importance of improving the everyday practice of infection control by healthcare professionals.

The HCV National Register: towards informing the natural history of hepatitis C infection in the UK.

The aim of this paper is to describe the development of a national hepatitis C register and the completeness of the data it contains. This is a descriptive report of the structure and function of the register, including case definitions, registration and follow-up procedures, and methods used to maximize data quality and to obtain comparative data sources. The register contains data on HCV-infected individuals who acquired their infections on a known date and by a known route; to date all are transfusion recipients identified during the UK lookback exercise, who tested positive or indeterminate for anti-HCV after receiving 'infected' blood issued before the introduction of routine testing of the blood supply for anti-HCV. By 31 December 1999, 871 (87%) of 996 eligible transfusion recipients had been registered, and 984 (99%) flagged in the NHS Central Registers. Registered patients had been infected for an average of 11.1 years (SEM 0.1); around half were being cared for by clinicians with a specialist interest in liver disease. Except for the information on tobacco use, current alcohol use, and hepatitis B status, data were more than 80% complete, and for most variables, more than 90% complete. The consistency of data abstraction was found to be 98% (SEM 0.5). In conclusion, the Register contains high quality anonymised data on one of the largest cohorts of individuals with HCV infections acquired on a known date and by a known route. It could serve as a model for other chronic disease registers; developers may find the structure, design, and methodological issues addressed useful.

Selective transmission of hepatitis B virus after percutaneous exposure.

In 3 clusters of postsurgical hepatitis B virus (HBV) infection, HBV DNA sequence mismatches were observed between the transmitting surgeons and the patients whom they infected. Sequence analysis of clones amplified from the C gene of HBV suggested that the mismatches were due to transmission of a minority variant in the circulation of each surgeon. Compared with 5 other transmitters from whom transmission of the dominant variant was demonstrated, the 3 surgeons who transmitted minority variants carried significantly more heterogeneous HBV populations. Transmission of minority variants was not correlated with the transmitters' hepatitis B antigen status, the presence of the position 1896 precore mutant, or the level of HBV viremia. In 1 cluster, a variant comprising <10% of the HBV population circulating in the transmitting surgeon established infection in all 3 patients who acquired HBV through him, which substantiates the phenomenon of true selection.

Surgeons who test positive for hepatitis C should be transferred to low risk duties.

HCV-infected surgeons may transmit HCV to patients during exposure-prone procedures. Current UK policy allows HCV-infected surgeons to practise unrestricted unless they have been associated with transmission, and, at present, surgeons are not routinely tested for HCV infection. The overall outcome for patients exposed to an HCV-infected surgeon may be worse than that for patients exposed to a surgeon who is an HBeAg negative carrier of HBV. However, because most acute HCV infections are anicteric, surgeon associated HCV transmission is less likely to be detected by surveillance. Surgeons have been observed to sustain intraoperative injuries in around 5% of procedures. If surgeons were required to report every intraoperative injury and to be tested to determine whether the patient could have been exposed to HCV, compliant surgeons would be tested for HCV at least annually. Investigations of HBV transmission, however, have suggested that patients may be exposed to a surgeon's blood in as many as 1 in 5 procedures, and that much surgeon to patient transmission is the result of inapparent intraoperative exposure, which the surgeon does not recognise. Thus, requiring surgeons to report intraoperative injuries would not identify all those patients who might have been exposed to HCV, and, since no vaccine or prophylaxis is available, could not prevent infection. A more satisfactory alternative is regular testing of surgeons for HCV, coupled with restriction of practice of those found to be infected.

Transmission of hepatitis C virus from a surgeon to a patient. The Incident Control Team.

An investigation was carried out to find the source of infection in a patient who developed hepatitis C virus (HCV) infection after cardiothoracic surgery, and to determine whether other patients had become infected. Virological tests on specimens from the patient and potential sources (blood donors and members of the surgical team) showed that the patient and the surgeon who acted as first assistant were infected with HCV of the same genotype: 4a. No other source of infection was identified. Ninety-one per cent (277) of the 304 other exposed patients available for follow up were tested--none had antibody to HCV. It was concluded that hepatitis C may be transmitted from surgeon to patient during exposure prone procedures, and that the transmission rate in this incident was 0.36% (1/278; 95% confidence interval 0.0061%-1.98%).

Acute hepatitis B infection in England and Wales: 1985-96.

Confirmed acute hepatitis B infections are reported to the Public Health Laboratory Service Communicable Disease Surveillance Centre by laboratories in England and Wales. These reports have been used to monitor trends in the incidence of hepatitis B virus (HBV) infection over time, and between exposure categories and age groups. Between 1985 and 1996 a total of 9252 cases of acute HBV infection were reported; the number of reports fell from 1761 in 1985 to 581 in 1996. Most infections were reported in adults aged 15-44 years [n = 7365 (80%)], and infections were more commonly reported in males [n = 6490 (70%)] than females [n = 2658 (29%)]. The probable means of acquisition was known for just over half of all adult cases [4827/8956 (54%)]. Injecting drug use was the most common exposure [n = 1901 (21%)], followed by sex between men and women [n = 1140 (13%)] and sex between men [n = 1025 (11%)]. The number of infections in injecting drug users fell in the late 1980s, but increased again from 1991 onwards. In children aged under 15 years, infections acquired by mother to baby transmission accounted for 35/170 (21%) of the total. Surveillance indicates that the incidence of acute hepatitis B infection fell in the late 1980s, probably reflecting changed behaviour in injecting drug users. An increase in the number of infections in injecting drug users since 1993 may indicate ongoing transmission that has not been contained by the introduction of needle exchange schemes or by selective vaccination.

Occupational human immunodeficiency virus infection in health care workers: worldwide cases through September 1997.

The average estimated risk of human immunodeficiency virus (HIV) infection for health care workers following a percutaneous or mucous exposure is <0.5% in incidence studies, although a case-control study suggests it is much higher for highest-risk percutaneous exposure. To characterize exposures resulting in HIV transmission, we reviewed available data on occupational cases reported worldwide, identifying 94 documented and 170 possible cases. The majority of documented infections occurred in nurses, after contact with the blood of a patient with AIDS by means of percutaneous exposure, with a device placed in an artery or vein. High-exposure job categories, e.g., midwives and surgeons, are represented mostly among possible cases. Transmission occurred also through splashes, cuts, and skin contaminations, and in some cases despite postexposure prophylaxis with zidovudine. Health care workers could benefit if these data were incorporated in educational programs designed to prevent occupational bloodborne infections.

Molecular methods of measurement of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection: implications for occupational health practice.

Over the past decade, several molecular techniques for the detection of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) have been developed that have implications for occupational health practice. This review describes the techniques used for qualitative and quantitative detection of the viral genome, and briefly explains nucleic acid sequencing and analysis of phylogenetic trees. The review also discusses the current and potential uses of these techniques in investigations of transmission of bloodborne viruses by patient to worker and worker to patient, in the management of occupational exposure to blood, in research, and in the development of guidance and policy on infected healthcare workers who perform procedures prone to exposure.

Risk of hepatitis A infection in sewage workers.

OBJECTIVE: To evaluate the risk of hepatitis A virus (HAV) infection among sewage workers from occupational exposure to raw sewage. METHODS: An analytical cross sectional study of 241 company employees with possible occupational exposure to sewage in a large water and sewerage company was carried out. Previous exposure to hepatitis A virus infection was assessed, as were its associations with possible risk factors. RESULTS: Frequent occupational exposure to raw sewage was a significant risk factor for HAV infection, independently of other known risk factors (odds ratio 3.73, 95% confidence interval 1.48 to 9.37). Of 50 employees who reported occupational exposure to raw sewage most of the time, 30 (60%) had had HAV infection. CONCLUSION: Employees who are likely to be at risk of frequent exposure should have their immunity ensured. The salivary assay for IgG anti-HAV used in the study was highly specific and would be suitable for prevaccination testing of older employees, who are more likely to be immune.

Failed postnatal immunoprophylaxis for hepatitis B: characteristics of maternal hepatitis B virus as risk factors.

A retrospective case-control study was conducted to determine why some infants born full-term without obstetric intervention to hepatitis B e antigen (HBeAg)-seropositive mothers become infected by hepatitis B virus (HBV) despite having received passive-active immunoprophylaxis. Cases and controls comprised 12 hepatitis B surface antigen (HBsAg)-seropositive infants and 22 HBsAg-seronegative infants, respectively. Infants infected by putative vaccine-escape mutants were excluded. Risk factors, after adjustment for the level of maternal viremia, were the following allelic base changes in maternal HBV:C158, A328, G365, and A479 (P = .017, .005, .003, and .005, respectively). High-level maternal viremia (i.e., > or = 10(8) genome equivalents/mL) was a significant factor only after adjustment for G365 (P = .027). HBV DNA sequences recovered from one of the cases, the case's mother, and three infected contacts all had the high-risk mutations. Specific allelic mutations in maternal HBV and level of maternal viremia are potential predictors of vertical breakthrough infection.

Enhanced surveillance of acute symptomatic hepatitis B in England and Wales.

A prospective incidence study was used to estimate the effect on transmission of hepatitis B virus (HBV) in England and Wales of maximising uptake of HBV vaccination in patients at risk attending genitourinary medicine (GUM) clinics or any medical services. Laboratory based surveillance in 1993 gave an incidence of acute symptomatic hepatitis B of 1 case per 100,000 population. Transmission through sexual intercourse was twice as common as through injecting drug use. Less than 20% of patients with acute HBV infection had attended a GUM clinic before their illness, but 42% had had access to other medical services where vaccination could have been offered routinely. Sixty per cent of patients' sexual partners and 37% of other members of their household had been offered vaccination. Compared with universal infant or pre-adolescent vaccination, extending the current selective policy to all who attend GUM clinics or any medical services would have a limited impact on the incidence of HBV, particularly as uptake of three doses of vaccine in adults is likely to be low.

Incidence of seroconversion to positivity for hepatitis C antibody in repeat blood donors in England, 1993-5.

OBJECTIVE: To estimate the rate of seroconversion to positivity for hepatitis C antibody in repeat blood donors in England and to describe the probable routes of infection in these donors. DESIGN: Retrospective survey of blood donors becoming positive for hepatitis C antibody and of the results of donation testing. SETTING: The 14 blood centres in England. SUBJECTS: All repeat donors giving blood between January 1993 and December 1995. MAIN OUTCOME MEASURES: Number of donors developing hepatitis C between donations during the three years of testing for hepatitis C antibody at English blood centres and the rate of seroconversion among repeat blood donors. Probable routes of infection. RESULTS: 14 donors during 1993-5 fulfilled the case definition for seroconversion to positivity for hepatitis C antibody. The estimated seroconversion rate for infection with hepatitis C in repeat donors was 0.26 per 100 000 person years (95% confidence interval 0.15 to 0.43). Counselling after diagnosis found that four of these donors had risk factors specified in the criteria excluding people from giving blood but these factors had not come to light before donation. Another of the donors who seroconverted had a risk factor that has since been included in the exclusion criteria. Heterosexual intercourse was considered to be the most likely route of infection for five of the 14 donors. CONCLUSIONS: The rate of seroconversion for positivity to hepatitis C antibody in repeat blood donors in England was extremely low. During 1993-5 fewer than 1 in 450 000 donations were estimated to have come from repeat donors who had become positive for hepatitis C antibody since the previous donation.

A case-control study of HIV seroconversion in health care workers after percutaneous exposure. Centers for Disease Control and Prevention Needlestick Surveillance Group.

BACKGROUND: The average risk of human immunodeficiency virus (HIV) infection after percutaneous exposure to HIV-infected blood is 0.3 percent, but the factors that influence this risk are not well understood. METHODS: We conducted a case-control study of health care workers with occupational, percutaneous exposure to HIV-infected blood. The case patients were those who became seropositive after exposure to HIV, as reported by national surveillance systems in France, Italy, the United Kingdom, and the United States. The controls were health care workers in a prospective surveillance project who were exposed to HIV but did not seroconvert. RESULTS: Logistic-regression analysis based on 33 case patients and 665 controls showed that significant risk factors for seroconversion were deep injury (odds ratio= 15; 95 percent confidence interval, 6.0 to 41), injury with a device that was visibly contaminated with the source patient's blood (odds ratio= 6.2; 95 percent confidence interval, 2.2 to 21), a procedure involving a needle placed in the source patient's artery or vein (odds ratio=4.3; 95 percent confidence interval, 1.7 to 12), and exposure to a source patient who died of the acquired immunodeficiency syndrome within two months afterward (odds ratio=5.6; 95 percent confidence interval, 2.0 to 16). The case patients were significantly less likely than the controls to have taken zidovudine after the exposure (odds ratio=0.19; 95 percent confidence interval, 0.06 to 0.52). CONCLUSIONS: The risk of HIV infection after percutaneous exposure increases with a larger volume of blood and, probably, a higher titer of HIV in the source patient's blood. Postexposure prophylaxis with zidovudine appears to be protective.

Low detection rate and maternal provenance of hepatitis B virus S gene mutants in cases of failed postnatal immunoprophylaxis in England and Wales.

Hepatitis B virus (HBV) infection occurred despite full passive-active immunoprophylaxis in 20 of 321 infants born to mothers seropositive for hepatitis B e antigen. In 2 (12%) of 17 infected infants, mother-infant DNA sequence mismatches were found in a segment of the HBV S gene coding for antigenic determinants of the HBV surface antigen (HBsAg) amplified from sera by polymerase chain reaction (PCR). Point substitutions occurred in codons 120, 134, and 144 of the HBsAg polypeptide in the variant sequence of 1 infant and in codon 126 in the other; all were missense mutations. Mutant sequences could not be recovered from maternal sera by PCR cloning but were selectively generated using an amplification refractory mutation system. The frequency of potential vaccine escape mutants is therefore low, and these preexist maternally as minor variants.