Hepatitis E virus infection: an emerging occupational risk?

BACKGROUND: Hepatitis E virus (HEV) infection is endemic in many developing countries, causing substantial morbidity. Transmission is primarily faeco-oral and is associated with both sporadic infections and epidemics in areas where poor sanitation and weak public health infrastructures exist. Recently, it has become clear that HEV is also an endemic disease in industrialized countries. Moreover, a porcine reservoir and growing evidence of zoonotic transmission have been reported in these countries, suggesting the possibility of occupational transmission to man. AIMS: To summarize the current knowledge on the epidemiology and prevention of transmission of HEV infection in occupational settings. METHODS: The following key words were used to explore PubMed: hepatitis E, disease, epidemiology, profession(al), occupation(al). RESULTS: After screening of the results, 107 publications were retained. In non-endemic regions, seroprevalence varied from a few per cent (2-7.8%) in Europe, Japan and South America to 18.2-20.6% in the USA, Russia, UK, southern France and Asia. A meta-analysis of 12 cross-sectional studies evaluating HEV immunoglobulin G (IgG) seroprevalence in individuals occupationally exposed to swine showed greater odds of seropositivity in the exposed group but also a high degree of heterogeneity. A funnel plot suggested publication bias. CONCLUSIONS: There was a significant association between occupational exposure to swine and HEV IgG seroprevalence, but the level of prevalence detected depended also on the type of HEV IgG kits used. Further research, including on mechanisms and risk factors for infection, as well as the development of better serological tests for identification of infection, is required.

Hepatitis B vaccination policies for student healthcare workers in Europe.

Student healthcare workers represent a particular risk group for hepatitis B virus (HBV) transmission and should be vaccinated as early as possible after the start of their career. An overview of specific HBV policies in European Union countries was conducted through a cross-sectional survey. Answers were received from 17 countries. HBV vaccination was mandatory for medical students and student nurses in five countries and recommended in nine. Pre-vaccination testing was done in five countries and serotesting after vaccination in 12 countries. Policies to ensure student healthcare workers' immunity against HBV should be diverse due to different policies regarding universal HBV vaccination.

[Collaboration between occupational physicians and other specialists including insurance physicians]. / Die Kooperation zwischen Arbeitsmedizinern und anderen Fachärzten einschliesslich Versicherungsmedizinern. Eine Ubersicht der aktuellen Literatur.

Collaboration between various stakeholders is essential for a well-operating vocational rehabilitation process. Researchers have mentioned, among other players, insurance physicians, the curative sector and employers. In 2011 the WHO organised the congress "Connecting Health and Labour: What role for occupational health in primary care". The congress was also attended by representatives of the WONCA (World Organisations of Family Medicine). In general, everyone agreed that occupational health aspects should continue to be seen as an integral part of primary health care. However, it is not easy to find literature on this subject. For this reason we conducted a review. We searched for literature relating to collaboration with occupational physicians in Dutch, English and German between 2001 and autumn 2011. Our attention focused on cooperation with specialists and insurance physicians. Therefore, we searched PUBMED using MeSH terms and made use of the database from the "Tijdschrift voor bedrijfs- en verzekeringsgeneeskunde (TBV) [Dutch Journal for Occupational - and Insurance Medicine]". We also checked the database from the "Deutsches Arzteblatt [German Medical Journal]" and made use of the online catalogue from THIEME - eJOURNALS. Last but not least, I used the online catalogue from the German paper "Arbeits -, Sozial -, Umweltmedizin [Occupational -, Social -, Milieu Medicine]". Additionally, we made use of the "snowball - method" to find relevant literature. We found many references to this subject. The Netherlands in particular has done a lot of research in this field. However, there is little research on the cooperation between occupational physicians and specialists; in particular insurance physicians. This is interesting, because several authors have mentioned its importance. However, cooperation with other specialists seems not to be the norm. Therefore, cooperation between curative physicians (specialists but also family doctors), insurance physicians and other stakeholders is essential and should be improved. In the future researchers should develop techniques, which help to improve collabora- tion. For example, Dutch investigators advocate the development of guidelines. There is agreement that collaboration between occupational physicians and some other specialists is important. In particular, collaboration between specialists in physical medicine has been investigated. Also, curative physicians and insurance physicians have an important role in disability management. So all stakeholders should work together more intensively. However, literature is difficult to find and not often part of international literature. This must change urgently.

Co-exposure to lead increases the renal response to low levels of cadmium in metallurgy workers.

PURPOSE: Research on the effect of co-exposure to Cd and Pb on the kidney is scarce. The objective of the present study was to assess the effect of co-exposure to these metals on biomarkers of early renal effect. METHODS: Cd in blood (Cd-B), Cd in urine (Cd-U), Pb in blood (Pb-B) and urinary renal biomarkers, i.e., microalbumin (µ-Alb), beta-2-microglobulin (ß2-MG), retinol binding protein (RBP), N-acetyl-ß-d-glucosaminidase (NAG), intestinal alkaline phosphatase (IAP) were measured in 122 metallurgic refinery workers examined in a cross-sectional survey. RESULTS AND CONCLUSIONS: The median Cd-B, Cd-U, Pb-B were: 0.8 µg/l (IQR = 0.5, 1.2), 0.5 µg/g creatinine (IQR = 0.3, 0.8) and 158.5 µg/l (IQR = 111.0, 219.3), respectively. The impact of Cd-B on the urinary excretion of NAG and IAP was only evident among workers with Pb-B concentrations ≥ 75th percentile. The association between Cd-U and the renal markers NAG and RBP was also evidenced when Pb-B ≥ 75th percentile. No statistically significant interaction terms were observed for the associations between Cd-B or Cd-U and the other renal markers under study (i.e., µ-Alb and ß2-MG). Our findings indicate that Pb increases the impact of Cd exposure on early renal biomarkers.

Need for a comprehensive, consistently applied national hepatitis B vaccination policy for healthcare workers in higher educational institutions: a case study from South Africa.

BACKGROUND: Hepatitis B virus (HBV) is transmitted by infected blood and other body fluids, placing healthcare workers (HCWs) and student HCWs at increased risk of HBV infection through occupational exposure. AIM: To establish the existence, content and implementation of hepatitis B (HB) vaccination policies for student HCWs being trained at higher educational institutions (HEIs) in South Africa. METHODS: Self-administered structured questionnaires were sent to 23 nursing colleges and 11 universities in South Africa that train doctors, nurses or dentists. FINDINGS: Twelve (35%) questionnaires were returned. Ten HEIs had a policy consisting mainly of recommendations given to students at registration. Nine HEIs made HB vaccinations available, with four HEIs covering the cost through student fees. Seven HEIs did not require a record of previous vaccination. Six HEIs did not accept non-responders (NRs), three HEIs would only accept an NR after receiving a second three-dose vaccination series and counselling, six HEIs regarded an HBV carrier as infectious, and 10 HEIs would accept HBV carriers as students. The low response rate makes it difficult to generalize the results, but may suggest a lack of an HB vaccination policy for student HCWs at non-responding HEIs. CONCLUSIONS: Policies of responding HEIs regarding HB vaccination, HBV carriage and response to HB vaccination were variable, sometimes inappropriate and not sufficiently comprehensive to protect student HCWs against occupationally acquired HBV. This emphasizes the need for a comprehensive, consistently applied, nationally coordinated vaccination policy to ensure that student HCWs receive proper protection against HBV infection.

[Work related health risks among dentist's assistants in Flanders, Belgium]. / Arbeidsgebonden gezondheidsrisico's voor tandartsassistenten in Vlaanderen.

The aim of this research project was to learn more about work-related health risks among dental assistants in Flanders, Belgium. Forty-seven dental assistants completed an extensive questionnaire concerning ionized radiation, protection against infection and exposure to chemicals such as mercury, disinfectants and acrylates. Collective and personal means of protection, musculoskeletal disorders and work-related stress were also evaluated. Pain in the lower back, neck pain and shoulder pain were reported by, respectively, 15%, 17% and 22% of the respondents. Eczema resulting from skin irritation or contact-allergy was reported by 13%. Twenty-three percent of the assistants did not consistently make use ofa radiation badge; 80% wore a mouth mask and 33% wore protective glasses; and 82% was vaccinated against hepatitis B. Almost 10% reported verbal or physical aggression by patients. The mean stress score was 3.95 on a scale from 0 to 10. The results may contribute to the formulation of a number of recommendations for the improvement of the health of dental assistants.

Comparative immunogenicity of two vaccination schedules of a combined hepatitis A and B vaccine in healthy volunteers.

In 1996, a combined vaccine against both hepatitis A and B was licensed and commercialized and has been recommended for healthcare personnel in Belgium. This study compares the immunogenicity against hepatitis B virus (HBV) and safety of two vaccination schedules (0-1-12 months and 0-1-6 months) with this vaccine. This is a randomized, stratified and controlled study in healthy adult workers, who are not occupationally exposed to HBV. Seroconversion (≥1 IU/L) and seroprotection (≥10 IU/L) rates were compared using Fisher's exact test; geometric mean concentrations (GMCs) of anti-HBs were compared using one-way ANOVA. All statistical analyses were carried out with SPSS 11 on Apple Macintosh. A total of 399 subjects were enrolled in the study, and 356 were analysed according to the protocol. The rate of ≥10 IU/L at 6 months was 70.6% in the group 0-1-12 and 79.9% in the group 0-1-6; this rate decreased to 55.9% at 12 months in the first group. Seroconversion and seroprotective rates against HBV measured at month 13 in group 0-1-12 (98.9% and 95.6%) and measured at month 7 in group 0-1-6 (99.4% and 97.1%) were not statistically significantly different. GMC of anti-HBs after the 0-1-12 schedule was more than two fold higher than after 0-1-6 schedule (P < 0.001). Reported side effects were comparable in both groups with a slight tendency to fewer side effects in the 0-1-12 group after the third dose. The results from our study show that the completed schedule 0-1-12 offers at least equal protective immunogenicity against HBV as the completed 0-1-6 schedule. People not receiving their third dose at 6 months can be given this dose up to 12 months after the first dose. The drawback of this flexibility, however, is the longer time period before the protection becomes effective.

Analysis of surgical errors in malpractice claims in Belgium.

The relative importance of the different factors that cause surgical error is unknown. Malpractice claim file analysis may help to identify leading causes of surgical errors and identify opportunities for prevention. We retrospectively reviewed 427 surgical malpractice claims from 3202 malpractice liability cases in which patients alleged error between 1996 and 2006. Surgeon-reviewer examined the litigation file and medical record to determine whether and injury attributable to surgical error had occurred and, if so, what factors contributed. Detailed descriptive information concerning etiology and outcome was recorded. The reviewer identified surgical errors that resulted in patient injury in the 427 studied claims. Sixty-three percent of these cases involved significant or major injury; 6% involved death. In most cases (48%), errors occurred in intra operative care; 15% in preoperative care; 37% in postoperative care. Nine percent of the cases had errors occurring during multiple phases of care; in 28%, more than one clinician played a contributory role. System factors contributed to error in 90% of cases. The leading system factors were inexperience/lack of technical competence (57%) and communication breakdown (42%). Cases with technical errors (57%) were more likely than those without technical errors (43%) to involve elective surgery (57% vs. 60%, Fisher's Exact Test < 0.001). There were no clear contributions to error from multiple personnel (26% vs. 31%, Fisher's Exact Test 0.28) and errors in multiple phases of care (73% vs. 68%, Fisher's Exact Test 0.28). In addition technical error cases were more likely than those without technical errors to have been caused by lack of clear lines (14% vs. 21%, Fisher's Exact Test 0.03), abnormal or different anatomy (6% vs. 2%, Fisher's Exact Test 0.04), interruption or distraction (14% vs. 4%, Fisher's Exact Test < 0.001). On the other hand, they were less likely to have been caused by judgment errors (47% vs. 59%, Fisher's Exact Test < 0.001). There were significant more problems caused by the numbers of personnel involved in university hospitals than in non-university hospitals. On the other hand, they were less likely to have been caused by failure of vigilance/memory (16% vs. 58% Fisher's Exact Test < 0.001), breakdown (19% vs. 50%, Fisher's Exact Test < 0.001), lack of supervision (2% vs. 34%, Fisher's Exact Test < 0.001) and lack of clear lines (1% vs. 22%, Fisher's Exact Test < 0.001) in university hospitals than in non-university hospitals. System factors play an important role in most surgical errors, including technical errors and some non technical errors. Malpractice claims analysis could encrypt the leading areas for intervening to reduce errors.

Healthy hire effect, job selection and inhalation exposure among young adults with asthma.

The aim of the present study was to assess whether asthma onset prior to entering the workforce influences whether a person holds a subsequent job with asthma-related inhalation exposures. The data of 19,784 adults from the European Community Respiratory Health Survey were analysed. For each respondent, a current or previously held job was linked to a job exposure matrix assigning high, low or no exposure to dust, gases or fumes. Jobs were also categorised according to the risk of exposures related to occupational asthma. Associations between asthma and subsequent occupational exposures were assessed using logistic regression models, with a random intercept for study centre and fixed adjustment for age, sex, type of study sample and smoking status. Of the respondents, 8% (n = 1,619) reported asthma with onset before completion of full-time education. This population was at decreased risk of having a job with high (odds ratio 0.79; 95% confidence interval 0.68-0.92) or low (0.91; 0.80-1.03) exposure to dust, gases or fumes. The associations were consistent across exposure types (dusts, gases or fumes) and for jobs with a high risk of occupational asthma. Adults with asthma onset prior to entering the workforce may be less likely to hold jobs involving inhalation exposures.

Miscoding: a threat to the hospital care system. How to detect it?

BACKGROUND: Artificially influencing the case mix of hospitals may have several deleterious consequences for the hospital care system. One distinguishes over-evaluation (up-coding) and under-evaluation (under-coding) of the case mix. Apart from its financial consequences, miscoding may cause a fracture in epidemiological time series and, by increasing artificially the severity of illness, may affect the assessment of the quality of hospital care, based on administrative data. METHODS: Fixed effects models were used to assess deviant coding behavior at the hospital level. To do so, we examined the linear evolution over time of characteristics such as length of stay and of 21 "triggering" conditions susceptible to increase the case mix of a stay. In case of deviant coding, these triggering conditions were checked to direct the audit towards fraud-suspected discharge abstracts. Hereto, a method consisting in comparing a single hospital's linear evolution over time with the national linear evolution over time was developed, using an interaction term between linear evolution over time and hospitals. To test this methodology, fraud-directed audits were carried out in addition to the usual, at random audits. RESULTS: Important inter-hospital differences in the linear evolution over time of several characteristics of Belgian hospitals were identified, as well as evidence not only of improving coding practices, but also of up-coding, fraudulent under-coding and of numerous coding errors without financial impact. The coding errors, ascertained in the at random audit, resulted in a wrongful gain for the faulty hospitals of 28.23 days in 258 stays, whereas in case of fraud-directed audits these figures amounted up to 642.68 days in 334 stays. CONCLUSION: Fraud-directed audit may constitute a valuable tool in the quality assurance of administrative databases, improving their use in epidemiology and assessment of the quality of care.

How trunk turns affect locomotion when you are not looking where you go.

How well do we maintain heading direction during walking while we look at objects beside our path by rotating our eyes, head, or trunk? Common experience indicates that it may be fairly hazardous not to look where you are going. In the present study, 12 young adults walked on a treadmill while they followed a moving dot along a horizontal line with their gaze by rotating primarily either their eyes, head, or trunk for amplitudes of up to 25 degrees . During walking the movement of the center of pressure (COP) was monitored using force transducers under a treadmill. Under normal light conditions, the participants showed little lateral deviation of the COP from the heading direction when they performed the eye or head movement task during walking, even when optic flow information was limited. In contrast, trunk rotations led to a doubling of the COP deviation in the mediolateral direction. Some of this deviation was attributed to foot rotation. Participants tended to point their feet in the gaze direction when making trunk turns. The tendency of the feet to be aligned with the trunk is likely to be due to a preference to have feet and body in the same orientation. Such alignment is weaker for the feet with respect to head position and it is absent with respect to eye position. It is argued that feet and trunk orientation are normally tightly coupled during gait and that it requires special abilities to move both segments independently when walking.

The occupational risk of Helicobacter pylori infection among workers in institutions for people with intellectual disability.

OBJECTIVES: A cross-sectional study to evaluate the occupational risk for Helicobacter pylori infection, on top of other risk factors, in staff members of institutions for people with intellectual disability. In these institutions, the residents had a documented high prevalence of H pylori infection (86% presenting antibodies). As a control group, the study used administrative workers from other companies. METHODS: All participants completed a questionnaire concerning sociodemographic characteristics, medical history and employment data and they underwent a serology test. RESULTS: 671 staff members of the institutions and 439 subjects in the control group participated in the study. Prevalence of H pylori antibodies was significantly higher in the study group than in the control group (40.6% vs 29.2%; p<0.001). Crude odds ratio for occupational risk was 1.68; adjusting for the confounding effect of age, gender, body mass index, smoking, tropical journeys and number of household members during childhood resulted in an even higher (adjusted) OR of 1.98 (95% CI 1.42 to 2.69). In multiple logistic regression analysis adjusting for variables shown to be confounders, faecal contact continued to be significantly associated with H pylori infection. Attributable risk was 49.5%. CONCLUSIONS: H pylori infection is an occupational risk in healthcare workers working in institutions for people with intellectual disability. We identified faecal contact as an independent occupational risk factor for H pylori infection.

Voiding habits and wetting in a population of 4,332 Belgian schoolchildren aged between 10 and 14 years.

OBJECTIVE: To determine the prevalence of daytime- with/without night-time wetting, in Belgium, in a group of 10 to 14 year old schoolchildren, and to study the voiding habits. SUBJECTS AND METHODS: A questionnaire of 41 questions was developed and completed by 4,332 parents at home. RESULTS: Wetting or soiling episodes were reported by a total of 528 (12%) of the children: monosymptomatic nocturnal enuresis by 62 (1%), daytime wetting with/without night-time wetting by 343 (8%), and faecal soiling by 123 (3%). We found significantly more girls in the wetting group, and the capacity to regularly postpone the voiding was significantly lower in this group. Significantly more children had nocturia in the group with wetting. CONCLUSIONS: Children with daytime wetting with/without night-time wetting have very often bladder-sphincter dysfunctions, which is in turn correlated with recurrent urinary tract infections. Eight percent of the 10 to 12 year old schoolchildren report daytime wetting with/without night-time wetting with some frequency. Surprisingly few parents, especially in the daytime wetting group, searched for medical help. Physicians and paediatricians should be encouraged to be more attentive to wetting in children and initiate discussion about urinary en faecal problems with parents and children.

Results of a questionnaire evaluating the effects of different methods of toilet training on achieving bladder control.

OBJECTIVE: To analyse if family situation, personal habits and toilet training methods can influence the achievement of bladder control. SUBJECTS AND METHODS: A questionnaire with 41 questions was distributed to 4332 parents of children completing the last 2 years of normal primary school. The questionnaire had been tested for reproducibility of the answers in a random subgroup of 80 parents. The aims of the investigation were explained in an accompanying letter and the response rate was 76.7%. The result were analysed using the chi-square test (Yates corrected). RESULTS: Two groups of children were identified, one with no lower urinary tract symptoms (3404) and one with complaints of daytime and night-time wetting, and urinary tract infections (928). The groups were termed the 'control' and 'symptom' groups, respectively. There were no differences in the family situation between the groups. The symptom group reported more 'below average' school results and less independence in homework and hygiene. The age at which toilet training started was significantly higher in the symptom group and scheduled voiding was used significantly less. The reaction of the parents when the attempt at voiding was unsuccessful was significantly different; in the control group most parents just postponed the effort and had the child try again later, whereas in the symptom group more parents asked the child to push, made special noises or opened the water tap. CONCLUSIONS: These data show significant differences in toilet training between children with and with no lasting problems of bladder control. Postponing the onset of the training after 18 months of age and using certain methods to provoke voiding (asking to push, opening the water tap) probably increases the risk of later problems with bladder control.

Hospital based clinical surveillance for dengue haemorrhagic fever in Bandung, Indonesia 1994-1995.

In Indonesia, by law dengue haemorrhagic fever (DHF) cases must be reported within 24 h to the district health authority. The objective of this study was to evaluate the adequacy, accuracy and reporting delay of this reporting system. In four major hospitals of the city of Bandung, medical records of hospitalised DHF cases admitted between April 1994 and March 1995 were reviewed. This list of DHF cases was compared with the list of reported cases to the Bandung Municipality Health Office. During the study period, 569 DHF cases and 81 dengue shock syndrome (DSS) cases were diagnosed. Only 199 (31%) of the 650 hospitalised cases with suspected DHF/DSS were reported to the Bandung Municipality Health Office. The percentage of fatal cases was significantly lower among all hospitalised cases 11/650 (1.7%) than among reported cases 5/199 (2.5%). In only 443 of the 583 hospitalised cases (76%) in which a dengue serological test was performed, was this test positive. Of the 199 reported DHF/DSS cases 151 (76%) had a positive haemagglutination inhibition test. This study shows that the surveillance system for DHF/DSS in Bandung should be strengthened. DHF/DSS cases should be reported on the basis of a diagnosis made during hospitalisation preferably after a serological confirmation is obtained.

Occupational risk factors of lung cancer: a hospital based case-control study.

OBJECTIVES: To investigate the relation between lung cancer and exposure to occupational carcinogens in a highly industrialised region in western Europe. METHODS: In a case-control study 478 cases and 536 controls, recruited from 10 hospitals in the Antwerp region, were interviewed. Cases were male patients with histologically confirmed lung cancer; controls were male patients without cancer or primary lung diseases. Data were collected by questionnaires to obtain information on occupations, exposures, and smoking history. Job titles were coded with the Office of Populations, Censuses and Surveys industrial classification. Exposure was assessed by self report and by job-task exposure matrix. Exposure odds ratios were calculated with logistic regression analysis adjusted for age, smoking history, and marital and socio-economic status. RESULTS: A job history in the categories manufacturing of transport equipment other than automobiles (for example, shipyard workers), transport support services (for example, dockers), and manufacturing of metal goods (for example, welders) was significantly associated with lung cancer (odds ratios (ORs) 2.3, 1.6, and 1.6 respectively). These associations were independent of smoking, education, civil, and economic status. Self reported exposure to potential carcinogens did not show significant associations with lung cancer, probably due to nondifferential misclassification. When assessed by job-task exposure matrix, exposure to molybdenum, mineral oils, and chromium were significantly associated with lung cancer. A strong association existed between smoking and lung cancer: OR of ex-smokers 4.2, OR of current smokers 14.5 v non-smokers. However, smoking did not confound the relation between occupational exposure and lung cancer. CONCLUSIONS: The study has shown a significant excess risk of lung cancer among workers in manufacturing of metal goods, manufacturing of transport equipment (other than automobiles), and transport support services. Assessment of exposure to specific carcinogens resulted in significant associations of chromium, mineral oils, and molybdenum with lung cancer. This study is, to our knowledge, the first study reporting a significant association between occupational exposure to molybdenum and lung cancer.

Prevalence of respiratory symptoms: marked differences within a small geographical area.

BACKGROUND: Geographical differences in prevalence of respiratory symptoms have been reported between countries in the EC Respiratory Health Survey (ECRHS). The differences between two neighbouring centres in the Antwerp area were surprising. We therefore extended the screening phase of this study to four other areas with different features in this region. METHODS: Methods and questionnaires of the first phase of the ECRHS were used to estimate prevalence rates of respiratory symptoms in all areas. Information on some major personal and environmental risk factors was also obtained. RESULTS: Higher prevalence rates of both respiratory symptoms and personal risk factors were recorded in Urban Antwerp, Berendrecht-Zandvliet (harbour area) and Zwijndrecht (industrial area) than in Suburban Antwerp, Essen and Kasterlee (both rural). Neither personal nor environmental risk factors could provide satisfactory explanations for the area differences in symptoms. CONCLUSIONS: These large differences between groups of subjects living within a small geographical area prove that estimations of prevalence rates of a whole country based on measurements of prevalence in one specific area should be interpreted very cautiously. Epidemiological research within small geographical areas may thus still prove as informative as comparisons between countries for elucidating causes for different asthma prevalence.

Higher asthma occurrence in an urban than a suburban area: role of house dust mite skin allergy.

Understanding of geographical differences in asthma prevalence may be helpful in explaining recent increases in the occurrence of asthma. We wondered whether differences in allergic sensitization or other factors could explain differences in reported occurrence of asthma between an urban centre and a neighbouring suburban area. From the European Community Respiratory Health Survey (ECRHS) questionnaire, responses on asthma symptoms and risk factors and results of 11 skin allergy tests were available from 656 young adults living in urban or south suburban Antwerp, Belgium. Answers to five asthma questions were selected as dependent variables, and eight personal or environmental risk factors, as well as house dust mite (HDM) allergy, as independent variables. The effect of each independent variable on the association of asthma variables with area was assessed. Prior asthma diagnosis, present asthma symptoms, the selected risk factors and HDM allergy were all more frequently recorded in urban Antwerp. Difference in HDM allergy accounted for most of the difference in prior (mostly childhood) asthma diagnosis, since correction for it decreased the odds ratio from 2.10 to 1.65. On the contrary, the regional differences in recent asthma symptoms were not explained by HDM allergy differences nor by any other factor under study. This urban-suburban comparison indicated that house dust mite allergy is a major determinant of prior (childhood) asthma, whereas factors contributing to higher urban prevalence of present asthma symptoms could not be identified. Furthermore, our results indicate that it may be inappropriate to combine data from neighbouring areas, when their similarity has not been verified.

Training in first aid at the workplace.

All workers, including seafarers and fishermen, may be confronted with life-threatening situation, and they should be trained in the cardiopulmonary resuscitation (CRP) techniques. In this paper, which was presented during the meeting of the co-ordinators of the EU Project on the health of seafarers held in Gdynia in April 1996, the Author reports on the experiences in the CPR training, which was conducted by occupational physicians, who were responsible for the medical aspects of the disaster plan of the Province of Antwerp including the Antwerp port.