Occupational contact urticaria: lessons from the French National Network for Occupational Disease Vigilance and Prevention (RNV3P).

BACKGROUND: Occupational contact urticaria (OCU) is an occupational contact dermatitis that can cause serious health consequences and disability at work. OBJECTIVES: To describe OCU and its temporal trends by the main causal agents and activity sectors in a nationwide scheme in France. METHODS: Using data from the French National Network for Occupational Disease Vigilance and Prevention (RNV3P), we described OCU reported during the period 2001-10 and analysed the temporal trends of OCU and OCU attributed to the most frequent agents over the study period. Trends analyses were supported by reporting odds ratios using a logistic regression model with reference to 2001, or with time as a continuous variable. RESULTS: During the study period, 251 cases of OCU were reported in RNV3P, half of which were due to natural rubber latex, in particular in the health and social work activity sector (HSW). The number of these cases declined significantly over the study period (19% per year), and particularly after 2006. Conversely, the other causes of OCU did not decrease. CONCLUSIONS: Using surveillance data from a French national network, this study has found that there was a significant decline in OCU due to natural rubber latex, particularly in the HSW, when powdered latex gloves were banned from French hospitals. Our results show the effectiveness of this preventive measure, and suggest that this practice should be extended to other sectors.

Occupational allergic contact dermatitis and major allergens in France: temporal trends for the period 2001-2010.

BACKGROUND: Occupational allergic contact dermatitis (OACD) is one of the most common occupational skin diseases in developed countries, but data about its temporal trends in incidence remain sparse. OBJECTIVES: The aim of this study is to describe OACD trends in terms of industrial activities and main causal agents in France over the period 2001-2010. MATERIALS AND METHODS: Data were collected from the French National Network of Occupational Disease Vigilance and Prevention (RNV3P, Réseau National de Vigilance et de Prévention des Pathologies Professionnelles). All OACD considered probably or certainly associated with an occupational exposure were included in the study. Trends were examined (i) on annual crude numbers of OACD and (ii) on reported odds ratios of OACD calculated using logistic regression models. RESULTS: Overall, 3738 cases of OACD were reported and the mean age of OACD cases was 35 years, 52% being women. The most frequent occupations were hairdressers, health care workers, cleaning staff and masons. The total number of OACD cases remained stable over the study period, but increases in OACD related to isothiazolinones (P = 0·002), epoxy resins (P = 0·012) and fragrances (P = 0·005) were observed. Conversely, decreases were noted for cement compounds (P = 0·002) and plant products (P = 0·031). These trends highlight specific sectors and exposures at risk of OACD. CONCLUSIONS: Trends in OACD depend on the nature of exposure. Observed decreases were consistent with prevention measures taken during the study period, and the increases observed serve to highlight those areas where preventative efforts need to be made to reduce skin allergies in the workplace.

Under-estimation of self-reported occupational exposure by questionnaire in hospital workers.

OBJECTIVES: The aim of the study was to determine whether self-reported occupational exposure to cleaning/disinfecting agents in hospital workers is accurate, in comparison to expert assessment, taken to be the gold standard. METHODS: In the Epidemiological Study of the Genetics and Environment of Asthma (EGEA), participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardised procedure to estimate intensity, frequency and probability of exposure for each job. The present analysis focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. Agreement and differences between self-reported and expert estimates were studied by kappa and phi coefficients and McNemar tests, respectively. RESULTS: In the survey of 1571 adults, 176 ever hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5% vs 32.7%, p=0.01), ammonia (7.4% vs 18.8%, p<0.0001), alcohol (64.9% vs 93.0%, p<0.0001) and quaternary ammonium components (16.6% vs 70.9%, p<0.0001), compared to expert assessment. CONCLUSION: Occupational exposure to disinfecting/cleaning agents is common and high in hospitals. A large underestimation of self-reported exposure and a lack of knowledge of product components was observed. Our results show the relevance of expert assessment in epidemiological studies to limit measurement bias. This work underlines the need for health education programmes on the occupational risks induced by these types of products.

Do young adults with childhood asthma avoid occupational exposures at first hire?

Information on the healthy worker hire effect in relation to asthma is scant. We aimed to assess whether and how childhood asthma-related characteristics (before hire) relate to occupational exposures at first hire. Analyses were conducted in 298 children examined at the first survey of the Epidemiological Study on the Genetics and Environment of Asthma (1991-1995), who reported a training period or a job at follow-up in 2003-2007 (aged 17-29 yrs; 53% males). Exposure likelihood to dust, gases and/or fumes in their first occupation was estimated by the ALOHA job exposure matrix. Asthma before the first occupation and two asthma classifications for severity (Global Initiative for Asthma 2002 guidelines) and symptoms were defined by questionnaire. In their first job, 47% of subjects were exposed. After adjustment (age, sex and education), pre-hire onset asthmatics (59%) were nonsignificantly less likely to be exposed (OR 0.67, 95% CI 0.41-1.11). Associations were stronger when considering those with severe asthma or high symptom score in childhood (OR 0.27 (95% CI 0.11-0.63) and OR 0.49 (95% CI 0.25-0.99), respectively). The association was observed in those who completed a university degree (OR 0.55, 95% CI 0.29-1.04) but not in the others (OR 0.98, 95% CI 0.44-2.22), with consistent results for all asthma characteristics. Results suggest a healthy worker hire effect in subjects with more severe or more symptomatic asthma in childhood. Education may modulate self-selection.

[Compensation for occupational respiratory diseases in France]. / Réparation des maladies respiratoires professionnelles en France.

Respiratory physicians must be aware of the administrative procedures for the compensation of occupational diseases in order to advise their patients. These procedures for declaration, recognition and compensation are dependent on the patient's social insurance. However, the general principles of this insurance coverage are similar. They are based on a "mixed" system: 1) a presumed cause, when the disease appears on a government list published in the national record (Journal Officiel), and if all administrative and exposure criteria described in that list are met, 2) a case-by-case opinion, with certain limitations, if the presumed cause does not apply. However, these procedures do not apply to self employed workers who do not benefit from occupational disease social insurance. Furthermore, patients with asbestos-related diseases receive additional compensation, the criteria for which are reviewed here: compensation funds and anticipated retirement.

Genetic differences in omega-gliadins involved in two different immediate food hypersensitivities to wheat.

BACKGROUND: Anti-gliadin IgE are expressed in patients with food allergy associated to skin immediate hypersensitivity to hydrolyzed wheat proteins (IHHWP). It is not known if they react with omega5-gliadins, the major allergens in wheat dependant exercise-induced food anaphylaxis (WDEIA), encoded on wheat chromosomes 1B. METHODS: Unmodified gliadins from 14 wheat varieties expressing most of the 1B omega-gliadin alleles, were immunoprobed after SDS-PAGE and blotting, with four sera from patients with IHHWP, and two with WDEIA. Gliadins reacting with IgE were visualized using chemiluminescence and identified according to their mobility and typical SDS-PAGE pattern. The resulting signal was also measured to compare their IgE reactivity. RESULTS: IHHWP and WDEIA sera exhibited distinct patterns of reactivity. IgE of patients with IHHWP reacted mainly with all omega-gliadins alleles and one gamma-gliadin encoded respectively on chromosomes 1D and 1B, but not with any omega5-gliadins alleles as for WDEIA. A few other reactive alleles of omega-gliadins were encoded on chromosomes 1A. Unassigned additional bands of the whole gliadin pattern were also reactive. The four patients with IHHWP exhibited almost the same pattern of reactivity. Main differences concerned band reactivity which modulated the overall reactivity of each wheat variety. CONCLUSIONS: The IgE epitopes involved in IHHWP and WDEIA are different. This suggests that the protein state and the route of exposure to very similar gluten structures, probably orientate the pattern of epitope reactivity and the wheat food allergy manifestations.

Factors associated with severity of occupational asthma with a latency period at diagnosis.

BACKGROUND: Severity of occupational asthma at diagnosis is an important prognostic factor. The aim of this study was to determine which factors affect the severity of occupational asthma with a latency period at diagnosis. METHODS: The study population consisted of 229 consecutive subjects with occupational asthma with a latency period recruited by four occupational health departments and divided into two groups according to the severity of the disease at diagnosis. The moderate-severe (FEV(1) <70% predicted, or PD(20) methacholine /=70% predicted and PD(20) methacholine >300 microg, n = 128) groups were compared in terms of clinical and demographic parameters. Multivariate analysis using logistic regressions was performed to examine factors associated with asthma severity. RESULTS: Duration of symptoms before diagnosis was significantly longer in the moderate-severe group (mean +/- SD: 6.3 +/- 6.8 years vs 3.4 +/- 4.4 years, P < 0.001). Sex ratio, age, atopy, smoking habits, duration of exposure before symptoms, and molecular weight of the causal agent were not significantly different between the two groups. On multivariate analysis, only duration of symptoms before diagnosis was associated with asthma severity (aOR = 1.12, 95% CI 1.05-1.18, P < 0.001). CONCLUSIONS: Severity of occupational asthma with a latency period at diagnosis was associated with duration of symptoms before diagnosis, but not with the type of causal agent. This finding emphasizes the need for early diagnosis and avoidance of exposure.

Hepatitis B vaccination in women healthcare workers: a seroepidemiological survey.

OBJECTIVE: To assess the concentration and kinetics of antibody response after hepatitis B vaccination among women healthcare workers. DESIGN: Longitudinal retrospective seroepidemiological survey among women vaccinated against hepatitis B working in a university hospital and followed-up in an occupational health department. A structured form was used to collect socio-demographic characteristics, clinical data, age at vaccination, vaccination schedule, measurement of antibodies to hepatitis B surface antigen (anti-HBs antibody). Subjects were considered seronegative against hepatitis B when anti-HBs antibody concentration was less than 10 mIU/ml. SETTING: A 1260-bed general hospital in Paris, France. PARTICIPANTS: All women healthcare workers visiting the occupational health department between January 1997 1st and December 2000 31st and who had a measurement of anti-HBs antibody. RESULTS: Irrespective of the age at the primary vaccination, 810 (92%) women were seropositive (anti-HBs antibody > or = 10 mIU/ml). Only 22 women (4.5%) vaccinated before 26 years of age were seronegative, against 46 (13.2%) vaccinated after 25 years of age (p < 0.001). Seven years after vaccination, 78% of women were still seropositive. An inadequate vaccination schedule (adjusted hazard ratio (HR), 3.0; 95% confidence interval [CI], 1.6-5.5) and an age greater than 25 years at primary vaccination (HR, 2.6; 95% CI, 1.5-4.4) were associated with being seronegative against hepatitis B. CONCLUSIONS: Despite vaccination, some women healthcare workers were seronegative against hepatitis B virus. Vaccinating early in the career of a health-care worker using an adequate schedule seems key-elements to guarantee an anti-HBs measurement > or =10 mIU/ml.

HD-16: a new quality of life instrument specifically designed for insomnia.

BACKGROUND AND PURPOSE: To design a new quality of life (QoL) instrument specifically for insomnia. PATIENTS AND METHODS: Based on severe insomniacs' interviews, we have built a new quality of life scale that has been tested in one group of 240 severe insomniacs, in one group of 422 mild insomniacs and in one group of 391 good sleepers. Ten steps led to the construction of a specific QoL scale. RESULTS: Five dimensions have been validated as both relevant and independent from each other. Sixteen items out of the 43 initially tested were retained and significantly different within the groups in each dimension. Based on the 16 items selected, we called the scale Hotel Dieu 16 (HD-16). We have therefore verified the score's specificity (correlation score of +0.36) and the reliability of the scale (Cronbach coefficient alpha=0.78). CONCLUSION: HD-16 may be used as a focused instrument to better assess an insomniac's quality of life.

[Human granulocytic ehrlichiosis in Europe]. / L'ehrlichiose granulocytique humaine en Europe.

Human granulocytic ehrlichiosis is an emerging infectious disease, which is transmitted by the tick Ixodes ricinus in Europe, like other diseases: Lyme disease, tick-borne encephalitis, babesiosis... This tick lives in the forest and its hematophagic activity ranges from April to October. Flu and febrile symptoms ten days after tick bite should suggest diagnosing the disease. Disease evolution is generally favorable, even if serious complications may occur. Leukopenia, thrombocytopenia, and elevated serum transaminases are common laboratory findings. Complementary assays useful for the diagnosis are: blood smear, indirect immunofluorescence, and polymerase chain reaction. Biological diagnostic criteria are more and more accurate, with the evolution of knowledge and technique. Tetracycline treatment generally leads to clinical and biological recovery. Informing physicians and occupationally exposed people should reinforce current prevention measures against tick bites.

Rye flour induces a stronger early bronchial response than wheat flour in occupational asthma.

BACKGROUND: Our aims were to compare the doses of wheat and rye flour that induce early bronchial responses in occupationally exposed asthmatic subjects and to assess the effects of the dose of inhaled flour, the duration of exposure and the dose rate. METHODS: Ten patients underwent tests with lactose, wheat flour and rye flour. We compared the decrease in forced expiratory volume in 1 s (FEV(1)) observed during the challenge with flour and with lactose. We also calculated the amount of flour that was instantaneously active. RESULTS: Seven subjects had significantly decreased FEV(1) values following exposure to wheat and rye flour and two subjects only did so for rye flour. The provocative dose (PD, dose required to reduce FEV(1) by 15%) of rye was lower than that of wheat flour (geometric mean; PD(15) rye: 95 microg; wheat: 368 microg). The calculated doses of rye and wheat flour were better correlated with the change in FEV(1) than were the cumulative doses. CONCLUSION: The bronchial response was greater with rye than with wheat flour. The response was related to the dose of allergen inhaled and to the dose rate.

Healthy worker effect and changes in respiratory symptoms and lung function in hairdressing apprentices.

AIMS: To compare the prevalence and incidence of respiratory symptoms and lung function values between hairdressing apprentices and office apprentices. METHODS: A total of 322 hairdressing apprentices and 277 office apprentices (controls) were studied. Two cross sectional surveys were conducted in 1994 and 1996/97 with longitudinal follow up for a subgroup of apprentices (191 hairdressing apprentices and 189 office apprentices). RESULTS: In the initial phase, the prevalence of respiratory symptoms was significantly lower among hairdressing apprentices than among office apprentices. Lung function test results showed significantly higher values for hairdressing apprentices. Non-specific bronchial reactivity was similar in the two groups. In the final phase, results for respiratory symptoms were similar. The incidence of respiratory symptoms was not significantly different between hairdressing apprentices and office apprentices. Subjects who dropped out had lower values for FVC and FEV1 in the initial phase than those who completed the final phase. There was a significant deterioration of FEV1 and FEF25-75% in hairdressing apprentices compared to office apprentices. There was a link between atopy and the incidence of most of the respiratory symptoms (day/night cough, wheezing, dyspnoea, mucosal hyperresponsiveness) and between smoking and the incidence of bronchial hyperreactivity. There was no significant correlation between change in lung function tests and specific hairdressing activities reported at the end of the apprenticeship or with environmental working conditions in hairdressing salons. CONCLUSIONS: Although a healthy worker effect can be suspected, results showed a significant deterioration of baseline values of lung function tests in the hairdressing apprentice group. However, no clear link was shown between change in lung function tests and specific parameters of occupational activities.

Bronchial challenge with flour: early response is dependent on the dose of activated allergen inhaled.

Specific bronchial challenges provide information about the relationship between inhaled dose of allergen and change in lung function, but the intermediate pathways remain largely obscure. The aim of this study was to investigate the relationships between the early asthmatic response and 1) the inhaled dose of wheat flour, 2) the concentration of wheat flour, 3) the duration of the exposure, and 4) the deactivation of inhaled allergens and mediators. Thirty-one patients with occupational asthma to wheat flour were studied. Particle aerosols were generated by a computer-controlled aerosoliser and the results were expressed as the provocative dose causing a 20% fall in forced expiratory volume in one second (FEVi) (PD20). The cumulative dose (from the beginning of the challenge), the last inhaled dose, and an estimated dose (taking into account exponential deactivation), were calculated. Twenty patients had high reactivity to flour (reaching a PD20 value). Eleven patients had intermediate reactivity (no measurable PD20 but significantly greater fall in FEV1 compared with lactose challenge). A better correlation between change in FEV1 and dose was obtained for the estimated dose than for the cumulative or last inhaled dose. The bronchial response to wheat flour can be measured by the individual specific hyperreactivity and is expressed by provocative dose of flour. However, deactivation of the allergen and mediators has to be taken into account. This problem can be addressed by using a mathematical model.

[Specific bronchial provocation test with solid aerosols. Quantification of results]. / Test de provocation bronchique spécifique avec aérosols solides. Quantification des résultats.

OBJECTIVES: To determine 1) the level of specific bronchial reactivity by challenge with flour and 2) the criteria of positivity using a new method for the expression of the results. METHOD: Thirty-eight asthmatic subjects, occupationally exposed to wheat flour, performed a challenge with lactose then with flour. The instantaneous measurement of the concentration and of the inspiratory airflow were used to calculate the inhaled dose and to establish the dose-response relationships. The results were given 1) by the dose of flour provoking a 20% fall in FEV1 (PDf20), 2) by the comparison of the variation of the FEV1 during the challenge with flour to the distribution of the values observed during the challenge with lactose (inferior limit of the confidence interval at 99.7%). RESULTS: The variations of the FEV1 were not significantly related to the inhaled dose of lactose. The specific bronchial reactivity to flour was a continuous data and three groups were distinguished: 1) subjects (n = 15) with high bronchial reactivity had a fall of FEV1 of more than 20% 2) subjects (n = 13) without significant variation of the FEV1 for doses higher than 1,400 micrograms by comparison to the distribution of the values of the lactose test 3) subjects (n = 10) with a significant fall of FEV1 by comparison to the distribution of the values of the lactose test but lower than 20%. For this group with moderate reactivity, the flow of the inhaled dose may be determinant for the bronchial response. CONCLUSIONS: PDf 20 measures the specific bronchial reactivity. However, if the fall in FEV1 is lower than 20%, the specific challenge with flour may be compared to the challenge with lactose to detect the subjects with moderate reactivity. Our results confirmed the role of the inhaled dose and suggested the role of the dose rate in the outset of bronchial obstruction among asthmatic subjects.

Detection of avian oncogenic Marek's disease herpesvirus DNA in human sera.

The avian herpesvirus Marek's disease virus (MDV) has a worldwide distribution and is responsible for T-lymphoma in chickens. The question as to whether MDV poses a public health hazard to humans was first raised when the virus was isolated in 1967. However, no irrefutable results have been obtained in immunological and virological studies. We used a nested-PCR to detect MDV DNA in human serum samples. A total of 202 serum samples from individuals exposed and not exposed to poultry was tested by nested-PCR for a target sequence located in the MDV gD gene. The assay system was specific and sensitive, making it possible to detect a single copy of the target sequence. Forty-one (20%) of the 202 serum samples tested positive for MDV DNA. The prevalence of MDV DNA was not significantly different in the group exposed to poultry and the group not exposed to poultry. There was also no difference due to age or sex. Alignment of the 41 gD sequences amplified from human sera with eight gD sequences amplified from MDV-infected chicken sera showed a maximum nucleotide divergence of 1.65%. However, four 'hot-spot' mutation sites were identified, defining four groups. Interestingly, two groups contained only human MDV-gD sequences. The status of the MDV genome detected in human blood is discussed.

Computerized equipment for the delivery of inhaled doses of solid particles in specific bronchial challenge.

An apparatus to generate solid particles was tested for use in diagnosing occupational asthma. This equipment measures the inhaled dose of dry particles during specific inhalation challenge. It includes an aerosol generator, a cyclone type particle size selector, and an inhalation chamber to which a patient breathing at tidal volume can be connected for the test. It is fully controlled by a standard personal computer in automatic mode, acting on the flow rate and the aerosol generator to maintain the concentration at a fixed value, usually 3 mg/m3. The dose of aerosol delivered to the patient was calculated from the aerosol concentration, and the inhaled volume was calculated by integration of the corresponding signals. The coefficient of variation for this measurement was estimated to be 12%. The mass median aerodynamic diameter (MMAD) of aerosol inside the inhalation chamber was measured for three substances: lactose, wheat flour, and buckwheat flour. The MMAD of the aerosol inside the chamber was also estimated from the particle size distribution of the raw powder. The relative difference between the measured MMAD and the calculated value was less than 15%. The corresponding relative difference between the measured geometrical SD and the calculated value was found to be less than 26%.