Dominique Tripodi

IFN-γ release assay versus tuberculin skin test for monitoring TB infection in healthcare workers

Healthcare workers (HCW) are a risk group for TB. Even in countries with low TB incidence, the risk of TB in HCW is elevated for a wide range of tasks in healthcare, and the prevention of nosocomial infection of HCW remains as a challenge. IFN-γ release assays (IGRA) facilitate the screening of HCW for latent TB infection. In comparison with the tuberculin skin test, the IGRA reduces the number of x-rays and the amount of chemoprevention needed. However, a borderline zone should be introduced for the interpretation of IGRA results in the serial testing of HCW. More data on disease progression depending on conversion and reversion in IGRA is needed and a better test, which is able to distinguish recent from remote latent TB infection, would be desirable in the future.

Evaluation of the tuberculin skin test and the interferon-γ release assay for TB screening in French healthcare workers

IntroductionUsing French cut-offs for the Tuberculin Skin Test (TST), results of the TST were compared with the results of an Interferon-γ Release Assay (IGRA) in Healthcare Workers (HCW) after contact to AFB-positive TB patients.MethodsBetween May 2006 and May 2007, a total of 148 HCWs of the University Hospital in Nantes, France were tested simultaneously with IGRA und TST. A TST was considered to indicate recent latent TB infection (LTBI) if an increase of >10 mm or if TST ≥ 15 mm for those with no previous TST result was observed. For those with a positive TST, chest X-ray was performed and preventive chemotherapy was offered.ResultsAll HCWs were BCG-vaccinated. The IGRA was positive in 18.9% and TST ≥ 10 mm was observed in 65.5%. A recent LTBI was believed to be highly probable in 30.4% following TST. Agreement between IGRA and TST was low (kappa 0.041). In 10 (16.7%) out of 60 HCWs who needed chest X-ray following TST the IGRA was positive. In 9 (20%) out of 45 HCWs to whom preventive chemotherapy was offered following TST the IGRA was positive. Of those considered TST-negative following the French guidelines, 20.5% were IGRA-positive. In a two-step strategy - positive TST verified by IGRA - 18 out of 28 (64.3%) IGRA-positive HCWs would not have been detected using French guidelines for TST interpretation.ConclusionThe introduction of IGRA in contact tracings of BCG-vaccinated HCWs reduces X-rays and preventive chemotherapies. Increasing the cut-off for a positive TST does not seem to be helpful to overcome the effect of BCG vaccination on TST.

Gene expression profiling in sinonasal adenocarcinoma

BackgroundSinonasal adenocarcinomas are uncommon tumors which develop in the ethmoid sinus after exposure to wood dust. Although the etiology of these tumors is well defined, very little is known about their molecular basis and no diagnostic tool exists for their early detection in high-risk workers.MethodsTo identify genes involved in this disease, we performed gene expression profiling using cancer-dedicated microarrays, on nine matched samples of sinonasal adenocarcinomas and non-tumor sinusal tissue. Microarray results were validated by quantitative RT-PCR and immunohistochemistry on two additional sets of tumors.ResultsAmong the genes with significant differential expression we selected LGALS4, ACS5, CLU, SRI and CCT5 for further exploration. The overexpression of LGALS4, ACS5, SRI, CCT5 and the downregulation of CLU were confirmed by quantitative RT-PCR. Immunohistochemistry was performed for LGALS4 (Galectin 4), ACS5 (Acyl-CoA synthetase) and CLU (Clusterin) proteins: LGALS4 was highly up-regulated, particularly in the most differentiated tumors, while CLU was lost in all tumors. The expression of ACS5, was more heterogeneous and no correlation was observed with the tumor type.ConclusionWithin our microarray study in sinonasal adenocarcinoma we identified two proteins, LGALS4 and CLU, that were significantly differentially expressed in tumors compared to normal tissue. A further evaluation on a new set of tissues, including precancerous stages and low grade tumors, is necessary to evaluate the possibility of using them as diagnostic markers.

Prävalenz der latenten Tuberkulose-Infektion bei Beschäftigten im Gesundheitswesen – Ein Dreiländervergleich

INTRODUCTION Health-care workers are regularly screened for tuberculosis. To date, there has been no systematic analysis of the results of such a screening. A TB network for company doctors was created when interferon-γ release assays (IGRAs) were introduced in order to systematically collate their experience with IGRAs in preventive check-ups. METHOD Data have so far been recorded from 2,028 preventive check-ups. There are also data from preventive check-ups in France (n=148) and Portugal (n=2,889) for the purposes of a combined analysis. QuantiFERON-TB® Gold In-Tube and the tuberculin skin test with RT23 were used in the three cohorts. RESULTS The prevalence of latent tuberculosis infections (LTBI) is dependent on age and country. Among young health-care workers (<25 years old), 3% had a positive IGRA in Germany, compared with 18% in Portugal. Among health-care workers aged 55 and over, 25% were positive in Germany and 45% were positive in Portugal. In the French cohort an increase from 23% to 33% was observed when the youngest and oldest age categories were compared. Active tuberculosis has so far been diagnosed in 12 health-care workers in Portugal, four of whom developed culturally confirmed TB within the first two years following a positive IGRA. The risk of progression subsequent to a positive IGRA was 0.2% per annum. DISCUSSION There is a low prevalence of LTBI among young health-care workers. In them a positive IGRA following close contact with an infectious patient is likely to indicate recent infection. Apart from that, older infections appear to prevail, as the IGRA results depend greatly on age, and the risk of progression following a positive IGRA appears to be low in the study groups. A positive IGRA should therefore be interpreted with caution as an indication of the need for chemotherapy.

Occupational dermatitis to epoxydic and phenolic resins

Contact dermatitis to epoxydic and phenolic resins are the most frequent contact dermatoses due to plastics, in particular in the form of airborne dermatitis. The chemical formulas of the various components of these resins and their additives are complex and the patch tests available in the trade are insufficient and often arrive at a late stage in the progress of industry, in particular in advanced technologies like aeronautical engineering, shipbuilding or the new floor and wall coverings in buildings. This article is a review of the actions to be taken with these allergies, as well as with regards to their diagnosis, prevention and medico-legal compensation.

‘Airborne’ contact dermatitis due to Leica immersion oil

Background Contact dermatitis has often been described in healthcare staff, resulting essentially from the use of natural rubber latex gloves, antiseptics, and especially aldehydes. This study reports an unusual cause of contact dermatitis in laboratory technicians.

Wellbeing and occupational risk perception among health care workers: a multicenter study in Morocco and France

BackgroundThe study analyzes health care workers’ (HCWs) occupational risk perception and compares exposure to occupational risk factors in Moroccan and French hospitals.MethodAcross nine public hospitals from three Moroccan regions (north, center and south), a 49 item French questionnaire, based on the Job Content Questionnaire, and 4 occupational risks subscales, was distributed to 4746 HCWs. Internal consistency of the study was determined for each subscale. Confirmatory factor analysis was conducted on the Moroccan questionnaire. Psychosocial job demand, job decision latitude and social support scores analysis was used to isolate high strain jobs. Occupational risks and high strain perception correlation were analyzed by univariate and multivariate logistic regression. A comparative analysis between Moroccan and French (Nantes Hospitals) investigations data was performed.ResultsIn Morocco, 2863 HCWs (60 %) answered the questionnaire (54 % women; mean age 40 years; mean work seniority 11 years; 24 % physicians; 45 % nurses). 44 % Moroccan HCWs are at high strain. Casablanca region (1.75 OR; CI: 1.34–2.28), north Morocco (1.66 OR; CI: 1.27–2.17), midwives (2.35 OR; 95 % CI 1.51–3.68), nursing aides (1.80 OR; 95 % CI: 1.09–2.95), full-time employment (1.34 OR; 95 % CI 1.06–1.68); hypnotics, sedatives use (1.48 OR; 95 % CI 1.19–1.83), analgesics use (1.40 OR; 95 % CI 1.18–1.65) were statistically associated to high strain. 44% Moroccan HCWs are at high strain versus 37 % French (Nantes) HCWs (p < 0.001).ConclusionMoroccan HCWs have high strain activity. Moroccan HCWs and more Moroccan physicians are at high strain than Nantes HCWs. Moroccan and French’s results showed that full time workers, midwives, workers using hypnotics, and analgesics are at high strain. Our findings underscore out the importance of implementing a risk prevention plan and even a hospital reform. Further research, with an enlarged study pool will provide more information on psychosocial risks (PSR) and HCWs’ health.

Occupational diseases due to cooling fluids

Contact dermatitis to cutting fluids is a very frequent cause of occupational skin disease, with different mechanisms for those caused by irritation or allergies. The different allergens in question are many and complex. Different batteries of patch tests are available but the interpretation of the relevance of positive tests is not simple. The aim of this work is to make clearer the investigative methods and the interpretation of the relevance of the results of patch tests, for more effective prevention.