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Introduction: Few data on the diagnostic performance of serological tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are currently available. We evaluated sensitivity and specificity of five different widely used commercial serological assays for the detection of SARS-CoV-2–specific IgG, IgM, and IgA antibodies using reverse transcriptase-PCR assay in nasopharyngeal swab as reference standard test.Methods: A total of 337 plasma samples collected in the period April–June 2020 from SARS-CoV-2 RT-PCR positive (n = 207) and negative (n = 130) subjects were investigated by one point-of-care lateral flow immunochromatographic assay (LFIA IgG and IgM, Technogenetics) and four fully automated assays: two chemiluminescence immunoassays (CLIA-iFlash IgG and IgM, Shenzhen YHLO Biotech and CLIA-LIAISON® XL IgG, DiaSorin), one electrochemiluminescence immunoassay (ECLIA-Elecsys® total predominant IgG, Roche), and one enzyme-linked immunosorbent assay (ELISA IgA, Euroimmune).Results: The overall sensitivity of all IgG serological assays was >80% and the specificity was >97%. The sensitivity of IgG assays was lower within 2 weeks from the onset of symptoms ranging from 70.8 to 80%. The LFIA and CLIA-iFlash IgM showed an overall low sensitivity of 47.6 and 54.6%, while the specificity was 98.5 and 96.2%, respectively. The ELISA IgA yielded a sensitivity of 84.3% and specificity of 81.7%. However, the ELISA IgA result was indeterminate in 11.7% of cases.Conclusions: IgG serological assays seem to be a reliable tool for the retrospective diagnosis of SARS-CoV-2 infection. IgM assays seem to have a low sensitivity and IgA assay is limited by a substantial rate of indeterminate results.

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The estimation of exposure risk to ionizing radiation in the environment is a public health challenge. The use of radioactive materials in medicine, power generation and industry raises questions concerning also the effects due to low doses of ionizing radiation. As complex molecular mechanisms at the cellular level, in response to environmental stresses, are evoked, the application of high-throughput screening, like the microarray technology, may provide a more detailed analysis of a potential damage. In this study we focused on workers exposed to low-LET ionizing radiations and we compared the expression profile of their peripheral blood lymphocytes (PBMC) with a reference sample of non-exposed people, working at the same hospital. According to our technology, the experimental design that better fitted our objective was the balanced block consisting in the equal distribution of cyanine 5 and cyanine 3 labels within the two classes of exposed and control samples. The purpose was to combine the oligo microarray technology with informatics in order to develop a specific stress gene profile to be used as a molecular signature of the radiation exposure. Our study aims at providing further insight into the harmful effects of low-dose radiation exposure in humans in order to increase the bulk of information on the radiation-inducible genes that have been identified so far, and whose modulation was mainly described as the result of an immediate-early response in ex-vivo irradiated PBMC. The identification of such a gene set in human peripheral blood lymphocytes would improve the classical methods to estimate ionizing radiation exposure, enabling a rapid and non-invasive monitoring for any populations at risk.

The use of radioactive materials in medicine, power generation and industry is a considerable concern for occupational exposure, since human health risks from low doses of radiation are still debated. The functional genomics seems to be the best approach to study the complexity of response to ionizing irradiation (IR). We performed in vitro and in vivo studies to verify the effects of the exposure to low doses IR on gene profiles. BALB/c 3T3 cells were exposed to a 137Cs radiation source and allowed to repair potentially lethal damages for 20 h. Cell survival and IR-induced transformation was determined. Gene expression in irradiated and control cells was evaluated by microarray technology. A dose-related reduction in cloning efficiency was induced by 1.5-6 Gy exposure. Cell proliferation was induced at lower doses, thus suggesting a hormetic effect. A study was carried out in 28 workers that were exposed to low-LET ionizing radiations at a large health care facility. We compared the expression profile of their peripheral blood lymphocytes (PBMC) with a reference sample of non-exposed people, working at the same place. A balanced block design was used. Labeled c-RNA was synthetised from PBMC m-RNA, purified and applied the oligonucleotide slide (Human1A oligo microarray, G4110A) according to the Agilent 60-mer oligo microarray processing protocol. Slides were scanned in Agilent dual laser Microarray Scanner. The scanned image was analysed by bioinformatics techniques. By this approach, 270 genes were identified, which were correlated to the occupational IR exposure, including chromatin assembled genes and genes involved in apoptosis, DNA repair and response to stress. This IR transcriptional fingerprint could add information to the current models of risk for chronic low dose exposure.

Urban soil may be a source of occupational exposure to various pollutants in gardening and land cultivation. This paper presents data of a one-year follow-up of lead, cadmium, nickel, chromium, and vanadium in the environment of the city of Bologna. Samples of soil and leaves were collected at three locations; gardens from the inner-city high-traffic area, parks in moderate-traffic area, and parks in suburban, low-traffic area. The top and deeper layers of soil and leaves were mainly polluted by lead at all locations, which corresponded to the traffic density. Personal samplers recorded greater concentrations of airborne metals than did the area samplers but the values kept below the threshold limit established by the American Conference of Governmental Industrial Hygienists for the working environment. Due to cumulative nature and interactive effects of toxic metals with other toxic and essential elements, long-term exposure to metals in the urban environment may be a health risk for occupationally exposed gardeners.

Tuberculosis (TB) is still a threat for healthcare workers (HCW), due to the non decreasing incidence, the spread of drug-resistance, the introduction of new tests for the screening, the relevant costs of surveillance of exposed subjects. These issues implicate a revision of activities to prevent TB in health-care settings.A multidisciplinary working group, led by occupational physicians, examined the activities to prevent TB performed in 9 Italian hospitals and reviewed the literature, with the aim to formulate evidence-based procedures.In the considered hospitals, 23.000 HCW are classified as exposed to TB, out of 32.000 HCW exposed to biological risks; yearly, about 6000 subjects are screened for preventive, periodical or post-exposure surveillance and 110-130 chemoprophylaxis are prescribed. A high proportion of HCW (54-75%) refused or interrupt to assume the drugs. In the period 2004-2008, 14 occupational TB were diagnosed (9/100.000 HCW exposed to biological risks).Critical issues are the availability of a specific, written TB control plan, including risk assessment, protocols for identifying, evaluating, managing infectious TB patients, health surveillance, education programs, specifically addressed to increase Standard Precaution adoption and compliance to the screening and to adequate risk perception. Risk assessment identify HCW to be included in TB testing (characterized by low positive predictive value), unrecognized TB and environmental control needed; TB risk classification should include no more than 3 or 4 classes and performed by assessing the issues suggested in the Italian guideline. Tubercolin skin test should be used for HCW screening, adding in vitro test in specific circumstances (for example, skin test positivity in BCG vaccinated HCW); the frequency of the screening should not exceed 2 years. Periodical revision of preventive activities should follow up to date scientific literature and need appropriate data computing.

The biological risk from exposure to bloodborne pathogens in health care environments represents a frequent prevaand widespread risk, involving a large number of exposed workers. On the basis of the available scientific innovations, the recent legislation regarding health and safety of workers and the experiences of SIMLII guidelines on health surveillance (HS) workers exposed to biological risk, a multicenter study was carried out, involving nine relevant hospitals and about 32 000 healthcare workers (HCW). A review of the literature was performed, with particular reference to the last 10 years. For each hospital, protocols of HS have been examined according to tasks and biological risk from bloodborne viruses (HBV, HDV, HCV, HIV) as well as management of HCW infected with this pathogens. Differences of risk management in the hospitals, in relationship also with recommendations of the literature have been evaluated. The literature supplies important indications for HS management of HCW exposed to bloodborne pathogens, with relevant information also for patient safety. Preventive examinations are in line with the recommendations of literature and similar across the hospitals for HCV and HIV, while they are different for HBV. Periodic surveillance was different for the frequency, among the hospitals and also as compared to national SIMLII guidelines. As for management, no differentiation among the hospitals was detected as referred to different risk of exposure, while differences were observed around definitions of restrictions. Finally, good medical practices to support occupational physicians in the prevention and management of HCWs’ exposed to biological risks are suggested

Background. Nosocomial transmission of varicellazoster virus, certain paramixovirus and rubivirus might pose a risk of morbidity for varicella (V), rubella (R), mumps (Mu) and measles (Me) in health care workers (HCW), patients and coworkers. International literature and European legislation recommend preventive interventions to minimize the risk. Methods. A literature review and a seroprevalence study were carried out in 9 hospitals located in north and central Italy, in order to evaluate risk assessment, health surveillance and fitness for work of HCW exposed to V, R, Mu and Me. Antibodies (Ab) against V, R, Mu and Me were determined. For a subgroup of 4 hospitals; sociodemographic, occupational data and sera were collected and analyzed. Results. About 36000 tests on about 9000 HCW were analyzed. Differences in seroprevalence ratios (V 85.7-95.1%, R 47-96.8%, Me 71.4-97.8%, Mu 52.5-87.6%) were detected. In a subgroup, a relevant number of non immune HCW was also found among women in fertile age and areas at higher risk. Statistically significant differences were detected only for selected variables and viruses. Discussion and conclusions. Data of multicenter study confirm literature evidences and allow to define good medical practices for manage and minimize the risk of nosocomial transmission of V, R, Me and Mu. Recommendation are issued about serologic screening on HCW exposed to all 4 viruses thorough the modern analytical techniques, in order to assess risk on individual a group basis and to select priorities for intervention. Vaccination should be prescribed for those HCW non immune, selecting areas and HCW according to priorities.

Introduction. The influenza illness is a concern for health care workers (HCW) due to the potential nosocomial transmission and sickness absenteeism. Immunization and Isolation Precautions might be effective preventive measures. Aims. To formulate recommendations on vaccination in healthcare settings. Methods. A multidisciplinary working group, led by occupational physicians (OP), examined the information on seasonal influenza immunisation campaign in 9 Italian hospitals in the period 2005-2009 and reviewed scientific evidence. Results. Many health organizations recommend vaccination of HCW. The literature shows that seasonal influenza vaccination of healthy adult have a modest effect in reducing work day lost; there is no evidence that it affects transmission or it prevents the disease in elderly residents. These observations might be conditioned by methodological limitations. Further studies are required to avoid the risk of bias and in pediatric settings. The rate of flu vaccination among HCW is widely variable and it depends on individual risk perception and information about efficacy and side effects. In the considered hospitals, in the fiveyears period the vaccination rate ranged between 0 and 29%: the median value was 16-17% in 2005, 2008 and 2009 (only against H1N1 influence), 11% and 13% in 2007 and 2006 respectively. OP participation in the vaccination campaign seems to increase the immunization rate. Discussion. Seasonal influenza immunization of HCW might be effective. We recommend to formalize written procedures in health care settings, to perform data computing and to periodically revise immunization activities and promotion and scientific litterature, with the aim to appropriately address resources. Key words: influenza, health care workers, good medical

Ensuring the security of information transmitted over the Internet is an urgent priority in the increasingly digital world. A unique approach to safeguarding data transmission by embedding messages with optical chaos is described, that is known as Optical Chaotic Cryptography. The approach makes use of a pair of lasers that generate chaos, a behavior of a large class of nonlinear systems. A standard DFB telecommunication laser routed to chaos exhibits a widened spectrum, typically on the order of 10-100 GHz, showing a non-periodic and complex behavior. The transmitter produces an optical carrier with an extremely broadened spectrum. Synchronization is usually obtained by injecting a part of chaotic output of the transmitting laser into the receiver laser, to extract the hidden signal. One notable characteristic of the chaotic regime is its strong sensitivity to starting conditions and systems parameters.

Work-related upper limb disorders are one leading occupational diseases in many industrialized countries. The paper reviews the evidence of work-relatedness of the most common upper limb disorders (namely carpal tunnel syndrome, hand-wrist and shoulder tendinitis, trapezius myalgia, hand hammer syndrome). Attention is drawn to the difference in the number of reported cases in Italy and other countries, assuming, as an underlying cause, underreporting of such conditions in Italy.

Exposure assessment tests were undertaken to measure the biomechanical overload factors affecting the upper limbs. The tests were carried out on a group of 86 workers employed on the cutting, boning and trimming line of a pork meat processing plant. Anamnestic screening and clinical tests targeted at correlated disorders were also performed and were followed by instrumental tests. The results are reported with respect to frequency of repetitive technical actions, degree of muscular involvement, postural risk, several complementary factors and distribution of recovery periods. The clinical investigation showed a high prevalence of carpal tunnel syndrome, tendon disorders of the hand and epicondylosis of the elbow, in addition to other disorders. The report confirms the presence of additional risks for the workers, both in the past and under present circumstances, and suitable preventive measures are formulated.

he paper describes a case of ulnar neuropathy in a man who made household fittings and toys using bamboo. Several years after starting the job he showed symptoms and physical signs of ulnar nerve entrapment at the elbow, which were confirmed by electrophysiological findings. Job analysis revealed biomechanical risk factors consisting of a high repetition of forceful flexion and extension of the elbow, wrist and fingers without sufficient rest periods. Chronic musculoskeletal overuse gradually leads to tendon and nerve disorders. The ulnar neuropathy described can be classed under cumulative occupational trauma, which is the most important cause of musculoskeletal disorders among the working population.

The work associated with repetitive efforts and inadequate resting periods, strong physical exertion, awkward postures or static positioning exposes workers to the risk of cumulative trauma disorders of the upper limbs. These risk factors are present in many agricultural activities. A study was carried out among workers on an agricultural farm. The workers' histories were taken and they were given periodical medical check-ups. The presence of upper limb disorders was shown in a group of workers. A sample of 42 people was selected for the study by means of specific tests: electromyography, ultrasonography and laser-doppler ftowmetry. The tests showed a high incidence of carpal tunnel syndrome and microcirculation disorders. The study confirmed that electromyography, ultrasonography and/or laser-doppler flowmetry are highly useful tools for identifying cumulative trauma disorders., Pokreti koji se ponavljaju, neprimjereni odmori, teška fizička opterećenja te nefiziološki položaji tijela dovode do povećanog rizika razvoja bolesti kumulativne traume gornjih udova. Ovi čimbenici rizika prisutni su u mnogim poljoprivrednim djelatnostima. Od 74 radnika na poljoprivrednom dobru podvrgnuta periodskim pregledima, u 42 je primijenjena elektromiografija, ultrasonografija i mjerenje krvnog protoka laser-doppler metodom. Testovima je utvrđena visoka učestalost sindroma karpalnog tunela i poremećaja mikrocirkulacije. Ispitivanje je potvrdilo da su eiektromiografija, ultrasonografija i/ili laser-doppler mjerenje krvnog protoka veoma korisne metode u dijagnostici bolesti kumulativne traume.

Chaotic signals have been proposed as broadband information carriers with the potential of providing a high level of robustness and privacy in data transmission. Laboratory demonstrations of chaos-based optical communications have already shown the potential of this technology, but a field experiment using commercial optical networks has not been undertaken so far. Here we demonstrate high-speed long-distance communication based on chaos synchronization over a commercial fibre-optic channel. An optical carrier wave generated by a chaotic laser is used to encode a message for transmission over 120 km of optical fibre in the metropolitan area network of Athens, Greece. The message is decoded using an appropriate second laser which, by synchronizing with the chaotic carrier, allows for the separation of the carrier and the message. Transmission rates in the gigabit per second range are achieved, with corresponding bit-error rates below 10-7. The system uses matched pairs of semiconductor lasers as chaotic emitters and receivers, and off-the-shelf fibre-optic telecommunication components. Our results show that information can be transmitted at high bit rates using deterministic chaos in a manner that is robust to perturbations and channel disturbances unavoidable under real-world conditions. © 2005 Nature Publishing Group.