COVID19 outbreak in Lombardy, Italy: An analysis on the short-term relationship between air pollution, climatic factors and the susceptibility to SARS-CoV-2 infection.

Short-term exposure to air pollution, as well as to climate variables have been linked to a higher incidence of respiratory viral diseases. The study aims to assess the short-term influence of air pollution and climate on COVID19 incidence in Lombardy (Italy), during the early stage of the outbreak, before the implementation of the lockdown measures. The daily number of COVID19 cases in Lombardy from February 25th to March 10th, 2020, and the daily average concentrations up to 15 days before the study period of particulate matter (PM10, PM2.5), O3, SO2, and NO2 together with climate variables (temperature, relative humidity - RH%, wind speed, precipitation), were analyzed. A univariable mixed model with a logarithm transformation as link function was applied for each day, from 15 days (lag15) to one day (lag1) before the day of detected cases, to evaluate the effect of each variable. Additionally, change points (Break Points-BP) in the relationship between incident cases and air pollution or climatic factors were estimated. The results did not show a univocal relationship between air quality or climate factors and COVID19 incidence. PM10, PM2.5 and O3 concentrations in the last lags seem to be related to an increased COVID19 incidence, probably due to an increased susceptibility of the host. In addition, low temperature and low wind speed in some lags resulted associated with increased daily COVID19 incidence. The findings observed suggest that these factors, in particular conditions and lags, may increase individual susceptibility to the development of viral infections such as SARS-CoV-2.

Clinical and radiological criteria for the differential diagnosis between asbestosis and idiopathic pulmonary fibrosis: Application in two cases.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) and asbestosis are pulmonary interstitial diseases that may present overlapping clinical aspects in the full-blown phase of the disease. For both clinical entities the gold standard for diagnosis is histological examination, but its execution poses ethical problems, especially when performed for preventive or forensic purposes. OBJECTIVE: To evaluate the application of internationally accepted clinical, anamnestic and radiological criteria for differential diagnosis between asbestosis and IPF, and to assess the ability to discriminate between the two diseases. Even if clinically similar, the two diseases present extremely different prognostic and therapeutic perspectives. METHODS: Two clinical cases of IPF are reported, in which the differential diagnosis was made by studying occupational exposure to asbestos, the onset and progression of clinical symptoms, and the identification of specific radiological elements by means of chest High Resolution Computed Tomography (HRCT). RESULTS: The diagnosis of IPF could be made on the basis of the absence of significant exposure to asbestos, the early onset and rapid progression of dyspnea and restrictive ventilatory defects, in association with a pulmonary radiological pattern characterized by peculiar elements such as honeycombing. DISCUSSION: The diagnostic procedure adopted to make a differential diagnosis with asbestosis provides practical clinical elements facilitating the differentiation between the two forms of pulmonary fibrosis, a fundamental aspect of the activity of the occupational physician.

Urinary biomarkers of nucleic acid oxidation and methylation in workers exposed to low concentrations of benzene.

The study aims to investigate the influence of exposure to low concentrations of benzene on urinary biomarkers of nucleic acid oxidative damage and methylation. Benzene exposure was characterized for 93 coke production workers by measuring both airborne benzene and S-phenylmercapturic acid (SPMA) and unmodified benzene (U-B) in urine samples, collected at the end of the shift (ES) and at the next morning before shift (next BS). In the same urinary samples, biomarkers of nucleic acid oxidative damage and methylation were determined. Urinary concentrations of cotinine and creatinine were also determined to evaluate the smoking effect and to normalize urinary concentrations of analytes, respectively. The biomarkers of benzene internal dose, of oxidative damage (8-hydroxyy-7,8-dihydroguanine, 8-hydroxy-7,8-dihydroguanosine and 8-hydroxy-7,8-2'deoxyguanosine) and some of the biomarkers of nucleic acid methylation (5-Methyl-Cytosine, 1-Methyl-Guanine and 7-Methyl-Guanine) were higher in the ES than the next BS samples. Positive associations between ES 5-Methyl-Cytosine and both SPMA and U-B were found. In conclusion, occupational exposure to low levels of benzene seems to be related to urinary ES 5-Methyl-Cytosine that could be a possible biomarker to evaluate the changes of the nucleic acid methylation status.

Occupational exposure to carbon fibers impregnated with epoxy resins and evaluation of their respirability.

Objectives: The study aims to investigate occupational exposure to carbon fibers impregnated with epoxy resins (carbon fiber reinforced [CFR]) in workers at an airplane fuselage section construction plant, by environmental and biological monitoring.Materials and methods: Determination of airborne CFR was done by environmental sampling with active samplers, 11 of which were stationary and 19 personal samplings. The subsequent analyses were performed in the scanning electron microscope fitted with an X-ray microanalysis system (SEM-EDXA). Biological monitoring was carried out by determining CFR in exhaled breath condensate (EBC) collected from 19 male workers who wore personal environmental samplers (exposed workers) and from 10 male workers at the same factory who had no occupational exposure to CFR (internal controls). CFR analysis was done by SEM, applying the method used for determining asbestos fibers in aqueous samples.Results: The airborne CFR concentrations were found to be significantly higher (p = 0.03) at personal samplings (median value 7.01 ff/L, range 1.24-11.16 ff/L) than stationary samplings (median value 1.93 ff/L, range 0.55-10.09 ff/L). The aerodynamic diameters calculated starting from the length and geometric diameter of the sampled CFRs were always higher than 20 µm. CFR was not found in any of the EBC samples collected from the exposed workers and controls.Conclusions: Despite the evidence of occupational exposure to low concentrations of CFR, the absence of such fibers in the EBC in the exposed workers confirms their non-respirability, as expected based on their aerodynamic diameter.

Position Paper on Asbestos of the Italian Society of Occupational Medicine.

The Position Paper (PP) on asbestos of the Italian Society of Occupational Medicine (SIML) aims at providing a tool to the occupational physician to address current diagnostic criteria and results of epidemiological studies, and their consequences in terms of preventive and evaluation actions for insurance, compensation and litigation. The PP was based on an extensive review of the scientific literature and was compiled by a Working Group comprising researchers who have contributed to the international literature on asbestos-related diseases, as well as occupational physicians with extensive experience in the evaluation of risks and the medical surveillance of workers currently and formerly exposed to asbestos. The PP was drafted and reviewed between 2017 and 2018; its final version was prepared according to the guidelines of AGREE Reporting Checklist. All the members of the Working Group subscribed to the document, which was eventually approved by SIML's Executive Committee. The first section addresses industrial hygiene issues, such as methods for environmental monitoring, advantages and limitations of different microscopy techniques, the potential role of microfibers and approaches for retrospective assessment of exposure, in particular in epidemiological studies. The second section reviews the biological effects of asbestos with particular attention to the diagnostic aspects of asbestosis, pleural changes, mesothelioma and lung cancer. In the following section the criteria of causal attribution are discussed, together with different hypotheses on the form of the risk functions, with a comparison of the opinions prevalent in the literature. In particular, the models of the risk function for mesothelioma were examined, in the light of the hypothesis of an acceleration or anticipation of the events in relation to the dose. The last section discusses topics of immediate relevance for the occupational physician, such as health surveillance of former exposed and of workers currently exposed in remediation activities.

Biological monitoring of exposure to polycyclic aromatic hydrocarbons and to metallic elements in Italian Navy workers operating near the industrial area in Taranto (South Italy).

OBJECTIVES: To assess, by means of biological monitoring, exposure to polycyclic aromatic hydrocarbons (PAHs) and to metallic elements in Italian Navy workers operating near the industrial area in Taranto, and thereby estimate the health risk. METHODS: A total of 450 workers in the Italian Navy were examined; they had office type jobs, and 150 of them worked near the industrial area in Taranto (exposed group), 150 in Taranto but far from this area (internal control group) and 150 in Brindisi (external control group). The recruited workers were administered a questionnaire inquiring about current and previous working activities, personal medical history, lifestyle and dietary habits, and their residence location. Then they collected a urine sample for the determination of 1-hydroxypyrene, 2-naphthol, cotinine and the metallic elements As, Cd, Co, Cr, Mn, Ni, Pb, Cu, Zn and Hg. The latter were measured in 110 workers in each group. In addition, in some of the work sites of the three groups, environmental samplings were carried out to determine PAHs and the 10 metallic elements, also taking into account the wind direction. RESULTS: Airborne benzo(a)pyrene concentrations at the different sampling sites ranged from 0.02 to 0.06 ng/m3 and naphthalene between <25 and 65.3 ng/m3, regardless of the wind direction. Among the metallic elements, As, Cd, Co, Cr, Hg, Pb, Cu and Zn were present at concentrations below or just above the limit of detection (LOD). Mn and Ni were slightly higher in the work sites of the exposed group. The urinary concentrations of 1-hydroxypyrene, 2-naphthol and the single metallic elements were not higher in the exposed workers group than in the other 2 groups. Smokers had significantly higher urinary 1-hydroxypyrene and 2-naphthol concentrations, whereas cigarette smoking did not condition a higher urinary elimination of metallic elements in the three groups with the exception of Cd and Pb. Moreover, residence location conditioned Mn, Hg and As urinary excretion, consumption of shellfish and/or crustaceans in the 72 hours before urine collection conditioned As elimination, and consumption of legumes in the 72 hours before urine collection conditioned Ni elimination. CONCLUSIONS: This research did not find a higher urinary excretion of 1-hydroxypyrene, 2-naphthol and As, Cd, Co, Cr, Mn, Ni, Pb, Cu, Zn and Hg in the exposed workers group as compared to the internal control group working far from the industrial area of Taranto, nor in the group working in another city far away from Taranto, Brindisi. Therefore, it indicated that workers in the Italian Navy operating near the industrial area in Taranto were not exposed to a greater risk attributable to exposure to PAHs and metallic elements than the two control groups.

Radon Levels in Indoor Environments of the University Hospital in Bari-Apulia Region Southern Italy.

Since 1988, the International Agency for Research on Cancer (IARC) has classified radon among the compounds for which there is scientific evidence of carcinogenicity for humans (group 1). The World Health Organization (WHO) recommends a reference radon level between 100 and 300 Bq/m³ for homes. The objective of this study is to measure the radon concentrations in 401 workplaces, different from the patient rooms, in 28 different buildings of the university hospital in Bari (Apulia region, Southern Italy) to evaluate the exposure of health care workers. Radon environmental sampling is performed over two consecutive six-month periods via the use of passive dosimeters of the CR-39 type. We find an average annual radon concentration expressed as median value of 48.0 Bq/m³ (range 6.5-388.0 Bq/m³) with a significant difference between the two six-month periods (median value: February/July 41.0 Bq/m³ vs. August/January 55.0 Bq/m³). An average concentration of radon lower than the WHO reference level (100 Bq/m³) is detected in 76.1% of monitored environments, while higher than 300 Bq/m³ only in the 0.9%. Most workplaces report radon concentrations within the WHO reference level, therefore, the risk to workers' health deriving from occupational exposure to radon can be considered to be low. Nevertheless, the goal is to achieve near-zero exposures to protect workers' health.

Applicability of the Nordic Occupational Skin Questionnaire for Screening Contact Dermatological Disorders in Sea Fishers.

This survey aimed to evaluate the applicability of the Nordic Occupational Skin Questionnaire (NOSQ) as a preliminary screening tool to investigate the presence of contact dermatological disorders in sea fishermen. The Italian version of the NOSQ was administered to 143 male fishermen working at an Apulia (Southern Italy) Fisheries, and 136 male workers who had never worked as sea fishers (controls). A significantly higher rate of frequency of transient itchy wheals on the hands, wrists, and forearms was recorded in the fishermen as compared to the controls (49.6% vs. 8.1%; p < 0.001), while there was no significant difference in the frequency of eczema (8.4% vs. 6.6%). In 46.1% of the fishermen, the onset of transient itchy wheals was associated with contact with specific agents and the most common causes were algae and aquatic plants (49.3%) and seabed sludge (25.3%). In conclusion, the administration of the NOSQ can be useful in preliminary screening for dermatitis in fishermen, although it could show a possible overestimation of the prevalence of transient itchy wheals.

Risk due to exposure to metallic elements in a birdshot factory.

The contribution of biological and environmental monitoring to the risk assessment of occupational exposure to lead (Pb), arsenic (As), and antimony (Sb) was studied in 18 workers at a birdshot factory (Exposed) and in 18 control workers (Controls) by the determination of both airborne Pb (PbA) and airborne As (AsA) only in the exposed workers and blood Pb (PbB), erythrocytic zinc protoporphyrin (ZPP), urinary Sb (SbU), and the urinary As species in exposed workers and controls. PbA (12-42 µg/m3) and AsA (1-4 µg/m3) were strongly correlated (r = .95). PbB, ZPP, and the sum of As3+As5+MMA were significantly higher in the exposed workers. As3 was higher than the limit of detection in 14 exposed workers and 1 control, As5 only in 1 exposed worker, SbU in all the exposed workers and in 4 controls. Monitoring for more metallic elements reveals a wider spectrum of exposures than can be achieved by lead surveillance alone and is preferable for characterizing occupational risk wherever possible.

Biological monitoring of exposure to low concentrations of benzene in workers at a metallurgical coke production plant: new insights into S-phenylmercapturic acid and urinary benzene.

CONTEXT: Urinary S-phenylmercapturic acid (SPMA) and benzene (U-Ben) are usually measured at the end of the work shift (ES), although their kinetic of elimination is not clearly known. OBJECTIVE: To investigate SPMA and U-Ben elimination 16 h after the ES, in 93 coke production workers exposed to low benzene concentrations. MATERIALS AND METHODS: Airborne benzene (A-Ben) was measured by passive samplings, while SPMA, U-Ben, methyl-tert-butyl ether (U-MTBE), cotinine (U-Cot) and creatinine were determined on urine samples collected at ES and before the beginning of the next work shift (next BS). RESULTS: Median A-Ben concentrations were 17.2 µg/m3 in the personal and 34.7 µg/m3 in the stationary samplings. SPMA was always detectable, whereas U-Ben was below the limit of quantification in 26.7% of the ES and 35.6% of the next BS samples, and U-MTBE in more than the 80.0% of the samples. At both the sampling times, SPMA and U-Ben showed a positive dependence on personal A-Ben, as well as on creatinine and U-Cot values. DISCUSSION AND CONCLUSION: SPMA and U-Ben at the next BS were dependent on the exposure to low benzene concentrations suffered in the previous work shift, prompting a reconsideration of the urine sampling time recommended by the American Conference Governmental Industrial Hygienists (ACGIH).

Biological accidents at work among resident physicians in specialist training at Bari University Hospital, Italy.

The phenomenon of accidents at work was investigated among the resident physicians of the School of Medicine, Bari University, by a self-administered anonymous questionnaire probing personal details and inquiring about any accidents at work experienced during the training period, and by a comparison with the accidents reported to the Hospital Accidents Registry. At least 1 biological accident was reported by 18.2% of the 450 participants, this percentage being significantly higher in the surgical area (33.3%), where biological accidents were much more rarely reported to either the Residency School Director or the Accidents Registry. In conclusion, despite an overall reduction compared with the past, the frequency both of biological accidents and of underreporting is still high among resident physicians, particularly in the surgical area.

Influence of Occupational and Environmental Exposure to Low Concentrations of Polychlorobiphenyls and a Smoking Habit on the Urinary Excretion of Corticosteroid Hormones.

The effects of occupational exposure to low concentrations of polychlorobiphenyls (PCBs) on the urinary excretion of corticosteroid hormones were evaluated, taking into account the influence of cigarette smoking. The study included 26 males working as electrical maintenance staff in a steel factory, previously exposed to a mixture of PCBs (exposed workers), and 30 male workers with no occupational exposure to PCBs (controls). Serum PCBs (33 congeners), urinary 17-hydroxycorticosteroids, 17-ketosteroids (KS) and pregnanes, and their respective glucuronidated and sulfonated compounds, were determined for each subject. PCBs were significantly higher in the exposed workers than controls, and were correlated with age. Both the urinary concentrations of the total 17-KS and pregnanes, and those of some single steroids and their glucuronidated compounds, were significantly lower in the exposed workers than controls, but higher in smokers than the non-smokers + ex-smokers. Two-way analysis of variance showed a negative association between serum PCBs and both total glucuronidated 17-KS and total and glucuronidated pregnanes, and a positive association between cigarette smoking and both total and glucuronidated 17-KS. PCBs seem to act as endocrine disruptors by reducing the urinary excretion of corticosteroid hormones, particularly of the glucuronidated fraction. Cigarette smoking could boost these effects of PCBs in smokers.

DNA damage and repair capacity in workers exposed to low concentrations of benzene.

DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling-station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t-muconic acid, S-phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m(3)), attendants (median 13.8 µg/m(3)), and controls (median 4.1 µg/m(3)). There were no differences in TI and 8-oxodG among the three groups, or between smokers and non-smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2 O2 -damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained.

Evaluation of chromosome aberration and micronucleus frequencies in blood lymphocytes of workers exposed to low concentrations of benzene.

The frequency of chromosome aberrations (CA) and micronuclei (MN) was investigated in the peripheral lymphocytes of workers occupationally exposed to low or very low concentrations of benzene. The study included 43 exposed workers (all males), namely 19 fuel-tanker drivers and 24 filling-station attendants, and 31 male subjects with no occupational exposure to the toxicant (controls). Benzene exposure was verified by means of environmental monitoring with passive personal samplers (Radiello(®)), and through biological monitoring, i.e. by measurement of urinary trans,trans-muconic acid, S-phenylmercapturic acid and benzene. The frequency of CA and MN in peripheral lymphocytes was determined according to standard procedures. Exposure to benzene was found to be significantly higher for fuel-tanker drivers (median 246.6 µg/m(3)) than for filling-station attendants (median 19.9 µg/m(3)). Both groups had significantly higher exposure than controls (median 4.3 µg/m(3)). No increased frequency of CA and MN was observed in either fuel-tanker drivers or filling-station attendants compared with controls. In all subjects examined as a single group, the frequency of MN was significantly dependent on age. Only in the fuel-tanker drivers was the frequency of MN found to depend not only on age, but also on exposure to benzene. In conclusion, the frequency of MN, but not of CA, could be influenced by exposure to benzene concentrations of up to one order of magnitude lower than the threshold limit value (time-weighted average).

[The INSuLa Project: the knowledge survey of company physicians]. / Progetto INSuLa: I'indagine conoscitiva sui medici competenti.

The technological advancements, the occurrence of new emerging occupational risks and diseases, and the changes in the regulatory framework for occupational health and safety induce a constant evolution of occupational medicine. Consequently, the skills and training needs of the occupational physicians should be periodically revalued and upgraded in order to identify technical and operational issues and problems of this discipline. In this context, the aim of this national survey, carried out using a self-administered questionnaire submitted to a sample of 1,237 occupational physicians, has been to gain helpful information to ensure a continuous improvement of the quality and effectiveness of measures aimed at protecting the health and safety of workers. The questionnaire, that consists of 43 questions divided into 5 different areas (personal and professional information, training and updating needs of occupational physicians, professional activities and relationships with the corporate prevention system, relationships with the supervisory board of the Local Health Authority, relationships with the National Health Service), allowed to obtain personal and professional data, to assess the training needs and demands of occupational physicians and to evaluate their relationships with the other stakeholders of the Italian prevention system and with the National Health Service. The preliminary results of this survey appear extremely important. In fact, this findings, highlighting the current problems of occupational physician, constitute the starting point to identify, develop and implement management methodologies, operative procedures and training programs that are effective and modern.

[Protocols for the health surveillance of fisherman]. / Protocolli per la sorveglianza sanitaria dei lavoratori della pesca.

AIM: To define protocols for health surveillance of workers in the marine fishing sector for specific occupational risk factors, considering the latest and most advanced scientific knowledge. MATERIALS AND METHODS: The specific literature was analyzed to identify the occupational risk factors to which fishermen are exposed. Then, for each risk factor a protocol for the relative health checkups and their time schedule was defined. RESULTS AND DISCUSSION: The risk factors to which fishermen are exposed are essentially noise, vibrations, solar and ultraviolet radiation, climatic agents (heat, cold, wind, rain, damp), chemical agents, shifts, work rate, night work, physical strain, stress, manual handling of loads, upper limb repetitive tasks, incongruous postures. The health protocols stipulate the health screening investigations to be carried out in all workers of a homogeneous group, and in-depth diagnostic investigations to be carried out in symptomatic workers. Complementary health investigations must be focused on a functional exploration of the organs specifically exposed to the risk factor. For hearing impairments due to noise exposure, the medico-legal measures with which the occupational health physician must comply, in cases of occupational disease, are indicated.

[Monitoring of the occupational and environmental exposure to low doses of benzene]. / Il monitoraggio dell'esposizione occupazionale ed ambientale a basse dosi di benzene.

AIM: To verify which of the various biomarkers of internal dose of benzene can be considered reliable for biological monitoring of exposure to the low concentrations present nowadays in working and living environments. MATERIALS AND METHODS: The specific literature was analyzed to assess the reliability of the different biomarkers of internal dose. RESULTS AND CONCLUSIONS: T,t-muconic acid is a non specific biomarker for benzene, valid for exposure to concentrations up to one order of magnitude less than the threshold limit of 3250 microg/m3. S-phenylmercapturic acid (SPMA) is a reliable marker even for exposure to concentrations up to two orders below the threshold value of 3250 microg/m3, and can be considered the biomarker of choice for biological monitoring of workers exposed to benzene. Urinary benzene does not seem to have any real advantages over SPMA for monitoring occupational exposure to benzene, but it does seem to be more reliable than SPMA to assess exposure to concentrations like those present in living environments. A smoking habit influences the urinary excretion of all the described biomarkers, and for the current low levels of occupational and environmental exposure to benzene, must be taken into account when interpreting the results of biological monitoring.

Environmental contamination by dog’s faeces: a public health problem?

The risk to public health from the large number of dog stools present on streets of urban areas is cause for concern. Dog faeces may be a serious hazard because they may contain microorganisms that are both pathogenic to humans and resistant to several classes of antibiotics. The aim of this study was to evaluate the potential for zoonotic infections and for the presence of antibiotic resistant bacteria in canine faeces which contaminates the urban environment. A total of 418 canine faecal samples were collected from streets in seven areas of Bari, Southern Italy. We have isolated multi-drug resistant Enterococci and meticillin-resistant Staphylococcus aureus from these dog faecal samples. The presence of the resistant bacteria in an urban environment may represent a public health hazard which requires control measures by competent authorities. No Salmonella, Yersinia or Campylobacter species were isolated. Giardia cysts were detected in 1.9% of the samples. The predominant Enterococcus species were E. faecium (61.6%), E. gallinarum (23.3%) and E. casseliflavus (5.5%). Other species, including E. faecalis were also isolated. These strains were resistant to clindamycin (86.3%), tetracycline (65.7%), erythromycin (60.27%) and ampicillin (47.9%). High-level aminoglycoside resistance (HLAR) was found in 65.7% of enterococci. Resistance to three or more antibiotics and six or more antibiotics were observed in 67.12% and 38.4% of Enterococcus spp., respectively. Resistance to vancomycin and teicoplanin was not detected in any of the Enterococcus spp. isolated. Methicillin-resistant Staphylococcus aureus was isolated in 0.7% of the faecal samples. Canine faeces left on the streets may represent a risk factor for transmission of microorganisms and a reservoir of multidrug- resistant bacteria thus contributing to the spread of resistance genes into an urban area.

Helicobacter pylori clarithromycin resistance detected by Etest and TaqMan real-time polymerase chain reaction: a comparative study.

The aim of the work was to compare H. pylori clarithromycin-resistance according two methods. Etest was performed on H. pylori isolated from gastric biopsy samples. TaqMan Real-Time-PCR (RT-PCR) was performed on paraffin-embedded gastric biopsy samples of the same patients. Forty-seven out of 88 strains were resistant to clarithromycin by Etest, whereas RT-PCR detected this resistance on paraffin-embedded specimens of 50 patients. RT-PCR performed on paraffin-embedded biopsy specimens of 47 patients infected with H. pylori resistant to clarithromycin as detected by Etest, revealed the presence of a resistant strain only in 40 samples. RT-PCR performed on samples of 41 patients harbouring clarithromycin-susceptible H. pylori strains showed the presence of 31 susceptible and 10 resistant strains. RT-PCR detected 18 cases with heteroresistant status. The difference between the two tests in detecting clarithromycin-resistance was not statistically significant even if RT-PCR detected more resistant cases. The genotyping resistance on paraffin-embedded gastric biopsy specimens may be used to establish resistance to clarithromycin before the treatment when culture and susceptibility testing are not available. In case of failure of an empirical clarithromycin-based triple antimicrobial treatment, RT-PCR performed on paraffin-embedded biopsy sample will establish the primary resistance to clarithromycin. In addition, this test can be useful for epidemiological investigation as well as for monitoring the evolution of clarithromycin resistance along the time.