Epidemiologia delle infezioni da amebe a vita libera

Le amebe a vita libera (spesso conosciute come Free-Living Amoebae, FLA) sono protozoi presenti in tutte le matrici ambientali a diffusione cosmopolita. L’etichetta di organismi “a vita libera” deriva dal fatto che il loro serbatoio è l’ambiente acquatico naturale, e quello realizzato dall’uomo è un habitat secondario favorevole. Sono protozoi unicellulari che possono vivere all’interno di un ospite in condizioni di parassitismo facoltativo o avere un’esistenza autonoma. Per tale proprietà sono anche definite amebe anfizoiche. In particolare, anche se in realtà è Acanthamoeba spp. il protozoo più frequentemente rilevabile nell’ambiente, amebe a vita libera sono state isolate da suolo, sedimenti, polveri, aria, acque naturali e reflue, dolci, marine, termali, e sono state anche rilevate in acque confezionate, potabilizzate e sottoposte a trattamenti di disinfezione (acque destinate al consumo umano e di piscina) e in biofilm. Numerose specie di amebe a vita libera sono state segnalate in torri di raffreddamento, impianti di climatizzazione, deumidificatori, unità di dialisi, riuniti dentistici, apparecchi per il trattamento domestico dell’acqua e su lenti a contatto. Individuate nell’uomo e in animali a sangue caldo e freddo, in soggetti malati sono state isolate da ferite, dalla cornea, dai polmoni e dal sistema nervoso centrale, anche se la loro presenza è stata dimostrata anche in individui sani. La loro distribuzione e diversità nell’ambiente sono fortemente influenzate da temperatura, umidità, pH, disponibilità di nutrienti e appare chiara l’esistenza di un loro andamento stagionale. In condizioni ambientali ostili le amebe producono cisti che excistano solo in condizioni favorevoli liberando trofozoiti. Sopravvivenza e moltiplicazione sono anche associate sia alla presenza di batteri, soprattutto Gram-negativi, sia alla concentrazione degli stessi batteri. Infatti, con rapporti di concentrazione ameba: batteri di 1:104, lo sviluppo dei protozoi è inibito. Per il basso numero di infezioni riscontrate, le amebe non hanno mai rappresentato un argomento sanitario di interesse prioritario, anche se la mancanza di farmaci efficaci e l’esito quasi sempre fatale delle malattie indotte da alcune specie, le hanno sempre rese oggetto di interesse e di studio. Negli ultimi decenni tuttavia, un’attenzione particolare è stata loro rivolta per il ruolo che rivestono come veicolo di trasmissione di microrganismi patogeni presenti nell’ambiente idrico. Infatti, circa un quarto degli isolati di origine ambientale, clinica o derivanti da lenti a contatto contengono microrganismi endosimbionti, definiti Amoeba-Resistant Microorganisms (ARM), microrganismi resistenti alle amebe, che sono in grado di mantenere la loro vitalità a livello intracellulare. Le amebe fungono così da riserva per altri microrganismi, proteggendoli da fattori ambientali ostili e fornendo condizioni favorevoli alla loro replicazione. Per questa circostanza, nel 2017, presso la III Sezione del Consiglio Superiore di Sanità, presieduta dalla Prof.ssa Anna Teresa Palamara, e coordinata dalla Dott.ssa Anna Gaspardone, è stato istituito un Gruppo di Lavoro il cui compito è stato quello sia di approfondire gli aspetti sanitari associati alle amebe a vita libera rilevabili nelle acque, sia di valutare la rilevanza del problema in un’ottica di salvaguardia della salute. A seguito delle attività del Gruppo di lavoro è stato quindi predisposto il documento condiviso e di seguito presentato che produce informazioni sulle caratteristiche tassonomiche ed ecologiche di questi organismi, sulle loro possibili implicazioni di carattere sanitario, sul loro adattamento nelle reti di distribuzione idrica e sulle dinamiche di interazione con gli altri microrganismi. Inoltre, il volume fornisce un indirizzo metodologico univoco e specifiche raccomandazioni per minimizzare il rischio associato alla presenza di amebe nell’ambiente idrico, nonché, in Appendice, metodi analitici colturali e molecolari per la ricerca di questi organismi nelle acque

Investigating the spatio-temporal dimension of past human-elephant interactions: a spatial taphonomic approach

Human-proboscidean interactions are key nodes of complex ecological, cultural and socio-econom- ic systems. In the last decades, evidence has been provided in support of an early human exploitation of proboscidean carcasses, offering further insights into past human behaviors, diet and subsistence strategies. Nevertheless, the mode of acquisition of the carcasses, the degree of exploitation, its timing relative to carnivore scavenging and to the decom- position of the carcass, its ecological and socio-eco- nomical role are hitherto not fully understood and a matter of debate. By summarizing the empirical evidence for human-elephant interactions in Early and Middle Pleistocene open-air sites of western Eurasia, this contribution elaborates on the need for a more rigorous, spatially explicit inferential procedure in modeling past human behaviors. A renewed analytical approach, namely spatial ta- phonomy, is introduced. In its general term, spatial taphonomy refers to the multiscale investigation of the spatial properties of taphonomic processes. Building upon a long lasting tradition of tapho- nomic studies, it seeks for a more effective theoret- ical and methodological framework that accounts for the spatio-temporal dimension inherent to any complex system. By bridging into a spatio-tempo- ral framework the traditional archaeological, geo- archaeological and taphonomic approaches, spatial taphonomy enhances our understanding of the processes forming archaeological and palaeonto- logical assemblages, allowing a finer comprehen- sion of past human behaviors.The symposium and the volume "Human-elephant interactions: from past to present" were funded by the Volkswagen Foundation

Validation of a questionnaire about knowledge and perception of biological risk among biomedical students of Sapienza University of Rome

Background and aim. Healthcare workers and Biomedical students are continuously exposed to biological risk in their clinical practice. The objective of this study was to evaluate the validity and reliability of an Italian questionnaire on the knowledge and perception of biological risk in Biomedical students at the beginning of their professional training. Material and methods.An electronic questionnaire was administered to students attending the second semester of the first year of Biomedical Courses at Sapienza University of Rome. The questionnaire consists of 40 questions divided into five sections collecting sociodemographic data, health status and level of knowledge and perception of biological risk. The statistical analysis was performed with Statistical Package for Social Sciences (SPSS) version 25. Results. A total of 309 individuals answered the online questionnaire, with a response rate of 83.5%. The analysis of internal consistency was performed by two dichotomous variables that measured the knowledge level on hygiene behaviour and gloves use. The analysis showed a standardized Cronbach’s alpha equal to 0.765, corresponding to a good reliability. A better reliability was found out among physiotherapy and medical students, with a Cronbach’s alpha equal to 0.944 and 0.881, respectively. Regarding vaccines, 97.7% of the sample was given a Hepatitis B vaccination and 98.7% of students consider vaccinations essential for healthcare workers. Conclusion. Results of Cronbach’s alpha showed a good reliability of the questionnaire. First-year Biomedical students may be exposed to occupational biological risk mainly because of their inexperience. A training educational path should be implemented in order to acquire competences, knowledge, attitudes and practical skills, correct behaviors and a personal and professional responsibility

Quality assessment of medical record as a tool for clinical risk management: a three year experience of a teaching hospital Policlinico Umberto I, Rome

Introduction: The medical record was defined by the Italian Ministry of Health in 1992 as "the information tool designed to record all relevant demographic and clinical information on a patient during a single hospitalization episode". Retrospective analysis of medical records is a tool for selecting direct and indirect indicators of critical issues (organizational, management and technical). The project’s aim being the promotion of an evaluation and self-evaluation process of medical records as a Clinical Risk Management tool to improve the quality of care within hospitals. Methods: The Authors have retrospectively analysed, using a validated grid, 1,184 medical records of patients admitted to the Teaching Hospital “Umberto I” in Rome during a three-year period (2013-2015). Statistical analysis was performed using SPSS for Windows © 19:00. All duly filled out criteria (92) were examined. “Strengths” and "Weaknesses" were identified through data analysis and Best and Bad Practice were identified based on established criteria. Conclusion: The data analysis showed marked improvements (statistically significant) in the quality of evaluated clinical documentation and indirectly upon behaviour. However, when examining some sub-criteria, critical issues emerge; these could be subject to future further corrective action

Apolipoprotein(a) kringle-IV type 2 copy number variation is associated with venous thromboembolism

In addition to the established association between high lipoprotein(a) [Lp(a)] concentrations and coronary artery disease, an association between Lp(a) and venous thromboembolism (VTE) has also been described. Lp(a) is controlled by genetic variants in LPA gene, coding for apolipoprotein(a), including the kringle-IV type 2 (KIV-2) size polymorphism. Aim of the study was to investigate the role of LPA gene KIV-2 size polymorphism and single nucleotide polymorphisms (SNPs) (rs1853021, rs1800769, rs3798220, rs10455872) in modulating VTE susceptibility. Five hundred and sixteen patients with VTE without hereditary and acquired thrombophilia and 1117 healthy control subjects, comparable for age and sex, were investigated. LPA KIV-2 polymorphism, rs3798220 and rs10455872 SNPs were genotyped by TaqMan technology. Concerning rs1853021 and rs1800769 SNPs, PCR-RFLP assay was used. LPA KIV-2 repeat number was significantly lower in patients than in controls [median (interquartile range) 11(6-17) vs 15(9-25), p<0.0001]. A significantly higher prevalence of KIV-2 repeat number ≤7 was observed in patients than in controls (33.5% vs 15.5%, p<0.0001). KIV-2 repeat number was independently associated with VTE (p = 4.36 x10-9), as evidenced by the general linear model analysis adjusted for transient risk factors. No significant difference in allele frequency for all SNPs investigated was observed. Haplotype analysis showed that LPA haplotypes rather than individual SNPs influenced disease susceptibility. Receiver operating characteristic curves analysis showed that a combined risk prediction model, including KIV-2 size polymorphism and clinical variables, had a higher performance in identifying subjects at VTE risk than a clinical-only model, also separately in men and women